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Journal of Molecular Biology Jun 1996Capsids of papilloma and polyoma viruses (papovavirus family) are composed of 72 pentameric capsomeres arranged on a skewed icosahedral lattice (triangulation number of...
Capsids of papilloma and polyoma viruses (papovavirus family) are composed of 72 pentameric capsomeres arranged on a skewed icosahedral lattice (triangulation number of seven, T = 7). Cottontail rabbit papillomavirus (CRPV) was reported previously to be a T = 7laevo (left-handed) structure, whereas human wart virus, simian virus 40, and murine polyomavirus were shown to be T = 7dextro (right-handed). The CRPV structure determined by cryoelectron microscopy and image reconstruction was similar to previously determined structures of bovine papillomavirus type 1 (BPV-1) and human papillomavirus type 1 (HPV-1). CRPV capsids were observed in closed (compact) and open (swollen) forms. Both forms have star-shaped capsomeres, as do BPV-1 and HPV-1, but the open CRPV capsids are approximately 2 nm larger in radius. The lattice hands of all papillomaviruses examined in this study were found to be T = 7dextro. In the region of maximum contact, papillomavirus capsomeres interact in a manner similar to that found in polyomaviruses. Although papilloma and polyoma viruses have differences in capsid size (approximately 60 versus approximately 50 nm), capsomere morphology (11 to 12 nm star-shaped versus 8 nm barrel-shaped), and intercapsomere interactions (slightly different contacts between capsomeres), papovavirus capsids have a conserved, 72-pentamer, T = 7dextro structure. These features are conserved despite significant differences in amino acid sequences of the major capsid proteins. The conserved features may be a consequence of stable contacts that occur within capsomeres and flexible links that form among capsomeres.
Topics: Animals; Antigens, Viral; Bovine papillomavirus 1; Capsid; Capsid Proteins; Cottontail rabbit papillomavirus; Humans; Papillomaviridae; Polyomavirus; Rabbits; Sequence Alignment; Simian virus 40; Viral Structural Proteins
PubMed: 8656427
DOI: 10.1006/jmbi.1996.0317 -
Antimicrobial Agents and Chemotherapy Jul 2015Children undergoing hematopoietic stem cell transplantation (HSCT) are at risk for life-threatening viral infections. Cidofovir is often used as a first-line agent for... (Clinical Trial)
Clinical Trial
Children undergoing hematopoietic stem cell transplantation (HSCT) are at risk for life-threatening viral infections. Cidofovir is often used as a first-line agent for adenovirus infections, despite the absence of randomized controlled trials with HSCT patients, and as a second-line agent for resistant herpesvirus infections. The frequency and severity of adverse effects, particularly nephrotoxicity, in pediatric HSCT recipients are unclear, and pharmacokinetics (PK) of cidofovir in children have not previously been reported. This study was an open-label, nonrandomized, single-dose pilot study to determine the safety and PK of cidofovir in pediatric HSCT recipients with symptomatic adenovirus, nucleoside-resistant cytomegalovirus (CMV) or herpes simplex virus (HSV), and/or human papovavirus infections. Subsequent dosing and frequency were determined by clinical response and side effects, as assessed by the treating physician. Blood and urine samples were obtained from patients for PK studies and assessment of toxicity and virologic response. Twelve patients were enrolled (median age, 9 years; 33.5 days posttransplantation). Four of seven patients with adenovirus infection were successfully treated and eventually cleared their infections. Four of twelve patients died of disseminated viral disease and multiorgan failure. Two of twelve patients had evidence of acute kidney injury after the first dose, and one of these patients developed chronic kidney disease; two other patients developed late nephrotoxicity. The mean drug half-life was 9.5 h. There was no correlation between nephrotoxicity and plasma maximum concentration, clearance, or half-life. PK were similar to those reported for adults, although the drug half-life was significantly longer than that for adults. Cidofovir was well tolerated in the majority of patients. However, effective therapeutic strategies are urgently needed to support patients until immune reconstitution is achieved.
