CALCIUM CHANNEL COMPOSITIONS AND METHODS

Abstract: Calcium channel (alpha)1-subunit and (alpha)2-subunit-encoding cDNAs, and related compositions and methods, are provided.

Description: CALCIUM CHANNEL COMPOSITIONS AND METHODS TECHNICAL FIELD The present invention relates to molecular biology and pharmacology. More particularly, the invention relates to calcium channel compositions and methods of making and using same. 10 BACKGROUND OF THE INVENTION Calcium channels are membrane-spanning, multisubunit proteins that allow controlled entry of Ca 2 ions into cells from the extracellular fluid. All cells throughout the animal kingdom, and at least some ,c bacterial, fungal and plant cells, possess one or more types of calcium channel. The most common type of calcium channel is voltage-dependent. In a voltage-dependent channel, the "opening," to allow an influx of Ca +2 ions into the 2 Q cells to begin, requires a depolorization to a certain level of the potential difference between the inside of the cell bearing the channel and the extracellular medium bathing the cell and the rate of influx of Ca +2 into the cell depends on this potential difference. All 25 "excitable" cells in animals, such as neurons of the central nervous systems, peripheral nerve cells, and muscle cells, including those of skeletal muscles, cardiac muscles, and venous and arterial smooth muscles, have voltage-dependent calcium channels. 3Q Calcium channels are physiologically important because the channels have a central role in regulating intracellular Ca +2 levels and these levels are important for cell viability and function. Thus, intracellular Ca +2 concentrations are implicated in a 2 5 number of vital processes in animals, such as neurotransmitter release, muscle contraction, pacemaker activity, and secretion of hormones and other substances. A number of compounds useful in treating various diseases in animals, including humans, are thought to exert their beneficial effects by modulating functions of voltage-dependent calcium channels. Many of these compounds bind to calcium channels and block, or reduce the rate of, influx of Ca +2 into cells in response to depolorization of the inside and outside of the cells. An understanding of the pharmacology of ø compounds that interact with calcium channels, and the ability to rationally design compounds that will interact with calcium channels to have desired therapeutic effects, have been hampered by a lack of understanding of the structure of channel subunits and the genes that code 5 for them. Thus, it has not been possible to obtain the large amounts of highly purified channel subunits that are required to understand, at the molecular level, the nature of the subunits and their interactions with one another, with the cell membranes across which the 0 channels allow Ca +2 ions to pass, with Ca +2 and other ions, and with low molecular weight compounds that affect channel function. For example, with the availability of large amounts of purified calcium channel subunits, functional channels could be prepared and used to screen 5 the effects of compounds on channel function, thereby providing a basis for the design of therapeutic agents which affect the calcium channel, or various combinations of channel subunits could be crystallized and have their structures determined to high resolution employing X-ray Q or neutron diffraction techniques, providing yet another basis for rational design of therapeutic agents that affect channel function. Certain diseases, such as Lambert-Eaton Syndrome, involve autoimmune interactions with calcium channels. The ready availability of calcium channel subunits would make possible immunoassays for the diagnosis of such diseases and an understanding of them at the molecular level that could lead to effective methods for treating them. The lack of information on genes that code for calcium channel subunits has prevented the understanding of the molecular properties of the mature calcium channel subunits and their precursor proteins (i.e., the mature Q subunits with signal peptides appended to the amino-terminus) and the regulation of expression of calcium channel subunits. An understanding of these properties, and of how expression of calcium channel subunit genes is regulated, may provide the basis for 5 designing therapeutic agents which have beneficial effects through affecting calcium channel function or concentration Furthermore, the availability of sequences of genes coding for calcium channel subunits would make possible the diagnosis of defects, which might underlie a o number of diseases, in genes coding for such subunits. The availability of a DNA with the sequence of a segment, of at least about 12, and more preferably at least about 30, nucleotides of a cDNA encoding a subunit of a calcium channel from the cells of a tissue of an 5 animal would make possible the isolation and cloning of cDNA's, and possibly genomic DNA's, coding for the corresponding subunit of different calcium channels from the same or different tissues and animals of the same or different species. The availability of the sequences of 0 numerous full-length cDNA's coding for corresponding subunits of calcium channels from a variety of tissues and animal species would contribute to elucidating structure-function relationships in the subunits and this knowledge, in turn, would be useful in the design of therapeutic agents whose activities are exerted through binding to calcium channels. Voltage-dependent calcium channels are thought to consist of two large subunits, of between about 130 and about 200 kilodaltons ("kD") in molecular weight, and a number (generally thought to be one or three) of different smaller subunits, of less than about 60 kD in molecular weight. At least one of the larger subunits and possibly some of the smaller are glycosylated. Some of the subunits are capable of being phosphorylated. There is confusion in the art concerning the naming of the various subunits of voltage-dependent calcium channels. The two large subunits of voltage-dependent calcium channels are designated herein the "(alpha) 1 -subunit" and the "(alpha) 2 -subunit". The (alpha)^subunit is not detectably changed in molecular weight when treated with dithiothreitol ("DTT") or with enzymes which catalyze removal of N-linked sugar groups from glycosylated proteins. The (alpha) _-subunit has a molecular weight of about 150 to about 170 kD when analyzed by sodium dodecylsulfate ("SDS")-polyacrylamide gel electrophresis ("PAGE") after isolation from mammalian muscle tissue and has specific binding sites for various 1,4-dihydropyridines ("DHPs") and phenylalkylamines. The (alpha)2-subunit is somewhat less well characterized than the (alpha)^-subunit. The molecular weight of the (alpha) 2 -subunit is at least about 130-150 kD, as determined by SDS-PAGE analysis in the presence of DTT after isolation from mammalian muscle tissue. However, in SDS-PAGE under non-reducing conditions (in the presence of N-ethylmaleimide) , the (alpha) 2 -subunit migrates with a band of about 160-190 kD. It is not known in the art whether the smaller fragment (of about 30 kD) , which appears to be released upon reduction, is the product of a gene different from the gene which encodes the 130-150 kD fragment (and, consequently, the two fragments are different subunits of the calcium channel) or whether both fragments are products of the same gene (and, consequently, the (alpha) 2 -subunit is about 160-190 kD and is split into (at least) two fragments upon reduction) . There is evidence that the (alpha) 2 -subunit, whatever its size, and the corresponding fragment produced under reducing conditions, whether part of the (alpha) 2 -subunit or not, are glycosylated with at least N-linked sugars and do not have specified binding sites for 1,4-dihydropyridines and phenylalkylamines that are known to bind to the (alpha)ι~subunit. Reference herein to the precursor of an (alpha) ~subunit means the protein with the a ino acid sequence corresponding to the sequence of the full-length mRNA which, upon translation, results, ultimately, in (alpha) ι~subunit resident as part of a calcium channel in a cell membrane. The precursor protein is converted by various processing steps into the (alpha) ~subunit. The details of the processing between the precursor and the mature (alpha)ι~subunit are not clear, but the processing possibly involves phosphorylation and also cleavage of the primary translation product to yield the mature (alpha) ~subunit of the calcium channel. Similarly, reference herein to the precursor of an (alpha) 2 -subunit means the protein with the amino acid sequence corresponding to the sequence of the full-length mRNA which, upon translation, results, untimately, in (alpha) 2 -subunit resident as part of a calcium channel in a cell membrane. The precursor protein is converted by various processing steps into the (alpha)2-subunit. As with the (alpha) .^-subunit, the details of the processing between the precursor and the mature (alpha)2-subunit are not clear, but the processing presumably involves at least removal of a leader sequence (i.e., a signal peptide) , glycosylation, and, possibly, cleavage to yield what are now thought to be other subunits of the calcium channel. The cDNA and corresponding amino acid sequence of the (alpha)i-subunit precursor of a rabbit back skeletal muscle calcium channel has been reported. Tanabe et al. , Nature 328, 313-318 (1987). Calcium channel activity, measured electrophysiologically by voltage-clamp techniques, has been induced in Xenopus laevis oocytes when total mRNA isolated from mammalian brain and cardiac muscle is injected into the oocytes. Also, it has been reported 5 that calcium channel-containing preparations, when reconstituted into lipid bilayers, confer voltage-dependent calcium channel activity on the bilayers. However, there is no evidence that the o (alpha) ι~subunit alone or the (alpha) 2 -subunit alone provides a functional calcium channel in oocytes, lipid bilayers or any other situation. It has been recently reported by Hofmann, et al., Trends in Pharmacolog. Sci. 8, 393-398 (1987) that mRNA prepared using the cDNA 5 of (alpha) ~subunit obtained by Tanabe, et al. was unable to induce calcium channel activity in Xenopus laevis oocytes. DETAILED DESCRIPTION OF THE INVENTION Q In short, we have discovered a cDNA which codes for the (alpha) ~subunit of an animal calcium channel (see Table 1) and a cDNA which codes for the (alpha) 2 ~ subunit of an animal calcium channel (see Table 2 and Example 4) . 5 Thus in one of its aspects, the invention is a DNA which comprises a cDNA which codes for the (alpha)2-subunit of an animal calcium channel, and the RNA, coding for such a subunit, made upon transcription of such a DNA according to the invention.. In another of its aspects, the invention is a substantially pure (alpha) 2 -subunit of an animal calcium channel. By a "substantially pure" subunit or protein is meant a subunit or protein that is sufficiently free of other polypeptide contaminants to be considered homogeneous by SDS-PAGE or to be unambiguously sequenced. In another of its aspects, the invention entails an eukaryotic cell with an heterologous calcium channel, said cell made by a process comprising administering to said cell a first composition, which consists essentially of a first RNA which is translatable in said cell into the precursor of the (alpha)!