bluuebunny/crossref_metadata_2025 huggingface dataset:
Trypsin Action on the Growth of Sendai Virus in Tissue Culture Cells III. Structural Difference of Sendai Viruses Grown in Eggs and Tissue Culture Cells
Authors: Homma Morio , Ohuchi Masanobu
Published: January 2020

Polypeptides of egg-borne Sendai virus (egg Sendai), which is biologically active on the basis of criteria of the infectivity for L cells and of hemolytic and cell fusion activities, were compared by polyacrylamide gel electrophoresis with those of L cell-borne (L Sendai) and HeLa cell-borne Sendai (HeLa Sendai) viruses, which are judged biologically inactive by the above criteria. Densitometer profiles on the stained gels of egg Sendai resolved six polypeptides (virion protein [VP] 1 to VP6), in which VP2 and VP4 were identified as glycoproteins by PAS stain. Comparative electropherograms of both L Sendai and HeLa Sendai revealed that there were significantly larger amounts in the VP2 region of these viruses but VP4 was present only in greatly reduced amounts as compared to egg Sendai. It was also found that VP2 of L Sendai and HeLa Sendai consisted of two components, VP2a and VP2b, but the one of egg Sendai consisted of only VP2a. A mild trypsin treatment which converts both L Sendai and HeLa Sendai to a biologically active form selectively removed VP2b from these viruses and increased concomitantly the amounts of materials in the VP4 region. The same treatment of egg Sendai affected neither its biological activities nor its electropherogram. Consequently, gross polypeptide profiles on the stained gels of L Sendai and HeLa Sendai after trypsin treatment became favorably comparable to that of egg Sendai. Electrophoresis of labeled L Sendai and HeLa Sendai with a
3
H-amino acids mixture and
14
C-glucosamine resolved at least three glycoproteins, GP1, GP2, and GP3, each corresponding to VP2a, VP2b, and VP4, respectively. The trypsin treatment of these viruses removed almost all the radioactivity of GP2 and simultaneously increased the radioactive counts of GP3 and raised small amounts of rapidly moving heterogeneous glycoprotein, GP4. A possible relationship between the biological modification and the above characteristic polypeptide patterns of Sendai virus was discussed.
Comparative Studies of Wild-Type and “Cold-Mutant” (Temperature-Sensitive) Influenza Viruses: Polypeptide Synthesis by an Asian (H2N2) Strain and Its Cold-Adapted Variant
Authors: Kendal Alan P. , Kiley Michael P. , Maassab H. F.
Published: January 2020

The structure and replication of a cold-adapted, temperature-sensitive (TS) mutant of an Asian (H2N2) influenza virus was compared with that of its wild-type (WT) parent. Viruses were grown in a chicken kidney cell system, and at the nonpermissive temperature of 40 C, production of infectious TS virus was about 100,000-fold less than at 35 C, in contrast to WT virus. Major structural polypeptides of each virus grown at 35 C were similar, except that the hemagglutinin glycopolypeptide (HA) of the TS virions was slightly more heterogenous than that of WT virions. Synthesis of viral polypeptides was examined by sodium dodecyl sulfate acrylamide gel electrophoresis of pulse-labeled infected cells. This revealed a defect in the synthesis of TS viral hemagglutinin that was most pronounced at the nonpermissive temperature. Other TS viral polypeptides appeared to be synthesized normally at 40 C. A defect in the TS virus hemagglutinin was also indicated by serological studies that demonstrated that TS virus hemagglutinin had lost antigenic sites present on the WT virus. Thus, it is concluded that the virus mutant examined contains lesions in the hemagglutinin gene, although the possibility of additional unrecognized lesions is not excluded.
Antigenic Properties of Bacteriophage φ29 Structural Proteins
Authors: Tosi Mario , Anderson Dwight L.
Published: January 2020

Serological methods and electron microscopy were used to study the structural proteins of the small
Bacillus subtilis
bacteriophage φ29. This virus has a large number of fibers attached at both ends of its prolate head. A complex neck assembly is comprised of 12 symmetrically arranged appendages as the outer component. Head fibers, neck appendages, and the head surface bind anti-φ29 antibodies. Immune sera absorbed with defective lysates of suppressor-sensitive (
sus
) mutants have been used to determine the genetic control of neck appendages production. Studies on the serum-blocking power of lysates defective in different tail components showed that appendages contain the main serum-blocking protein. This finding suggests an essential role of the neck appendages in phage adsorption or DNA injection.
Effects of Simian Virus 40-Induced Transformation on Isoaccepting Species of Transfer RNA from Mouse Fibroblasts
Authors: Portugal F. H. , Simonds J. S. , Twardzik D. , Oskarsson M.
Published: January 2020

Alterations in isoaccepting species of tRNA in mouse fibroblasts transformed by simian virus 40 were determined for alanine, arginine, histidine, leucine, lysine, phenylalanine, serine, tyrosine, and valine. Significant differences between transformed cells in culture and newborn mouse cells are attributed to tRNA alterations accompanying differentiation of mouse cells.
Formation of Lipid-Nucleotide Complex by RNA Tumor Virus Preparations
Authors: Flügel Rolf M. , Wells Robert D.
Published: January 2020

RNA tumor virus preparations utilize α-
32
P-deoxyribonucleoside triphosphates as substrates to form lipid-nucleotide products which are tightly associated with protein.
Biochemical Studies on the χ Mutation of Bacteriophage T4: Differential Inhibition of χ
+
and χ DNA Synthesis by Mitomycin C
Authors: Shimizu Kenji , Sekiguchi Mutsuo
Published: January 2020

