bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transcriptional regulation of flocculation genes inSaccharomyces cerevisiae
Authors: Teunissen Aloys W. R. H. , Van Den Berg Johan A. , Yde Steensma H. 
Published: May 2005

AbstractNorthern analysis showed that DNA from the flocculation geneFLO1hybridized to mRNA molecules of 4·8 kb. This transcript was specific for theFLO1gene at the right end of chromosome I since disruption of this gene resulted in the disappearance of the transcript. We further found an absolute correlation between flocculation and the presence of transcripts hybridizing toFLO1DNA, both in various flocculent and non‐flocculent strains and in cells from the non‐flocculating and flocculating stages of growth. In all cases transcripts were present in flocculating and absent from non‐flocculating cultures. From these results we conclude that theFLO1gene is transcriptionally regulated.Mutations inTUP1orSSN6cause flocculation. Several transcripts hybridizing toFLO1DNA were present in the mutants but not in the corresponding wild‐type strains. Disruption of theFLO1gene in thetup1andssn6strains showed that one of the transcripts corresponded to theFLO1gene. Disruption ofFLO1did not abolish flocculation completely but only reduced it, indicating that at least two flocculation genes, includingFLO1, are activated or derepressed by mutations in theTUP1/SSN6regulatory cascade.
Nucleotide sequence and chromosomal localization of the gene encoding the old yellow enzyme from Kluyveromyces lactis
Authors: Miranda Manuel , Ramírez Jorge , Guevara Soledad , Ongay‐Larios Laura , Peña Antonio , Coria Roberto 
Published: May 2005

AbstractA 6·6 kb genomic DNA fragment from the yeast Kluyveromyces lactis was isolated. Sequence analysis of this fragment revealed the presence of two incomplete open reading frames (ORFs) in one strand, one coding for the carboxyl terminus of the plasma membrane H+‐ATPase and the other for the amino terminus of an unidentified product. In the complementary strand, a full‐length ORF which encodes for a protein homologous to the yeast NADPH‐dependent Old Yellow Enzyme was found. The deduced amino acid sequence of this ORF predicts a protein of 398 residues with 84% similarity in its full length to OYE1 from Saccharomyces carlsbergensis and OYE2 from Saccharomyces cerevisiae. In addition, an internal region showed considerable similarity to the bile acid‐inducible polypeptide from Eubacterium sp., to the NADH oxidase from Thermoanaerobium brockii, to the trimethylamino dehydrogenase from bacterium W3A1 and to the estrogen‐binding protein from Candida albicans, suggesting a functional or structural relationship between them. Inactivation of the KYE1 (Kluyveromyces Yellow Enzyme) gene by deletion of 0·6 kb fragment between positions +358 and +936 produced viable cells with a slight increase in their generation time. Haploid cells carrying the disrupted allele showed one‐third of the NADPH oxidase activity, compared to wild‐type cells. Southern blotting analysis of digested DNA and chromosomes separated by contour‐clamped homogeneous electric field electrophoresis from K. lactis indicated that this is a single‐copy gene and it is localized on chromosome II, whose molecular size has been estimated to be approximately 1·3 Mb. The sequence reported in this paper has been deposited in the GenBank data base (Accession No. L37452).
The DNA sequence of a 7941 bp fragment of the left arm of chromosome VII of Saccharomyces cerevisiae contains four open reading frames including the multicopy suppressor gene of the pop2 mutation and a putative serine/threonine protein kinase gene
Authors: Coglievina Maristella , Bertani Iris , Klima Raffaella , Zaccaria Paolo , Bruschi Carlo Vito 
Published: May 2005

AbstractWe report the sequence of a 7941 bp DNA fragment from the left arm of chromosome VII of Saccharomyces cerevisiae which contains four open reading frames (ORFs) of greater than 100 amino acid residues. ORF biC834 shows 100% bp identity with the recently identified multicopy suppressor gene of the pop2 mutation (MPT5); its deduced protein product carries an eight‐repeat domain region, homologous to that found in the hypothetical regulatory YGL023 protein of S. cerevisiae and the Pumilio protein of Drosophila. ORF biE560 protein exhibits patterns typical of serine/threonine protein kinases, with which it shares high degrees of homology. The complete nucleotide sequence was submitted to the EMBL Data Library under Accession Number X83690.
Biochemical similarity of Schizosaccharomyces pombe ras1 protein with RAS2 protein of Saccharomyces cerevisiae
Authors: Onozawa Takashi , Danjoh Inaho , Fujiyama Asao 
Published: May 2005