-sub nit of a calcium channel of an animal of a first species, and a second composition which consists essentially of a second RNA which is translatable in said cell into the precursor of the (alpha) 2 -subunit of a calcium channel of an animal of a second species, said first and second species being the same or different, provided that at least one of said precursor of said (alpha)!-subunit and said precursor of said (alpha) 2 -subunit is foreign to said cell. Preferred cells for this purpose are Xenopus laevis oocytes. In another of its aspects, the invention entails a method for assaying a compound for calcium channel agonist or antagonist activity which comprises electrophysiologically measuring the calcium channel activity of a cell described in the immediately preceeding paragraph when such cell is exposed to a solution of the compound being tested for such activity. For similar methods applied with Xenopus laevis oocytes and acetylcholine receptors, see e.g., Mishina et al. Nature 313, 364 (1985) and, with such oocytes and sodium channels, see Noda et al., Nature 322, 826-828 (1986). In a further of its aspects, the invention is an eukaryotic cell containing a DNA which comprises a cDNA which can be expressed to make the (alpha) 2 -subunit of a calcium channel. Such a cell according to the invention can also contain a DNA which comprises a cDNA which can be expressed to make the (alpha) ^subunit of a calcium channel. Preferably, the (alpha) 2 -subunit or the (alpha)^subunit made from such a cDNA in such a cell will be foreign to the cell, i.e., will have an amino acid sequence which differs from that of any calcium channel (alpha)ι~subunit or (alpha) 2 -subunit which occurs in a cell of the same type which does not contain a DNA from which the (alpha)^subunit or the (alpha) 2 -subunit encoded by such a cDNA is expressed. Preferred among such cells are those of mammalian origin, such as COS cells, NIH3T3 cells, mouse L cells or the like, or those of yeast such as S. cerevisiae or P. pastoris. Methods of making such cells of the invention, by transforming cells with suitable heterologous DNAs, to be maintained in the cell as episomes or (preferably) integrated into chromosomal DNA of the cell, and then culturing transformants or subculturing (or passaging, in the case of mammalian cells) from such a culture or a subculture thereof, are well known to those of ordinary skill. Among such cells of the invention, the invention entails also an eukaryotic cell with an heterologous calcium channel, said calcium channel made by a process comprising expression of a first cDNA, which codes for the precursor of the (alpha).^-subunit of a calcium channel of an animal of a first species, and a second cDNA, which codes for the precursor of the (alpha) 2 -subunit of a calcium channel of a second species, said first and second species being the same or different. Usually at least one of said precursor of said (alpha) ι~subunit and said precursor of said (alpha) 2 -subunit is foreign to said cell. Again, preferred among such cells are those of mammalian origin or those of yeast such as S. cerevisiae cells or P. pastoris. In a preferred embodiment, such a cell will also contain another heterologous gene, which comprises a transcriptional control element (e.g., a promoter or promoter/enhancer combination) , which is active in said cell and the transcriptional activity of which responds to an ion or molecule capable of entering said cell through a functional calcium channel (e.g., Ca ++ , Ba ++ , Ca +÷ ionophores) , linked operatively for expression to a structural gene for an indicator protein, such a chloramphenicol acetyltransferase, luciferase or β-galactosidase. These cells of the invention, which have functional, foreign calcium channels (i.e., functional calcium channels wherein at least one of the (alpha)!-subunit and the (alpha) 2 -subunit is foreign to the cell) will be useful for, among other purposes, assaying a compound for calcium channel agonist or antagonist activity. First, such a cell can be employed to measure the affinity of such a compound for the functional calcium channel. Secondly, such a cell can be employed to measure electrophysiologically the calcium channel activity in the presence of the compound being tested as well as a ion or molecule, such as Ca ++ or Ba , which is known to be capable of entering the cell through the functional channel. For similar studies which have been carried out with the acetylcholine receptor, see Claudio et al. Science 238 1688-1694 (1987) . These methods for assaying a compound for calcium channel agonist or antagonist activity are also part of the present invention. Such cells according to the invention, in the preferred embodiment, wherein the cell also contains an heterologous gene with a transcriptional control element, which is active in the cell and responsive to an ion or molecule capable of entering the cell through a functional calcium channel and is linked operatively for expression to a structural gene for an indicator protein, can also be employed, in another method according to the invention for assaying a compound for calcium channel agonist or antagonist activity. This method comprises exposing a culture of such cells to a solution of a compound being tested for such activity, together with an ion or molecule, which is capable of entering the cells through a functional calcium channel and affecting the activity of the transcriptional control element controlling transcription of the gene for the indicator protein, and comparing the level of expression, in the cells of the culture, of the gene for the indicator protein with the level of such expression in the cells of another, control culture of such cells. A "control culture," as clearly understood by the skilled, will be a culture that is, and is treated, substantially the same as the culture exposed to the compound being assayed except that the control culture is not exposed to the compound being assayed. Levels of expression of the genes for the indicator proteins are ascertained readily by the skilled by known methods, which involve measurements of the concentration of indicator protein via assays for detectable compounds produced in reactions catalyzed by the indicator protein. As indicated above, indicator proteins are enzymes which are active in the cells of the invention and catalyze production of readily detectable compounds (e.g., chromogens, fluorescent compounds). In a still further aspect, the invention is a method for diagnosing Lambert-Eaton Syndrome in a person by im unoassay which method comprises combining serum from the person with (alpha)^subunit of a first animal species and (alpha) 2 -subunit of a second animal species (the same as or different from the first species) and ascertaining whether antibodies in the serum react with one or both of the subunits to a greater extent than antibodies in control serum (e.g., from a person or group of persons known to be free of the Syndrome) . Any im unoassay procedure known in the art for detecting antibodies in serum against a given antigen can be employed in the method. Preferably, in the method, both of the (alpha) subunits are from a mammalian calcium channel, most preferably human. The invention entails also a labeled (e.g., 32 P or a biotinylated) RNA or single-stranded DNA of at least 12 (preferably at least 30) bases in length in a sequence which comprises a sequence of at least 12 (preferably at least 30) contiguous bases between bases -238 and 3495, inclusive, in Table 2 below, or such a labeled RNA or single-stranded DNA with a sequence taken from the cDNA, described in Example 4, which encodes an human neuronal (alpha) 2 ~subunit. The use of such DNAs and RNAs as probes, to identify and isolate cDNAs coding calcium channel (alpha)2-subunits or to identify tissue in which (alpha) 2 -subunit mRNA is made, is clear to the skilled. In this regard, see, e.g., Example 4. The primary strategy for cloning cDNAs encoding the (alpha) 1 and the (alpha) polypeptide subunits of the DHP-sensitive calcium channels from rabbit skeletal muscle was to screen rabbit back skeletal muscle lambda gtll cDNA expression libraries with antibody probes specific to each of the proteins. See generally Ausubel et al. Current Protocols in Molecular Biology, Wiley-interscience, New York (1987) ; Davis et al. Basic Methods in Molecular Biology, Elsevier Science Publishing Co., New York (1986). Monoclonal antibodies capable of immunoprecipitating the M r 155K-170K DHP receptor (alpha) ! protein from rabbit skeletal muscle triads have been described previously by Leung, et al . J. Biol. Chem. 262, 7943-7946 (1987). Polyclonal antisera specific for the (alpha) 2 polypeptide subunit was prepared in guinea pigs using SDS polyacrylamide gel purified (alpha) 2 protein as described by Nakayama, et al. J. Biol. Chem. 262, 6572-6576 (1987). One of the (alphas-specific monoclonal antibodies, designated as IIF7 by Leung, et al. supra, and the (alpha) 2 -specific polyclonal antisera were used for screening of 1.0 X 10 recombinant phages of an oligo-dT primed lambda gtll cDNA library. Probes based on the Tanabe et al. (alpha)i-subunit cDNA sequence (Nature 328,313-318 (1987) ) could also be used to identify clones with fragments of the (alpha)ι~subunit cDNA. Once a positive clone was found using an antibody-screening method, the clone was used to screen further for overlapping clones. A sequential series of overlapping clones was thus generated. These clones were sequenced and fragments were subcloned into either pIBI 24/25 (IBI, New Haven, CT) or M13 mpl8/19. In cloning the (alpha)ι~subunit, the DNA sequence was compared to the primary sequence of the DHP receptor (alpha) _- subunit reported by Tanabe et al. Nucleotide differences resulting in amino acid differences were confirmed by sequencing in both directions. As pertains to the (alpha)ι~subunit, initially, two cDNA clones which reacted positively with the IIF7 monoclonal antibody were isolated and found to be related by cross-hybridization. DNA sequencing of one of these clones revealed the presence of a cDNA insert of 453 base pairs (bp) . Significantly, this insert coded for a 151 amino acid open reading frame with 28% homology to a region for the Electrophorus electroplax sodium channel sequence. The cDNA insert derived from this clone was used to rescreen the lambda gtll cDNA library and a rabbit back skeletal muscle Okayama-Berg cDNA library (MacLennan, et al., Nature 316, 696-700 (1985)) to isolate overlapping cDNA clones. The cDNA clones were analyzed using the dideoxy chain-termination method of Sanger to determine the entire coding sequence