Biochemical studies were carried out to determine the effect of χ mutation on T4 DNA synthesis. The rate and final extent of DNA synthesis are almost the same with T4D- and T4χ-infected cells, although the burst size of T4χ is about one-sixth that of the wild type. The DNA synthesis of T4χ-infected cells is more readily inhibited by mitomycin C than is that of T4 wild type. When mitomycin C was added during active phage growth, DNA synthesis of T4χ halted almost immediately. T4 DNA polymerases isolated from χ
+
- and χ-infected cells, however, exhibit no difference with regard to their sensitivities to mitomycin C, priming activities with alkylated or ultraviolet light-irradiated templates and other enzymatic properties.
Replication of Bacteriophage φX174 DNA in a Temperature-Sensitive
dnaC
Mutant of
Escherichia coli
C
Authors: Kranias Evangelia G. , Dumas Lawrence B.
Published: January 2020

Bacteriophage φX174 cannot grow in a temperature-sensitive
dnaC
mutant of
Escherichia coli
C at the nonpermissive temperature. The inability to grow is the result of inhibition of virus DNA synthesis. Parental replicative form synthesis is not temperature sensitive. Single-stranded virus DNA continues to be synthesized for at least 45 min after shifting to the nonpermissive temperature late in infection. In contrast, the replication of the replicative form terminates within 5 min after shifting to the nonpermissive temperature.
Factors Influencing the Adsorption of Bacteriophage 2 to Cells of
Pseudomonas aeruginosa
Authors: Reese John F. , Dimitracopoulos George , Bartell Pasquale F.
Published: January 2020

Phage 2 adsorbed to
Pseudomonas aeruginosa
strain BI in 5 mM Tris buffer, providing that cations like Na
+
, Mg
2+
, or Ca
2+
were present. Adsorption was observed over a broad pH range, reaching a maximum level around pH 7.5, which coincided with the pH required for maximal activity of the phage 2-associated slime polysaccharide depolymerase. Mutants of strain BI and other strains of
P. aeruginosa
possessing slime layers that were devoid of phage 2 depolymerase substrate were incapable of adsorbing phage 2. On the other hand, those strains containing substrate for the phage 2 depolymerase in the slime layer were capable of adsorbing phage 2. The same relationship of phage depolymerase-substrate interaction to phage adsorption was observed with
Pseudomonas
phage 8, which possesses a depolymerase that differs in its specificity from the phage 2 depolymerase. The receptor-like activity of purified slime containing the specific substrate for the phage-associated depolymerase was demonstrable by its ability to inactivate phage. However, receptor-like activity or phage inactivation was not observed with those slimes that were devoid of the depolymerase substrate.
Analysis of Minimal Functions of Simian Virus 40 III. Evidence for “Host Cell Repair” of Oncogenicity and Infectivity of UV-Irradiated Simian Virus 40
Authors: Seemayer N. H. , Defendi V.
Published: January 2020

The in vitro transforming capacity of simian virus 40 (SV40) for Syrian hamster cells is highly resistant to inactivation by UV light in comparison to infectivity. In the same cell system, we demonstrated a “host cell repair mechanism” sensitive to caffeine which is, to a large extent, responsible for the high resistance to UV inactivation of the transforming capacity of SV40. The survival of infectivity of UV-irradiated SV40 in CV-1 cells was also sensitive to caffeine, again indicating host cell repair. On the other hand, depression of normal cell DNA synthesis by hydroxyurea during the first 24 h postinfection only modestly reduced, and to a similar extent, the transforming capacity of UV-irradiated and nonirradiated SV40.
Purification and Some Properties of Bacteriophage ST-1
Authors: Bowes J. Michael , Dowell Clifton E.
Published: January 2020

Bacteriophage ST-1 is shown to be a small, isometric, single-stranded deoxyribonucleic acid (SS-DNA) virus with a diameter of about 260 nm. Standard methods for growth, assay, preparation of high-titer lysates, and purification of the phage are suggested. ST-1 infects K-12 and not C strains of
Escherichia coli
and requires a divalent cation to adsorb to susceptible bacteria. Adsorption also requires an activation of the particle brought on by incubation at 37 C. The latent and eclipse periods are essentially identical (9 to 11 min) in ST-1 infections, with an average burst size about 250 phages per cell. Multiple densities of ST-1 infectivity are observed during purification in CsCl gradients. The virus recovered from different densities has the same sedimentation coefficient and, therefore, all phage containing fractions are pooled during purification. The purified ST-1 particle has a sedimentation coefficient of 121
S
relative to φX-174 (114
S
) in a sucrose gradient and a molecular weight of 6.8 × 10
6
(as estimated from its relative sedimentation). The nucleic acid is assumed to be SS-DNA on the basis of (i) the specific incorporation of
3
H-thymine, (ii) the dependence of its UV absorption on temperature, and (iii) its reaction with formaldehyde. ST-1 SS-DNA sediments at 24.4
S
relative to φX-174 SS-DNA (23.8
S
).
Inhibition of Virus Release by Antibodies to Surface Antigens of Influenza Viruses
Authors: Dowdle W. R. , Downie J. C. , Laver W. G.
Published: January 2020

When influenza virus was mixed with antisera to its surface subunits before inoculation of cell cultures, anti-hemagglutinin antibodies neutralized infectivity but anti-neuraminidase did not. When the antisera were added after infection of cell cultures, anti-hemagglutinin and anti-neuraminidase antibodies were equally effective in reducing virus titers in culture fluids. Decreased virus titers were not due to interference of antibody with assay and were not accompanied by a reduction in the synthesis of hemagglutinin and neuraminidase subunits. Both antisera also effectively prevented in vitro virus spread. Inhibition of virus release by neuraminidase antibody appeared unrelated to its antienzyme property. Hydrolysis of
N
-acetyl neuraminic acid residues of infected host cells proceeded unimpaired in the presence of subunit antisera. Anti-hemagglutinin and anti-neuraminidase antibodies may act to prevent virus release by binding newly formed virus subunits to each other and to anti-genically altered cell membranes.
Interactions of Polyoma and Mouse DNAs II. Polyoma-Induced Mouse DNA Replication and Pseudovirion Formation
Authors: Türler Hans
Published: January 2020