AbstractSchizosaccharomyces pombe contains single ras oncogene homologue, ras1, that functions in the signal transduction pathway conducting the cell's mating processes. To understand the biochemical basis of yeast ras proteins, we have purified the ras1 protein and compared the major biochemical constants with those of RAS2 protein from Saccharomyces cerevisiae and mammalian ras proteins. The purified ras1 protein showed a remarkably high Kd value for GDP binding (178 nM) and for binding with ATP. In contrast, the Kd value for GTP binding and the rate of GTPase activity were 64 nM and 77 × 10−6 s−1 at 37°C, respectively; both were higher than normal p21ras protein, but at the same level as the RAS2 protein. We directly measured rate of GTP binding and GDP binding which were 3.9 × 10−3 s−1 and 1.8 × 10−3 s−1 at 30°C, respectively. On the other hand, exchange rates between bound and free nucleotides remained almost constant throughout the tested combination of GTP and GDP, and were several‐fold lower than the binding rate. These results suggest that the release of the guanine nucleotide is the rate‐limiting step in the ras–GTP/GDP cycle. As a whole, the biochemical properties of the ras1 protein are close to those of the RAS2 protein, although these two proteins function differently in the signal transduction pathway in the cells.
The red ade mutants of Kluyveromyces lactis and their classification by complementation with cloned ADE1 or ADE2 genes from Saccharomyces cerevisiae
Authors: Zonneveld B. J. M. , van der Zanden A. L. 
Published: May 2005

AbstractSeventy‐six red adenine mutants of Kluyveromyces lactis were isolated. By complementation they could be assigned to two groups with 31 and 45 mutants. Transformation of several strains from each group with plasmids containing the Saccharomyces cerevisiae ADE1 or ADE2 gene showed that the largest group was ade2 and the other group was ade1. Several previously isolated ‘ade1’ mutants were classified to either group and given new gene and allele numbers. ADE1 was localized at chromosome III, closely linked to the mating type gene, making it a convenient marker for mating type. ADE2 was localized at chromosome V.
Isolation and characterization of a novel yeast gene, ATH1, that is required for vacuolar acid trehalase activity
Authors: Destruelle Monika , Holzer Helmut , Klionsky Daniel J. 
Published: May 2005

AbstractWe have isolated a plasmid containing a gene, ATH1, that results in eight‐ to ten‐fold higher acid trehalase activity in yeast cells when present in high copy. The screening procedure was based on overproduction‐induced mislocalization of acid trehalase activity; overproduction of vacuolar enzymes that transit through the secretory pathway leads to secretion to the cell surface. A DNA fragment that confers cell surface expression of acid trehalase activity was cloned and sequenced. The deduced amino acid sequence displayed no homology to known proteins, indicating that we have identified a novel gene. A deletion in the genomic copy of the ATH1 gene eliminates vacuolar acid trehalase activity. These results suggest that ATH1 may be the structural gene encoding vacuolar acid trehalase or that the gene product may be an essential regulatory component involved in control of trehalase activity. The sequence has been deposited in the GenBank data library under Accession Number X84156 S. cerevisiae ATH1 gene.
Yeast sequencing reports. Gcs1, a gene encoding γ‐glutamylcysteine synthetase in the fission yeast Schizosaccharomyces pombe
Authors: Coblenz Anke , Wolf Klaus 
Published: May 2005

AbstractBy complementation of a mutant resistant to N‐methyl‐N′‐nitro‐N‐nitrosoguanidine (MNNG) we have identified the gcs1 gene, encoding a putative γ‐glutamylcysteine synthetase. The gene is possibly interrupted by two introns and has 49% identical and 80% similar amino acids compared with the homologous protein from rat. In comparison with the Saccharomyces cerevisiae homologue it possesses 41% identical and 74% similar amino acids. The gsc1 sequence appears in the EMBL database under Accession Number X 85017.
Use of polymerase chain reaction epitope tagging for protein tagging in Saccharomyces cerevisiae
Authors: Schneider B. L. , Seufert W. , Steiner B. , Yang Q. H. , Futcher A. B. 
Published: May 2005