of the (alpha) _ subunit of the calcium channel and a restriction map was made for comparison and orientation of DNA sequences. An oligo-dT-primed expression cDNA library was constructed in lambda gtll, using young adult rabbit back skeletal muscle poly (A+) RNA (kindly provided by J. Robbins, University of Cincinnati) isolated in guanidine isothiocyanate (see Gubler, et al., Gene 25, 263-269 (1983); Lapeyre, et al., Gene 37, 215-220 (1985); Huynh et. al, DNA Cloning: A Practical Approach, Vol. I 49-78 (IRL, Oxford, 1985)). Double-strand cDNA was synthesized and EcoRI adapaters were added. After the addition of the adapters, the double-strand cDNA was size-selected on a Sepharose CL-4B or Bio-Gel A-50m column. Fragments > 1500 bp were ligated into EcoRI digested, dephosphorylat- ed lambda gtll. The library was packaged in vitro with Gigapack-plus, (Stratagene, San Diego, CA) and an efficiency of > 95% recombinants was determined by plating in the presence of X-gal and IPTG. Two clones of a total 1 X 10 6 recombinants were identified by screening the expression library with monoclonal Ab IIF7 reactive with the M r 170,000 (alpha)! subunit of the rabbit skeletal muscle calcium channel. Positive plaques were visualized by binding HRP-goat anti-mouse IgG followed by color development with 4-chloro-l-naphthol. Each clone contained a -500 bp insert and was related by cross-hybridization. One clone was DNA sequenced to identify an open reading frame (nts 2847-3300) and was used to identify a 6.5 Kb transcript by Northern analysis The 453 bp insert noted above was used to rescreen the lambda gtll library and 8 of 1 X 10 6 clones were positive. One clone (1700 bp) extended the farthest 5' to nt 2237; its 522 bp PstI fragment, nts 2294-2816, was used to screen 1 X 10 6 transformants of a rabbit back skeletal muscle cDNA library constructed according to the method of Okayama and Berg (see MacLennan, et. al.. Nature 316, 696-700 (1985)). Three positive clones were isolated, of which the largest (5.0 Kb) extended 5' to nt -750. The Okayama-Berg cDNA library was rescreened with a 5' 250 bp (PstI)-EcoRI fragment (the PstI site is donated by the Okayama-Berg vector) (nts -750-1006) . The longest clone isolated, of 5 positives, was 5.3 Kb, extending 5' to nt - 450. To clone the 5' end of (alpha) _, a random primed rabbit back skeletal muscle lambda gtll cDNA library was synthesized as described above with the following modi ications: (1) pd(N) 6 hexamers (Pharmacia, Inc. Piscathaway, NJ) were used to random prime the first strand cDNA reaction, (2) Adapters containing Ncol, Kpnl, and EcoRI sites: 5'-CCATGGTACCTTCGTTGACG-3' 3'-GGTACCATGGAAGCAACTGCTTAA-5' were ligated to the double-strand cDNA as described above, and (3) the double-strand cDNA was size-selected on a 1 ml Bio-Gel A50m column. Fragments > 600 bp were ligated into lambda gtll. 1 X 10 6 recombinants of this library were screened in duplicate with the 1,648 bp EcoRI/XhoI fragment corresponding to nt 1006-2653 and an oligonucleotide probe spanning the initiating methionine: 5'-GGGAAGCCATGGAGCCATCCTCACCCCAGG-3'. Forty clones were Q positive with both probes, of which one (1.55 Kb) extended 78 nts 5' of the start codon and -450 bp 3' of the EcoRI site. Table 1 (below) shows the 5,975 nucleotide sequence of the cDNA encoding the (alpha)2-subuni . 5 There is a 5,619 nucleotide sequence reading frame which encodes a sequence of 1,873 amino acids (Table 1). The sequence context of the designated initiation codon is consistent with the proposed consensus sequence of Kozak, Nucleic Acids Res. 15, 8125-8132 (1987). The 3' non-coding sequence of the cDNA is 234 nucleotides in length, excluding the poly (dA) tract, and contains a consensus polyadenylation signal ATTAAA (nucleotides 5832-5837) 17 nucleotides upstream from the poly (dA) tract. This cDNA sequence is consistent with an -6,500 nucleotide DHP receptor (alpha)i mRNA. Furthermore, the DNA sequence is 99.4% identical to the cDNA sequence encoding the DHP receptor reported by Tanabe, et. al., supra. Nucleotide differences were identified at 33 positions, of which three, nucleotides 5423, 5444 and 5504 also result in amino acid changes. Table 1 GCGGGGAACACTGGGGACGCAGGGAΛGΛGAGCGCCGCGCCGTGGGGGAGCAGCAGGAACCCCCGTCGCCACGGAACCC -1 ATG GAG CCA TCC TCA CCC CAG GAT GAG GGC CTG AGO AAG AAA CAG CCC AAG AAG CCC CTG βO Mβ( Glu Pro Sβr Sβr Pro Gin A»p Glu Gly Lau Arq Lye L i Gin Pro Lyi Lyi Pro Leu 40 CCC GAG GIC CTG CCC AGG CCG CCC CGG CCT C!G IIC TCC CTG ACC CTG CAG AAC CCG CIG 120 Pro Glu val Leu Pro Arq Pro Pro Arq Ala Lau P β Cye Lβq Thr Lau din Aβn Pro Lau CAG GIC AAC GTC AIC C*C ACC AAC ACG CCC CCC ATG AGC AGC AAA GCA GCC GGC CTG GAC 480 Gin vat Asn Val lla Gin $»r A»n Thr Ala Pro U«t Sβr Sβr Lya Gly Ala Gly Lau Aao _ ' β _ IβO GTC AAG CCC CIG AGG CCC ITC CCf " GIG CIC ACA CCC CΪC CCC CΪG GIC KG ~ GCG GTG|CCT 3<0 Vil Lya AH Leu Arq All Phe Arq Vil Leu Arq Pro Leu Arq Leu Vil Ser Gly VillPrσ 200 AGI TTG CAG GTG GTC CTC AAC TCC AIC TTC AAG CCC ATG CTC CCC CTG TTC CAClAIC CCC fJOO Sβr Leu Gin Val Val Leu Asn Sβr He Pha Lya Ala Uβl Lau Pro Lau Phβ Mlalllβ Ala Table 1 (cont.) 220 CIG CIC GIC CIC TIC AIC GIC AIC AIC TAC CCC AIC AlC CGG CIG GAG CIC TIClAAG GCC 660 Leu Leu Vi I Leu Phβ Uβt Vil lie He Tyr All lla Me Gly Leu Glu Leu Phβ I ya Cly 2<0 AAG ATG CA AAG ACC TGC TAC TAC ATC GCC ACA G C ATC GTG CCC ACA GIC GAG AAT CAG 72C Lyi Met Mil Lyi Thr Cyi Tyr Tyr Hi Gly Thr Aap III Vil All Thr Vil Glu Asn Glu 260 AAG CCC TCC CCC TGC GCT ACG ACC CCC TCG GCG CCC CCC TGC ACC ATC AAC GGC AGC GAG 780 Lya Pro Sβr Pro Cyi All Arq Thr Gly Sβr Gly Arq Pro Cyβ Thr He Ajn Gly Sβr Glu 200 TCC CGG GGC GCC TCC CCG CCG CCC AAC CAC GCC ATC ACG CAC TIC C C AAC TTC GCC TIC 840 Cy» Ar o Gl Gl Trp Pro Gl Pro Asn Ilia Gly lla Thr Mia Pha Aap A»n Pha Gly P β m 300 TCC ATG CTC ACC GTC TAC G TCC ATC ACC AIC G*G GCC TGC ACA CAΪ GIC CTC TAC ICG 900 Hj Sβr Uβt Leu Thr Val Tyr Gin Cyβ lie Thr Uβt Glu Gly Trp Thr Aap Vil Lau Tyr ITD _ ___ _ _ __ 3?o C GTC A C CAT CCC ATC GCG AAC GAG TCGlCCC ICG A C TAC III G?C AC CΪC A e CΪG CIG 9G0 HI val Aan Aap Ala He Gly Aan Glu Irpl ro Trp Me Tyr Phe Vil Thr Leu Me Leu Leu 340 CGG TCC MC TIC AIC CIC AAC CIG GIG CIG GCC GIC CIG ACIICCG GAA TTC ACC AAC C Q I0J0 Gly Ser Phe Phe lie Lou Asn Leu Vil Leu Gly Val Leu Sor Id y Glu Phβ Thr Lys Glu 380 CCG GAG AAG GCC AAG TCC AGG CCA ACC TIC CAG AAC CTG CGG G G AAG CAG CAG CTG GAC. 1θ80 Arq Glu Lys Ala Lyi Sβr Arq Gly Ihr Phβ Gin Lyi Leu Arq Glu Lyi Gin Gin Leu Glu 380 GAG GAC CTT CCG GCC TAC ATG ACC TCG ATC ACG C G GCC GAG GIC ATC GAC GTC GAG CAC 1140 Glu Aap Leu Ar Gly Tyr Uβt Sβr Trp Mβ Thr Gin Gly Glu Val Uβt Aap Vil Glu Aap 400 CTG AGA GAA GCA AAG CTG TCC TIG GAA G G GGA GCC TCC GAC ACG GAA ACC CTG TAC GAA 1200 L#u Arq Glu Gly Lya Leu Sβr Leu Glu Glu Gly Gly Sβr A»p Thr Glu Sβr Leu Tyr Glu Table 1 (cont.) 420 ATC GAG GGC TTG AAC AAA ATC AIC CAG TTC ATC CCA CAC TCG AGG CAG TCG AAC CGT GTC 1260 Ma Glu Gly Lau Aan Lya lla He Gin Phβ Me Ar Mia Trp Arq Gin Trp Aan Arq Val 4 40 TTT CCC TCG AΛG TCC CAT CAC CTG GIC AAG TCG ACAlGIC HC lAC IGG CIG GIC AIC CIG I32C Phβ Arq Trp Lya Cya Mia Asp Leu vil Lyi Sβr Arqlvil Phe Tyr Trp Leu Vil Me Leu ___ 4G0 Ale GΪG GCC CΪC AAC ACC CIC I C AΪC CCC ICGlGAC CAC AAC CAC CCG CTC TCG CTG 1380 Me Vil All Leu Am Thr Leu Ser He All StrfClu Hit Mil Aan Gin Pro Leu Trp Leu Tyr TrplThr Sβr Leu Sβr Aan Leu Val Ala Sar Lau Leu Aan Sβr lie Arq Sβr Me Ala __ __ ___ ___ __ 560 TCGlCIG CIG CΪG CIG CΪC IΪC CΪC IΪC AΪC AΪC AIC ΪΪC CCC CΪG CΪG CCC ΛI5 CAG CΪC 1T40 Sβr iLeu Leu Leu Lau Leu Phe Leu Ph He Me Me Phe All Leu Leu Cly Met Qln Leu 600 TIClGCO GCG CCα TAC CAC TTC C Q CAC ACC CAA GTC CCA CCC ACC AAC TTC CAC AAC TTC 1600 PhβlGly Gly Arq Tyr Aap Phe Glu Aap Thr Glu Val Arq Arq Sar Aan Phe Aap Aan Phe Table 1 (cont.) 620 CCC CAG CCC CTC ATC ACC CTC TTC CAG GTC CTG ACC GOT G G C C TCC AAC TCC GIG ATC 1880 ro Gin All Lau He Sar Vil Pha Gin Vil Lβu Thr Cly Glu Aap Trp Am Sir Val Uβt TAC AAC GCG ATC ATG CCC TAC CCA CCC CCG TCC TAC CCG CCC GTT CTClGIG TGC ATC TAT 1920 -17-1- o D o o O o O O o to o o IX -r SUBSTITUTE SHEET -17-2- O o o o o a Ci o — ' o ιo to ID to to- o ID o SUBSTITUTE SHEET -17-3- o O o O - ' o ____ o o © D o us «- d — o «o w-t to ew r. «-ι — — •n o o ►» to- SUBSTITUTE SHEET Table 1 (cont.) 12B0 ATC AAG TCC TTC CAG CCC CTC CCC TAC|CΪC CCC CΪG CΪC AΪC CΪC AΪC CIG ΪIC I IC AIC 36«0 lla Lya S β r Ph β CIn Ala L β u Pro Ty lVal AH Leu Leu He Vil Uβt Liu Phi Phe Hi __ _____ _____ 1300 TAC CCC GIC AΪC CCC AΪC CAG AΪC IIIICCA AAG ATC CCC CTO GTO CAC CCQ ACC C G ATC 390D Tyr AH Vil Me Cly Uat CIn Uat PhalGly Lya Me Ala Lβu Val Aap Oly Thr αin Me 1320 AAC CCC AAC AAC AAC TTC CAQ ACC TTC CCC C Q CCC GTC CTG CTG CTC TTC AGO TCT GCG 3980 Aan Arq Aan Aan Aan Pha Gin Thr Phβ Pro CIn Ala Val Lβu Lβu Lβu Phe Arq Cye Ala 13-40 H ACA CCC G A G CCG TCG C*A CAG ATC CTC CTC CCC TCC ACC TAC CCG AAG TTG TGC CAC CCA 40 0 Thr Cly Glu AH Trp CIn Glu Me Lβu Lβu Ala Cye Sβr Tyr Gly Lya Lβu Cya Aap Pro rrg ® I m m -I Tε le 1 (cont.) Pha I lβ Ser Pho Tyr Uet Leu Cys AH Phe leu lie Me Aan Lβu Phβ Vil AH V l Mβ I4QO to AlClCAC AAC TTT CAC TAC CIC ACA CCC CAC TCC TCC ATC CTG CCC CCT CAC CAC CTG CAC 4200 c Uβt IAsp an Phβ Asp Tyr Lβu Ihr Arq A»p Trp Sβr Me Lβu Gly Pro Mlβ Mlβ Lβu Aap 1420 to GAG TTC AAG CCC ATC TCG CCA C*G TAT C C CCA GAG CCC AAG GCG CCA ATC AAG CAC CTG 426C -f Glu Phβ Lyi AH He Irp AH Glu Tyr Aap Pro Glu All Lya Gly Arq He Lye His Lβu H 1440 c GAC GTC GTG ACC CTG CIG ACA ACG AIC CAG CCC CCT CTG GCC TTC GCG AAG TTC TGT CCA 4320 m Asp Val Val Thr leu Lβu Ar Arq He Gin Pro Pro Lβu Gly Phβ Gly Lye Phe Cyβ Pro MOO CO CAC CGG G T C GCC ΪGT AAC CCC CIG GIG CCC AIC AAC ATC CCC CTG AAC ACT GAC GCC ACG z 4360 m Il l s Ar q Va l Ala Cya Lya Arq leu Val Gly Uβl Aan Uβt Pro Lβu Aan Sβr Aap Gly Thr 1400 H GIC ACC TTC AAT CCC ACC CIC TTT CCC CIG GIC CCC ACG CCC CTC AAG ATC AAG ACA GAA 4440 Val Thr Phβ A$n Ala Thr leu Pha Ala leu Val Arq Thr All Lβu Lyi He Lyi Thr Glu 1500 GGT AAC TTC GAG CAG CCC AAC C»G G»G CTG ACG CCC ATC AIC AAG AAG ATC TCG AAG AGA 4500 Cly Aan Phβ Glu Gin Ala Aan Glu Glu lau Ar AH Me He lya Lya He Trp Lye Arq 1320 ACC AGC AIC AAG CIA CTG CAC C G GTC AIC CCT CCC ATA GCA CAT CAC CAQ GTC ACC GTC 4S6D Thr Sβr Uβl Lys leu leu Aap CIn Val He Pro Pro Me Gly Aap Aap Glu Val Thr Vil I 15 0 CCG AAG TTC TAC CCC ACA TTC CIC AT CAG G G CAC TTC CCG AAG TTC ATC AAG CCC CAG 4620 Gly Lya Phβ Tyr AH Thr Pha Lau He Gin Glu Mil Phe A q lya Pha Uβt Lya Arq Gin Table 1 (cont.) «560 G*G GAA TAT TAT CGG TAT CCG CCC AAC AAC CAC ACC CTG C G AfC C G CCT CCC CTG CCG 4680 Clu Glu lyr Tyr Gly Tyr Arq Pro lya Lya Aβp Ihr Val CIn lie CIn Ala Oly Lβu Arq 1500 ACC ATA GAG GAG GAG CCC CCC CCT CAG AIC CCC CCC ACC ATC TCA CCA C C CIG ACC CCC 4740 Thr He Glu Glu Glu AH AH Pro Glu Ha Arq Arq Thr He Sβr Gly Aap Lβu Thr All i r J 1600 GAG GAG G G CTG G*G AGA GCC AIC GTG C G CCT CCG ATG GAG GAG ACG ATC TTC CGG AGG 4600 Clu Glu Glu leu Glu Arq AH Uet Val Glu Ala Ala Uβt Glu Clu Arq He Phe Arq Arq 1B20 ACC GGA GCC CTG TTT GCC C G CTC CAC ACC TTC CTG GAA ACG ACC AAC TCC CTA CCC CCG 48G0 1hr Gly Gly Leu Phβ Cly CIn