| enhancer effect of bovine papillomavirus e2 protein in replication of polyomavirus dna. | in polyomavirus, both transcription from the early promoter and viral dna replication initiated at the origin of dna replication is controlled by binding of proteins to the enhancer region. we have developed a simple model system to study the role of an enhancer binding factor in the initiation of polyomavirus dna replication. a reporter plasmid was constructed which has the enhancer region replaced by two binding sites for a transcription factor, the e2 protein encoded by bovine papillomavirus ... | 1991 | 1662803 |
| two cellular single-strand-specific dna-binding proteins interact with two regions of the bovine papillomavirus type 1 genome, including the origin of dna replication. | we have identified and purified to near homogeneity two specific single-stranded dna-binding factors (spsf i and ii) with molecular masses of 42 and 39 kda, respectively, from calf thymus. gel retention analysis and competition experiments demonstrate that the ubiquitous proteins spsf i and ii specifically interact with single-stranded dna derived from the minimal in vitro origin of replication of bovine papillomavirus type 1 and a region of the viral genome proposed to be involved in plasmid ma ... | 1992 | 1326653 |
| growth complementation of influenza virus temperature-sensitive mutants in mouse cells which express the rna polymerase and nucleoprotein genes. | in order to establish cell lines which complement the growth of temperature-sensitive (ts) mutants of influenza virus, three rna polymerase and nucleoprotein (np) genes each linked to the mouse mammary tumor virus ltr were cloned into the bovine papillomavirus vector dna. after co-transfection of mouse c127 cells with these recombinant plasmids, a cell line, clone 76, in which the expression of the three polymerase and np genes could be stimulated by dexamethasone, was established. the clone 76 ... | 1991 | 1663110 |
| phylogenetic analysis of 48 papillomavirus types and 28 subtypes and variants: a showcase for the molecular evolution of dna viruses. | papillomaviruses are attractive models for studying the molecular evolution of dna viruses because of the large number of isolates that exhibit genomic diversity and host species and tissue specificity. to examine their relationship, we selected two amino acid sequences, one of 52 residues within the early gene e1 and the other of 44 residues within the late gene l1, which allowed insertion- and deletion-free alignment of all accessible papillomavirus sequences. we constructed phylogenetic trees ... | 1992 | 1326639 |
| papillomavirus l1 major capsid protein self-assembles into virus-like particles that are highly immunogenic. | infection by certain human papillomavirus types is regarded as the major risk factor in the development of cervical cancer, one of the most common cancers of women worldwide. analysis of the immunogenic and structural features of papillomavirus virions has been hampered by the inability to efficiently propagate the viruses in cultured cells. for instance, it has not been established whether the major capsid protein l1 alone is sufficient for virus particle assembly. in addition, it is not known ... | 1992 | 1334560 |
| tumor progression in transgenic mice containing the bovine papillomavirus genome. | | 1991 | 1667568 |
| transcription factor e2 regulates bpv-1 dna replication in vitro by direct protein-protein interaction. | | 1991 | 1668086 |
| sequence-specific alkylation of dsdna with derivatives of pyrimidine oligonucleotides conjugated to 2-chloroethylamine groups. | reaction of homopyrimidine oligonucleotides bearing a 5'-terminal alkylating aromatic 2-chloroethyl-amino group with a bovine papilloma vector expressing human interferon-gamma was investigated. the oligonucleotide derivatives bound to corresponding homopurine-homopyrimidine sequences in dsdna and alkylated guanosine residues at these sites in the purine strand of the target. the alkylated dna can be cleaved at the modified residues. at ph 5.4, the reaction was highly specific to the target sequ ... | 1991 | 1668255 |
| generation of c127-derived cell lines expressing estrogen or progesterone receptors for studying gene regulation on bovine papilloma virus minichromosomes. | to study regulation of transcription by multiple steroid hormones we have stably introduced expression vectors for human estrogen and rabbit progesterone receptors into the genome of the murine fibroblast cell line c127. these cells express functional endogenous glucocorticoid receptor and support bovine papilloma virus minichromosomes, a useful system for studying the role of chromatin structure on gene expression. three clones containing progesterone receptor integrates and six containing estr ... | 1991 | 1668831 |
| diagnosis of nasopharyngeal carcinoma by means of recombinant epstein-barr virus proteins. | the immune response of patients with nasopharyngeal carcinoma to epstein-barr virus (ebv) antigens is diagnostic of the tumour. existing tests use ebv antigens produced in ebv-infected lymphoblastoid cells, but the virus replicates poorly in these cells. serum samples from 18 patients diagnosed as having nasopharyngeal carcinoma were screened by western blot analysis, enzyme-linked immunosorbent assay (elisa), and immunofluorescence tests for antibodies to the ebv-coded alkaline deoxyribonucleas ... | 1991 | 1672175 |
| the e5 oncoprotein of bovine papillomavirus binds to a 16 kd cellular protein. | the e5 oncoprotein of bovine papillomavirus type 1 is the smallest known viral transforming protein. it is a 44 amino acid polypeptide asymmetrically oriented in golgi and plasma membranes which appears to modify (either directly or indirectly) the internalization and phosphorylation of at least two growth factor receptors: egf and csf-1. to identify cellular proteins associated with e5, we have constructed two e5 fusion proteins, each of which contains a well-characterized epitope at the e5 ami ... | 1990 | 1688529 |
| two dna-bound e2 dimers are required for strong transcriptional activation and for cooperation with cellular factors in most cells. | the e2 transcriptional activator encoded by papillomaviruses binds as a dimer to the palindromic sequence accgnnnncggt present in several copies in the viral genomes. we show that strong activation requires that a minimum of two e2 binding sites are actually occupied by the protein. studies with constructs bearing two e2 sites separated by variable lengths of dna showed that there is no stereospecific constraint for e2 homosynergy. the capacity of e2 to cooperate with cellular factors interactin ... | 1991 | 1653009 |
| antibody-mediated neutralization in vivo of infectious papillomaviruses. | specific antibody-mediated neutralization of infectious human papillomavirus type 11 (hpv-11) was achieved in the athymic mouse xenograft system, in which hpv-11 induced morphological transformation of human foreskin. virus-specific neutralization was demonstrated by the ability of an hpv-11-specific polyclonal antiserum to neutralize hpv-11 infectivity and not bovine papillomavirus type 1 (bpv-1) or cottontail rabbit papillomavirus (crpv) infectivity. in all three virus infectivity systems, neu ... | 1990 | 1693698 |
