Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
|---|
| gene transfer of the cd80 costimulatory molecule into ocular melanoma cells using a novel episomal vector. | the cd80 (b7.1) molecule, which is a necessary costimulatory signal for t-cell activation and proliferation, is a powerful inducer of antitumor immunity. in this study, primary human ocular melanoma cells were transfected with a novel vector (b45-neo episomal vector) containing the complementary dna (cdna) for human cd80 to determine if this vector system is useful for stimulating cd8+ t cells. | 1997 | 9375572 |
| nmr-based discovery of lead inhibitors that block dna binding of the human papillomavirus e2 protein. | the e2 protein is required for the replication of human papillomaviruses (hpvs), which are responsible for anogenital warts and cervical carcinomas. using an nmr-based screen, we tested compounds for binding to the dna-binding domain of the hpv-e2 protein. three classes of compounds were identified which bound to two distinct sites on the protein. biphenyl and biphenyl ether compounds containing a carboxylic acid bind to a site near the dna recognition helix and inhibit the binding of e2 to dna. ... | 1997 | 9379433 |
| the bovine papillomavirus e6 protein binds to the ld motif repeats of paxillin and blocks its interaction with vinculin and the focal adhesion kinase. | the bovine papillomavirus type 1 (bpv-1) e6 oncoprotein can transform fibroblasts and induce anchorage-independent growth and disassembly of the actin stress fibers. we have previously shown that the e6 protein interacts with the focal adhesion protein, paxillin, suggesting a direct role of e6 in the disruption of the actin cytoskeleton. we have now mapped the e6 binding sites on paxillin to the ld motif repeats region, which has been implicated in mediating paxillin binding to two other focal a ... | 1997 | 9407131 |
| papillomaviruses: progress for human and veterinary medicine. | 1997 | 9414949 | |
| bovine papillomavirus and cancer. | bovine papillomavirus (bpv) induces papillomas of cutaneous or mucosal epithelia in cattle. the papillomas are benign tumours and generally regress, but occasionally persist and provide the focus for malignant transformation to squamous cell carcinoma, particularly in the presence of environmental cofactors. this has been experimentally demonstrated for bpv-2 and cancer of the urinary bladder, and bpv-4 and cancer of the upper alimentary canal in cattle feeding on bracken fern. in this review, s ... | 1997 | 9414951 |
| interaction of prion peptide huprp106-126 with nucleic acid. | synthetic prion peptide prp106-126 has been used as a model to understand prion diseases. the conformation of the peptide depends on the environmental conditions and it forms amyloid in vitro. the potential of this prion peptide to interact with nucleic acids has been studied using a fluorescent labelled nucleic acid by kinetic and equilibrium methods. a decrease in the fluorescence of the labelled dna induced by the peptide with time is observed which is ph, ionic strength and temperature depen ... | 1997 | 9672613 |
| human papillomavirus type 16 e5 protein (review). | the association of certain human papillomavirus (hpv) types with malignancies of the anogenital tract is well established. the virus type most frequently associated with cellular transformation is hpv 16, as has been shown in epidemiological studies. its transforming capacity has also been demonstrated in many in vitro cell transformation experiments. the most potent oncogenes of hpv 16 are the e6 and e7 proteins, but the e5 protein, whose homologue is the main oncogene of bovine papillomavirus, ... | 1997 | 21528338 |
| methods for the construction of human papillomavirus vectors. | a number of vector systems have been developed for the delivery of therapeutic genes into cells (1). many viral vectors suffer from the disadvantage of random integration into the chromosome, making the expression of the cloned genes dependent on the chromosomal context of the inserted dna. papillomaviruses (pvs) are potentially important vector systems because of their extrachromosomal replication in target cells. the pvs are small dna viruses that infect humans and a wide range of animals. hum ... | 1997 | 24493421 |
| antiapoptotic activity of bovine papilloma virus. | transformed fibroblasts have been recently shown to be sensitive for induction of apoptosis by tgf-beta-treated neighbouring untransformed cells. cells transformed by a variety of different transformation principles were regularly sensitive for intercellular induction of apoptosis, but fibroblasts transformed by bovine papillomavirus (bpv) represented a striking exception. in contrast to chemically transformed c127 cells, bpv-transformed c127 cells showed resistance against intercellular inducti ... | 1996 | 21541598 |
| bovine papillomavirus type 4. | papillomavirus induce benign tumours (papillomas) in a variety of animals. the papillomas generally regress but occassionally persist and may eventually progress to squamous cell carcinoma. one of the most extensively studies papillomaviruses is bovine papillomavirus type 4 (bpv4). bpv-4 induces papillomas of the upper alimentary canal which are at high risk of progressing to cancer in cattle eating bracken fern. in this review, several aspects of the biology of the virus are described and compa ... | 1996 | 21541627 |