Val Aap Thr Pha leu Clu Arq Thr Aβn Sβr Lβu Pro Pro 1640 GTC ATC CCC AAC CAA AGA CCG CTC CAG TTT CCT GAQ ATA GAA ATG CAA CAQ CTT GAG TCG 4B20 Vil Uβt AH Aan Gin Arq Pro lau CIn Pha Ala Glu Me Clu Uβt Glu Glu Lβu Glu Ser 1600 ftl CCT GTC TTC TTG C*G CAC TTC CC1 CAA CAC CCA AGA ACC AAC CCT CTC CCT CGT CCC AAT 4960 5040 TTT TCC AGC GTC CAC ICt GAA AGG G G TTC CCC GCA G G CCC GAG ACA CCC C T CCC GGA 5100 Phβ Sβr Sβr Val Mlβ Cyt Glu Arq Glu Phβ Pro Gly Glu Ala Glu Thr Pro Ala AH Gly 1720 CCA CCA GCC CTC ACC C C TCC C C ACG CCC CIC CCA CCT CAC ACC AAG CCC TGT GCT GCA 5180 Arq Gly AH leu Sβr Mla Sar II11 A q All lau Gly Pro Mlβ Sar Lyβ ro Cya All Gly 1740 AAA CTG AAT CGG C G CTG GTC C G CCG GCA AIC CCC ATC AAC CAG GCA CCT CCT GCC CCC 5220 lya leu Aan Gly CIn Lβu Val CIn Pro Gly Ual Pro Me Aan Gin Ala Pro Pro Ala Pro Table 1 (cont.) 1760 TGC CAG CAG CCT AGC ACA CAT CCC CCA GAG CCC GCG CAG ACG AGG ACC TCC CTG ACA GGG 5280 Cya Gin Gin Pro Sβr Thr Aap Pro Pro Glu A Gly Gin Arq Arq Thr Sar Leu Thr Gly 1760 TCI CTG CAA CAC GA CCA CCC C C ACC ACC ACC TCC GAG CCG AGC ACC CCC ACG CCC CCG 534D Sβr Leu Gin Asp Glu Ala Pro CIn Arq Arq Sβr Ser Glu Gly Sβr Thr Pro Ar Ar Pro 1600 CCT CCT CCT ACA CCT CTC CTC ATC CAA GAG CCT CIG GTT CGA GCG GCC CTG CAC ACC TTG 5 00 0 ) AH Pro Ala Thr AH leu Lβu He CIn Clu AH Lβu Val Arq Gly Gly Leu Aap Thr Leu c 1620 00 CCA CCT CAT CCT GCC TIC GTC ATC CCA ACA ACC CAC CCC CTG GTA CAC CCC TCT CAG AIC 5 80 Ale Ala Asp AH Gly Phβ Val Uet AH Thr Sβr Gin Ala Lβu val Aap AH Cyβ Gin Uβt 1640 H CAA CCG GAG GAA GTA GAG GTC CCA GCC ACA GAG CTA CTG AAA GAQ CCA GAG CC GTC CAG 5520 C Glu Pro Glu Glu Vil Glu Vil AH All Thr Glu Lβu Lβu Lya Glu Arq GIU ter Vil Gin 1660 rø GGC ATC GCC ACT GTC CCG GGA AGC CTG AGC CCC ACG TCC TCC CTG GCC AGC CTT GAC CAG 55BO 0) Gly Uet All Sβr Vil Pro Gly Ser Lau Ser A Arq Ser Sαr Leu Gly Ser Leu Aip Gin I 1673 V [D GTC CAG GGC TCC CAC CAA ACC CTT ATT CCT CCC ACG CCG TCATGCCTGTCCAGTGTCCACATGACC 56 6 ^ j Val Gin Gly Sβr Gin Glu Thr Lβu He Pro Pro Arq Pro AAGGCGACCGCGACAGIGCGTCCACAAGCTCACCCCTCCATCCCACCCTCCCTCTGTCTCACCCCTCCTGCTGACCTGG 57Ϊ5 CCCCGTCTGCAACCGACCAGGAAGCCACCACCCICCCCIGGCCAGCAAGAGCCAICAIICTAAACCATCCAGAAACCCC 5604 AΛAAAAAAAAAAAA 5897 -19- As pertains to the (alpha) 2 -subunit, in an initial screen with the guinea pig (alpha) 2 -specific polyclonal antisera, three cDNA clones were isolated and shown to be related to each other but not any (alpha) _ cDNA sequences by cross-hybridization. Two of these cDNA clones were used to rescreen the lambda gtll cDNA library to isolate overlapping cDNA clones. The cDNA clones were analyzed to establish the coding DNA sequence of the (alpha)2 subunit of the calcium channel and a restriction map was made. Approximately 7,850 nucleotides of (alpha) 2 cDNA was cloned, which is consistent with an -8,000 nucleotide (alpha) 2 mRNA. An oligo-dT-primed expression cDNA library was constructed in lambda gtll, using young adult rabbit back skeletal muscle poly (A+) RNA as described for the (alpha) 1-subunit. Double-stranded cDNA fragments > 1500 bp were ligated into lambda gtll and a primary plating of 1 X 10 6 recombinants was screened with guinea pig anti-160 Kd (alpha) 2 polyclonal anti-sera. Three positive plaques were visualized by binding HRP-Protein A, followed by color development with 4-chloro-l- naphthol. Two clones, (2.5 Kb and 3.6 Kb) overlapped to encode 4.75 Kb of an -8 Kb transcript identified by Northern analysis. (alpha) 2 cDNA clones extending in the 5' and 3' direction (oriented by DNA sequencing and identification of a long open reading frame) were isolated by rescreening the same lambda gtll cDNA library with the (EcoRI)-Hindlll fragment of one clone (nts 43-272, 5' proximal; EcoRI site from adapter) or the EcoRI - (EcoRI) fragment of a second clone (-1.0 Kb in the 3' untranslated region). A total of 14 clones were isolated, seven from each end, of which an overlapping pair of clones (one extending -2,750 nts 3' and the other extending 350 nts 5') encoded -7850 nts of the (alpha) 2 transcript; 308 nts of 5' untranslated sequence, 3318 nts S UB ST I TUTESHEET -20- of coding sequence, and -4224 nts of 3' untranslated sequence. Only 176 nts of 3' untranslated sequence was confirmed in both directions and is reported. Table 2 represents the 3,802 nucleotides of the cDNA sequence encoding the (alpha) 2 -subunit and its precursor, including 308 nucleotides of 5' untranslated sequence, a 3,318 nucleotide open reading frame, and 176 nucleotides of 3' untranslated sequence. Table 2 5" AGAACGCAGGCCCAGCCTCGTCTGICCCCGCICCGCCCCCGCCCGCACCCCCGAGGTCTGTTGGCAAAAGT -236 CGCCCTTGAJ_GCCGGCGGACGCCACGCAGCCCCCGCCCCGAACACCCGACCCCCGCTAGCCGGGICCGCCCGCCCCTTT -159 CCC GAGCCCAGCCCCGCCGMCCCCCCCCCCCCCGCCCCCCCCCCCCCCGTTCCCCGCCCCCCCCGCCCCCCGGTGGC -60 AGCGCCGC1CGGICCCCCGCCCCCGGGCCGGCTCCGCGCCCGTCGGCGCGTCIGAGGGGCTTGCTCCCAGCTCGCGAAG -I -26 -7 ATG CCT CCG GCC CCC CCG CTG CCC TCG ACC CIG ACA CTT TCG CAG CCC TCC CTG ATC CTG 60 Uet Ala Ala Gly Arq Pro leu AH Irp Thr Lau Ihr Lau Trp CIn Ala Trp Lβu Me Lβu -1 «1 14 (D ATC GCG CCC TCG TCG C c'cAC CCG TTC CCT TCA CCC CTC ACT ATC AAG TCA TCC QTC CAT 120 C Me Gly Pro Sβr Sβr Glu Glu Pro Phβ Pro Sβr AH Val Thr He Lye Sβr Trp Val AID m 3 AAC ATC CAA GAA CAC CTG GTC ACA CTG CCA AAA ACA GCA ACT GCA GTC AAT CAQ CTT GTT 180 H Lya Uβt Gin Glu Asp Lβu val Thr Lau Ala Lya Thr Ala Ser Cly Val Aan Gin Leu V|| 54 c GAT ATT TAT CAC. AAA TAT CAA CAT TTG TAT ACT GTG C*A CCA AAT AAT CCA CCT CAG CTG 240 Aβp l ie Tyr Glu lya Tyr Gin Aip lau Tyr Thr Val Glu Pro Am Aan AH Arq Gin Lβu 74 ω GTC CAA ATT CCA CCC ACA CAC ATT G*G AAG CTT CTC AGC AAC ACA TCT AAA CCC CTG GTG 300 I val Glu Me AH AH Ar Aap l ie Clu lya Lau Lau Sar Aan Arq Sar Lya AH Lau V|| m 94 CCC CTG CCT TTG GAA CCA GAG AAA GTT CAA QCA CCC AC CAA TCG ACG G A CAT TTT GCA 380 Arq Lβu Ala leu Glu AH Glu Lya Val Gin AH AH MH Gin Trp Ar Glu Aip Phe AH 114 AGC AAT GAA GTT GIC TAC TAT AAC CCG AAC CAT CAT CTT CAT CCT GAA AAA AAT GAC AGI 420 Sβr Aan Glu Val Val Tyr Tyr Aan Ala Lya Aap Aβp leu Aap Pro Glu Lya Am Aip Sβr U4 CAA CCA CCC ACC C G ACG ATC AAA CCI GIT TIC ATT GAC CAT CCT AAC TTT ACA ACA C A 480 Glu Pro Gly Sβr Gin A q l ie lya Pro Val Pha l la Aap Aβp Ala Aan Pha Arq Ar CIn GTA TCC TAT CAG CAC GCA CCT GTC CAT ATC CCC ACT GAC ATC TAT G*A GCA TCG ACA A ' 5 T 4 540 val Sβr Tyr CIn MH AH AH Val Mla Me Pro Thr Aap Me Tyr Clu Gly Sβr Thr l ie Table 2 (cont.) 174 GIG TTA AAC GAA CTC AAC TCC ACA ACT CCC TTA CAT GAC GTT TTC AAA AAA AAT CCA GAG 600 val Lβu Aan Glu Lβu Am Trp Thr Sar AH Lβu Aap Aβp Vι I Ph β Lyi Lyi Aan Arq Clu 194 GAA GAC CCT TCA CTG TTG TCG CAG GTG TTT GCC AGT GCC ACT CCC CTG GCC CGG TAT TAC 660 Glu Aap f r o Sβr Lβu Lβu Trp Gin Vil Phβ Gly Sβr All Thr Gly Leu All Arq Tyr Tyr 214 CCA CCT TCT CCA TGG GTT GAT AAT ACC CCA ACC CCA AAC AAG ATT CAT CTT TAT GAT CIA 720 Pro AH Sβr Pro Trp Vil Aip Aan Sβr Arq Thr Pro Aan Lya He Aap Lau Tyr Asp Vil 234 2 c CCC ACA ACA CCA TCG TAC ATC CAA GGT CCT CCA TCC CCT AAA CAT ATC CTT ATT CTG GIC 760 Arq Arq Arq Pro Trp Tyr He CIn Cly Ala AH Sβr Pro Lya Aap U β t L β u He L β u Val CO 254 ϋ> CAT GTC ACT GGA AGC GTT AGT GCA CTG ACA CTC AAA CTC ATC CCG ACA TCC GTC TCC C A 640 Α Aβp Val Sβr Gly Sβr Vβ I Sβr Gly Leu Thr Leu Lye Lβu He Arq Thr Ser Val Ser Clu 274 c -4 ATG TTG GAA ACC CTC TCA GAT CAT GAT TTT GTG AAC GIC CCT TCA TTT AAC AGC AAT CCT 900 Uβt Lβu Glu Thr Lβu Sβr Aap Aap Aap r \χ χ » Vil Am Vil AH Sβr Phβ Aan S β r Aan Ala m 294 CAG CAT GTA AGC TGC TTT C G C C CTT GIC CAA GCA AAT GTA AGA AAT AAG AAA GTG TTG 960 Gin Asp Vil S β r Cya Ph β Gin Mil Lβu Val Gin AH A Vi | Arq Aan Lyi Lya Vil Leu 314 AAA CAT GCA CTG AAT AAT ATC ACA CCA AAA GCA ATC ACA GAT TAT AAG AAG GGC TTT AGT 1020 Lya Aap AH Vil Aan Ajn Me Thr Ala Lyi Gly Hi Thr Alp Tyr lyi Lyi Cly Phβ S β r 334 TTT CCT TTT GAG CAC CTG CTT AAT TAT AAT GTA TCC ACA CCC AAC TCC AAT AAG ATT ATC 1080 Ph β Ala Ph β Glu Gin Lau leu Aan Tyr Am Vil Sβr Arq Ala Aan Cyβ Aan Lya He He 354 ATC TTG TTC ACG GAC GCA GCA G A A GAG ACA CCC CAG G G ATA TTT CCC AAA TAC AAT AAA 1140 Mel L β u Ph β Thr Aap Cly Gly Glu Glu Arq AH Oln Glu He Phβ AH Lyi ϊyr Aan Ly i Table 2 (cont.) 374 GAC AAG AAA GTA CCT GTA TIC ACA TTC TCA GTT GCC CAA AT AAT TAC CAC ACA GGA CCT 1200 Aap lya Lya Va l Ar Val Phβ Thr Phβ Sβr Val Gly Gin Mlβ Aβn Tyr Aap Arq Gly Pro 394 ATT CAG TCG ATG GCT TCC GAA AAT AAA CCT TAT TAT TAT GAA ATT CCA TCC ATT CCA CCC 1260 Me Gin Trp Uβt AH Cya Glu Aan lya Gly Tyr Tyr Tyr Glu He Pro Sβr lie Gly Ala 414 (f) TTA AAC AAC CAC CTG ATT CTT GCA GIG ATG CCA CTT GAT GTC TCT TTG CAA CAT ATT AAA 1500 X Lβu Lye Aan Gin Lau Ha Lβu Gly Val Uβl Gly Val Aap Val Sβr Leu Clu Aap He Lya m 494 JJJ AGA CTG ACA CCA CCT TTT ACA CTC TCC CCC AAT GCC TAC TAT TTT GCA ATT GAT CCT AAT 1560 Arq Lβu Thr Pro Arq Phβ Thr Lβu Cyβ Pro Aβn αiy Tyr Tyr Phβ All II* Aip Pro Afn 514 CCT TAT GTC TTA TTA CAT CCA AAT CTT CAQ CCA AAG CCT ATT GCT GTA CCT ATA CCA ACA 1620 Gly Tyr Val Leu Lau MH Pro Aan Lβu CIn Pro Lya Pro He Gly Val Cly He Pro Thr 534 ATT AAT TTG ACA AAA ACG ACA CCC AAT CTT C G AAC CCC AAA TCT CAQ CAQ CCA GTC ACA I860 He Aen Lβu Arq Lye Arq Arq Pro Aan Val Gin Aan Pro Lye Sβr αtn Clu Pro Vil Thr 55 TTG CAT TTC CTC CAT CCA CAQ TTG C*G AAT CAC ATT AAA GTC CAQ ATT CCA AAT AAA ATG 1740 Lβu Aap Phe Leu Aap AH Glu Leu Glu A Aap He Lye Vil Qtu Me Arq Aan Lyi Uat Table 2 (cont.) 574 ATC GAT GCA CAA AGT GCA CAA ACA TTC AGA ACT CTQ CTT AAA TCT CAA CAT G G ACA 1800 He Aap Gly Glu Ser Gly Glu tyβ Thr he Arq Thr Leu Val Lye Ser Gin Aap Glu Arq 594 TAT ATT CAC AAA GGA AAC AGO ACA TAC ACC TCG ACT CCT GTC AAC GCC ACA CA TAT ACC 1860 ω Tyr He Aap Lye Gly Am Arq Thr Tyr Thr Trp Thr Pro Vil Am Gly Thr Aap Tyr Ser c -14 D3 ACT TTG CCC TTO CTA TTA CCA ACC TAC AGT TTT TAC TAT ATA AAA CCC AAA ATA GA CAC 1920 ω Ser Leu AH Leu Vil Leu Pro Thr Tyr Ser Phe Tyr Tyr II* Lyi All Lyi lit Glu Qlu H H c m x m m -I Table 2 (cont.) 634 ACA ATA ACT AC CCC AGA TAT TCA GAA AC CTG AAA CCC CAT AAT TTT CAA GAA TCT CCC 1080 Thr l ie Thr Gin Ala Ar Tyr Sβr Clu Thr lau lya Pro. Aep Aβn Phe Clu Clu Sβr Cly 654 TAC ACA TTC CTA CCA CCA *GA CAT TAC TGC ACT C C CTT AAA CCT TCA CAT AAT AAC ACT 2040 Tyr Thr Phe leu AH Pro Arq Aap Tyr Cya Sar Aap lau Lya Pro Sβr Aβp A|n Aan Thr 674 CAA TTT CTT TTA AAT TTC AAT G G TTT ATT CAT AGA AAA ACT CCA AAC AAC CCA TCC TCT 2100 Glu The leu Lβu Asn Phβ Asn Glu Phβ He Asp A q Lyi Thr Pro A A|n Pro Sβr Cy c * 694 AAT ACA CAC TTG ATT AAT ACA GTC TTG CTG CAT CCA GCC TTT ACA AAT CAA CTT GTT CAA 2160 0) Asn Thr Asp Leu He Aan Arq Val Lβu Lβu Aβp Ala Gly Phβ Thr Aβn Glu Lau Val Gin 714 Α _| AAT TAC TGG ACT AAG C*G AAC AAT ATC AAG GCA GTG AAA CCA CCQ TTT GTT GIC ACT CAT 3220 c C Aan Tyr Trp Sβr Lys Gin Lya Aβn lla Lya Gly Val Lyi All Arq Phβ Vtl Yβl Thr AJD »" CGT GCG ATT ACC ACA GTT TAT CCC AAA CAG GCT CCA G AAT TCG C Q C*A AAC CCA CAG 2260 (0 Gly Gly He Thr Arq Val Tyr Pro Lya Clu Ala Gly Glu Aan Trp Gin Clu Aan Pro Glu X 754 T ACA TAT GAA CAC ACC TTC TAT AAA ACC AGC CTC CA1 AAT CAT AAC TAC GTT TTC ACT C T 2340 Thr Tyr Glu A»p Sβr Phβ Tyr Lya Ar Sβr leu Aβp Aan Aep Aan Tyr Val Phβ Thr Ala -I 774 CCC TAC TTT AAC AAA ACT CCA CCT CCC CCC TAT G*G TCA CCC ATT ATC CTA AGC AAA GCT 