Secondary mouse embryo (ME) cultures which had been grown prior to infection in the presence of 5-bromodeoxyuridine (BUdR) and 5-fluorodeoxy-uridine were found to be permissive for polyoma virus (16). The DNA extracted from the progeny virus yielded two bands on CsCl isopycnic centrifugation. The light band (LL) contained supercoiled circular (polyoma DNA I), open circular (polyoma DNA II), and linear (polyoma DNA III) molecules, as was seen by electron microscopy. The hybrid band (HL) contained exclusively linear molecules. This DNA was pure, density - labeled, pseudovirion DNA, i.e., fragmented HL mouse DNA. The quantitative comparison of HL and LL polyoma DNA III from six different virus preparations always revealed an excess of HL DNA, the ratio of HL/LL being between 1.2 and 2.2. These results led to the conclusion that in BUdR-prelabeled, polyoma-infected ME cells pseudovirion DNA is excised both from unreplicated and newly replicated regions of mouse DNA.
T4-Induced Activity Required for Specific Cleavage of a Bacteriophage Protein In Vitro
Authors: Goldstein Judith , Champe Sewell P.
Published: January 2020

We have examined the acid-soluble products formed during incubation of labeled substrate protein from T4-infected cells with unlabeled phage-infected cell extracts. If the substrate protein is prepared from cells infected with a T4 mutant blocked in cleavage of phage head precursor proteins, the products formed in vitro include a peptide indistinguishable by several criteria from one of the T4 internal peptides. Denatured as well as undenatured protein can serve as the substrate for the formation of this peptide. As expected, this peptide is not formed if protein from either uninfected cells or cells infected with wild-type T4 is used as substrate. The formation of this peptide in vitro is dependent on a factor present in extracts of phage-infected cells but absent from extracts of uninfected cells.
Proposal for Numbering Mutants of Avian Leukosis and Sarcoma Viruses
Authors: Vogt Peter K. , Weiss Robin A. , Hanafusa Hidesaburo
Published: January 2020

A system for the numbering of mutants of avian sarcoma and leukosis viruses is proposed.
Comparison of JC and BK Human Papovaviruses with Simian Virus 40: Restriction Endonuclease Digestion and Gel Electrophoresis of Resultant Fragments
Authors: Osborn June E. , Robertson Sylvia M. , Padgett Billie L. , Zu Rhein Gabrielle M. , Walker Duard L. , Weisblum Bernard
Published: January 2020

JC virus was found to have a buoyant density of 1.20 g/cm
3
in linear sucrose-D
2
O and 1.35 g/cm
3
in cesium chloride isopycnic gradients. DNA extracted either from JC-infected cultures or from gradient-purified virions occupied a dense position relative to linear DNA in cesium chloride/ethidium bromide gradients, and the circular configuration of the extracted DNA was confirmed by electron microscopy, with a measured molecular weight of 2.93 × 10
6
. DNA from BK virus was similarly prepared and compared to JC and to an SV40 DNA standard by digestion with restriction endonuclease preparations from
Haemophilus influenzae, Haemophilus parainfluenzae
, and
Escherichia coli.
Digests were electrophoretically analyzed on gradient polyacrylamide slab gels or agarose gels, and the three viruses were found to have distinctly different cleavage patterns by this form of analysis: JC and BK viruses were almost entirely different from SV40 and significantly different from each other. Thus, JC and BK human papovaviruses appear to be discrete new members of the papovavirus group, rather than SV40 variants.
Inhibition of the Initiation of Cellular DNA Synthesis After Reovirus Infection
Authors: Cox Donald C. , Shaw James E.
Published: January 2020

The synthesis of cellular DNA was measured in synchronized L cells after reovirus infection. Initiation of the synthetic phase of the cell cycle was completely inhibited in cells infected 8 h before the beginning of DNA synthesis.
Structural Components of Oriboca Virus
Authors: Rosato Robert R. , Robbins Mary Louise , Eddy Gerald A.
Published: January 2020

Analysis of purified Oriboca virions by neutral, sodium dodecyl sulfate polyacrylamide-gel electrophoresis indicated the presence of three structural polypeptides designated V-1, V-2, and V-3 on the basis of their relative electrophoretic mobilities in 8% gels. Polypeptides V-2 and V-3 are glycopeptides associated with the virion envelope as demonstrated by the preferential incorporation of labeled glucosamine into the polypeptides and by release of the polypeptides from the intact virion by the nonionic detergent NP-40. Polypeptide V-1 is the protein component of the nucleoprotein core of Oriboca virus as evidenced by the specific incorporation of uridine into the nucleoprotein, its release from the intact virion by NP-40 treatment, and its separation by both rate-zonal and isopycnic density gradient centrifugation from both the intact virion and envelope components. Molecular weights have been tentatively assigned to the polypeptides by extrapolation from the structural polypeptides of Sindbis virus when both are run in the same gel. Polypeptide V-1 has an apparent molecular weight of 20,000 to 23,000; V-2, 30,000 to 32,000; and V-3, 83,000 to 85,000.
Mode of Action of Acid pH Values on the Development of Vesicular Stomatitis Virus
Authors: Fiszman Marc , Leaute J.-B. , Chany C. , Girard Marc
Published: January 2020