AbstractEpitope tagging is the insertion of a short stretch of amino acids constituting an epitope into another protein. Tagged proteins can be identified by Western, immunoprecipitation and immunofluorescence assays using pre‐existing antibodies. We have designed vectors containing the URA3 gene flanked by direct repeats of epitope tags. We use the polymerase chain reaction (PCR) to amplify the tag‐URA3‐tag cassette such that the ends of the PCR fragments possess homology to the gene of interest. In vivo recombination is then used to direct integration of the fragment to the location of interest, and transformants are selected by their Ura+ phenotype. Finally, selection for Ura− cells on 5‐fluoro‐orotic acid plates yields cells where recombination between the repeated epitopes has ‘popped out’ the URA3 gene, leaving a single copy of the epitope at the desired location. PCR epitope tagging (PET) provides a rapid and direct technique for tagging that does not require any cloning steps. We have used PET to tag three Saccharomyces cerevisiae proteins, Cln1, Sic1 and Est1.
PMT3 and PMT4, two new members of the protein‐O‐mannosyltransferase gene family of Saccharomyces cerevisiae
Authors: Immervoll Thomas , Gentzsch Martina , Tanner Widmar 
Published: May 2005

AbstractTwo genes PMT3 and PMT4 were identified by polymerase chain reaction of genomic DNA using primers derived from regions of high homology between the products of three genes PMT1, PMT2 of Saccharomyces cerevisiae and part of a PMT1 related sequence of Kluyveromyces lactis. Pmt1p and Pmt2p are mannosyltransferases involved in the transfer of a mannosyl residue from dolichyl phosphate‐D‐mannose (Dol‐P‐Man) to seryl and threonyl residues in proteins. The products encoded by the PMT3 and PMT4 genes have almost identical hydropathy profiles in comparison to PMT1 and PMT2: a hydrophobic N‐ and C‐terminal third each with multiple potential transmembrane helices and a central hydrophillic part.The predicted Pmt3p contains 753 amino acids, four potential N‐glycosylation sites and it is significantly homologous to Pmt1p, Pmt2p and Pmt4p. Pmt4p contains 762 amino acids and two potential N‐glycosylation sites. Northern blot analysis showed a single mRNA transcript of PMT3 and PMT4 of 2·8 kb. Thus PMT3 and PMT4 are two new members of the PMT gene family. The pmt4 null mutant the pmt3 pmt4 double null mutant, but not pmt3 null mutant, showed a small but significant shift of chitinase due to under glycosylation of the enzyme. The triple disruption pmt2 pmt3 pmt4 and the quadruple disruption result in a lethal phenotype. The EMBL data library Accession Number for PMT3 is X83797 and for PMT4 X83798.
An overview of membrane transport proteins in Saccharomyces cerevisiae
Authors: André Bruno 
Published: May 2005

AbstractAll eukaryotic cells contain a wide variety of proteins embedded in the plasma and internal membranes, which ensure transmembrane solute transport. It is now established that a large proportion of these transport proteins can be grouped into families apparently conserved throughout organisms. This article presents the data of an in silicio analysis aimed at establishing a preliminary classification of membrane transport proteins in Saccharomyces cerevisiae. This analysis was conducted at a time when about 65% of all yeast genes were available in public databases. In addition to ∼60 transport proteins whose function was at least partially known, ∼100 deduced protein sequences of unknown function display significant sequence similarity to membrane transport proteins characterized in yeast and/or other organisms. While some protein families have been well characterized by classical genetic experimental approaches, others have largely if not totally escaped characterization. The proteins revealed by this in silicio analysis also include a putative K+ channel, proteins similar to aquaporins of plant and animal origin, proteins similar to Na+‐solute symporters, a protein very similar to electroneural cation‐chloride co‐transporters, and a putative Na+‐H+ antiporter. A new research area is anticipated: the functional analysis of many transport proteins whose existence was revealed by genome sequencing.
Processing of pre‐ribosomal RNA in Saccharomyces cerevisiae
Authors: Venema Jaap , Tollervey David 
Published: May 2005