| the functional bpv-1 e2 trans-activating protein can act as a repressor by preventing formation of the initiation complex. | the products encoded by the e2 open reading frame of the papillomaviruses are dna-binding transcription factors involved in the positive or negative regulation of multiple viral promoters. to further understand the mechanisms by which the same transcription factor may act differentially, the full-length bpv-1 e2 protein was expressed and purified from yeast and assayed in vitro for its capacity to modulate transcription. e2 stimulated transcription of the hsv thymidine kinase (tk) promoter when ... | 1991 | 1653173 |
| immunofluorescent detection of bovine papillomavirus e4 antigen in the cytoplasm of cells permissive in vitro for viral dna amplification. | the e4 gene of several human papillomavirus types is expressed in association with vegetative viral dna synthesis in differentiated epidermal cells. to develop reagents to study expression of the bovine papillomavirus type 1 (bpv-1) e4 gene in warts and in virus-transformed cell lines, rabbit polyclonal antiserum was raised to the bpv-1 e4 antigen produced as a fusion polypeptide in escherichia coli. by immunoblotting analysis of productively infected bovine fibropapilloma tissue, e4-related pro ... | 1991 | 1654378 |
| enhancer activation by a single type of transcription factor shows cell type dependence. | promoter and enhancer elements contain multiple binding sites for ubiquitous and cell type-specific transcription factors which stimulate transcription synergistically. here we show that cell type-dependent enhancer activity can be achieved by mechanisms other than interactions between cell type-specific transcription factors and dna. the ability of the sv40 enhancer and the e2 transactivator from bovine papillomavirus (bpv-1) to stimulate transcription from a reporter gene with different minima ... | 1991 | 1714381 |
| comparison of neutralization of bpv-1 infection of c127 cells and bovine fetal skin xenografts. | bpv-1 induces focus formation in murine c127 cells and fibropapillomas in bovine fetal skin xenografts. in this study, we compared the specificity of neutralization of bpv-1 in both assay systems, using sera and monoclonal antibodies (mabs) selected to define neutralizing epitopes. sera from rabbits and cattle, inoculated with intact bpv-1 or pbv-2 virions, neutralize bpv-1 infectivity in both c127 cells and xenografts. selected human sera and murine mabs that react with intact bpv-1 particles, ... | 1991 | 1715330 |
| an element in the bovine papillomavirus late 3' untranslated region reduces polyadenylated cytoplasmic rna levels. | expression of the two bovine papillomavirus type 1 (bpv-1) late genes, l1 and l2, coding for the two capsid proteins, is limited to terminally differentiated keratinocytes in bovine fibropapillomas. this pattern of expression is determined both by the activity of the late promoter and by the inhibition of late region expression in less well differentiated cells. inhibition of l1 and l2 mrna production in nonpermissive cells must occur since the late region potentially could be transcribed from e ... | 1991 | 1717710 |
| identification of linear epitopes of the bpv-1 l1 protein recognized by sera of infected or immunized animals. | sera from cattle that had been inoculated with bpv-1 virions or with recombinant l1 proteins and serum from a rabbit that had been immunized with sds-denatured virions were evaluated for their reactivity with 466 overlapping synthetic peptides corresponding to 95% of the bpv-1 l1 protein. the late serological response of cattle to both intact virions and recombinant l1 proteins exhibited a similar profile of reactivity with approximately 70% (7 of 10) of l1 antigenic sites. however, the l1 serol ... | 1991 | 1718315 |
| antigenic and immunogenic epitopes shared by human papillomavirus type 16 and bovine, canine, and avian papillomaviruses. | all types of papillomaviruses (pv) share common, so-called group-specific epitopes. to identify the major group-specific epitopes, we immunized 26 guinea pigs or rabbits with purified bovine pv type 1 (bpv), canine pv, or avian pv from the common chaffinch. the resulting hyperimmune sera, as well as a commercially available rabbit antiserum to bpv and seven monoclonal antibodies to bpv, were tested in an enzyme-linked immunosorbent assay with a set of 66 overlapping 20-amino-acid peptides repres ... | 1991 | 1719234 |
| differentiation of parapoxviruses by application of orf virus-specific monoclonal antibodies against cell surface proteins. | monoclonal antibodies were produced against orf virus-specified cell surface proteins in an attempt to develop reagents capable of differentiating between members of the parapoxviridae. two immunization protocols were used to induce an anti-orf response in balb/c mice, one of which resulted in virus replication in the recipient. the monoclonal antibodies produced were tested for crossreactivity with bovine papular stomatitis virus (bps) and milker's node virus (mnv) by indirect immunofluorescenc ... | 1991 | 1719690 |
| the e5 oncoprotein target: a 16-kda channel-forming protein with diverse functions. | | 1991 | 1724370 |
| the b subgroup bovine papillomaviruses lack an identifiable e6 open reading frame. | analysis of the corrected dna sequence for the bovine papillomavirus type 4 (bpv4) genome revealed that there is no open reading frame (orf) that might encode an e6 protein. the other two b subgroup bovine papillomaviruses, bpv3 and bpv6, were found to have the same arrangement of orfs in this region as bpv4. thus, we conclude that e6 functions are either not required by these viruses or are performed by another viral (or host) protein. furthermore, the position that might be expected to be occu ... | 1991 | 1654923 |
| the bovine papillomavirus e5 oncogene can cooperate with ras: identification of p21 amino acids critical for transformation by c-rash but not v-rash. | we have previously used a series of insertion-deletion mutants of the mutationally activated v-rash gene to identify several regions of the encoded protein that are dispensable for cellular transformation (b. m. willumsen, a. g. papageorge, h.-f. kung, e. bekesi, t. robins, m. johnsen, w. c. vass, and d. r. lowy, mol. cell. biol. 6:2646-2654, 1986). to determine if some of these amino acids are more important for the biological activity of c-rash, we have now tested many of the same insertion-de ... | 1991 | 1658623 |
| characterization of the cis elements involved in basal and e2-transactivated expression of the bovine papillomavirus p2443 promoter. | transcriptional transactivation and repression by the viral e2 proteins are important regulatory mechanisms for the papillomaviruses. in the bovine papillomavirus type 1 (bpv-1), several viral promoters can be transactivated by e2 through e2-dependent enhancer elements located in the viral long control region (lcr), including promoters involved in e2 expression itself. this report demonstrates that the bpv-1 p2443 promoter is transactivated by e2-responsive elements in the lcr and that this prom ... | 1991 | 1846195 |
| identification of the origin of replication of bovine papillomavirus and characterization of the viral origin recognition factor e1. | expression of the viral polypeptides e1 and e2 is necessary and sufficient for replication of bpv in mouse c127 cells. by providing these factors from heterologous expression vectors we have identified a minimal origin fragment from bpv that contains all the sequences required in cis for replication of bpv in short term replication assays. this same sequence is also required for stable replication in the context of the entire viral genome. the identified region is highly conserved between differ ... | 1991 | 1661672 |