The effect of low pH's on the development of vesicular stomatitis virus (VSV) was studied. L cells infected with VSV were incubated at pH 6.6. A 99% inhibition in the yield of infectious particles was observed by comparison with the yield at pH 7.4. Such inhibition was not due to inhibition of viral RNA synthesis, since at pH 6.6 all the known species of VSV RNA molecules were synthesized. Furthermore, all the known species of VSV proteins were also synthesized. However, no viral particles nor nucleocapsids were detected. Raising the pH to 6.9 resulted in the appearance of nucleocapsids and viral particles, although the yield of infectious virus was still inhibited by 90%. The lack of infectivity of these pH 6.9 viral particles was correlated with their inability to promote primary transcription. The hypothesis that low pH's alter the correct positioning of the viral proteins into the cell membrane is presented.
Use of Bacteriophage φX174 Replicative from Progeny DNA as Templates for Transcription
Authors: Truffaut Nicole , Sinsheimer Robert L.
Published: January 2020

The synthesis of φX174-specific RNA has been studied in infected cells in which the thymine of the viral (+) strand of the parental RF
*
, of the complementary (−) strand of the parental RF, or of both strands of the progeny RF molecules has been replaced with 5-bromouracil (5 BU). By irradiation of such cells with UV light at a wavelength of 313 nm it was possible to affect, specifically, the 5 BU-labeled strands. When the progeny RF molecules contain thymine, irradiation has no effect upon the synthesis of viral-specific RNA, regardless of 5 BU substitution in either strand of parental RF. If, however, progeny RF is labeled with 5 BU, irradiation produces a major decrease of viral RNA synthesis. It is concluded that many progeny RF molecules can serve as templates for transcription at late times of infection. Irradiation, prior to RF replication, of cells in which, particularly, the complementary strand of RF contains 5 BU, appears to decrease the ability of the parental RF to replicate.
Early Biochemical Events Occurring After Infection of
Bacillus cereus
569-SP1 with Bacteriophage GSW
Authors: Ben-Horin Hevion , Walz M. Antoinette , Saz Arthur K.
Published: January 2020

After infection of
Bacillus cereus
569-SP1 with the 5-hydroxymethyluracil-containing phage GSW, new dTTPase, dUTPase, and dUMP-hydroxymethylase activities appear. No significant changes in activities of other pyrimidine ribonucleoside or 2′-deoxyribonucleoside triphosphate nucleotidohydrolases were detected. dUTP and dUMP inhibit the dTTPase activity, whereas dTTP failed to inhibit dUTPase activity. The
K

m

value for the substrate dUTP is 10
−4
M and for dTTP is 4.85 × 10
−4
M. Thymidylate synthetase activity is inhibited only when cells are infected during the late lag or very early log phases of growth; when cells are infected with phage during mid-log, thymidylate synthetase activity is unaffected. The data support the suggestion that, although phage GSW may inhibit an otherwise expected increase in activity of thymidylate synthetase, it fails to affect the already existing activity. The data presented do not allow discrimination as to whether the phage specifies inhibition of de novo synthesis of thymidylate synthetase or the increase in activity of already existing but not fully expressed enzyme.
Continued Synthesis of Bacterial DNA After Infection by Bacteriophage T4
Authors: Scofield Margaret S. , Collinsworth William L. , Mathews Christopher K.
Published: January 2020

Early in infection by bacteriophage T4, before replication has commenced, one can detect the presence of newly synthesized DNA which cosediments with parental phage DNA on sucrose gradients. As shown earlier (R. E. Murray and C. K. Mathews, 1969), some of this represents covalent attachment of new material to parental phage DNA molecules. However, as shown herein, most of it is bacterial DNA, which is synthesized after infection and presumably degraded to T4 DNA-sized pieces. The small amount of phage-specific DNA synthesis which occurs is apparently a repair process, for its extent is greatly increased if the phage are irradiated with ultraviolet light prior to infection. Analysis by means of pulse labeling with [
3
H]thymidine and DNA-DNA hybridization shows that host DNA synthesis continues at a significant rate (40 to 80% of the preinfection rate) as late as 10 min after infection at 37 C. Very early in infection this is primarily replicative synthesis, but later a repair process predominates. Presumably this represents attempted repair of damage being inflicted on host DNA by phage-coded nucleases.
Abortive Infection of Lysogenic
Bacillus subtilis
168(SPO2) by Bacteriophage φ1
Authors: Rettenmier Carl W. , Hemphill H. Ernest
Published: January 2020

Virulent bacteriophage φ1 was not able to productively infect strains of
Bacillus subtilis
which were lysogenic for the temperate bacteriophage SPO2, although it adsorbed to, penetrated, and killed these bacteria. Studies of phage and host nucleic acid production in the nonpermissive host demonstrated that normal φ1 transcription was initiated early in the latent period, but this was followed by a general failure of host and phage nucleic acid synthesis about 10 to 15 min after infection. Mixed infections of φ1 and SPO2c
1
, a clear-plaque mutant of SPO2, indicated that a similar inhibition of φ1 development occurred when this phage infected nonlysogenic
B. subtilis
cells committed to the SPO2c
1
lytic cycle. It is proposed that the SPO2- and SPO2c
1
-mediated interference did not act directly on the φ1 genome, but rather these phages altered the host physiology in such a manner that some normal step in φ1 development triggered a collapse of vital metabolic activities.
Biochemistry of DNA-Defective Amber Mutants of Bacteriophage T4 IV. DNA Synthesis in Plasmolyzed Cells
Authors: Collinsworth William L. , Mathews Christopher K.
Published: January 2020