2400 Pro Tyr Phβ Am lye Sβr Cly Pro Cly AH Tyr Clu Sβr Cly He Uet Val Ser lye Ala 794 GTA GAA ATA TAT AIC C*A GCA AAA CM CTT AAA CCT CCA GTT GTT GCA ATT AAA ATT CAT 2460 Val Clu He lyr He CIn Gly lya Lβu leu Lya Pro Ala Val Val Cly He Lya lie Asp 614 GTA AAT TCT TCG ATA G*G AAT TTC ACC AAA ACT TCA AIC ACG GAT CCG TCT CCT CGT CCA 2520 Val Aan Sβr Trp lie Glu A Table 2 (cont.) 634 GIT TGT CAC TGC AAA CCA AAC ACT CAT CIA ATG CAT TCT GTG ATT CTA CAT C*C GGT GCG 2580 Vβl Cya Aap Cyi Lyi Arq A >βιnn $ Sββrr Aap Val Uβt Aap Cyβ Val He Lβu Aβp Aap Gly Gly 654 TTT CTT TTG ATC CCC AAC CAT CAT CAT TAT ACC AAT Q ATT GCA ACA TTC TTT GGA GAC 2640 Phβ Leu leu Uβt AH Aan Mlβ Aβp Aap Tyr Thr Aan Gin He Cly Ar Phe Phe Gly Glu 674 ATT GAT CCA ACC TTG AIC ACA CAC CTG GIC AAT ATA TCA GTT TAT GCC TTT AAC AAA TCT 2700 βr 94 GC 2760 r 14 CT 2620 ll 5a CA 2660 lu A 5 G 4 2940 lu 3 00 C ly 94 AAT TCT TCC ACA ATC TTT CAT CTA GAA AAG CIC ATG AAC ACC AAT TTA ATA TTC ATA ATC 3060 Am Cya Sβr Arq He Phβ Mlβ Val Glu lya lau Uβt Aan Thr Aβn Leu He Phβ Me Uβt 1014 GTA G A G AGC AAG CCG ACA TCT CCC TGT CAC ACA CCG CTG CTC ATA CAA CCA CAG CAA ACT 3120 Val Glu S β r Lye Cly Thr Cya Pro Cya Aap Thr Arq Lβu Lβu He CIn AH Glu CIn Thr -22-3- o o u — •- c U _ < •» t to. V) u > < SUBSTITUTE SHEET -23- Table 2 also shows the signal peptide of the (alpha)2-subunit, shown as the first 26 negatively numbered amino acids. An arrow identifies the cleavage site between the signal peptide and the mature (alpha) 2 -subunit. The N-terminal amino acid sequence previously determined is shown in bold sequence (Thr(+8) , Trp(+12), and Asp(+14) were not previously determined.) The nucleotide sequence shown was determined from two clones which overlapped to span the coding sequence of the (alpha)2-subunit. Five nucleotide differences among individual clones were observed resulting in four amino acid changes. Differences occurred in the sequence at positions 169, 347, 348, 984, and a deletion of nts 1858-1860. The amino acids were finally determined to be as follows: Asn at residue 31, Lys at residue 90, and a deletion of Ser at residue 594. An in-frame upstream stop codon is underlined as well as the start and stop codons of an upstream short open reading frame. Three putative transmembrane regions are enclosed in boxes. Potential N-glycosylation and phosphorylation sites are indicated as described for Table 1. The open reading frame encodes a sequence of 1,106 amino acids (Table 2). The previously determined NH 2 -terminal amino acid sequence of the (alpha) 2 protein is encoded by nucleotides 79-129 in the same open reading frame (amino acid residues 1-17, Table 2). The nucleotide sequence adjacent to the designated initiating codon agrees with the proposed consensus sequence. An in-frame termination codon is present upstream beginning at nucleotide -27. In addition, an out-of-frame potential initiation codon is located beginning at nucleotide -229 and is followed by a nonsense codon at nucleotides -179 to -181. The 5' untranslated sequence of the (alpha)2 cDNA, 308 nucleotides cloned and sequenced thus far, is unusually long. This region is -24- exte ely G+C rich, approximately 80% G+C, which is similar to other relatively long 5' non-coding sequences which have been reported. Table 1 shows the 1,873 amino acid sequence deduced from the cDNA of the (alpha) -^ subunit of the rabbit skeletal muscle calcium channel. Based on the identification of a clone using the (alpha) -^-specific IIF7 monoclonal antibody, we have determined that the protein sequence encoded by the 453 bp cDNA insert (amino acid residues 950—1,100) contains the epitope recognized by this monoclonal antibody. The complete sequence yields a calculated Mr of 212,143 for the (alpha) ^ protein, in contrast to the observed Mr 155K-170K, previously reported by others using SDS polyacrylamide gel electrophoresis. The amino acid sequence determined and reported here is 99.8% identical to that recently described by Tanabe et al., supra, showing three amino acid differences at residues 1,808 (Thr to Met), 1,815 (Ala to Val), and 1,835 (Ala to Glu). The calcium channel (alpha)^-subunit protein contains five potential N-glycosylation sites at Asn residues 79, 257, 797, 1,464, and 1,674 and seven potential cAMP-dependent phosphorylation sites at Ser residues 687, 1,502, 1,575, 1,757, 1,772, and 1,854, and Thr 1,552. Analogous to the (alpha)-subunit of the sodium channel, the (alpha) 1 -subunit of the skeletal muscle calcium channel contains four internal repeated sequence regions. An analysis of the hydropathy profile of the (alpha)^protein sequence reveals that each repeat contains five hydrophobic segments and one segment with strong positive charge. Since the (alpha)-^-protein sequence lacks an hydrophobic amino-terminal sequence characteristic of a signal peptide, it has been proposed that the segments of the four internally repeated regions represent twenty-four transme brane segements and that -25- the amino-and carboxy-termini extend intracellularly. That model is consistent with two of the potential glycosylation sites (Asn residues 79 and 257) being localized extracellularly and all of the potential phosphorylation cites being localized intracellurly. This generally agrees with previous biochemical studies suggesting that the (alpha) _- subunit (which has been identified as the putative 1,4-dihydropyridine receptor) is not glycosylated but is phosphorylated. Table 2 shows the 1,106 amino acid sequence deduced f om the cDNA of the (alpha) 2 -subunit of the rabbit skeletal muscle calcium channel. The sequence yields a calculated M r of 125,018 for this protein, in contrast to the observed M r 165K-175K (under non-reducing conditions; M r 135K-150K under reducing conditions) determined previously by SDS polyacrylamide gel electrophoresis. The (alpha) 2 amino acid sequence deduced here from the cDNA confirms the sequence of 17 amino acids reported earlier as supposedly that of the amino terminal 17 amino acids of the (alpha) 2 -subunit. The (alpha)2-subunit precursor has a 26 amino acid (residues -1 to -26) signal peptide. While this proposed signal peptide is hydrophobic and of an appropriate length characteristic of signal sequences, it is somewhat unusual in that the peptide has Glu at position-1 and the Gin at position-12 defines a rather short central hydrophic region. The (alpha) 2 protein contains 18 potential N-glycosylation sites (Asn residues 68, 112, 160, 300, 324, 444, 451, 580, 589, 652, 671, 758, 801, 865, 872, 962, 975, and 1,005) and two potential cAMP-dependent phosphorylation sites at Thr 477 and Ser 822 (Table 2) . An analysis of the (alpha) 2 protein sequence for regional hydropathy reveals that, in distinct contrast to similar analysis of the (alpha) _ protein, this protein is substantially hydrophilic, although it -26- does contain a number of hydrophobic regions. Further characterization of the hydrophobic regions of polarity index and hydrophobic moment analyses indicates that three segments may represent transmembrane domains of the (alpha)2 protein. The topography of the (alpha) 2 protein is not, however, easily predicted from the deduced primary amino acid sequence. This problem is further compounded by the determination that the (alpha)2 protein lacks significant homology with any protein in the Dayhoff protein sequence database or with other known ion channel and receptor proteins. If the proposed (alpha) 2 signal sequence is, in fact, cleaved between the Glu-residue at position -1 and the Glu residue at position, then the amino terminus of the mature protein would be extracellular. Furthermore, assuming that the three hydrophobic segments function as transmembrane domains, and that there are only three such domains, the carboxyl-terminus of the (alpha) 2 protein would be intracellular. Such a transmembrane topography would be consistent with 8 out of the 18 potential N-glycosylation sites being localized extracelluarly and the single potential phosphorylation site being localized intracellularly. Previous biochemical studies indicate that the (alpha) 2 -subunit of the skeletal muscle calcium channel is not phosphorylated but is extensively glycosylated. Rabbit and human genomic DNAs were digested with various restriction enzymes and Southern blots of these DNAs were hybridized with radiolabeled cDNA clones specific for the (alpha)^subunit or the (alpha) - subunit. Under conditions of high stringency, very few hybridizing bands were observed in rabbit genomic DNA with either the (alpha) _- or (alpha) 2 -specific probes. This result is consistent with a low-copy number, perhaps only a single-copy, each of the -27- (alpha)- j ^ and (alpha) 2 -subunit genes in the rabbit genome. Southern blot of the same DNA preparations were also probed under conditions of low stringency with the same (alpha)_- and (alpha) 2 -specific probes. While additional hybridizing bands were observed in rabbit genomic DNA under low stringency conditions with both the (alpha) _- and (alpha) 2 -specific probes, substantially greater hybridization was observed with the (alpha) _- specific cDNA probes. These results suggest that the (alpha)_- and (alpha) 2 -subunits of the skeletal muscle DHP-sensitive calcium channel may share significant homology with genes encoding other voltage- dependent DHP-sensitive calcium channels, voltage- dependent calcium channels which are not DHP-sensitive (e.g., T- and N-types) , and possibly ligand-gated calcium channels (e.g., glutamate receptor). Interestingly, hybridization bands were observed in human genomic DNA with the (alpha)-^-specific cDNA probes under both high and low stringency conditions, whereas significant hybridization of (alpha) 2 -specific cDNA probes were observed only under low stringency conditions. Thus, while there are human genes homologous to the rabbit (alpha) _- and (alpha) 2 -subunit genes, greater evolutionary sequence divergence may have occurred in the (alpha)2 gene relative to the (alpha) _ gene. A further aspect of the invention provides for a diagnostic assay for Lambert Eaton Syndrome (LES) . LES is an autoimmune disease characterized by an insufficient release of acetylcholine from motor nerve terminals which normally are responsive to nerve impulses. A recent publication (Kim and Neher, Science 239, 405-408 (1988)) demonstrates that IgG from LES patients block individual voltage-dependent calcium channels and thus prevent function. A diagnostic assay for LES based on immunological reactivity of LES IgG with calcium channel -28- (alpha) 2 -subunit alone or in combination with (alpha)-L-subunit is thus provided for. For example, such an assay may be based on immunoprecipitation of LES IgG by the calcium channels subunits of the invention. EXAMPLE 1 Isolation of RNA for cDNA Library On the day before RNA is isolated, prepare the following. As a precaution, all glassware should be baked and all stock solutions in the list immediately below should be sterilized by autoclaving. 200 ml Of 0.1 NaOAc, pH 5.2, 1 mM EDTA 50 ml of 0.2 M Na 2 EDTA, pH 8.0. 