| transient replication of bpv-1 requires two viral polypeptides encoded by the e1 and e2 open reading frames. | bovine papillomavirus (bpv) dna is maintained as an episome with a constant copy number in transformed cells and is stably inherited. to study bpv replication we have developed a transient replication assay based on a highly efficient electroporation procedure. using this assay we have determined that in the context of the viral genome two of the viral open reading frames, e1 and e2, are required for replication. furthermore we show that when produced from expression vectors in the absence of ot ... | 1991 | 1846806 |
| cooperative binding of the e2 protein of bovine papillomavirus to adjacent e2-responsive sequences. | the dna-binding properties of purified full-length e2 protein from bovine papillomavirus type 1 have been investigated by utilizing a quantitative gel shift analysis. by using a recombinant baculovirus which express the e2 open reading frame from the polyhedrin promoter, the full-length e2 protein was synthesized in insect cells and purified to homogeneity by using an e2 binding site (accgn4cggt)-specific oligonucleotide column. the kd of e2 binding to a 41-bp oligonucleotide containing a single ... | 1991 | 1848322 |
| relationship of histone acetylation to dna topology and transcription. | an autonomously replicating plasmid constructed from bovine papiloma virus (bpv) and pbr322 was stably maintained as a nuclear episome in a mouse cell culture. addition to a cell culture of sodium butyrate (5 mm) induced an increase in plasmid dna supercoiling of 3-5 turns, an increase in acetylation of cellular histones, and a decrease in plasmid transcription by 2- to 4-fold. after withdrawal of butyrate, dna supercoiling began to fluctuate in a wave-like manner with an amplitude of up to 3 tu ... | 1991 | 1662766 |
| transcription factors junb and c-jun are selectively up-regulated and functionally implicated in fibrosarcoma development. | bovine papillomavirus transgenic mice develop skin tumors arising from dermal fibroblasts in a process comprised of three distinctive stages: mild and aggressive fibromatoses, and fibrosarcoma. in both tissue biopsies and derivative cell lines, the proto-oncogenes junb and c-jun are induced in the latter two stages, in contrast to jund and fos. fibrosarcoma cell lines have increased ap-1 dna-binding activity. overexpression of junb or c-jun by transfection into the mild fibromatosis stage elicit ... | 1992 | 1459456 |
| persistence of bovine papillomavirus (pbpv-1) as an extrachromosomal element in tissues of microinjected xenopus laevis. | | 1991 | 1849256 |
| histone hyperacetylation does not alter the positioning or stability of phased nucleosomes on the mouse mammary tumor virus long terminal repeat. | activation of mouse mammary tumor virus transcription by the hormone-bound glucocorticoid receptor results in disruption of a nucleosome that is specifically positioned on the promoter. limited treatment of cells with the histone deacetylase inhibitor sodium butyrate prevents receptor-dependent promoter activation and nucleosome disruption [bresnick, e. h., john, s., berard, d. s., lefebvre, p., & hager, g. l. (1990) proc. natl. acad. sci. u.s.a. 87, 3977-3981]. on the basis of this observation, ... | 1991 | 1849427 |
| analysis of the influences of the e5 transforming protein on kinetic parameters of epidermal growth factor binding and metabolism. | the e5 protein of the bovine papillomavirus induces cellular transformation when transfected into nih 3t3 cells, and the extent of focal transformation is enhanced by cotransfection with the epidermal growth factor (egf) receptor (martin et al., cell 59:21-32, 1989). to determine whether e5 affects egf:receptor interactions we analyzed the kinetics of 125i-egf processing using a mathematical model that enabled us to evaluate rate constants for ligand association (ka), dissociation (kd), internal ... | 1992 | 1639860 |
| the late region differentially regulates the in vitro transformation by cottontail rabbit papillomavirus dna in different cell types. | papilloma induced by the cottontail rabbit papillomavirus (crpv) progress at a high frequency to cancers. this property makes the crpv system unique to study the role of papillomaviruses in cancer development. in contrast to bovine papillomavirus type 1, no convenient in vitro transformation system for crpv has been available. here, we describe two in vitro systems that we have developed. transformation of nih 3t3 cells is greatly facilitated by deletions in the crpv late region. specifically, a ... | 1991 | 1849681 |
| functional analysis of e2-mediated repression of the hpv18 p105 promoter. | transcription of the transforming genes e6 and e7 of the human papillomavirus type 18 (hpv18) can be repressed by the product of the e2 open reading frame. mutations were introduced in the cis-responsive elements upstream from the e6 and e7 transcriptional promoter, p105. the effect of these mutations in the absence or presence of e2 was examined in the human cervical carcinoma cell line c33, transfected with expression plasmids. in the presence of hpv18 e2, repression was relieved only when bot ... | 1991 | 1645591 |
| delay time for influenza virus hemagglutinin-induced membrane fusion depends on hemagglutinin surface density. | we have studied the kinetics of low-ph-induced fusion between erythrocyte membranes and membranes containing influenza virus hemagglutinin by using assays based on the fluorescence dequenching of the lipophilic dye octadecylrhodamine. stopped-flow mixing and fast data acquisition have been used to monitor the early stages of influenza virus fusion. we have compared this with the kinetics observed for fusion of an nih 3t3 cell line, transformed with bovine papillomavirus, which constitutively exp ... | 1991 | 1850019 |
| bovine papillomavirus type 1 alters the processing of host glucose- and calcium-modulated endoplasmic reticulum proteins. | we have previously characterized five proteins induced by the presence of the e2 open reading frame (orf) region of bovine papillomavirus type 1 (bpv-1) in c127 mouse fibroblasts (r. m. levenson, u. g. brinckmann, m. k. o'banion, e. j. androphy, j. t. schiller, f. tabatabai, l. p. turek, k. neary, m. t. chin, t. r. broker, l. t. chow, and d. a. young, virology 172:170-179, 1989). by specific immunoprecipitation, we now find that one of the papillomavirus-associated proteins (pvp1) is a highly gl ... | 1991 | 1645780 |
| direct interaction between sp1 and the bpv enhancer e2 protein mediates synergistic activation of transcription. | the physical interaction of heterologous site-specific dna-binding proteins is an important theme in eukaryotic transcriptional regulation. in this paper, we show that the cellular transcription factor sp1 and the bpv-1 (bovine papillomavirus type 1) enhancer protein e2 activate transcription synergistically from two papilloma viral promoters and a series of synthetic promoter constructs in transient transfection experiments. furthermore, sp1 can target e2 to a promoter region even in the absenc ... | 1991 | 1850324 |
| [papillomatosis of cattle and its relationship to equine sarcoid]. | the aetiology and the pathogenesis of equine sarcoids are described. aspects of therapy are discussed. | 1991 | 1646494 |