Requirements for bacteriophage T4 DNA synthesis have been investigated in situ by use of plasmolyzed infected cells. When such cells are incubated with dATP, dGTP, dTTP, hydroxymethyldeoxycytidine triphosphate, and rATP, significant semiconservative synthesis of DNA occurs. This DNA hybridizes preferentially to T4 DNA. T4 amber mutants defective in genes 44 and 45, which display a DNA-negative phenotype in vivo, are unable to synthesize DNA in situ. By contrast, T4 amber mutants bearing lesions in genes 41 and 62, which also display a DNA-negative phenotype in vivo, do allow DNA synthesis in situ, the extent of synthesis being 80 to 90% that of the wild-type synthesis under the same conditions. Cells infected with gene 42 mutants (dCMP hydroxymethylase) are unable to synthesize DNA in situ even though exogenous nucleotides are provided. Also one gene 1 mutant (deoxynucleotide kinase) was found to synthesize DNA in situ, but two other gene 1 mutants did not. These results point to possible roles of hydroxymethylase and kinase in DNA metabolism, in addition to provision of essential DNA precursors, as has recently been suggested by Wovcha et al. (1973).
Synthesis of Avian Oncornavirus DNA in Infected Chicken Cells
Authors: Ali M. , Baluda M. A.
Published: January 2020

The intracellular synthesis and integration of viral DNA (vDNA) into the host cell genome was studied in cultured chicken embryo fibroblasts infected with avian sarcoma or leukemia viruses. The newly synthesized vDNA was detected by hybridization with 70
S
viral RNA. Extraction of infected cell DNA by the selective procedure of Hirt resulted in the enrichment of newly synthesized vDNA in the low molecular weight supernatant fraction while leaving the bulk of cellular DNA containing integrated vDNA in the high molecular weight pellet fraction. This approach led to detection of intracellular vDNA synthesis within 1 h after infection and to vDNA integration into cellular DNA within 24 h. There was a several-fold increase in the vDNA content of infected cells during the initial phase of virus infection. But only a part of this newly synthesized vDNA appeared to become covalently linked with high molecular weight cellular DNA. Most of the remaining unintegrated vDNA gradually disappeared. The sedimentation profiles of minimally sheared cellular DNA in alkaline sucrose velocity gradients suggest that vDNA is synthesized as free linear molecules of approximately 3 × 10
6
daltons which subsequently are covalently linked to host cell DNA.
Surface Membrane Glycopeptides Which Coincide with Virus Transformation and Tumorigenesis
Authors: Glick Mary Catherine , Rabinowitz Zelig , Sachs Leo
Published: January 2020

Glycopeptides from the surface of clones of hamster embryo cells were examined at various intervals after infection with polyoma virus. Two types of transformed cells were examined: (i) clones that showed delayed transformation or an initially low tumorigenicity, and (ii) clones that were rapidly transformed showing an initially high tumorigenicity. The glycopeptides were removed from the cell surface by trypsin and, after Pronase digestion, were examined by filtration through Sephadex G-50. With delayed transformation, a specific group of glycopeptides was increasingly evident over an 85-day period as the cells showed phenotypic properties of transformation and the ability to form tumors. In the other series, all but one clone of hamster embryo cells showed rapid transformation after infection with polyoma virus. This clone was less tumorigenic and showed little of the specific glycopeptides. In all cases of delayed or rapid transformation examined, the specific group of glycopeptides increased proportionately to the ability of the cells to form tumors. All of the cells derived from progressively growing tumors formed by injection of these transformed hamster cells into adult animals showed an abundance of this group of glycopeptides. These results suggest that specific surface membrane glycopeptides accompany viral transformation and tumorigenesis.
Ribonucleotides Linked to DNA of Herpes Simplex Virus Type 1
Authors: Hirsch Ivan , Vonka Vladimír
Published: January 2020

Cells of a continuous cell line derived from rabbit embryo fibroblasts were infected with herpes simplex type 1 virus (HSV-1) and maintained in the presence of either [5-
3
H]uridine or [
methyl
-
3
H]thymidine or
32
PO
4
3−
. Nucleocapsids were isolated from the cytoplasmic fraction, partially purified, and treated with DNase and RNase. From the pelleted nucleocapsids, DNA was extracted and purified by centrifugation in sucrose and cesium sulfate gradients. The acid-precipitable radioactivity of [5-
3
H]uridine-labeled DNA was partially susceptible to pancreatic RNase and alkaline treatment; the susceptibility to the enzyme decreased with increasing salt concentration. No drop of activity of DNA labeled with [
3
H]thymidine was observed either after RNase or alkali treatment. Base composition analysis of [5-
3
H]uridine-labeled DNA showed that the radioactivity was recovered as uracil and cytosine. In the cesium sulfate gradient, the purified [5-
3
H]uridine-labeled DNA banded at the same position as the
32
P-labeled DNA. The present data tend to suggest that ribonucleotide sequences are present in HSV DNA, that they are covalently attached to the viral DNA, and that they can form double-stranded structures.
Polyadenylate Sequences on Newcastle Disease Virus mRNA Synthesized In Vivo and In Vitro
Authors: Weiss Susan Reich , Bratt Michael A.
Published: January 2020

Polyadenylate [poly(A)] sequences are associated with the 35 and 50
S
Newcastle disease virus (NDV)-specific RNAs as well as all six to seven of the 18-22
S
NDV-specific messenger RNAs extracted from infected chicken embryo cells. The poly(A) associated with the 18-22
S
RNA has an average size of 120 to 130 nucleotides. The 18-22
S
RNA synthesized in vitro by NDV's virion-bound polymerase contains six to seven species of the same size and relative proportions as its intracellular counterpart. This in vitro synthesized 18-22
S
RNA also contains covalently linked poly(A) sequences which, although variable in size, are usually larger and more heterogeneous than those from the infected cell. In vitro RNA synthesis is supported not only by magnesium (at an optimal concentration of mM) but by manganese (at an optimal concentration of 0.5 to 1.0 mM) as well. However, the major product made in the presence of manganese, although sedimenting at 18 to 22
S
, differs somewhat from the product made in the presence of magnesium.
Virion-Associated RNA Primer for Rous Sarcoma Virus DNA Synthesis: Isolation from Uninfected Cells
Authors: Sawyer Robert C. , Harada Fumio , Dahlberg James E.
Published: January 2020

