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Journal of Virology Feb 1983The lymphotropic papovavirus (LPV)-specific mRNAs were translated in vitro in rabbit reticulocyte lysates. The specific products were 84,000-dalton (84K), 41K, 35K, and...
The lymphotropic papovavirus (LPV)-specific mRNAs were translated in vitro in rabbit reticulocyte lysates. The specific products were 84,000-dalton (84K), 41K, 35K, and 26K proteins. Immunoprecipitation with anti-LPV hamster sera and analysis of partially purified LPV virions showed that the last three proteins were the LPV capsid proteins, and we designated the 41K, 35K, and 26K proteins VP1 (major capsid protein), VP2, and VP3, respectively. Several characteristics, such as the small amount of mRNA for the 84K protein at late stages of infection, its absence from partially purified virus preparations, no common tryptic peptides between the 84K and 41K proteins, and the pattern of in vivo phosphorylation, suggest that the 84K protein is not a simple dimer of the 41K protein. Normal human sera and sera from certain leukemic patients positive for antibody to LPV viral antigens immunoprecipitated the 41K protein.
Topics: Animals; Antibodies, Viral; B-Lymphocytes; Capsid; Chlorocebus aethiops; Humans; Leukemia, Lymphoid; Papillomaviridae; Polyomaviridae; Protein Biosynthesis; RNA, Messenger; RNA, Viral; Viral Proteins
PubMed: 6601195
DOI: 10.1128/JVI.45.2.872-875.1983 -
Virology Jan 2016Polyomaviruses induce cell proliferation and transformation through different oncoproteins encoded within the early region (ER): large T antigen (LT), small T antigen...
Polyomaviruses induce cell proliferation and transformation through different oncoproteins encoded within the early region (ER): large T antigen (LT), small T antigen (sT) and, in some cases, additional components. Each virus utilizes different mechanisms to achieve transformation. For instance, the LTs of Simian virus 40 (SV40), BK and/or JC virus can induce transformation; but Merkel Cell Polyomavirus (MCPyV) requires expression of sT. Lymphotropic Papovavirus (LPV) is closely related to Human Polyomavirus 9 (HuPyV9) and, under similar conditions, mice expressing LPV.ER exhibit higher rates of tumor formation than mice expressing SV40.ER. We have investigated the contributions of individual LPV.ER components to cell transformation. In contrast to SV40, LPV.ER transforms mouse embryonic fibroblasts (MEFs), but expression of LPV LT is insufficient to transform MEFs. Furthermore, LPV sT induces immortalization and transformation of MEFs. Thus, in the case of LPV, sT is the main mediator of oncogenesis.
Topics: Animals; Antigens, Viral, Tumor; Cell Transformation, Neoplastic; Cells, Cultured; Fibroblasts; Mice; Polyomavirus; Retinoblastoma-Like Protein p107; Retinoblastoma-Like Protein p130; Tumor Suppressor Protein p53
PubMed: 26517398
DOI: 10.1016/j.virol.2015.10.003 -
International Journal of Cancer Mar 1977Primary rabbit kidney cells were transformed by BKV(MM), a papovavirus isolated from the urine of a child with the Wiskott-Aldrich syndrome. The transformed cells...
Primary rabbit kidney cells were transformed by BKV(MM), a papovavirus isolated from the urine of a child with the Wiskott-Aldrich syndrome. The transformed cells contained BK T-antigen, but no antigen that reacted with SV40 U-antiserum. The transformed cells failed to produce tumors in nude mice, and BKV (MM) was not rescued from transformed cells by cell fusion or chemical induction methods. The transformed cells supported the growth of rabbit kidney vacuolating virus (RKV), and could be used to quantitate RKV by plaque formation under an agar overlay.
Topics: Agar; Animals; Antigens, Viral; BK Virus; Cell Aggregation; Cell Line; Cell Transformation, Neoplastic; Cells, Cultured; Child; Fluorescent Antibody Technique; Humans; Kidney; Mice; Polyomavirus; Rabbits; Viral Plaque Assay; Wiskott-Aldrich Syndrome
PubMed: 191410
DOI: 10.1002/ijc.2910190317 -
Lancet (London, England) Oct 1976
Topics: Child; Culture Techniques; Humans; Lymphocytes; Measles; Microscopy, Electron; Papillomaviridae; Polyomaviridae
PubMed: 62138
DOI: 10.1016/s0140-6736(76)90568-7 -
Journal of Clinical Pathology Nov 1977A technique is described whereby inclusion-bearing cells identified by light microscopy in stained smears of urinary sediment were reprocessed for examination in the...