| topological properties of bovine papillomavirus type 1 (bpv-1) dna in episomal nucleoprotein complexes: a model system for chromatin organization in higher eukaryotes. | sedimentation analysis of isolated episomal bovine papillomavirus type 1 (bpv-1) nucleoprotein complexes in sucrose gradients and subsequent separation of the purified dna in chloroquine gels revealed different classes of molecules, varying in their degree of superhelicity. since torsionally stressed dna favors the adoption of secondary structures, we employed the single-strand-specific s1 nuclease to detect such structural alterations in both naked dna and native chromatin. direct examination o ... | 1991 | 1648363 |
| bovine papillomavirus e5 oncoprotein binds to the 16k component of vacuolar h(+)-atpases. | the major transforming protein of bovine papillomavirus type 1, e5, is mainly associated with endomembranes, specifically binding to a cellular protein of relative molecular mass 16,000 (16k). at the same time as transformation, e5 causes the phosphorylation of tyrosine residues in epidermal and platelet-derived growth factor receptors. we show here that the 16k protein associated with e5 is the 16k component of vacuolar atpases. this protein is known to be an integral membrane protein in endoso ... | 1991 | 1649407 |
| the q300 gene: a novel transcription unit induced in simian virus 40-infected and -transformed mouse cells. | the q300 element is a single-copy 233-bp genomic mouse dna fragment carrying a high-affinity binding site for the simian virus 40 (sv40) large t antigen. this element was used to screen an embl3 mouse genomic library. we could identify a genomic clone containing an approximately 500-bp transcribed region flanking the q300 element. the transcribed region, termed the q300 transcription unit or q300 gene, is overexpressed in acutely sv40-infected or sv40-transformed mouse and rat cells. the q300 ge ... | 1991 | 1851876 |
| expression of epidermal growth factor precursor cdna in animal cells. | this chapter outlines in detail the optimal conditions for the expression of human recombinant proteins in mouse cells using a bovine papillomavirus-based mammalian expression vector. the procedures we have described were used to successfully express high levels of the human egf precursor in our laboratory and the human insulin receptor in the laboratory of whittaker. using this experimental approach we were able to demonstrate that expression of a cdna for prepro-egf produces a glycosylated mem ... | 1991 | 1649948 |
| an interaction between the 5' flanking distal and proximal regulatory domains of the rat prolactin gene is required for transcriptional activation by estrogens. | in vitro studies have demonstrated that the estrogen receptor (er) can bind to the rat prl estrogen response element (ere) located 1700 basepairs upstream of the transcriptional start site. however, the mechanism by which the receptor-dna complex influences the activity of rna polymerase located in the promoter region is not understood. to begin investigating this process, we developed cell lines derived from gh3 cells that contain steroid-responsive bovine papillomavirus minichromosomes. within ... | 1990 | 1963474 |
| papillomavirus infection of aged persian cats. | papillomavirus infection was confirmed in 2 persian cats with sessile hyperkeratotic skin lesions. skin lesions were not typical papillomas as found in other species. papillomavirus were demonstrated in negative stain preparations of homogenized tissue and within nuclei of cells in the stratum granulosum. papillomavirus group-specific antigens were detected within nuclei corresponding to those containing virions. attempts to transmit this disease to other cats or propagate the virus in tissue cu ... | 1990 | 1965634 |
| bovine papillomavirus e2 repressor mutant displays a high-copy-number phenotype and enhanced transforming activity. | the methionine codon at bovine papillomavirus type 1 nucleotide 3091 was mutated to determine whether it may serve as an initiation codon for an e2 transcriptional repressor protein and to determine the role of the repressor in the biological activities of the virus. a series of transient expression experiments with cv1 cells documented that the mutation reduced expression of repressor activity from the viral genome and resulted in increased expression of the e5 transforming gene. viral genomes ... | 1990 | 2153255 |
| phenotypic analysis of bovine papillomavirus type 1 e2 repressor mutants. | the bovine papillomavirus type 1 (bpv-1) e2 open reading frame encodes three proteins: the e2 transcriptional transactivator, the e2 transcriptional repressor (e2-tr), and the e8/e2 fusion peptide. in this study, we describe the phenotypes of bpv-1 mutants which are disrupted in their capacity to encode either the e2 transcriptional repressor or the e8/e2 fusion peptide. we also describe experiments which demonstrate that the e8/e2 gene product functions similarly to e2-tr. in the context of the ... | 1990 | 2153256 |
| characterization of bpv-like dna in equine sarcoids. | the dna from equine sarcoid samples from new york state and switzerland was isolated and probed with bovine papillomavirus type 1 (bpv-1) to determine if bpv genomes were present. twelve of 13 sarcoids from new york state and 17/20 sarcoids from switzerland contained dna that hybridized to the bpv-1 probe. restriction enzyme analysis of the positive samples demonstrated restriction fragment profiles characteristic of bpv-1 in 22 sarcoids and restriction fragment profiles characteristic of bovine ... | 1991 | 1650553 |
| the dna-binding domain of hpv-16 e2 protein interaction with the viral enhancer: protein-induced dna bending and role of the nonconserved core sequence in binding site affinity. | we expressed the carboxy-terminal portion of the e2 open reading frame (orf)-encoded protein of human papillomavirus type 16 (hpv-16) and purified it to near homogeneity. using dnase i footprinting techniques, we show that like the homologous protein from bovine papillomavirus type 1 (bpv-1), hpv-18, hpv-11, it binds dna at the enhancer consensus motif accn6ggt. base and phosphate backbone contact points were determined using methylation protection and interference and ethylation interference as ... | 1990 | 2154890 |
| in vitro interactions between bovine papillomavirus and human monocytes and macrophages. | limited data suggest that macrophages play a role in the pathogenesis of bovine papillomavirus (bpv) infections. in the present study, interactions between these cells and bpv-1 were explored by exposing in vitro human blood monocytes and monocyte-derived macrophages to purified virions. immediately or up to 28 days after exposure, cell culture supernatants as well as cell lysates were collected. interleukin 1 activity was detected in the supernatants of monocytes early after exposure to bpv (0- ... | 1991 | 1650765 |
| initiation of transcription from the minute virus of mice p4 promoter is stimulated in rat cells expressing a c-ha-ras oncogene. | transformation of fr3t3 rat fibroblasts by a c-ha-ras oncogene but not by bovine papillomavirus type 1 is associated with an increase in the abundance of mrnas from prototype strain mvmp of infecting minute virus of mice, an oncosuppressive parvovirus. this differential parvovirus gene expression correlates with the reported sensitization of ras- but not bovine papillomavirus type 1-transformed cells to the killing effect of mvmp (n. salomé, b. van hille, n. duponchel, g. meneguzzi, f. cuzin, j. ... | 1991 | 1651412 |