Uninfected chicken, duck, rat, and human fibroblast cells in culture contained a tRNA-like RNA molecule which was structurally identical to a virion-associated RNA primer for in vitro Rous sarcoma virus DNA synthesis. This primer RNA appeared to be a normal tRNA of these cells. It was not found in a number of lower eukaryotic cells or in
Escherichia coli.
Baboon Virus Isolate M-7 with Properties Similar to Feline Virus RD-114
Authors: Hellman Alfred , Peebles Paul T. , Strickland James E. , Fowler Arnold K. , Kalter S. S. , Oroszlan S. , Gilden R. V.
Published: January 2020

A virus (M-7) isolated from baboon placental tissue demonstrates many similarities to endogenous feline virus RD-114. Immunodiffusion analysis shows a group-specific antigen (gs-1) line of identity between M-7 and RD-114. Anti-RD-114 DNA polymerase IgG inhibits M-7 polymerase by 57% compared to 97% for RD-114. M-7 virus has helper activity as demonstrated by rescue of murine sarcoma virus (MSV) from sarcoma-positive leukemia-negative human amnion cells. The host range of the rescued M-7 pseudotype of MSV, MSV (M-7), is similar to that of RD-114 virus. MSV (M-7) is also able to transform baboon cells and causes no detectable transformation of feline cells without addition of helper feline leukemia virus. Interference properties of M-7 and RD-114 virus are identical. Virus-specific neutralizing antisera, although partially cross-reacting, can distinguish MSV (M-7) from MSV (RD-114). These similarities and differences between RD-114 and M-7 viruses are best explained as type-specific differences between two viruses within the same strain.
Structure and Molecular Length of the Large Subunits of RD-114 Viral RNA
Authors: Kung Hsing-Jien , Bailey James M. , Davidson Norman , Nicolson Margery O. , Mcallister Robert M.
Published: January 2020

By electron microscopy, the large subunits of RD-114 RNA have a molecular weight of 5.0 × 10
6
; they all have a characteristic secondary structure feature close to the middle.
Structural Proteins of Mammalian Oncogenic RNA Viruses: Murine Leukemia Virus Neutralization by Antisera Prepared Against Purified Envelope Glycoprotein
Authors: Steeves R. A. , Strand Mette , August J. T.
Published: January 2020

Goat and rabbit antisera prepared against a purified Rauscher murine leukemia virus glycoprotein (gp69/71) rapidly neutralized spleen focus-forming virus in Rauscher and Friend virus preparations. Absorption studies revealed that most of the neutralizing activity of goat anti-Rauscher virus gp69/71 serum was directed against type- and group-specific determinants.
Presence in Leukemic Cells of Avian Myeloblastosis Virus-Specific DNA Sequences Absent in Normal Chicken Cells
Authors: Shoyab M. , Evans R. M. , Baluda M. A.
Published: January 2020

3
H-labeled 35
S
RNA from purified avian myeloblastosis virus (AMV) was exhaustively hybridized with an excess of normal chicken DNA to remove all viral RNA sequences which are complementary to DNA from uninfected cells. The [
3
H]RNA which failed to hybridize was isolated by hydroxylapatite column chromatography which separates DNA-RNA hybrids from single-stranded [
3
H]RNA. The residual RNA hybridized to leukemic chicken DNA but did not rehybridize with normal chicken DNA. This demonstrates conclusively that DNA from AMV-induced leukemic cells contain viral-specific sequences which are absent in DNA from normal cells.
Male-Specific Bacteriophage MS2 Propagation in Fluorophenylalanine-Resistant
Escherichia coli
K12
Authors: Jenkins S. T. , Beard J. P. , Howe T. G. B.
Published: January 2020

Mutation of
Escherichia coli
K12 HfrH to resistance to fluorophenylalanine resulted in changes in the plaque morphology of bacteriophage MS2 on this strain and led to an increased efficiency of propagation of the phage in liquid cultures. Evidence was obtained that the mutation resulted in inhibition of early lysis in infected cells and that lysis involved the production of a lysozyme. Genetic studies suggested that the observed pleiotropy of the resistance mutation was due to informational suppression.
Elimination of the Early Inhibition of Protein Synthesis in
Escherichia coli
C3000 Infected with Purified R17 Bacteriophage
Authors: Scott John W. , Iglewski Wallace J.
Published: January 2020

Infection of
Escherichia coli
with an R17 bacteriophage suspension has been reported to result in early and late phases of inhibition of host protein synthesis (Yamazaki, 1969; Watanabe and Watanabe, 1968). However, early inhibition was observed when cultures were inoculated with only tryptone broth, which is often used to suspend R17 bacteriophage. Since early inhibition was not observed when
E. coli
cultures were inoculated with R17 bacteriophage suspended in phosphate buffer, early inhibition is not an intrinsic feature of R17 phage infection.
Replication of Sindbis Virus V. Polyribosomes and mRNA in Infected Cells
Authors: Simmons Daniel T. , Strauss James H.
Published: January 2020