AbstractPost‐transcriptional processing of precursor‐ribosomal RNA comprises a complex pathway of endonucleolytic cleavages, exonucleolytic digestion and covalent modifications. The general order of the various processing steps is well conserved in eukaryotic cells, but the underlying mechanisms are largely unknown. Recent analysis of pre‐rRNA processing, mainly in the yeast Saccharomyces cerevisiae, has significantly improved our understanding of this important cellular activity. Here we will review the data that have led to our current picture of yeast pre‐rRNA processing.
Degenerative Changes at the Scaphotrapezial Joint Following Herbert Screw Insertion: A Radiographic Study Comparing Patients with Scaphoid Fracture and Primary Hand Arthritis
Authors: NICHOLL J. E. , BUCKLAND-WRIGHT J. C. 
Published: May 2005

One method of Herbert screw insertion is to mobilize the scaphotrapezial joint and insert the screw through the articular surface of the distal scaphoid. Because of concern that this might predispose to osteoarthritis in the scaphotrapezial joint, we have investigated joint space width and the presence of osteophytes adjacent to the scaphotrapezial joint using high definition macroradiography. Twenty-eight patients with symptomatic primary osteoarthritis of their hands, 23 with a scaphoid fracture successfully treated conservatively and 18 treated with a Herbert screw were studied. The patients with primary osteoarthritis of their hands had more narrowing of the scaphotrapezial joint compared with the other two groups, but patients treated with a Herbert screw had a significantly higher incidence of osteophytosis on the distal scaphoid than the other two groups. With Herbert screw fixation, osteophytosis on the distal scaphoid may cause impingement and pain, and be a predictor of further degenerative joint changes.
Nutrition and lysosomal activity. The effect of dietary cod-liver oil on the distribution of polyunsaturated fatty acids in the kidney lysosomes of rats receiving deficient or adequate intakes of vitamin E
Authors: Iqbal M. , Dingle J. T. , Moore T. , Sharman I. M. 
Published: May 2005

1. In an attempt to explain the antagonism between polyunsaturated fatty acids (PUFA) and vitamin E in the promotion of post-mortem autolysis and increased lysosomal fragility in the kidney of rats, studies were made by gas chromatography of the incorporation of PUFA into the lysosomes.2. Kidneys were taken from rats that had received various diets, which differed in their fat components and which were with or without vitamin E. Since the inclusion of cod-liver oil in the diet reduces the period of dietary preparation necessary for rapid kidney autolysis, the effect of this oil on the PUFA distribution in the lysosomes was specially studied.3. In purified preparations of kidney lysosomes from rats that had received substantial amounts of cod-liver oil for several weeks, C 20:5 acid was incorporated mainly at the expense of C 18:2 (linoleic) and C 20:4 (arachidonic) acids. In less purified lysosomal fractions the incorporation of C 20:5 and C 22:6 acids and the corresponding reductions in linoleic and arachidonic were well advanced after 10 days, but were not maximal until about 30 days. The same changes took place in the reverse direction, with about the same rapidity, when rats that had previously been given cod-liver oil were changed to a diet containing lard.4. The percentage of PUFA in the kidney lysosomes of rats not dosed with vitamin E was not significantly different from that of rats given adequate doses.5. Thus the increased tendency to kidney autolysis, and the reduced stability of the lysosomes, caused by the feeding of cod-liver oil were associated with the partial replacement of linoleic acid and of the endogenous arachidonic acid by an acid, usually foreign to the rat, which is even more unsaturated. Since vitamin E did not prevent the entry of this acid into the lysosomes its potency in retarding autolysis and stabilizing the lysosomes must be exerted at some point subsequent to the incorporation of PUFA.6. Since change in the percentage of lysosomal PUFA in response to dietary changes is slow, this suggests that the lysosornal lipidsescape usage in general metabolism as an immediate source of calories and that they have a half-life of at least 15 days. Individual fatty acids, however, may differ in their half-lives.
The fermentation of sugar-beet pulp and sucrose in an artificial rumen, and the effect of linseed oil fatty acids on the fermentation
Authors: Czerkawski J. W. , Breckenridge Grace 
Published: May 2005