| serological responses to papillomavirus group-specific antigens in women with neoplasia of the cervix uteri. | certain types of human papillomaviruses have been linked to the development of carcinoma of the cervix uteri. we have analyzed 114 serum specimens from women with cervical intraepithelial neoplasia (cin) or carcinoma of the cervix uteri for the presence of serum antibodies against purified, disrupted bovine papillomavirus (bpv). the titers of immunoglobulin a (iga) antibodies against bpv were slightly elevated (p less than 0.025) in the sera from cin or cervical carcinoma patients compared with ... | 1990 | 2157738 |
| integrated hpv 1 genomes in a human keratinocyte cell line can be transactivated by a sv40/bpv1 recombinant virus which expresses bpv1 e2 proteins. | this paper describes studies carried out on an hpv 1 carrying human keratinocyte cell line (svd2) and two subclones of it. although these lines contain multiple copies of hpv 1 genomes, in situ hybridization revealed that integration was restricted to band q33 on the long arms of chromosome 2. an e4 1.25-kb mrna was specifically identified by northern blotting and a pcr generated cdna confirmed the presence of the e1/e4 spliced mrna which is abundant in hpv 1 containing papillomas. infection of ... | 1990 | 2158183 |
| mutational analysis of cis elements involved in e2 modulation of human papillomavirus type 16 p97 and type 18 p105 promoters. | cis-acting elements involved in e2 modulation of human papillomavirus type 16 (hpv-16) p97 promoter activity and hpv-18 p105 promoter activity were examined. in transfected primary human keratinocytes, each promoter had a basal activity that could be repressed by the bovine papillomavirus type 1 e2 gene product. mutational analysis of the e2-binding sites in the long control region upstream of each promoter revealed that e2 repression was mediated through the e2-binding sites proximal to each pr ... | 1990 | 2159546 |
| comparative analysis of inositol phospholipid metabolism in viral and chemical transformation of mammalian cells. | 1. inositol phospholipid metabolites were measured from virally and chemically transformed cells. 2. increased levels of pip and pip2 were observed from both transformed cell lines as compared with controls. 3. intracellular levels of ip3 were also increased approximately three folds in bpv-1 infected id 13 cells and in 3-mc transformed nih 3t3 cells. 4. the results suggest that phosphorylation of phosphatidylinositols and enhanced generation of ip3 second messenger molecules are the common sign ... | 1992 | 1360364 |
| a glutamine residue in the membrane-associating domain of the bovine papillomavirus type 1 e5 oncoprotein mediates its binding to a transmembrane component of the vacuolar h(+)-atpase. | the 44-amino-acid e5 oncoprotein is the major transforming protein of bovine papillomavirus type 1. it is a highly hydrophobic polypeptide which dimerizes and localizes to the golgi apparatus and endoplasmic reticulum membranes. recent evidence suggests that e5 modulates the phosphorylation and internalization of the epidermal growth factor and colony-stimulating factor 1 receptors and constitutively activates platelet-derived growth factor receptors in c127 and fr3t3 cells. although no direct i ... | 1992 | 1370089 |
| glucocorticoid receptor-dependent disruption of a specific nucleosome on the mouse mammary tumor virus promoter is prevented by sodium butyrate. | our laboratory has previously developed cell lines derived from mouse nih 3t3 fibroblasts and c127 mammary tumor cells that stably express mouse mammary tumor virus (mmtv) long terminal repeat fusion genes in bovine papillomavirus-based episomes. glucocorticoid hormone strongly activates transcription from episomes and induces the disruption of a single nucleosome in an array of phased nucleosomes on the mmtv promoter. sodium butyrate inhibits the glucocorticoid hormone-dependent development of ... | 1990 | 2160080 |
| transforming growth factor-beta expression in fibropapillomas induced by bovine papillomavirus type 1, in normal bovine skin, and in bpv-1-transformed cells. | there is substantial evidence to suggest that transforming growth factor-beta (tgf-beta) plays an important role in wound healing and tissue repair as well as in carcinogenesis. it has also been observed that naturally occurring bovine papillomavirus type 1 (bpv-1)-induced bovine fibropapillomas occur predominantly at traumatized sites of the body, suggesting that humoral factors released in wounds might be important for papillomavirus infection. we have therefore investigated the possible role ... | 1990 | 2160257 |
| levels of immunoglobulin g antibodies against defined epitopes of the l1 and l2 capsid proteins of human papillomavirus type 6 are elevated in men with a history of condylomata acuminata. | sera from 159 men attending the sexually transmitted disease clinic at karolinska hospital, stockholm, sweden, were analyzed for the presence of immunoglobulin a (iga) and igg antibodies to a panel of synthetic peptides derived from the e2, l1, and l2 regions of the human papillomavirus types 1 (hpv 1), 6, 8, 11, 16, 18, 31, and 33. the study subjects were divided into three groups: (i) asymptomatic men with no history of genital warts who served as controls, (ii) men with visible condylomata, a ... | 1992 | 1378454 |
| distribution and specific identification of papillomavirus major capsid protein epitopes by immunocytochemistry and epitope scanning of synthetic peptides. | monoclonal (mabs) and polyclonal antibodies were produced against the major capsid protein of detergent-disrupted, purified bovine papillomavirus type 1 (bpv-1). the precise locations of the corresponding epitopes were identified by the reactivity of mabs and selected polyclonal antibodies with synthetic, overlapping, hexameric peptides corresponding with 95% of the bpv-1 major capsid protein. the topography of these epitopes was determined by reactivity of antibodies with intact (conformational ... | 1990 | 1700026 |
| optimization of the hygromycin b resistance-conferring gene as a dominant selectable marker in mammalian cells. | the hyr gene, conferring resistance to hygromycin b (hy), has been modified for optimal expression in mammalian cells. modifications to the hyr gene and its expression cassette include: (1) removal of all upstream start codons, (2) conversion of the region around the start codon to the consensus sequence associated with efficient translation initiation, and (3) removal of downstream splice donor and acceptor sequences. the resulting hyr gene is an efficient dominant selectable marker that is use ... | 1990 | 2161383 |
| studies on vaccination against papillomaviruses: the immunity after infection and vaccination with bovine papillomaviruses of different types. | calves, free of antibodies to bovine papillomaviruses (bpv), were reared in isolation. one was infected with bpv-2, developed tumours and was resistant to homologous reinfection. groups of calves were infected with bpv-2, bpv-5 or bpv-6; they all developed and subsequently rejected type-specific tumours. they were then infected with bpv-4; they were not immune and oral papillomas were induced. groups of animals were vaccinated by intramuscular preparations of purified bpv-4 and bpv-6 and were ch ... | 1990 | 2161579 |
| demonstration of evolutionary differences between conserved antigenic epitopes in the minor nucleocapsid protein of human papillomavirus types 6b, 16 and 18. | we studied human papillomavirus (hpv) minor nucleocapsid protein (l2) by epitope scanning. conserved antigenic epitopes identified by rabbit antiserum to bovine papillomavirus (bpv) were revealed in hpv-6b (amino acids, aa, 196-205); hpv-16 (aa:s 376-85) and hpv-18 (aa:s 221-230). l2 proteins. the first two epitopes were situated in hydrophilic regions of the proteins. aligning the aa-sequences that corresponded to the epitopes with the total l2 sequences of bpv and hpv1a revealed consensus moti ... | 1990 | 1700908 |