Topics: Acute Kidney Injury; Adenovirus Infections, Human; Adolescent; Antiviral Agents; BK Virus; Child; Child, Preschool; Cidofovir; Cytomegalovirus Infections; Cytosine; Female; Hematopoietic Stem Cell Transplantation; Herpesviridae Infections; Humans; Male; Organophosphonates; Pilot Projects; Polyomavirus Infections; Viremia
PubMed: 25733509
DOI: 10.1128/AAC.04348-14 -
Journal of Virology Oct 1975Two new human papovavirus isolates (JMV and MMV) from the urines of patients with Wiskott-Aldrich syndrome were morphologically and serologically identical to BK virus... (Comparative Study)
Comparative Study
Two new human papovavirus isolates (JMV and MMV) from the urines of patients with Wiskott-Aldrich syndrome were morphologically and serologically identical to BK virus (BKV). The genomes of these two new isolates were found to be indistinguishable from prototype BKV DNA in a variety of nucleic acid hybridization experiments. Like BKV DNA, JMV and MMV DNAs share approximately 20% of their polynucleotide sequences with simian virus 40 DNA. The genome of JMV was indistinguishable from that of BKV by restriction endonuclease analysis; MMV DNA contained three instead of four R-Hind cleavage sites and one rather than no R-HpaII cleavage sites. Physical maps of the BKV and MMV genomes were constructed using restriction endonucleases, and these maps were oriented to the map of simian virus 40 DNA.
Topics: BK Virus; Base Sequence; Chromosome Mapping; DNA Restriction Enzymes; DNA, Circular; DNA, Viral; Genes; Humans; Molecular Weight; Nucleic Acid Conformation; Polynucleotides; Polyomavirus; Simian virus 40; Urine; Wiskott-Aldrich Syndrome
PubMed: 170425
DOI: 10.1128/JVI.16.4.959-973.1975 -
International Journal of Cancer Jun 1996We have analyzed by PCR skin lesions from classic, endemic and AIDS-related Kaposi's sarcoma (KS), as well as from KS-derived cell lines, the presence of ubiquitous... (Comparative Study)
Comparative Study
We have analyzed by PCR skin lesions from classic, endemic and AIDS-related Kaposi's sarcoma (KS), as well as from KS-derived cell lines, the presence of ubiquitous transforming viruses. BK virus (BKV), a transforming human papovavirus which has been associated with human tumors, was detected in 100% of KS skin lesions and 75% of KS cell lines. KS specimens contained a full-length, intact BKV early region, but minor rearrangements were observed in some tumors. BKV was also detected with a high prevalence (57-67%) in genital tissues and sperm, thus fulfilling the role of a sexually transmitted agent in KS. The closely related JC virus (JCV), which has never been associated with human malignancies, was present in 11-20% of KS specimens and was detected with a low prevalence (0-21%) in genital tissues and sperm. Simian virus 40 (SV40) was not detected in any KS lesions. Herpes simplex virus (HSV) DNA sequences were detected in 20-25% of KS lesions. Malignant human papillomavirus (HPV) types 16 and 18 and benign HPV types 6 and 11 were detected in KS specimens with a similar prevalence of 11-83%, suggesting that the presence of HPV-transforming sequences is not a specific trait of HPV interaction with KS tissue. Furthermore, JCV, SV40, HSV and HPV DNA sequences were not detected in KS cell lines, suggesting that these viruses are not associated to KS neoplastic cells in KS tissue. KS cell lines were also negative for DNA sequences of KS-HV, the novel herpesvirus detected in primary KS lesions. The constant association of BKV DNA with KS lesions and KS cell lines suggests that BKV-transforming functions may participate in the development of KS.
Topics: BK Virus; Base Sequence; Cell Transformation, Viral; DNA, Neoplasm; DNA, Viral; HIV Infections; Herpes Simplex; Humans; JC Virus; Molecular Sequence Data; Papillomaviridae; Papillomavirus Infections; Polymerase Chain Reaction; Sarcoma, Kaposi; Semen; Simian virus 40; Simplexvirus; Skin Neoplasms; Tumor Cells, Cultured; Tumor Virus Infections; Urogenital Neoplasms; Virus Latency
PubMed: 8647638
DOI: 10.1002/(SICI)1097-0215(19960611)66:6<717::AID-IJC1>3.0.CO;2-2 -
Blood Aug 2002
Topics: Antibodies, Monoclonal; Antibodies, Monoclonal, Murine-Derived; Antineoplastic Agents; Fatal Outcome; Humans; Leukoencephalopathy, Progressive Multifocal; Lymphoma, Large B-Cell, Diffuse; Male; Middle Aged; Papillomavirus Infections; Rituximab
PubMed: 12150156
DOI: 10.1182/blood-2002-04-1271 -
Journal of Virology Oct 2008Polyomavirus and papillomavirus (papovavirus) capsids are composed of 72 capsomeres of their major capsid proteins, VP1 and L1, respectively. After translation in the...