Cells infected with wild-type Sindbis virus contain at least two forms of mRNA, 26
S
and 49
S
RNA. Sindbis 26
S
RNA (molecular weight 1.6 × 10
6
) constitutes 90% by weight of the mRNA in infected cells, and is thought to specify the structural proteins of the virus. Sindbis 49
S
RNA, the viral genome (molecular weight 4.3 × 10
6
), constitutes approximately 10% of the mRNA in infected cells and is thought to supply the remaining viral functions. In cells infected with
ts2
, a temperature-sensitive mutant of Sindbis virus, the messenger forms also include a third species of RNA with a sedimentation coefficient of 33
S
and an apparent molecular weight of 2.3 × 10
6
. Hybridization-competition experiments showed that 90% of the base sequences in 33
S
RNA from these cells are also present in 26
S
RNA. Sindbis 33
S
RNA was also isolated from cells infected with wild-type virus. After reaction with formaldehyde, this species of 33
S
RNA appeared to be completely converted to 26
S
RNA. These results indicate that 33
S
RNA isolated from cells infected with either wild-type Sindbis or
ts2
is not a unique and separate form of Sindbis RNA.
Encephalomyocarditis Virus Infection of Mouse Plasmacytoma Cells II. Effect on Host RNA Synthesis and RNA Polymerases
Authors: Schwartz L. B. , Lawrence C. , Thach R. E. , Roeder R. G.
Published: January 2020

The effect of encephalomyocarditis virus infection of MOPC 460 mouse plasmacytoma cells on host RNA synthesis and RNA polymerases was investigated. Consistent with work performed in other virus host systems, rates of RNA synthesis appeared to be inhibited in infected cells, whereas RNA degradation appeared normal. These results were further extended with isolated nuclei, in which distinct RNA polymerase activities could be studied under conditions where problems with RNA turnover and endogenous nucleotide pool sizes were insignificant. Endogenous nuclear RNA polymerase II activity was inhibited early postinfection and at 1 to 2 h prior to endogenous RNA polymerase I plus III activity. However, the solubilized enzymes were fully active with exogenous DNA as template. In fact, the levels of RNA polymerases I, II, and III, isolated from infected cells and nuclei, were indistinguishable from levels in uninfected cells and nuclei at each stage of their partial purification procedure. The chromatographic properties of the enzymes on DEAE-Sephadex were also unaltered. Furthermore, the RNA synthetic activity of these isolated enyzmes, or of nuclei isolated from uninfected cells, was resistant to extracts of nuclei or of cytoplasmic fractions from infected cells. These results are discussed in terms of a possible inhibition of RNA synthesis in vivo at the level of transcription initiation.
Proteins Specified by Herpes Simplex Virus XII. The Virion Polypeptides of Type 1 Strains
Authors: Heine Jochen W. , Honess Robert W. , Cassai Enzo , Roizman Bernard
Published: January 2020

The polypeptides from purified virions of a herpes simplex 1 (human herpes-virus 1) strain, F1, which had been passaged a limited number of times in cell culture after isolation, formed 33 bands on electrophoretic separation in polyacrylamide gels cross-linked with
N, N′
-diallyltartardiamide in contrast to a maximum resolution of only 24 to 25 bands in gels cross-linked with
N, N′
-methylenebisacrylamide. This increase in the number of bands was due chiefly to an improved separation of glycosylated polypeptides from nonglycosylated polypeptides with which they co-electrophoresed on methylenebisacrylamide cross-linked gels. Purified virions of HSV-1 [F1] had a protein/DNA mass ratio of 10.7 ± 0.96, and based on a DNA molecular mass of 85 × 10
6
to 100 × 10
6
the estimated weight of virion polypeptides ranges from 16.4 to 19.4 × 10
−16
g. The number of molecules of each polypeptide per virion ranged from less than 50 to 1,500. Comparison of the virion polypeptides of two HSV-1 strains with similar isolation and limited passage history with those of four HSV-1 strains with histories of numerous passages outside the human host showed a number of nonrandom variations in virion polypeptides. Thus, although the virion polypeptides of two strains with similar isolation and limited passage history could not be differentiated, strains with extended passage histories differed markedly from each other and from the limited passage strains in the number and electrophoretic mobility of noncapsid polypeptides and notably in those of the envelope.
Effects of Different RNAs and Components of the Cell-Free System on In Vitro Synthesis of Sindbis Viral Proteins
Authors: Cancedda Ranieri , Swanson Richard , Schlesinger Milton J.
Published: January 2020

Cell-free extracts from Krebs ascites cells and rabbit reticulocytes synthesized a variety of viral-specific proteins when programmed with several different kinds of Sindbis viral RNAs. The RNAs included purified virion RNA (42
S
) and two species (26
S
and “33
S
”) of purified intracellular viral messenger RNAs from viral-infected BHK cells. Proteins formed in vitro were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, rate-zonal centrifugation in urea-sucrose gradients, two-dimensional tryptic peptide fingerprints, and immunoprecipitation with rabbit anti-Sindbis virus serum. The only major identifiable protein formed in vitro was viral capsid, but the relative amount of capsid produced was determined by the mRNA, the source of cell-free extract, and the components of the cell-free system. Virion RNA directed synthesis of larger-molecular-weight proteins than did intracellular viral RNAs, and some of this protein was distinct from that formed by the smaller viral RNAs. Indirect evidence is presented for in vitro synthesis of viral envelope proteins.
Viral Proteins Formed in a Cell-Free RABBIT Reticulocyte System Programmed with RNA from a Temperature-Sensitive Mutant of Sindbis Virus
Authors: Cancedda Ranieri , Swanson Richard , Schlesinger Milton J.
Published: January 2020

Viral messenger RNA was isolated from BHK cells infected with a temperature-sensitive mutant of Sindbis virus and was further purified using an oligo(dT) column. Addition of this mRNA cell-free extracts from rabbit reticulocytes led to formation of discrete authentic viral capsid protein when the reaction was performed at 29 C. However, this same protein-synthesizing system failed to make discrete viral capsid when incubated with the viral RNA at 39 C. Instead, larger-molecular-weight polypeptides that contained the viral capsid peptide sequences were produced. The inability to make a separate viral capside protein in vitro at elevated temperatures by the mRNA from this mutant exactly mimics the phenotype of this ts mutant in viral-infected cells. Three mechanisms are discussed that might account for a temperature-sensitive release of capsid. One of these is based on a model in which there are multiple sites for initiation of translation of polypeptides on a polycistronic viral mRNA.
Poly(A) Polymerase from Vaccinia Virus-Infected Cells II. Product and Primer Characterization
Authors: Brakel Christine , Kates Joseph R.
Published: January 2020