| vaccinia recombinants expressing early bovine papilloma virus (bpv1) proteins: retardation of bpv1 tumour development. | papillomaviruses are aetiological agents of epithelial proliferative diseases in animals and in man. it was previously demonstrated that animals inoculated with live vaccinia recombinants expressing early proteins of polyoma virus resist challenge with polyoma-tumour cells, and this approach has been extended to the development of a vaccine against papillomavirus-transformed cells. bovine papillomavirus type 1 (bpv1), a virus responsible for dermal lesions in cattle, is a prototype virus of the ... | 1990 | 2163573 |
| histopathological development of equine cutaneous papillomas. | the histopathological development of equine cutaneous papillomas was studied in 78 warts naturally occurring in 50 one to 3-year-old thoroughbred or arab horses and in 54 warts experimentally induced in three 2-year-old thoroughbreds. lesions in the natural cases were categorized into three phases, growth, development and regression. main lesions of the growing phase were marked hyperplasia of the basal cells and mild to moderate acanthosis, hyper- and parakeratosis with a few intranuclear inclu ... | 1990 | 2164051 |
| the e2 transactivator of bovine papillomavirus type 1 is expressed from multiple promoters. | the e2 proteins of bovine papillomavirus type 1 (bpv-1) are a family of site-specific dna-binding proteins which regulate viral transcription by repression and activation. repressors e2-tr and e8/e2 are expressed from promoters p5 (p3080) and p3 (p890), respectively. previous reports have provided evidence that the transcript for the 48-kilodalton transactivator is initiated from a promoter proximal to the open reading frame encoding this protein (p2440 or p4). our studies extend these findings ... | 1990 | 2164604 |
| cooperative activation of transcription by bovine papillomavirus type 1 e2 can occur over a large distance. | the viral transcriptional factors encoded by the e2 open reading frame bind to the specific dna sequence elements accgnnnncggt, allowing activation or repression of transcription. we have analyzed bovine papillomavirus type 1 e2 transactivation using recombinant genes containing e2-binding sites inserted at either 3' or 5' positions relative to the heterologous transcriptional initiation site of the herpes simplex virus thymidine kinase gene. in these hybrid plasmids, strong transactivation requ ... | 1990 | 2164642 |
| the effect of retinoids, carotenoids and phenolics on chromosomal instability of bovine papillomavirus dna-carrying cells. | antioxidants were found to protect against the genotoxic effects of chemical and physical mutagenic and clastogenic agents. this study focused on the capacity of antioxidants to reduce an intrinsic and persistent chromosome instability. as a model system, strains of c127 cells, which were transformed by bovine papillomavirus (bpv) dna and which carry bpv dna varying from 20 to 160 copies, were used. transformed cells of 10 different strains showed a persistently high incidence of mitotic irregul ... | 1990 | 2165562 |
| the central hydrophobic domain of the bovine papillomavirus e5 transforming protein can be functionally replaced by many hydrophobic amino acid sequences containing a glutamine. | the 44-amino-acid e5 transforming protein of bovine papillomavirus can induce growth transformation of cultured rodent fibroblast cell lines. previous studies revealed that efficient transformation of mouse c127 cells by the e5 protein required a central core of hydrophobic amino acids and several specific carboxyl-terminal amino acids. although a randomly derived sequence of hydrophobic amino acids could functionally replace the wild-type hydrophobic core, most such sequences could not. we show ... | 1992 | 1727496 |
| saturation mutagenesis using mixed oligonucleotides and m13 templates containing uracil. | | 1990 | 2166223 |
| human papillomavirus infection of the uterine cervix analyzed by nonisotopic in situ hybridization. | some types of human papillomaviruses (hpvs) have been suggested to be strongly related to uterine cervical carcinoma. an attempt to detect these in formalin-fixed, paraffin-embedded sections was made by either immunohistochemical or by in situ hybridization. anticapsid protein of bovine papillomavirus antibody labeled with peroxidase was used for immunohistochemistry, and biotin was used instead of radioisotopes to label probes for in situ hybridization, which resulted in low background and a ra ... | 1990 | 2167347 |
| papillomavirus trans-activator protein e2 activates expression from the promoter for the ribonucleotide reductase large subunit from herpes simplex virus type 2. | activation of the herpes simplex virus type 2 (hsv-2) large subunit of the ribonucleotide reductase (icp10) gene by papillomavirus dna encoding the e2 or e7 proteins was studied directly by immunofluorescence or by chloramphenicol acetyltransferase (cat) analysis with hybrid icp10 or ie175 and 38k promoter constructions. cotransfection with bovine papillomavirus type 1 or human papillomavirus type 16 (hpv-16) e2 dna enhanced cat expression from constructions in which cat is regulated by the icp1 ... | 1990 | 2167936 |
| identification of a 68-kilodalton nuclear atp-binding phosphoprotein encoded by bovine papillomavirus type 1. | e1 is the largest open reading frame (orf) of bovine papillomavirus type 1 (bpv-1) and is highly conserved among all papillomaviruses, maintaining its size, amino acid composition, and location in the viral genome with respect to other early genes. multiple viral replication functions have been mapped to the e1 orf of bpv-1, and evidence suggested that more than one protein was encoded by this orf. we previously identified a small protein (m) whose gene consists of two exons, one encoded by the ... | 1990 | 2168988 |
| the 68-kilodalton e1 protein of bovine papillomavirus is a dna binding phosphoprotein which associates with the e2 transcriptional activator in vitro. | the e1 open reading frame of bovine papillomavirus type 1 encodes factors necessary for extrachromosomal maintenance of the viral genome in transformed cells. to facilitate biochemical characterization of the gene products encoded by this open reading frame, we have expressed the full-length e1 protein in a baculovirus-insect cell system. this protein was found to be phosphorylated and localized to the nucleus of infected cells. the e1 protein alone has affinity for dna but appears to lack speci ... | 1991 | 1846189 |
| homologous recombination in bovine papillomavirus shuttlevecter; effect of relative orientation of substrate sequences. | relative orientation of recombination substrates, neo gene, strongly influenced homologous recombination events in a bovine papillomavirus shuttle vector. between direct repeats, recombination occurred at a high frequency while between inverted repeats, it was rare. double strand break near the mutation site increased the recombination frequency between inverted repeats but not between direct repeats. formation of long heteroduplex as a recombination intermediate may explain this apparently para ... | 1991 | 1846540 |