50 ml of 1 M Tris, pH 7.5 50 ml of 3.2 Tris, pH 7.2 50 ml of 0.01 M Tris (pH 8.0), 1 mM EDTA 50 ml PK buffer (0.1 M Tris, pH 7.2, 50 mM NaCl, 10 mM EDTA) 50 ml of 10% SDS, 4 1 of ultrapure H 2 0 On the morning of the RNA isolation, combine: 100 ml H 2 0 100 g guanidine isothiocyanate (IBI) 10.6 ml 1 M Tris, pH 7.5 10.6 ml 0.2 M EDTA Stir, but do not heat above 65"C to dissolve guanidine isothiocyanate. Dissect young adult rabbit back skeletal muscle on a clean glass plate and add about 10 g of muscle tissue (cut in -4mm pieces) to 50 ml of the guanidine isothiocyanate solution in e.g., a 100 ml Wheaton bottle. -29- Homogenize using "tissuemizer" from Tek an (large blade) for 10-20 sec, or until small pieces are no longer visible. Place in 60" H 2 0 bath, add 30 "ml of redistilled phenol which has been made 0.1% in 8.OH quinoline, 0.2% β-ME. Solution should be clear and homogenous after this addition. Add 30 ml of a 1:1 solution of chloroform:acetate buffer. Shake vigorously at 60" for 10 minutes; the solutions should appear opaque; if not, add sufficient chloroform:acetate until it turns milky- Cool on ice, spin to separate phases (7000 x g, 10-20 minutes) Take off and pass it vigorously through a 22 gauge needle. Treat with phenol:chloroform (1:1) saturated with acetate buffer. Extract aqueous with 3 x volume of chloroform. Add 2 vol of -20° EtOH, and ppt for 1-2 hours, but no longer. Collect precipitate; dry briefly (<5 minutes) under vacuum. Resuspend in 7 ml of PK buffer made 0.2% with respect to SDS. If precipitate develops, heat at 65" until solution clears. Add 1.5 mg of proteinase K. Incubate 20 minutes at 37° (if you have dried for too long, RNA will be very difficult to get into solution and vigorous pipetting will be necessary throughout the incubation) . Extract reaction with 1:1 phenol:chloroform (made 0.1% in 8-OH quinoline, 0.2% β-ME, saturate with 100 mM Tris, pH 8.5 or PK buffer pH 7.7), 2 x with chloroform, ppt by addition of 1/10 volume of 3.2 M Tris, pH 7.5 and 2 vol. of EtOH. Poly A + RNA may then be isolated from the RNA mixture by well-known hybridization methods utilizing matrix-immobilized oligo (dT) . -30- EXAMPLE 2 cDNA Cloning Procedure 1. First Strand Synthesis a. The following reagents and compositions are combined together and incubated on ice for 5 minutes: Final Concen¬ 0 Reagent Volume tration -5 μg poly A+ RNA, plus water to 10.5 μl 5X reverse transcriptase buffer 10 μl IX 0.5M DTT 1 μl 10 mM RNasin (24 U/μl) 2 μl -IU/μl 5X dNTPs 10 μl IX 5 oligo dT (250 μg/ml) 5 μl 25 μg/ml b. Next, the following three reagents are added to (a) and the mixture is incubated at 37°C for 60 minutes: o actinomycin D (600 μg/ml) 4 μl -50 μg/ml 32 P-gammadCTP (3200 Ci/mmol) 2.5 μl MMLV-reverse transcriptase 5 μl 200 U/μg RNA (BRL-200 U/μl) 50 μl (total a+b) c. The following reagents are added to (b) and 5 the mixture is incubated at 37 ° C for 30 minutes: RNasin (24 U/μl) 1 μl MMLV-reverse transcriptase 3 μl (BRL-200 U/μl) d. Take aliguots for analysis: 1 μl at time 0 for TCA 1 μl at 90 minutes for TCA 0.5 μl at 90 minutes for gel e. The reaction is stopped after 30 minutes by adding 2 μl of 0.5M EDTA and performing one phenol/ -31- chloroform extraction, followed by one chloroform extraction. Then 10 μl of 10 M NH 4 OAc plus two volumes of ethanol are added to precipitate the first strand. f. To analyze the synthesis, 0.5 μl of the reaction are run on a 1.5% agarose mini-gel, the gel is photographed, dried, and placed under film (generally an overnight exposure with an intensifying screen is adequate) . g. Calculate the mass of cDNA from the percent incorporation of label above background. 1 μg ss cDNA=l.4% incorporation. 2. Second Strand Synthesis a. The cDNA-RNA is spun down by centrifugation in a benchtop microfuge for 15 minutes. The pellet is washed in 95% ethanol and dried. b. The following mixture is assembled and incubated at 12 β C for 60 minutes. Final Concen¬ Volume tration cDNA RNA, plus water to 68 μl 5X 2nd strand buffer 20 μl IX 10 mM β-NAD 1.5 μl 0.15 mM 4 mM dNTPs 5 μl 200 μM/ml DNA poly erase I (10 U/μl) 2.5 μl 250 U/ml E.coli DNA ligase (2 U/μl) 2 μl 40 U/ml RNase H (2.3 U/μl) 1 ul 23 U/ml 100 μl c. To this mix is added the following, and incubation continues at 22"C for 60 minutes: DNA polymerase I (10 U/μl) 1.5 μl E. coli DNA ligase (2 U/μl) 1.5 μl d. The reaction is stopped after 60 minutes by adding 4 μl of 0.5M EDTA and performing one phenol/ chloroform extraction and one chloroform extraction. e. The aqueous phase is run over a G-50 column in a short Pasteur pipet and 100 μl fractions are -32- collected. The 500 μls containing the cDNA is collected and pooled, and butanol extracted down to a volume of -50 μl. The cDNA is precipitated by adding 10 μl of 10 M NH^OAc plus two volumes of ethanol. 3. T4 Polymerase Reaction a. The cDNA is spun down in a microfuge for 15 minutes. A 95% ethanol was is performed and the cDNA pellet is dried. The dry pellet is counted in a scintillation counter. Assume 100% efficiency of the 2nd strand reaction, and calculate mass of double-stranded cDNA from the first strand calculation. b. To the cDNA is added the following, and the mixture is incubated at 37°C for 20 minutes. cDNA + 10X T4 buffer 5 μl H 2 0 40.75 μl 4mM dNTPs 1.25 μl 0.1 mM DTT 2.5 μl T4 polymerase (10 U/μl) 0.5 ul 50 μl c. Aliquots are taken: 0.5 μl for gel at time 0 0.5 μl for gel at 20 minutes d. The reaction is stopped after 20 minutes by adding 2 μl of 0.5 M EDTA, followed by a phenol/chloroform extraction and a chloroform extraction. e. The aqueous phase is run over a G-50 column in a short Pasteur pipet and 100 μl fractions are collected. The 500 μls containing the cDNA is collected and pooled, and butanol extracted down to a volume of -50 μl. The cDNA is precipitated by adding 10 μl of 10 M NH 4 OAc plus two volumes of ethanol. f. The 0.5 μl samples taken at time 0 and 20 minutes are run on a 1.5% agarose mini-gel, which is subsequently photographed, dried, and placed under film. -33- 4. Addition of EcoRI Adapters (for insertion into lambda gtll) a. Oligos are synthesized having the following sequences: 20 mer: 5'-CCATGGTACCTTCGTTGACG-3' 24 mer: 3 f -GGTACCATGGAAGCAACTGCTTAA-5' b. The 20 mer is phosphorylated by combining the 0 following reagents and incubated at 37 β C for 15 minutes.: 225 pmoles 20 mer + water 6 . 8 μl 1QX kinase buffer 1. 2 μl 'P-gammaATP (7000 Ci/mmole) 1. 0 μl 5 kinase (2 U/μl) 1. 0 μl 10 μl c. The following two reagents are added to above mixture and it is incubated at 37"C for 30 minutes: 0 10 mM ATP 1 μl kinase (2 U/ml) 1 ul 12 μl (total b+c) d. The enzyme is then inactivated by boiling for 10 minutes. 5 e. The 24mer is hybridized to the phosphorylated 20mer by addition of 225 pmoles of the 24mer (plus water to bring volume to 15 μl) r and incubation at 65°C for 5 minutes. The reaction is then allowed to slow cool to room temperature. Q The adapters are now present at a concentration of 15 pmoles/μl, and are ready for cDNA-vector ligation. 5 -34- f. Combine the following: cDNA + hybridized adapters (15 pmol/μl) 50-fold molar excess ove CDNA water 16 μl lOx ligase buffer 2 μl ligase (10 U/μl) 2 ul 20 μl 5. Phosphorylation of cDNA a. The ligase is inactivated by heating the mixture to 72 β C for 15 minutes. b. The following reagents are added to the cDNA ligation reaction and it is heated at 37°C for 30 minutes: cDNA ligation reaction 20 μl water 24 μl 10X kinase buffer 3 μl 10 mM ATP 1 μl kinase (2 U/μl) 2 ul 50 μl c. The reaction is stopped by the addition of 2 μl 0.5M EDTA, followed by one phenol/chloroform extraction and one chloroform extraction. 6. Purification and Size-Selection of cDNA a. The cDNA is run over a BIO-GEL A-50 column that has been washed with > 5ml of TE buffer. The column has 0.8 ml bed resin in a 0.2 cm (inner diameter) x 30 cm siliconized glass tube with a glass wool plug in a yellow pipet tip at the bottom. b. The cDNA is dried down in a speed vac to ~20μl. 2.5μl of gel loading dye is added and the cDNA is run over the column. The counts begin coming off after running 200-250 μl TE buffer through the column. 5 minute fractions (-30 μl) are collected and counted in a scintillation counter. Free adapters may begin to elute off 350-400 μl after the cDNA starts to elute. -35- c. 0.5 μl of several of the collected fractions are fun on a 1.5% agarose minigel. The gel is photographed, dried down, and placed under film. 7. Ligation of cDNA to lambda gtll vector a. The fractions containing cDNA are pooled, butanol extracted down to 20-30 μl, and 5 μl of 10M NH 4 OAc plus two volumes of ethanol is added t precipitate the cDNA. It is spun in a microfuge for 15 minutes, and then subjected to a 95% ethanol wash and dry. b. The pellet is counted, and the mass of cDNA is calculated relative to the mass after the second strand synthesis. c. The cDNA is resuspended in TE (-0.10 pmol/μl) . d. The ligation reaction contains the following, which is incubated at 14-16°C overnight: (use 1 μg of lambda gtll vector = 0.035 pmol vector) lambda gtll (1 μg/μl) 1 μl cDNA insert (2-4 fold molar excess of cDNA over vector) water to 3 μl 5X ligase buffer 1 μl ligase (10 U/μl) 1 ul 5 μl 8. Packaging The vector is packaged using the Gigapack in vitro packaging kit supplied by Strategene, and following the instructions contained therein. REAGENTS 5x RT bu fer 250 mM Tris, pH 7.4 250 μl of 1M 375 mM KC1 375 μl of 1M 15 mM MgCl 2 75 μl of 0.2M H 2 0 300 ul 1000 μl -36- 5X dNTPs 5 mM dATP 14.1 μl 3 mM dCTP 9.1 μl 5 mM dGTP 13.6 μl 5 mM dTTP 13.3 ul 50 μl 5X 2nd Strand Buffer 100 mM Tris, pH 7.5 100 μl of 1M 500 mM KC1 500 μl Of 1M 50 mM (NH 4 ) 2 S0 4 50 μl of 1M 25 mM MgCI, 125 μl of 0.2M 250 μg/ml BSA 5 μl of 50 mg/ml water 220 ul 1000 μl 10X T4 buffer 670 M Tris, pH 8. .0 670 μl of 1M 167 mM (NH 4 ). 