1. An artificial rumen is described together with associated analytical and sampling procedures.2. The equipment was used to study the effects of linseed oil fatty acids on the fermentation of sugar-beet pulp and of sucrose by rumen micro-organisms.3. With sugar-beet pulp the addition of small amounts of linseed oil fatty acids had little effect on total gas production, utilization of sugar and the molar proportions of steam-volatile acids formed, but they strongly inhibited methane production, whereas large amounts of the fatty acids temporarily inhibited the production of gas and utilization of sugar.4. With sucrose even the smaller amounts of fatty acids had a marked inhibitory effect on the production of gas and utilization of sugar.5. The technique is assessed critically and the results are discussed in the light of previous experiments in vivo.
Studies on magnesium in ruminant nutrition
Authors: Suttle N. F. , Field A. C. 
Published: May 2005

1. In Expt 1, five groups of four dry non-pregant ewes were given 1 kg/day of a semi-purified diet containing either 0.05, 0.10 or 0.15% magnesium with 0 or 4.44% added potassium. Plasma Mg Concentrations were reduced by increasing the K intake (P < 0.001) and by reducing the Mg intake (P < 0.1). The effects were additive and, at the lowest Mg intake, supplementary K induced two cases of hypomagnesaemic tetany.2. Expt 2 was similar to Expt 1 except that the ewes were suckling single lambs, they were given 2 kg food/day and the lowest dietary Mg concentration was 0.075%. K again lowered plasma Mg values and induced two cases of tetany but reductions in Mg intake had no effect.3. After repletion on the basal diet, sixteen lactating ewes from Expt 2 were transferred to a diet containing 0.05% Mg with 0, 2.22 or 4.44% added K. Plasma Mg concentrations fell rapidly on each treatment; the effect was greatest in K-supplemented groups ( P < 0.05) and two cases of hypomagnesaemic tetany were induced at the highest K intake.4. In each experiment the K supplements caused a rapid increase in plasma K concentrations to a relatively constant level some 5 mg/100 ml above the resting value of 18.0 mg/100 ml.5. Some sheep refused K-supplemented diets at first and there was a tendency for refusals to be greatest at the lowest Mg intakes.6. The results are discussed in relation to the aetiology of hypomagnesaemic tetany.
Increased retention of orally administered zinc and raised blood cell zinc concentrations in iron-deficient rats
Authors: Spry C. J. F. , Piper K. G. 
Published: May 2005

1. Rats were made severely iron-deficient by feeding with Fe-deficient diets, which contained adequate amounts of zinc.2. Ten days after an oral dose of 250 μg65Zn the Fe-deficient rats had retained 17% whereas control rats had retained only 8% of the dose.3. When unlabelled Zn was given intravenously to the Fe-deficient and control rats there was a reduction in retention of the orally administered 65Zn. This effect was not produced when Fe was given before the oral dose of 65Zn.4. Total body Zn, whole blood Zn and plasma Zn concentrations of the rats were measured by atomic absorption spectrophotometry. Both the Fe-deficient rats and the control rats had the same total body Zn calculated as a proportion of body-weight. The plasma Zn concentrations were normal in all the animals. Blood cell Zn concentrations in the Fe-deficient animals were raised.5. The blood cell Zn concentration was directly related to the reticulocyte count in all the rats.6. It was concluded that Fe and Zn are absorbed by different metabolic pathways, and that there is an increased turnover of Zn in the Fe-deficient rats, possibly related to the short lifespan and increased Zn concentration of Fe-deficient rat erythrocytes. In the rat abnormalities of Zn concentration can only be considered significant if Fe status is also known.
Effect of acetoacetate on urinary excretion of xanthurenic acid and other tryptophan metabolites in rats
Authors: Nath M. C. , Shastri N. V. 
Published: May 2005

1. An experiment was performed to study the effect of sodium acetoacetate on urinary excretion of santhurenic acid and other tryptophan metabolites in male albino rats.2. Animals were fed on a nicotinic acid-deficient diet for a period of 3 weeks. The animals were then divided into two groups and, after the basal urinary excretion of the tryptophan metabolites had been estimated, the rats of both the groups were force-fed with L-tryptophan (100 mg per rat), the rats of the second group being simultaneously injected intraperitoncally with acetoacetate (200 mg/kg body-weight), and the urine samples during the following 24 h were collected and analysed.3. Acetoacetate-treated rats given tryptophan were found to excrete significantly greater amounts of kynurenine, hydroxykynurenine and xanthurenic acid than the corresponding control rats. There was no ditference between the amounts of kynurenic acid excreted by the animals in the two groups.