| transfection of lipoma cells with papilloma bovine virus subgenomic fragment. | lipoma cells with consistent chromosomal aberration have been transfected with plasmids carrying papilloma bovine virus subgenomic fragment (pbv 69). the successful transformation of the cells was ascerted on the changed growth pattern of the cells in liquid medium, colony formation in soft agar and modified cell appearance in electron microscopy; transfection with pbv 69 has not been, however, sufficient to immortalize lipoma cells. | 1991 | 1848483 |
| induction of bovine papillomavirus e2 gene expression and early region transcription by cell growth arrest: correlation with viral dna amplification and evidence for differential promoter induction. | the bovine papillomavirus type 1 (bpv-1) genome replicates as a latent plasmid in mouse c127 cells transformed in vitro by the virus. however, we have recently shown that bpv-1 dna amplification can be induced in a subpopulation of cells under culture conditions which suppress cell proliferation, a finding which led us to hypothesize that expression of a viral replication factor was regulated by cell growth stage. in this report, we describe the detection in these cells of abundant bpv-1 nuclear ... | 1990 | 2170685 |
| the e6/e7 promoter of human papillomavirus type 16 is activated in the absence of e2 proteins by a sequence-aberrant sp1 distal element. | the e6/e7 promoter of all genital human papillomaviruses is responsible for expression of the viral transforming genes. centered 60 bp upstream of the transcription start, it contains a 20-bp segment with partially overlapping binding sites for the viral e2 proteins and for a cellular factor that was identified by footprint experiments. bandshifts, bandshift competitions, and footprints revealed that protein complexes between nuclear extracts and these sequences have binding properties indisting ... | 1990 | 2170687 |
| complementation of a vesicular stomatitis virus glycoprotein g mutant with wild-type protein expressed from either a bovine papilloma virus or a vaccinia virus vector system. | using a complementation assay, we have evaluated the potential of two eukaryotic expression systems to produce functional virus proteins. the first expression system was based on a bovine papilloma virus (bpv) eukaryotic expression vector which contained a copy of the gene for the membrane glycoprotein g of vesicular stomatitis virus (vsv). this vector was transfected into a mouse cell line, and transformed cell clones constitutively expressing vsv g protein were selected. these cell clones were ... | 1990 | 2171187 |
| adenovirus infection induces amplification of persistent viral dna sequences (simian virus 40, hepatitis b virus, bovine papillomavirus) in human and rodent cells. | adenoviruses, types 2 and 12 induce amplification of sv40 dna sequences in cells of the sv40-transformed human newborn kidney cell line, nb-e. similarly, integrated hepatitis b virus dna sequences in the human hepatoma cell line, plc/*prf/5, and bovine papillomavirus (bpv) dna sequences in bpv-transformed mouse cells (id13) are amplified by adenovirus infection. thus, similar to herpes group or vaccinia viruses or dna damaging agents, adenoviruses are able to mediate selective dna amplification ... | 1990 | 2171240 |
| production and characterization of a fragment containing the hiv-gp120 binding region of cd4 using a bovine papilloma virus (bpv) vector. | we have used a bovine papilloma virus (bpv) based mammalian cell expression vector consisting of the complete bpv genome and a human cytomegalovirus transcription unit for the production of soluble cd4. mouse c-127 cells were transfected with vector dna together with a selectable g418 resistance plasmid. surviving clones were selected for high production using a solid phase elisa based on the immobilization of supernatant-derived cd4 onto nitrocellulose paper and subsequent detection with anti-c ... | 1990 | 2171457 |
| replication of bovine papillomavirus type 1 dna initiates within an e2-responsive enhancer element. | when bovine papillomavirus transforms cells in vitro, it maintains its genome as a multicopy nuclear plasmid. plasmid dna extracted from such transformed cells was analyzed by the two-dimensional gel electrophoresis technique of brewer and fangman (b. brewer and w. fangman, cell 51:463-471, 1987). the replication intermediates detected in these assays were found to be the sums of the oligomeric and monomeric forms of the replicating plasmids. the multimeric dnas were shown by field inversion gel ... | 1990 | 2173772 |
| proteins encoded by the bovine papillomavirus e1 open reading frame: expression in heterologous systems and in virally transformed cells. | the e1 open reading frame (orf) of bovine papillomavirus type 1 is required for the persistence of viral genomes as multicopy plasmid molecules in transformed rodent fibroblasts. e1 has been reported to contain two separate complementation groups (m and r, corresponding to n- and c-terminal domains, respectively) which regulate viral replication. however, e1 behaves as a single gene with respect to cell transformation and viral transcription. we examined the proteins translated from the entire o ... | 1990 | 2173778 |
| activation of the platelet-derived growth factor receptor by the bovine papillomavirus e5 transforming protein. | the bovine papillomavirus e5 gene encodes a 44 amino acid membrane-associated protein that can induce tumorigenic transformation of rodent fibroblast cell lines. genetic studies suggest that the e5 protein may transform cells by influencing the activity of cellular proteins involved in growth regulation. we report here that the endogenous cellular beta type receptor for the platelet-derived growth factor (pdgf) is constitutively activated in c127 and fr3t3 cells stably transformed by the e5 prot ... | 1991 | 1849073 |
| transactivation of heterologous promoters by hiv-1 tat. | to determine whether hiv-1 tat can transactivate a heterologous promoter lacking hiv sequences other than the tar element, tar was placed downstream of the chicken beta-actin promoter. tat increased expression directed by the actin-tar promoter to a degree equal to tat induction of the hiv-1 ltr. optimal transactivation was observed when tar was positioned downstream of the actin promoter such that the expected cap site of transcripts from this promoter would be the same as in transcripts direct ... | 1991 | 1662814 |
| targeting the e1 replication protein to the papillomavirus origin of replication by complex formation with the e2 transactivator. | the mechanism by which transcription factors stimulate dna replication in eukaryotes is unknown. bovine papillomavirus dna synthesis requires the products of the viral e1 gene and the transcriptional activator protein encoded by the e2 gene. experimental data showed that the 68-kilodalton (kd) e1 protein formed a complex with the 48-kd e2 transcription factor. this complex bound specifically to the viral origin of replication, which contains multiple binding sites for e2. repressor proteins enco ... | 1990 | 2176744 |
| cooperation between bovine papillomavirus type 4 and ras in the morphological transformation of primary bovine fibroblasts. | primary bovine fibroblasts derived from foetal palate can be transformed by bovine papillomavirus type 4 dna only in the presence of an activated ras gene, indicating that the virus does not encode all the information required for morphological transformation of non-established cells. a subgenomic fragment containing the complete e8 and e7 open reading frames (orfs) induces transformation in cooperation with activated ras but transformation is abolished when the e7 orf is deleted at the 3' end, ... | 1990 | 2177095 |