2 so 4 167 μl of 1M 67 mM MgCl 2 67 μl of 1M H 2 0 96 ul 1000 μl EXAMPLE 3 Screening cDNA Library with Antibody Plate lambda gtll library on Y1090 in LB agar and 50 μg/ml ampicillin. Grow overnight in 15 ml of LB, 0.2 % maltose and 50 μg/ml ampicillin. Pellet the cells and resuspend in 3 ml of 10 mM MgS0 4 . Plate four plates at 250,000 plaques/plate using 25 μl of phage (10,000/μl) and 300μl of said 3 ml solution of cells in 10 ml soft agar containing 50 μg/ml ampicillin. Grow at 42°C for 2.5 hours and overlay IPTG-treated filters which were soaked in 10 mM IPTG (Boehringer Mannheim Biochemicals, Indianapolis, IN) . Dry filters until just moist, lay them in the plates and incubate overnight at 37*C. -37- Orient the plates and spot 0.5μl of purified DHP receptor on one plate as a positive control. Wash the filters for 10 min at room temperature TBS (50mM TRIS, 15_ mM NaCl, pH 8.0). Wash filters in TBS, 20% FCS (filtered) for 30 min at room temp. Incubate the filters for 2 hours in TBS, 20% FCS, anti-DHS-receptor antibody (monoclonal or polyclonal). Wash for 10 min in TBS. Transfer filters to new plates and wash for 1 min in TBS, 0.1% NP40. Wash for 10 min in TBS and transfer to new plates. Incubate for at least 1 hour with TBS, 20% FCS containing an appropriate second antiboby (e.g. HRP-Protein A; or HRP-goat anti-mouse IgG) . Wash filters as described above for the first antibody. Develop the positive clones using about 40 ml/plate of 4-chloro-l-naphthol reagent which is made by dissolving 60 mg of said developer in 20 ml of ice cold MeOH and mixing 4-chloro-l-naphthol (Aldrich Chemical Company, Milwaukee, WI) into 100 ml of TBS containing 60μl of 30% H 2 0 2 . EXAMPLE 4 An Human Neuronal Calcium Channel (Alpha)2-Subunit- Encoding cDNA Because of the indications, mentioned supra, that human calcium channel (alpha) 2 -subunit genes had diverged somewhat from rabbit calcium channel (alpha) 2 - subunit genes, human (alpha) 2 -subunit- encoding fragments were isolated to use as probes to screen human brain cDNA libraries under high stringency conditions. Thus, an EcoRI-digested human genomic Southern blot was probed under both low and high stringency conditions with a fragment of rabbit (alpha) 2 -subunit- encoding cDNA (the fragment from nucleotide 43 to nucleotide 272 indicated in Table 2) . Under low -38- stringency conditions, two genomic fragments werre identified, of 3.0 kbp and 3.5 kbp in size. Under high stringency conditions, only the 3.5 kbp fragment maintained a stable hybrid. These two fragments were cloned into lambda-gtll. The 3.5 kbp fragment includes a small Pstl-Xbal fragment, of about 300 bp, which includes an 82 bp exon with 96.4 % homology to nucleotides 102 to 183 of the sequence in Table 2. This exon is preceded by the dinucleotide AG (splice donor) and followed by the dinucleotide GT (splice acceptor) , as understood in the art. The 3.0 kbp fragment includes an Xbal - Bglll fragment, of about 585 bp, which includes 104 bp of an exon (which includes the Bglll site at its downstream end) which, in the 104 bp, has 93.3 % homology to nucleotides 184 to 287 of the sequence in Table 2. Both the 300 bp, Pstl-Xbal fragment and the 585 bp, Xbal-Bglll fragments were used to probe duplicate lifts of a human basal ganglia cDNA library in lambda-gtll (the library having been obtained from the American Type Culture Collection, Pockville, Maryland, USA, and containing about 10 6 independent recombinants with an average insert size of 800 - 1000 bp) . Three positive clones were identified which hybridized to both probes under high stringency conditions, one with an insert size of about 1150 bp, another with an insert size of about 790 bp, and the third with an insert size of about 670 bp. The 1150 bp insert in the one clone extended into the coding region from about nucleotide 200 in the coding region and was found to have a sequence more than 90 % homologous to that of the corresponding segment of the cDNA whose sequence is presented in Table 2. Using the lambda genome with the 1150 bp insert as probe, an human brain stem cDNA library (also purchased from the American Type Culture Collection, and having about 4 x 10 6 independent recombinants with an average insert size of 800 - 1000 bp) was probed under high stringency -39- conditions. In this probing, four positive clones were identified, with inserts of about 950 bp, 1120 bp, 3000 bp and 2500 bp. Most of the 1120 bp insert overlapped the 1150 bp insert of the DNA used as probe but extended somewhat upstream from the upstream end of the 1150 bp insert. The 2500 bp insert extended downstream from about 650 bp from the 5'-end of the 1120 bp insert. The DNA with the 2500 bp insert was used to again probe the brain stem library, and a clone with a 2750 bp insert was found. The 2750 bp insert was found by restriction analysis and sequencing to extend in the 3'-direction beyond the translational stop signal of a reading frame that was found to begin in the 1120 bp insert described above. The 2750 bp insert and 1120 bp insert have a PvuII site in common and have been ligated using the PvuII site to provide a cDNA that encodes a human neuronal calcium channel (alpha) 2 -subunit. The 5'-1560 bp of this cDNA have been sequenced and, as illustrated in Table 3, found to be 91.2 % homologous with the corresponding 1575 bp segment indicated in Table 2. The human (alpha) 2 -subunit-encoding cDNA will be subcloned into the mammalian expression vector pSV2DHFR, which is available in the art, for expression in mammalian tissue culture cells. We obtained the human neuroblastoma cell line IMR32 from the American Type Culture Collection (accession no. CCL127) . A northern blot analysis was carried out on poly A + RNA from this cell line using the full-length human (alpha) 2 -subunit-encoding cDNA. Under low stringency washing, a single 8.2 kb fragment was found. The rabbit skeletal muscle (alpha) 2 - encoding messenger RNA also had a size similar to 8.2 kb. -40- TABLE 3 ftr-?? . M 1°?rT-J- 1- GGGCGGGGGAGGGGGATTGATCTTC 25 ■ RnU ft S l M.s_l-oCi I I I I I I I I I I I I I I CCCGGGGCCGGCTGGGGGGCGGTCGGGGCGTGTGAGGGGCTTGCTCCCAG 299 StMCt to wi-——- ■ ~™~^"^ • • • * GATCGCAAGATGGCTGCTGGCTGCCTGCTGGCCTTGACTCTGACACTTTT 75 I II I I II I I I I III II I I I II I I I I I II I I I I I I I I I I CTCGCGAAGATGGCTGCGGGCCGCCCGCTGGCCTGGACGCTGACACTTTG 349 CCAATCTT TGCTCATCGGCCCCTCGTCGGAGGAGCCGTTCCCTT 119 II I I I II I I I I I I I I I I I I I I I I I I i I I I I I I I I I I I Gcaggcgtggctgatcctgatcgggccc cgtcggaggagccgttccctt 399 CGGCCGTCACTATCAAATCATGGGTGGATAAGATGCAAGAAGACCTTGTC 169 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Ml cagccgtcacta caagtcatgggtggataagatgcaagaagacctggtc 449 ACACTGGCAAAAACAGCAAGTGGAGTCAATCAGCTTGTTGATATTTATGA 219 I I I I I I I I I I I I I I I I I I I I II I I I I I I I I I I I I I I I I I I I I I I I I I I I I acactggcaaaaacagcaagtggagtcaatcagcttgttgatatttatga 499 GAAATATCAAGATTTGTATACTGTGGAACCAAATAATGCACGCCAGCTGG 269 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I II I I I gaaatatcaagatttgtatactgtggaaccaaataatgcacgtcagctgg 549 • « * - • TAGAAATTGCAGCCAGGGATATTGAGAAACTTCTGAGCAACAGATCTAAA 319 I I I I I I I I I I I I I II II I I I I I I I I I I I I I I I I I I I I I I I I I I I I tggaaat gcagccagagacattgagaagcttctcagcaACAGATCTAAA 599 • • * • • GCCCTGGTGAGCCTGGCATTGGAAGCGGAGAAAGTTCAAGCAGCTCACCA 369 M I N I M I I I I I M l I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I GCCCTGGTGCGCCTGGCTTTGGAAGCAGAGAAAGTTCAAGCAGCCCACCA 649 -41- TABLE 3 (cont.) GTGGAGAGAAGATTTTGCAAGCAATGAAGTTGTCTACTACAATGCAAAGG 419 M i l l I I M I I I I I I I I I I I M I I I I I I I I I I I I I I I I I I I M M ATGGAGGGAAGATTTTGCAAGCAATGAAGTTGTCTACTATAACGCGAAGG 699 ATGATCTCGATCCTGAGAAAAATGACAGTGAGCCAGGCAGCCAGAGGATA 469 ιn II I M M II I II II I MM Mill I II II I II II I I I I II M II M - LU ATGATCTTGATCCTGAAAAAAATGACAGTGAACCAGGCAGCCAGAGGATC 749 AAACCTGTTTTCATTGAAGATGCTAATTTTGGACGACAAATATCTTATCA 519 I M II M I M I M II II II M II II III II II II I II II Mill AAACCTGTTTTCATTGACGATGCTAACTTTAGAAGACAAGTATCCTATCA 799 • * • • « GCACGCAGCAGTCCATATTCCTACTGACATCTATGAGGGCTCAACAATTG 569 15 I M II M M M M M II II II II II II II II II M II I I I II I GCACGCAGCTGTCCATATCCCCACTGACATCTATGAAGGATCGACAATCG 849 • • - • * TGTTAAATGAACTCAACTGGACAAGTGCCTTAGATGAAGTTTTCAAAAAG 619 M II I II I I II II I I I II II II II II I II I II II II II II II II II I TGTTAAACGAACTCAACTGGACAAGTGCCTTAGATGACGTTTTCAAAAAA 899 20 AA.TCGCGAGGAAGACCCTTCATTATTGTGGCAGGTTTTTGGCAGTGCCAC 669 M i l l M I I I I I M I I I I I I I I I I I M I I I I I I I I I I I I I I I I I I I AATCGAGAGGAAGACCCTTCACTGTTGTGGCAGGTGTTTGGCAGTGCCAC 949 TGGCCTAGCTCGATATTATCCAGCTTCACCATGGGTTGATAATGGTAGAA 719 M U M I I I I M i l l I I I I I I I I I I I I I I I I I I M I I I I I I I TGGCCTGGCCCGGTATTACCCAGCTTCTCCATGGGTTGATAATAGCCGAA 999 CTCCAAATATGATTGACCTTTATGATGTACGCAGAAGACCATGGTACATC 769 I (MM I I I I Ml I MM II MM MM II II I I I II I I II II II I CCCCAAACAAGATTGATCTTTATGATGTACGCAGAAGACCATGGTACATC 1049 • » » • * CAAGGAGCTGCATCTCCTAAAGACATGCTTATTCTGGTGGATGTGAGTGG 819 Mill II I II I M II II II M II II I II II II 1 M II II II I II II I 30 CAAGGTGCTGCATCCCCTAAAGATATGCTTATTCTGGTGGATGTGAGTGG 1099 35 -42- TABLE 3 (cont.) AAGTGTTAGTGGATTGACACTTAAACTGATCCGAACATCTGTCTCCGAAA Θ69 M I M I II M II If II II I II If I II II I II II I II II II II II AAGCGTTAGTGGACTGACACTCAAACTCATCCGGACATCCGTCTCCGAAA 1149 TGTTAGAAACCCTCTCAGATGATGATTTCGTGAATGTAGCTTCATTTAAC 919 II M M II II II II II II II M II If I II II I II II II II II II II TGTTGGAAACCCTCTCAGATGATGATTTTGTGAACGTGGCTTCATTTAAC 1199 AGCAATGCTCAGGATGTAAGCTGTTTTCAGCACCTTGTCCAAGCAAATGT 969 M I I I I II II I I I If II I II II I II I I II II II i I I II II I II II I I I I AGCAATGCTCAGGATGTAAGCTGCTTTCAGCACCTTGTCCAAGCAAATGT 1249 AAGAAATAAAAAAGTGTTGAAAGACGCGGTGAATAATATCACAGCCAAAG 1019 II I II II I I II If II II M II II II I I I I II II II I II II II II II AAGAAATAAGAAAGTGTTGAAAGATGCAGTGAATAATATCACAGCAAAAG 1299 • • • • * GAATTACAGATTATAAGAAGGGCTTTAGTTTTGCTTTTGAACAGCTGCTT 1069 MM I M I II If I II II II II II II II II I II II II II I II II II II I GAATCACAGATTATAAGAAGGGCTTTAGTTTTGCTTTTGAGCAGCTGCTT 1349 AATTATAATGTTTCCAGAGCAAACTGCAATAAGATTATTATGCTATTCAC 1119 II II II II II I II II II II II II If II II II II II I III I II I I I AATTATAATGTATCCAGAGCCAACTGCAATAAGATTATCATGTTGTTCAC 1399 GGA...TGGAGAAGAGAGAGCCCAGGAGATATTTAACAAATACAATAAAG 1166 I II i I I I I I I II II M I I I II M I I II II I II II I I II II II I I GGACGGAGGAGAAGAGAGAGCCCAGGAGATATTTGCCAAATACAATAAAG 1449 ATAAAAAACTACCTGTATTCACCTTCTCAGTTGGTCAACACAATTATGAC 1216 I II III II I II I I II II I II II II II II I II II I II II I III ACAAGAAAGTACGTGTATTCACATTCTCAGTTGGCCAACATAATTACGAC 1499 -43- TABLE 3 (cont. ) AGAGGACCTATTCAGTGGATGGCCTGTGAAAACAAAGGTTATTATTATGA 1266 II MM II II MM II II If II I II II II I II II II I I II II I III I AGAGGACCTATTCAGTGGATGGCTTGCGAAAATAAAGGTTATTATTATGA 1549 AATTCCTTCCATTGGTGCAATAAGAATCAATACTCAGGAATATTTGGATG 1316 II M II II II II II M II II II II II II II II I II II I I II II AATTCCATCCATTGGAGCCATAAGAATTAATACTCAGGAATACCTAGATG 1599 TTTTGGGAAGACCAATGGTTTTAGCAGGAGACAAAGCTAAGCAAGTCCAA 1366 M II II I II I II II II II II II II II I II I II II II II II II I I I I II TTCTGGGAAGACCGATGGTTTTAGCAGGAGACAAAGCTAAGCAAGTCCAA 1649 TGGACAAATGTGTACCTGGATGCATTGGAACTGGGACTTGTCATTACTGG 1416 II II I II II II II I II II II II I I II II II I II I II II II II II I II I I TGGACAAATGTGTACCTGGATGCACTGGAACTGGGACTTGTCATTACTGG 1699 AACTCTTCCGGTCTTCAACATAACCGGCCAATTTGAAAATAAGACAAACT 1466 I II Ml II II II II II I II II II I II 1 II II I I II II II II II If I II I AACTCTTCCGGTCTTCAACATAACTGGCCAATTTGAAAATAAGACAAACT 1749 TAAAGAACCAGCTGATTCTTGGTGTGATGGGAGTAGATGTGTCTTTGGAA 1516 II II MM II I I II III II II I II II II II II I I I I M I I M I I I I I I TAAAGAACCAGCTGATTCTTGGAGTGATGGGAGTTGATGTGTCTTTGGAA 1799 GATATTAAAAGACTGACACCACGTTTTACACTGTGCCCCAATGG 1560 I I M M I I I I M M I I I I I I I I I I I I I I I I I I I I M U M I I I GATATTAAAAGACTGACACCACGTTTTACACTCTGCCCCAATGGCTACTA 1849 -44- While the invention has been described herein with some specificity, the ordinarily skilled in the art will recognize numerous variations and modifications, in what is described, that are within the spirit of the invention. Such variations and modifications are within the scope of the invention as described in Claim herein. Various features of the invention are also described in the following claims.