| genetic analysis of the activation domain of bovine papillomavirus protein e2: its role in transcription and replication. | the bovine papillomavirus protein e2 serves dual functions in viral transcription and in the initiation of viral replication. as a transcription factor, e2 can cooperatively interact with cellular proteins such as sp1 and stimulate transcription of distal promoters. in replication, e2 and the helicase el are the only viral proteins required for accurate replication of templates containing the viral origin. the amino terminus of e2 is a functionally separable domain critical for activation of bot ... | 1996 | 8676438 |
| selection of the bovine papillomavirus type 1 nucleotide 3225 3' splice site is regulated through an exonic splicing enhancer and its juxtaposed exonic splicing suppressor. | alternative splicing is an important mechanism for the regulation of bovine papillomavirus type 1 (bpv-1) gene expression during the virus life cycle. however, one 3' splice site, located at nucleotide (nt) 3225, is used for the processing of most bpv-1 pre-mrnas in bpv-1-transformed c127 cells and at early to intermediate times in productively infected warts. at late stages of the viral life cycle, an alternative 3' splice site at nt 3605 is used for the processing of the late pre-mrna. in this ... | 1996 | 8676495 |
| simple procedure for creation of in-frame deletion mutations throughout an open reading frame. | a general method is presented for randomly mutagenizing open reading frames (orf) to generate in-frame deletions and insertions. the protocol requires expression of the orf of interest as a hybrid orf-beta-galactosidase fusion protein. this allows colorimetric screening for beta-galactosidase activity during subsequent mutagenesis steps. consequently, proteins with no suitable phenotypic selection or screening properties can be readily screened for mutations that disrupt and subsequently restore ... | 1996 | 8679203 |
| in vitro generation and type-specific neutralization of a human papillomavirus type 16 virion pseudotype. | we report a system for generating infectious papillomaviruses in vitro that facilitates the analysis of papillomavirus assembly, infectivity, and serologic relatedness. cultured hamster bphe-1 cells harboring autonomously replicating bovine papillomavirus type 1 (bpv1) genomes were infected with recombinant semliki forest viruses that express the structural proteins of bpv1. when plated on c127 cells, extracts from cells expressing l1 and l2 together induced numerous transformed foci that could ... | 1996 | 8709207 |
| transcriptional and replicational activation functions in the bovine papillomavirus type 1 e2 protein are encoded by different structural determinants. | a set of e2 proteins with mutations in the amino-terminal transactivation domain was made by a scheme called clustered charged-to-alanine scan. these mutant e2 proteins were tested for expression, stability, and compartmentalization in cells and for sequence-specific dna binding, as well as in functional assays for transcriptional and replicational activation. we identified four groups of mutants. first, mutants k111a, k112a, and e176a were unable to activate replication and transcription becaus ... | 1996 | 8709243 |
| bovine papillomavirus type 4 dna isolated from a skin lesion in a steer. | a lesion on the head of a steer, defined histologically as an epithelial papilloma, yielded dna which did not hybridise with any of the bovine papillomavirus dnas usually associated with the formation of skin lesions. dna from the lesion did hybridise with dna from bovine papillomavirus 4, even under stringent conditions, and contained a sequence that could be amplified by polymerase chain reaction with primers specific for that virus. bovine papillomavirus 4 had previously been isolated only fr ... | 1996 | 8733180 |
| vaccination of cattle with bovine papillomavirus type 4 l2 elicits the production of virus-neutralizing antibodies. | prophylactic vaccination of cattle with the n terminus (l2a, aa 11-200) of the minor capsid protein l2 completely prevented bovine papillomavirus type 4 (bpv-4) infection of the alimentary canal. to investigate the mechanisms underlying protection from viral infection, sera from vaccinated animals were analysed in neutralization assays both in the nude mouse xenograft system and in cattle. bpv-4 retained its infectivity when incubated with preimmune cattle sera, whereas, when incubated with immu ... | 1996 | 8758002 |
| characterization of the single-strand-specific bpv-1 origin binding protein, spsf i, as the hela pur alpha factor. | spsf i and ii are two cellular proteins which bind specifically to single-stranded dna. spsf i and ii binding sites are found in the minimal origin of replication of bpv-1 dna and near the p2 promoter of the cellular c-myc gene. dna-binding properties of the two proteins to single-stranded oligonucleotides of different lengths and sequences were quantified by determination of dna-binding constants. the binding constant of spsf proteins to the lower strand of the bpv-1 origin was determined to be ... | 1996 | 8759014 |
| transcriptional activation function is not required for stimulation of dna replication by bovine papillomavirus type 1 e2. | bovine papillomavirus type 1 replication was previously shown to require both the e1 initiator protein and the e2 transactivator protein. we show here that e1, in the absence of e2, is sufficient for low-level bovine papillomavirus type 1 dna replication in c-33a cells. in addition, studies of genetically isolated e2 point mutants demonstrate that enhancement of replication by e2 does not require its transcriptional activation function. the uncoupling of the e2 functions suggests that stimulatio ... | 1996 | 8794380 |