The product of the in vitro reaction of a vaccinia virus-induced poly(A) polymerase (see preceding paper) with ATP is shown to be poly(A) by nuclease resistance and by annealing with poly(U). Polyacrylamide gel electrophoresis indicates that the in vitro synthesized poly(A) is associated with large RNA which is sensitive to RNase. RNA which co-purifies with the virus-induced enzyme is similar to vaccinia virus-specific RNA with respect to size and poly(A) content. Double labeling studies indicate that the RNA which co-purifies with the enzyme becomes associated with the poly(A) synthesized in vitro. The poly(A) formed in vitro is located on the 3′-OH terminus of this RNA. During in vitro poly(A) synthesis
32
P from α-[
32
P]ATP is transferred to nucleosides other than 2′,3′-AMP, primarily to CMP. Inclusion of poly(U) in the in vitro reactions results in an increase in the transfer of
32
P to UMP.
Substructures and Polypeptides of Visna Virus
Authors: Lin Fu Hai , Thormar Halldor
Published: January 2020

The protein of Visna virus, disrupted by 8 M guanidine hydrochloride and heating, was resolved into 10 polypeptides by agarose gel column chromatography in 6 M guanidine hydrochloride. Two of the peaks contained glycopolypeptides. Nonidet-disrupted virions were resolved into two fractions by potassium tartrate gradient centrifugation, with densities of 1.08 and 1.24 g/ml, respectively. About 70% of the viral DNA polymerase directed by added template was released into the light fraction, in which very little endogenous enzyme activity was detected. Also released into the light fraction were all of the glycopolypeptides, 50% of the viral RNA, and a part of each of the other viral protein components. The data indicate that extensive degradation of subviral structures occurred, even under mild conditions for virion disruption. The 1.24-g/ml fraction was composed of 50% of the viral RNA, most of the endogenous DNA polymerase activity (80%), and a major internal polypeptide (GuHCl6) with an estimated mol wt of 28,000. Two other polypeptides were also consistently detected in the heavy fraction, but they constituted less than 25% of the ribonucleoprotein complex, compared with 75% for GuHCl6.
Early Synthesis of Membrane Protein After Bacteriophage T4 Infection
Authors: Beckey Andrew D. , Wulff Judith L. , Earhart C. F.
Published: January 2020

Proteins that associate with cellular membrane during the first 5 min after infection with bacteriophage T4 were examined. Several procedures, including electrophoretic separations in three sodium dodecyl sulfate polyacrylamide gel systems and inhibition of host protein synthesis by UV irradiation, were employed to distinguish host-specified proteins from those induced by T4. Residual host protein synthesis was found to account for much of the new protein in preparations of the total membrane and for almost all of the newly synthesized protein in the outer membrane. Preliminary evidence indicates that the synthesis of some host membrane proteins is shut off less rapidly than is host synthesis of soluble protein. One host-directed polypeptide of the outer membrane was unique in that its synthesis or incorporation into the membrane was preferentially inhibited by infection. Also, it was found that the detergent Sarkosyl solubilizes all early T4 membrane proteins; this observation provides the basis for a simple procedure for distinguishing phage proteins from host outer membrane proteins.
Marker Rescue in
Haemophilus influenzae
Bacteriophage
Authors: Boling Maxon E. , Setlow Jane K.
Published: January 2020

Rescue of wild-type markers from transfecting phage DNA in cómpetent
Haemophilus influenzae
cells by superinfection with temperature-sensitive phage (marker rescue) is approximately linearly dependent upon the concentration of transfecting DNA. The amount of marker rescue with a constant amount of transfecting DNA increases with increasing multiplicities of superinfecting phage up to about 4, and then decreases at higher multiplicities. Host restriction of transfecting DNA does not affect marker rescue. The frequency of wild-type recombinants from marker rescue is much greater than that from multiple infection with whole phages, and is comparable to that obtained with two mutant-transfecting DNAs. The amount of marker rescue decreases exponentially with time between entrance of the transfecting DNA and superinfection, and the rate of decrease is independent of map position of the rescued marker. Marker rescue is drastically reduced in the recombination-defective strains,
rec1
and
rec2.
Sarcoma and Helper-Specific RNA Tumor Virus Subunits in Transformed Nonproducer Mouse Cells Activated to Produce Virus by Treatment with Bromodeoxyuridine
Authors: Tsuchida Nobuo , Shih Maria S. , Gilden Raymond V. , Hatanaka Masakazu
Published: January 2020

A tumor line (58-2T) was established from a slowly growing tumor in a BALB/c mouse inoculated with M58-2 cells. The latter clonal cell line was isolated after bromodeoxyuridine treatment as a flat variant from nonproducer BALB/3T3 cells transformed by the Kirsten sarcoma virus. The 58-2T cells produced type C virus with two discrete virus-specific RNA species. One of the species, which was probably an endogenous virus RNA subunit, had a sedimentation coefficient of 35
S
as the largest major subunit, and had sequences
similar
to Rauscher leukemia virus RNA based on nucleic acid hybridization. The other RNA species had 30
S
as the largest major subunit and corresponded to Kirsten sarcoma virus-specific RNA. These two RNA species formed heterogeneous, 60 to 70
S
, high-molecular-weight RNA in virions.

DNA transcripts (58-2T DNA) from the activated virus contained base sequences complementary to Rauscher leukemia virus and Kirsten sarcoma virus. The Kirsten sarcoma virus-specific DNA sequences (58-2TS) were purified from 58-2T DNA by eliminating RLV-specific sequences.