A technique is described whereby inclusion-bearing cells identified by light microscopy in stained smears of urinary sediment were reprocessed for examination in the electron microscope. The nuclei of the abnormal cells were found to contain numerous virus particles, 35 nm in diameter, which morphologically resembled papovaviruses. The technique was applied in this case to identify further the virus producing the cytopathic changes in the Papanicolaou smear. It could be particularly valuable for retrospective studies of mounted cytological or histological material when suitable specimens are no longer available for virological investigation.
Topics: Humans; Methods; Microscopy, Electron; Papillomaviridae; Polyomaviridae; Staining and Labeling; Urine
PubMed: 73550
DOI: 10.1136/jcp.30.11.1015 -
Journal of the National Cancer Institute Mar 1976Human papovavirus BK caused the malignant transformation in vitro of brain cells prepared from newborn hamsters. The transformed cells produced BK virus T antigen and...
Human papovavirus BK caused the malignant transformation in vitro of brain cells prepared from newborn hamsters. The transformed cells produced BK virus T antigen and grew as tumors after sc inoculation ito hamsters that developed antibodies to BK virus T antigen. The histopathology of the tumors revealed an undifferentiated glioma.
Topics: Animals; Animals, Newborn; Antibodies, Viral; Brain; Cell Transformation, Neoplastic; Cells, Cultured; Cricetinae; Glioma; Neoplasms, Experimental; Polyomavirus
PubMed: 176404
DOI: 10.1093/jnci/56.3.671 -
Biomedica Biochimica Acta 1985A detailed restriction map of hamster papovavirus (HaPV)-DNA has been constructed on the basis of the complete nucleotide sequence of the viral genome. The HaPV DNA...
A detailed restriction map of hamster papovavirus (HaPV)-DNA has been constructed on the basis of the complete nucleotide sequence of the viral genome. The HaPV DNA restriction map is totally divergent from those of all other recently known papovaviruses. This map will be useful for future functional studies of the HaPV genome.
Topics: Animals; Base Sequence; Chromosome Mapping; Cricetinae; DNA Restriction Enzymes; DNA, Viral; Genes, Viral; Papillomaviridae; Polyomaviridae
PubMed: 3002333
DOI: No ID Found -
Virology May 1985Lymphotropic papovavirus (LPV) is a new member of the polyomavirus genus. Its host range in vitro is restricted to transformed cells of B-lymphocyte origin. Here the... (Comparative Study)
Comparative Study
Lymphotropic papovavirus (LPV) is a new member of the polyomavirus genus. Its host range in vitro is restricted to transformed cells of B-lymphocyte origin. Here the complete 5270-bp DNA sequence of LPV is presented. The LPV early region can encode a large T and a small t antigen but no middle T antigen and the late region can encode the three structural proteins VP1, VP2, and VP3. Based on sequence conservation of shared proteins LPV is equally related to both mouse polyomavirus (Py) and simian virus 40 (SV40) and represents a new distinct species of the polyomavirus genus. Sequence comparisons of LPV, SV40, and Py point out essential conserved sequence features of the polyomavirus genus more clearly than the comparison of only SV40 and Py. The most conserved proteins are VP1 with 42% and large T antigen with 28% of the amino acids conserved among the three viruses. Although least conserved the noncoding DNA sequences of LPV show significant homologies both to SV40 and Py (origin of viral DNA replication and putative early promoter). A 63-bp tandem repeat at the late side of the replication origin possibly represents a LPV enhancer element.
Topics: Amino Acid Sequence; Animals; B-Lymphocytes; Base Sequence; Cell Line; Chlorocebus aethiops; DNA Replication; DNA Restriction Enzymes; DNA, Viral; Genes, Viral; Papillomaviridae; Plasmids; Polyomaviridae; Polyomavirus; Sequence Homology, Nucleic Acid; Species Specificity; Transcription, Genetic; Viral Proteins
PubMed: 2998001
DOI: 10.1016/0042-6822(85)90108-4 -
T antigen of human papovavirus JC stimulates transcription of the POU domain factor Tst-1/Oct6/SCIP.DNA and Cell Biology Dec 1996Human papovavirus JC exhibits a strong tropism for glial cells in vivo. To a large extent, this effect is due to the pronounced glia specificity of viral gene...