Polyomavirus and papillomavirus (papovavirus) capsids are composed of 72 capsomeres of their major capsid proteins, VP1 and L1, respectively. After translation in the cytoplasm, L1 and VP1 pentamerize into capsomeres and are then imported into the nucleus using the cellular alpha and beta karyopherins. Virion assembly only occurs in the nucleus, and cellular mechanisms exist to prevent premature capsid assembly in the cytosol. We have identified the karyopherin family of nuclear import factors as possible "chaperones" in preventing the cytoplasmic assembly of papovavirus capsomeres. Recombinant murine polyomavirus (mPy) VP1 and human papillomavirus type 11 (HPV11) L1 capsomeres bound the karyopherin heterodimer alpha2beta1 in vitro in a nuclear localization signal (NLS)-dependent manner. Because the amino acid sequence comprising the NLS of VP1 and L1 overlaps the previously identified DNA binding domain, we examined the relationship between karyopherin and DNA binding of both mPy VP1 and HPV11 L1. Capsomeres of L1, but not VP1, bound by karyopherin alpha2beta1 or beta1 alone were unable to bind DNA. VP1 and L1 capsomeres could bind both karyopherin alpha2 and DNA simultaneously. Both VP1 and L1 capsomeres bound by karyopherin alpha2beta1 were unable to assemble into capsids, as shown by in vitro assembly reactions. These results support a role for karyopherins as chaperones in the in vivo regulation of viral capsid assembly.
Topics: Animals; Capsid; Capsid Proteins; DNA; Human papillomavirus 11; Humans; Mice; Molecular Chaperones; Oncogene Proteins, Viral; Polyomavirus; Protein Binding; Recombinant Fusion Proteins; Virus Assembly; alpha Karyopherins; beta Karyopherins
PubMed: 18701594
DOI: 10.1128/JVI.01221-08 -
Nucleic Acids Research Jan 1991Eukaryotic expression vectors have been used successfully in viral LT-expressing cell lines (ie. COS) to clone cDNAs encoding proteins that can be detected through their...
Eukaryotic expression vectors have been used successfully in viral LT-expressing cell lines (ie. COS) to clone cDNAs encoding proteins that can be detected through their bio-activity or reactivity with specific antibodies. Since Chinese hamster ovary cells (CHO) have been used extensively for the isolation and characterization of somatic cell mutants, we felt it would be an advantage to develop an expression cloning system in CHO cells. We have modified the eukaryotic expression vector CDM8 by replacing the polyoma and SV40 origins of replication with the 427bp non-coding region of the Syrian hamster papovavirus. Wild-type CHO cells and the CHO glycosylation-mutant Lec4A were transfected with plasmids bearing the early genes of either polyoma virus or hamster papovavirus in order to establish stable, LT antigen-expressing cell lines designated CHOP or CHOH, respectively. CHOP cell lines expressing polyoma LT antigen supported efficient replication of CDM8, but replicated pMH poorly. Conversely, CHOH cells expressing the hamster papovavirus LT antigen supported replication of pMH, and at a lower efficiency, CDM8. Replication of CDM8 and pMH vectors were equally efficient in selected CHOP and CHOH cell lines, respectively and comparable to that of CDM8 replication in COS-1 cells. A bacterial beta-galactosidase fusion gene inserted into the multiple cloning site of a CDM8 derivative was efficiently expressed when transiently transfected into CHOP and CHOH cells but not CHO cells since only the former supports autonomous plasmid replication. These results show that expression-cloning in CHO cells expressing either polyoma virus or hamster papovavirus LT antigens is possible using either the CDM8 or the pMH vectors, respectively.
Topics: Animals; Antigens, Polyomavirus Transforming; Cell Line; Cloning, Molecular; Cricetinae; DNA Replication; Female; Gene Expression; Genetic Vectors; Ovary; Plasmids; Transfection
PubMed: 2011514
DOI: 10.1093/nar/19.1.85 -
Genes & Development Nov 1987The enhancer of simian virus 40 (SV40) is active in a wide variety of tissues and hosts and thus has been called a general enhancer. Previous work has established that...
The enhancer of simian virus 40 (SV40) is active in a wide variety of tissues and hosts and thus has been called a general enhancer. Previous work has established that this region contains a number of subsegments, each with a different cell type specificity. By analyzing enhancer deletion mutants of SV40 with a restricted cell type specificity, we have identified a purine-rich DNA motif (Pu box) that is essential for activity of the mutant enhancer in lymphoid cells and also obtained evidence for an independent element that confers activity in kidney CV-1 cells. The Pu box element is positively regulated since binding of a cognate factor(s) was only observed in lymphoid cell extracts. The Pu box is also present in the 63-bp enhancer repeat of lymphotropic papovavirus (LPV), and competition experiments show that the SV40 and LPV sequences bind the same factor(s). Thus, the Pu box is likely to be a major determinant of the lymphotropic host range of LPV. In SV40, however, the Pu box is one of several enhancer elements with different cell specificities. We suggest that such an arrangement reflects a diversification strategy of SV40 to maximize its chance of adaptation to various types of host cells.