Claims: -45- WHAT IS CLAIMED IS: 1. A DNA which comprises a cDNA with a sequence which codes for the (alpha) 2 -subunit of an animal calcium channel or the precursor of said (alpha) 2 ~subunit. 2. A DNA according to Claim 1 wherein the sequence of said cDNA codes for the (alpha) 2 -subunit of a mammalian calcium channel or the precursor of said (alpha) 2 -subunit. 3. A DNA according to Claim 2 wherein the sequence of said cDNA codes for the (alpha) 2 -subunit of a skeletal muscle, cardiac, or neuronal calcium channel 5 or the precursor of said (alpha) 2 -subunit. 4. A DNA according to Claim 3 wherein the sequence of said cDNA codes for the (alpha) 2 -subunit of a rabbit or guinea pig skeletal muscle calcium channel or the precursor of said (alpha) 2 ~subunit. Q 5. A DNA according to Claim 4 wherein the sequence of said cDNA codes for the (alpha) 2 ~subunit of a rabbit skeletal muscle transverse-tubule calcium channel or the precursor of said (alpha) 2 -subunit. 6. A DNA according to Claim 5 wherein the 5 sequence of said cDNA is a cDNA sequence which codes for the amino acid sequence represented in Table 2. 7. The substantially pure (alpha) 2 -subunit of an animal calcium channel. 8. A substantially pure subunit according to 0 Claim 7 which is a subunit of a mammalian calcium channel. 9. A substantially pure subunit according to Claim 8 which is a subunit of a skeletal muscle, cardiac, or neuronal calcium channel. 5 -46- 10. A substantially pure subunit according to Claim 9 which is a subunit of a rabbit or guinea pig skeletal muscle calcium channel. 11. A substantially pure subunit according to Claim 10 which is a subunit of a rabbit skeletal muscle transverse-tubule calcium channel. 12. A substantially pure subunit according to Claim 11 which is made by a process comprising expressing in an eukaryotic cell a cDNA with a sequence which codes for the amino acid sequence represented in Table 2. 13. A substantially pure subunit according to Claim 12 wherein, in the process of making, said cDNA is expressed in a cell selected from the group consisting of a yeast cell and a mammalian cell. 14. A substantially pure subunit according to Claim 11 which has the sequence of amino acids 1 to 1080 represented in Table 2. 15. An eukaryotic cell with an heterologous calcium channel, said cell made by a process comprising administering to said cell a first composition, which consists essentially of a first RNA which is translatable in said cell into the precursor of the (alpha)__-subunit of a calcium channel of an animal of a first species, and a second composition which consists essentially of a second RNA which is translatable in said cell into the precursor of the (alpha) 2 -subunit of a calcium channel of an animal of a second species, said first and second species being the same or different, provided that at least one of said precursor of said (alpha) -_-subunit and said precursor of said (alpha) 2 -subunit is foreign to said cell. 16. A cell according to Claim 15 which is an amphibian oocyte and wherein, in the process of making, said first and second compositions are administered by microinjection. -47- 17. A cell according to Claim 16 which is an oocyte of Xenopus laevis. 18. A cell according to Claim 17 wherein said (alpha) -^-subunit is of a mammal of a first species and said (alpha) 2 -subunit is of a mammal of a second species, said first and second species being the same or different. 19. A cell according to Claim 18 wherein said first and second species are the same. 20. A cell according to Claim 18 wherein said (alpha) ^-subunit is of a skeletal muscle, cardiac or neuronal calcium channel and said (alpha) 2 -subunit is of a skeletal muscle, cardiac or neuronal calcium channel. 21. A cell according to Claim 19 wherein said (alpha) ^subunit is of a skeletal muscle, cardiac or neuronal calcium channel and said (alpha) 2 -subunit is of a skeletal muscle, cardiac or neuronal calcium channel. 22. A cell according to Claim 20 wherein each of the first and second mammals is selected from the group consisting of rabbit and guinea pig. 23. A cell according to Claim 21 wherein the mammal is selected from the group consisting of rabbit and guinea pig. 24. A cell according to Claim 22 wherein both the (alpha) -^-subunit and the (alpha) 2 -subunit are of a skeletal muscle calcium channel. 25. A cell according to Claim 23 wherein both the (alpha) -^-subunit and the (alpha) 2 -subunit are of a skeletal muscle calcium channel. 26. A cell according to Claim 25 wherein the mammal is a rabbit. 27. A cell according to Claim 26 wherein the translatable RNA of said first composition comprises a -48- sequence which encodes a protein with an amino acid sequence selected from the group consisting of that of Tanabe et al. and that represented in Table 1 and wherein 5 the translatable RNA of said second composition comprises a sequence which encodes a protein with the amino acid sequence represented in Table 2. 28. An eukaryotic cell with an heterologous calcium channel, said calcium channel made by a process 0 comprising expression of a first cDNA, which codes for the precuror of the (alpha)^-subunit of a calcium channel of an animal of a first species, and a second cDNA, which codes for the precursor of the (alpha) 2 ~ subunit of a calcium channel of an animal of a second 5 species, said first and second species being the same or different. 29. A cell according to Claim 28, wherein said cell is selected from the group consisting of a yeast cell and a mammalian cell.. o 30. A cell according to Claim 29 wherein said (alpha) -^-subunit is of a mammal of a first species and said (alpha) 2 -subunit is of a mammal of a second species, said first and second species being the same or different. 5 31. A cell according to Claim 30 wherein said first and second species are the same. 32. A cell according to Claim 30 wherein said (alpha) -^-subunit is of a skeletal muscle, cardiac or neuronal calcium channel and said (alpha) 2 -subunit is 0 of a skeletal muscle, cardiac or neuronal calcium channel. 33. A cell according to Claim 31 wherein said (alpha) -^-subunit is of a skeletal muscle, cardiac or neuronal calcium channel and said (alpha) 2 -subunit is of a skeletal muscle, cardiac or neuronal calcium channel. -49- 34. A cell according to Claim 32 wherein each of the first and second mammals is selected from the group consisting of rabbit and guinea pig. 35. A cell according to Claim 33 wherein the mammal is selected from the group consisting of rabbit and guinea pig. 36. A cell according to Claim 34 wherein both the (alpha) j -subunit and (alpha) 2 -subunit are of a skeletal muscle calcium channel. 37. A cell according to Claim 35 wherein both the (alpha) - j^ -subunit and the (alpha) 2 -subunit are of a skeletal muscle calcium channel. 38. A cell according to Claim 37 wherein the mammal is a rabbit. 39. A cell according to Claim 38 wherein said first cDNA encodes a protein with an amino acid sequence selected from the group consisting of that of Tanabe et al. , and that represented in the Table 1 and wherein aid second cDNA encodes a subunit with the amino acid sequence represented in Table 2. 40. A cell according to Claim 28, which is transformed with a heterologous gene which comprises a transcriptional control element, which is active in said cell and the transcriptional activity of which responds to an ion or molecule capable of entering said cell through a functional calcium channel, linked operatively for expression to a structural gene for an indicator protein. 41. A cell according to Claim 39 which is transformed with a heterologous gene which comprises a transcriptional control element, which is active in said cell and the transcriptional activity of which responds to an ion or molecule capable of entering said cell through a functional calcium channel, linked operatively for expression to a structural gene for an indicator protein. -50- 42. A cell according to Claim 40 wherein said indicator protein is selected from the group consisting of chloramphenicol acetyltransferase, lucif rase and β-galactosidase. 43. A cell according to Claim 41 wherein said indicator protein is selected from the group consisting of chloramphenicol acetyltransferase, luciferase and β-galactosidase. 44. A method of testing a compound for activity as a calcium channel agonist or calcium channel antagonist which comprises suspending a cell according to Claim 40 in a solution of said compound being tested and an ion or molecule, which is capable of entering said cell through a functional calcium channel and is capable of affecting the level of transcription from said transcriptional control element of said heterologous gene in said cell, and measuring the change in concentration of said indicator protein in said cell. 45. A method according to Claim 44 which comprises suspending a cell according to Claim 41 in a solution of said compound being tested and an ion or molecule, which is capable of entering said cell through a functional calcium channel and is capable of affecting the level of transcription from said transcriptional control element of said heterologous gene in said cell, and measuring the change in concentration of said indicator protein in said cell. 46. A method according to Claim 44 which comprises suspending a cell according to Claim 42 in a solution of said compound being tested and an ion or molecule, which is capable of entering said cell through a functional calcium channel and is capable of affecting the level of transcription from said transcriptional control element of said heterologous gene in said cell, and measuring the change in concentration of said -51- chloramphenicol acetyltransferase, luciferase or β-galactosidase in said cell. 47. A method according to Claim 44 which comprises suspending a cell according to Claim 43 in a solution of said compound being tested and an ion or molecule, which is capable of entering said cell through a functional calcium channel and is capable of affecting the level of transcription of said transcriptional control element of said heterologous gene, in said cell, and measuring the change in concentration of said chloramphenicol acetyltransferase, luciferase or β-galactosidase in said cell. 48. A method of diagnosing Lambert-Eaton Syndrome in a person comprising: combining substantially pure (alpha)__- and (alpha) 2 -subunits of a mammalian calcium channel with a sample of serum from said person; and testing for a reaction between antibodies of said serum sample and at least one of said calcium channel subunits. 49. A labeled RNA or single-stranded DNA of at least 12 bases in length in a sequence which comprises a sequence of at least 12 contiguous bases between bases -27 and 3319 indicated in Table 2 or the complement of a sequence of at least 12 contiguous bases between bases -27 and 3319 indicated in Table 2. 50. A DNA or RNA according to Claim 49 with a sequence which comprises at least 30 contiguous bases between bases -27 and 3319 indicated in Table 2 or the complement of a sequence of at least 30 contiguous bases between bases -27 and 3319 indicated in Table 2. 51. A DNA or RNA according to Claim 49 which is labeled with 32 P. 52. A DNA or RNA according to Claim " 50 which is labeled with 32 P. -52- 53. A DNA according to Claim 3 wherein the sequence of said cDNA codes for the (alpha) 2 -subunit of a human neuronal calcium channel or the precursor of said 5 (alpha) 2 -subunit. 54. A DNA according to Claim 53 wherein the sequence of said cDNA is a cDNA sequence which codes for the amino acid sequence encoded by the human neuronal (alpha) 2 -subunit-encoding cDNA described in Table 3. 0 55. A substantially pure subunit according to Claim 9 which is a subunit of an human neuronal calcium channel. 56. A substantially pure subunit according to Claim 55 which is made by a process comprising expressing 5 in an eukaryotic cell a cDNA with a sequence which codes for the amino acid sequence encoded by the human neuronal (alpha)2~subunit-encoding cDNA described in Table 3. 57. A substantially pure subunit according to Claim 56 wherein, in the process of making, said cDNA is o expressed in a cell selected from the group consisting of a yeast cell and a mammalian cell. 58. A labeled RNA or single-stranded DNA of at least 12 bases in length in a sequence which comprises a sequence of at least 12 contiguous bases of the protein- 5 encoding segment of the human neuronal (alpha) 2 - subunit-encoding cDNA described in Table 3. 59. A DNA or RNA according to Claim 58 with a sequence which comprises at least 30 contiguous bases of the protein-encoding segment of the human neuronal 0 (alpha) 2 -subunit-encoding cDNA described in Table 3. 60. A DNA or RNA according to Claim 59 which is labeled with 32 P. 61. A DNA or RNA according to Claim 60 which is labeled with 32 P.

Inventors: BRENNER ROBERT, ELLIS STEVEN BRADLEY, HARPOLD MICHAEL MILLER, SARTOR JEAN, SCHWARTZ ARNOLD, WILLIAMS MARK E, BRENNER, ROBERT, ELLIS, STEVEN, BRADLEY, HARPOLD, MICHAEL, MILLER, SARTOR, JEAN, SCHWARTZ, ARNOLD, WILLIAMS, MARK, E.
Applicants: SALK INST BIOTECH IND, THE SALK INSTITUTE BIOTECHNOLOGY/INDUSTRIAL ASSOCI
Application year: 1989
Main classification: C12Q1
IPC codes: C07K14, C12N1, C12N5, C12N15, C12P21, C12Q1, C12R1, G01N33