Human papovavirus JC exhibits a strong tropism for glial cells in vivo. To a large extent, this effect is due to the pronounced glia specificity of viral gene expression, which is mediated by the specific interaction of glial transcription factors such as Tst-1/Oct6/SCIP with viral promoter sequences. Here we show that, in return, expression of the glial transcription factor Tst-1/Oct6/SCIP can be strongly activated by T antigen, the early gene product of JC virus, in a dose-dependent manner. In transient transfection experiments, stimulation by T antigen was entirely dependent on a 335-bp segment of the Tst-1/Oct6/SCIP gene promoter that included the transcriptional start site. The same fragment was also bound by purified T antigen in immunoprecipitation assays due to the presence of three closely spaced and tandemly oriented GAGGC pentamers. However, when this array of pentamers was mutated so that binding of T antigen was strongly reduced, T-antigen-dependent transcriptional activation remained unaffected. Thus, similar to viral late gene expression, transcriptional stimulation of the Tst-1/Oct6/SCIP gene by T antigen was not dependent on binding to GAGGC pentamers present within the promoter. Nevertheless, our data provide strong support for a model in which JC virus influences gene expression of its host cell via its early gene product in a manner favourable for its own propagation.
Topics: Animals; Antigens, Polyomavirus Transforming; Binding Sites; DNA, Viral; Gene Expression Regulation, Viral; Glioblastoma; Humans; JC Virus; Mice; Octamer Transcription Factor-6; Recombinant Fusion Proteins; Sequence Analysis, DNA; Sequence Deletion; Transcription Factors; Transcription, Genetic; Transcriptional Activation; Transfection; Tumor Cells, Cultured
PubMed: 8985119
DOI: 10.1089/dna.1996.15.1057 -
Biochemistry Jul 1981Nuclear extracts from SV40-infected CV-1 monkey kidney cells and from polyoma-infected 3T3 mouse cells contain an endonucleolytic activity which cleaves circular viral...
Nuclear extracts from SV40-infected CV-1 monkey kidney cells and from polyoma-infected 3T3 mouse cells contain an endonucleolytic activity which cleaves circular viral DNA within the chromatin to full-length linear rods [Waldeck, W., Föhring, B., Chowdhury, K., Gruss, P., & Sauer, G, (1978) Proc. Natl. Acad. Sci. U.S.A. 75, 5964-5968; Scott, W. A., & Wigmore, D. J. (1978) Cell (Cambridge, Mass.) 15, 1511-1518]. Sedimentation of the nuclear extracts through sucrose density gradients revealed a preferential binding of the endonuclease to the viral chromatin. Deproteinized exogenous covalently closed superhelical DNA substrates such as SV40 and polyoma as well as Col E1 and PM2 DNAs were linearized by the endonuclease by introduction of one double-strand break per molecule. The reaction products, FOIII unit length rods, were shown to be devoid of single-strand nicks by electrophoresis in denaturing agarose gels. The double-strand break was randomly located within the various substrates since redigestion of the FOIII with single-cut restriction endonucleases failed to generate discrete pairs of reaction products. Neither linear double-stranded nor nicked circular FOII DNA structures were accepted as substrates. The endonucleolytic activity does not require the presence of ATP but is sensitive to EDTA. The enzyme activity is of cellular origin since nuclear extracts from uninfected CV-1 cells converted exogenous superhelical DNA to FOIII structures with the same properties as those described above. The biological properties of the endonuclease are discussed in the light of its possible function in permitting genetic exchange between different circular genomes. Further, it may play an essential role late during the replication of papovavirus DNA when the catenated daughter molecules are liberated from each other by an as yet unidentified mechanism.
Topics: Animals; Cell Line; Chlorocebus aethiops; Chromatin; DNA, Superhelical; Endonucleases; Kidney; Kinetics; Simian virus 40
PubMed: 6269583
DOI: 10.1021/bi00517a039