Topics: Animals; Base Sequence; Cell Line; DNA, Viral; Enhancer Elements, Genetic; Genes, Viral; Methylation; Molecular Sequence Data; Mutation; Papillomaviridae; Plasmids; Polyomaviridae; Purines; RNA, Viral; Simian virus 40; T-Lymphocytes; Transcription, Genetic; Transfection
PubMed: 2828177
DOI: 10.1101/gad.1.9.962 -
Journal of Virology Jul 1968The simian papovavirus SV40 replicated as well in simian cells incubated at 41 C as in cells incubated at 37 C, although the latent period was shortened at the elevated...
The simian papovavirus SV40 replicated as well in simian cells incubated at 41 C as in cells incubated at 37 C, although the latent period was shortened at the elevated temperature. Human adenoviruses differed in their responses to the elevated temperature. Some serotypes, such as 3, 4, 5, 7, 8, 16, and 21, replicated as well, or almost as efficiently, in human cells incubated at 41 C as in cells incubated at 37 C, whereas with other serotypes, such as 1, 2, 6, 12, and 14, maximal yields in cultures incubated at 41 C were much lower than the yields from companion cultures incubated at 37 C. This difference was also detected in simian cells co-infected with SV40 and a human adenovirus; maximal complementation occurred with some serotypes at the elevated temperature but not with other serotypes. The degree of complementation observed in the simian cells at 41 C was directly correlated with the ability of the adenovirus to replicate at 41 C in human cells. Therefore, the capacity of SV40 to serve as a helper virus is not affected by the elevated temperature, showing that the complementation event supplied by the simian virus is heat-stable between 37 and 41 C. Maximal complementation appeared to depend upon a characteristic present in the adenovirus genome.
Topics: Adenoviridae; Animals; Culture Techniques; Embryo, Mammalian; Haplorhini; Humans; Kidney; Methods; Simian virus 40; Temperature; Virus Replication
PubMed: 4301993
DOI: 10.1128/JVI.2.7.670-677.1968 -
The Journal of Biological Chemistry Dec 1993The E7 gene of the human papillomaviruses (HPV) encodes a 98-amino acid, multifunctional nuclear phosphoprotein with functional and structural similarities to adenovirus... (Comparative Study)
Comparative Study
The E7 gene of the human papillomaviruses (HPV) encodes a 98-amino acid, multifunctional nuclear phosphoprotein with functional and structural similarities to adenovirus E1A and the papovavirus T antigens. E7 is a viral oncoprotein, which will cooperate with an activated ras oncogene to transform primary rodent cells, and can cooperate with the HPV E6 protein for the efficient immortalization of primary human keratinocytes. Due to the compelling epidemiological and experimental association between HPV infection and cervical cancer, we have undertaken a detailed study of the structure of the HPV16 E7 protein. The E7 protein was expressed in Escherichia coli as a native, unfused polypeptide, and soluble protein was purified by conventional chromatographic techniques. The purified protein was assessed for various biochemical and biophysical properties. Purified E7 binds the retinoblastoma protein avidly and specifically, and it can dissociate the E2F transcription factor when assayed in vitro. Circular dichroism spectroscopy indicated that E7 reversibly binds Zn2+ and Cd2+, resulting in a substantial increase in the alpha-helical content of the metal-bound E7 consistent with the stabilization of a hydrophobic core in the COOH terminus of the protein.
Topics: Amino Acid Sequence; Animals; Base Sequence; Binding, Competitive; Chromatography, DEAE-Cellulose; Chromatography, Gel; Cloning, Molecular; DNA Primers; Escherichia coli; Female; Genes, Viral; Kinetics; Molecular Sequence Data; Oncogene Proteins, Viral; Papillomaviridae; Papillomavirus E7 Proteins; Papillomavirus Infections; Peptides; Protein Binding; Protein Structure, Secondary; Recombinant Proteins; Retinoblastoma Protein; Sequence Homology, Amino Acid; Tumor Virus Infections; Uterine Cervical Neoplasms; Vero Cells
PubMed: 8245034
DOI: No ID Found