| homologous recombination in a mammalian plasmid. | bovine papillomavirus (bpv) shuttle vectors replicate as a circular plasmid in mouse cell nuclei without impairing host cell viability. we used these vectors to analyze homologous recombination in mammalian cells. when several bpv-based plasmids carrying direct repeats were introduced into c127 cells, we detected many recombinant plasmid molecules that have lost the sequence between the repeats. many recombinant type molecules as well as parental type molecules were detected in all the cell clon ... | 1990 | 2177135 |
| the activation domain of the bovine papillomavirus e2 protein mediates association of dna-bound dimers to form dna loops. | the e2 transactivator protein of bovine papillomavirus binds its specific dna target sequence as a dimer. we have found that e2 dimers, preformed in solution independent of dna, exhibit substantial cooperativity of dna binding as detected by both nitrocellulose filter retention and footprint analysis techniques. if the binding sites are widely spaced, e2 forms stable dna loops visible by electron microscopy. when three widely separated binding sites reside on the dna, e2 condenses the molecule i ... | 1991 | 1849647 |
| the papillomavirus e2 protein: a factor with many talents. | the products of the papillomavirus e2 open reading frame play a key role in the regulation of the viral cycle. e2 proteins can activate or repress viral promoters by several distinct mechanisms and viral dna replication requires the expression of the full-length e2 protein together with the product of the e1 open reading frame. this is an interesting example of how a single eukaryotic dna-binding protein has evolved to perform several different functions and it provides a valuable model system f ... | 1991 | 1663669 |
| studies on the transmission of viral disease via the co2 laser plume and ejecta. | while recent reports have noted the presence of viral dna sequences in the laser plume, no significant effort has been made to study transmission of the virus in vivo via airborne laser debris. studies were undertaken to identify potential hazards to operating room occupants in gynecologic laser surgery. aco2 laser in the continuous wave mode using a power density of 666 w/cm2 was fired through a 5-cm metal cylinder at virus-infected tissues. airborne particulate debris, 100-200 microns, was rem ... | 1990 | 2178190 |
| overexpressed human metallothionein iia gene protects chinese hamster ovary cells from killing by alkylating agents. | experiments were designed to detect survival advantages that cells gain by overexpressing metallothionein (mt). chinese hamster ovary k1-2 cells and an x-ray-sensitive derivative were transfected with a bovine papillomavirus (bpv)-linked construct carrying the human metallothionein iia (hmt-iia) gene. transfectants survived 40-fold higher levels of cadmium chloride, harbored at least 30 copies of hmt-iia, and contained 25- to 166-fold more mt than the parent cells. even under conditions of reduc ... | 1990 | 2320583 |
| detection of papillomaviruses in cutaneous fibromas of white-tailed and mule deer. | naturally occurring cutaneous fibromas affecting white-tailed deer (odocoileus virginianus) and mule deer (o hemionus), and cutaneous fibropapillomas of domestic cattle were tested for papillomavirus using indirect immunofluorescence (if), peroxidase-antiperoxidase (pap), and negative-stain electron microscopic techniques. papillomavirus was consistently detected using rabbit antiserum against papillomavirus group-specific antigen in all mule deer fibromas and bovine fibropapillomas; only 16 of ... | 1985 | 2408523 |
| positive and negative e2-independent regulatory elements in the long control region of bovine papillomavirus type 4. | the long control region (lcr) of bovine papilloma-virus type 4 demonstrated enhancer activity when cloned upstream of a bacterial chloramphenicol acetyltransferase reporter gene under thymidine kinase promoter control. deletion analysis of the lcr revealed the presence of several positive and negative control elements, all of which could function independently of the viral e2 trans-activator. each of the three positive elements present appeared to be paired with a negative element which modulate ... | 1991 | 1849970 |
| structures of bovine and human papillomaviruses. analysis by cryoelectron microscopy and three-dimensional image reconstruction. | the structures of bovine papillomavirus type 1 (bpv-1) and human papillomavirus type 1 (hpv-1) were determined at 2.5 nm resolution by cryoelectron microscopy and three dimensional image reconstruction techniques. as expected, the reconstructions showed that both viruses consist of a t = 7 icosahedral capsid (approximately 60 nm in diameter) which surrounds a nucleohistone core. the capsid morphologies of the two viruses are nearly indistinguishable. each capsid consists of a shell layer (approx ... | 1991 | 1663794 |
| analysis of pp60c-src protein kinase activity in hamster embryo cells transformed by simian virus 40, human adenoviruses, and bovine papillomavirus 1. | we have examined the effect of dna tumor virus transformation of primary hamster embryo cells on the tyrosyl kinase activity of pp60c-src. our present study demonstrates that some clones of hamster embryo cells transformed by simian virus 40, adenovirus type 2, adenovirus type 12, or bovine papillomavirus 1 can possess elevated pp60c-src kinase activity when compared with normal hamster embryo cells. however, other clones of hamster embryo cells transformed by these same viruses were found to ha ... | 1986 | 2416954 |
| [papilloma viruses: group-specific antigens within lesions of the oral mucosa]. | the present study was undertaken with purpose to investigate the relationships between intraepithelial proliferations of malpighian mucosa and the presence of group specific papilloma virus antigens. the investigations allowing to give viral types or subtypes, the hybridization technics, are very heavy and not disponible in routine practice. the detection of widely distributed genus specific hpv antigen using pap immunohistochemical labeling in different lesions and their association with displa ... | 1986 | 2421394 |
| a region immediately adjacent to the origin of replication of bovine papilloma virus type 1 interacts in vitro with the nuclear matrix. | we have investigated the interaction of the 69% transforming fragment of the bovine papilloma virus type 1 (bpv1) with the nuclear matrix from 1361.5 cells (nih-3t3 cells transformed by a bpv chimeric construct). in vitro studies performed with end-labelled dna fragments and nuclear matrices prepared using a high-salt extraction procedure demonstrate the binding of a 672 bp fragment adjacent to the viral origin of replication and containing the plasmid maintenance sequence (pms-1). this fragment ... | 1991 | 1850268 |
| in vitro methylation of bovine papillomavirus alters its ability to transform mouse cells. | bovine papillomavirus (bpv) was methylated in vitro at either the 29 hpaii sites, the 27 hhai sites, or both. methylation of the hpaii sites reduced transformation by the virus two- to sixfold, while methylation at hhai sites increased transformation two- to fourfold. dna methylated at both hpaii and hhai sites did not differ detectably from unmethylated dna in its efficiency of transformation. these results indicate that specific methylation sites, rather than the absolute level of methylated c ... | 1986 | 2431294 |
| transforming activity of bovine and human papillomaviruses in cultured cells. | | 1991 | 1851373 |