| surface conformational and linear epitopes on hpv-16 and hpv-18 l1 virus-like particles as defined by monoclonal antibodies. | a panel of 24 monoclonal antibodies (mabs) was generated against human papillomavirus (hpv) types 16 and 18 l1 virus-like particles (vlps). the mabs were screened for reactivity to a variety of vlps prepared from hpv-6, -11, -16, -18, -31, -33, -35, and -45, cottontail rabbit papillomavirus, bovine papillomavirus type 1, and a set of 35 overlapping 20-amino-acid peptides spanning the entire hpv-16 l1 gene. type-specific linear and conformational surface epitopes were detected as well as several ... | 1996 | 8806551 |
| carboxyl terminus of bovine papillomavirus type-1 l1 protein is not required for capsid formation. | the papillomavirus major capsid protein l1 can assemble into capsids in vitro. to identify areas within the bovine papillomavirus type-1 l1 (bpv l1) protein that are important for virus assembly, we constructed a set of 24 baculovirus recombinants expressing bpv l1 deletion mutants that span the entire l1 open reading frame. virus-like particle (vlp) formation of the l1 mutants was examined by electron microscopy. wild-type (wt) bpv l1 expressed in recombinant baculovirus formed vlps, while caps ... | 1996 | 8806558 |
| serologic association between human papillomavirus type 16 infection and esophageal cancer in shaanxi province, china. | the existence of large geographic variations in the prevalence of esophageal cancer in some countries, such as china, indicates that environmental risk factors may be important in the development of this disease. some studies have implicated genital-mucosal strains of human papillomaviruses (hpvs) in the etiology of this cancer. | 1996 | 8841021 |
| different arrangement of human papillomavirus e2 binding sites distinguishes cutaneous types from those associated with mucosal lesions. | high-risk-type human papillomavirus dna sequences are found in a high percentage of carcinomas from the uterine-cervix, with the viral e1-e2 gene region usually disrupted and the e6 and e7 oncoproteins consistently expressed. the e2 protein is known to repress early transcription from genital hpv promoters having a proximal e2 binding site (e2bs) close to the tata box. on the contrary, the e2 protein activates cutaneous early promoters having a longer distance between these sites. using an in vi ... | 1996 | 8854400 |
| status and transcriptional activity of a bovine-papillomavirus-i-based expression vector in a recombinant production cell line. | we have analysed the status and transcriptional activity of the bovine papillomavirus-i (complete bpv-i genome)-based expression vector pces in ci27i-cell-line-derived 3ti cells used for the industrial production of recombinant human erythropoietin (rhuepo). complete tandem head-to-tail integration of about 600 vector copies at a single site of the cellular genome was observed. deletions, insertions or rearrangements of pces-specific sequences or extrachromosomal copies of vector sequences were ... | 1996 | 8867900 |
| ebna1 and e2: a new paradigm for origin-binding proteins? | 1996 | 8868083 | |
| tumour suppressor gene p53 in the horse: identification, cloning, sequencing and a possible role in the pathogenesis of equine sarcoid. | the tumour suppressor protein p53 enhances the genetic stability of the cell and plays a critical role in tumour suppression. equine p53 was analysed by sequencing exons 5 to 9, a region which includes most known mutations and all the mutational hotspots in the species that have been investigated. the fragment was amplified, cloned and sequenced from genomic and complementary dna. a comparison of the predicted amino acid sequences between the horse and other species resulted in identities betwee ... | 1996 | 8880979 |
| the initiator protein e1 binds to the bovine papillomavirus origin of replication as a trimeric ring-like structure. | the replication initiator protein e1 binds to the origin of replication of bovine papillomavirus in several forms. e1 can bind to its recognition sequence as a monomer together with the viral transcription factor e2, or as a trimeric e1 complex. the trimerization of e1 is mediated by the sequence-specific binding of e1 to dna, and results in an e1 complex that is linked topologically to the dna because the three molecules of e1 form a ring-like structure that encircles the dna. these results dem ... | 1996 | 8890182 |
| enhanced transcriptional activation by e2 proteins from the oncogenic human papillomaviruses. | a systematic comparison of transcriptional activation by papillomavirus e2 proteins revealed that the e2 proteins from high-risk human papillomaviruses (human papillomavirus type 16 [hpv-16] and hpv-18) are much more active than are the e2 proteins from low-risk hpvs (hpv-6b and hpv-11). despite the tropism of hpvs for particular epithelial cell types, this difference in transcriptional activation was observed in a number of different epithelial and nonepithelial cells. the enhanced activities o ... | 1996 | 8892874 |
| e2 proteins: modulators of papillomavirus transcription and replication. | 1996 | 8902804 | |
| the e5 gene product of rhesus papillomavirus is an activator of endogenous ras and phosphatidylinositol-3'-kinase in nih 3t3 cells. | we examined the effect of two rhesus papillomavirus 1 (rhpv) oncogenes on cytokine-induced signal transduction pathways leading to the possible activation of ras protein (p21ras) and phosphatidylinositol kinase. p21ras in both the activated (gtp-bound) and inactivated (gdp-bound) states were quantitated. nih 3t3 cell lines expressing the rhpv 1 e5 gene or epidermal growth factor receptor cdna had about a sixfold higher ratio of p21ras-bound gtp to p21ras-bound gdp as compared with parental nih 3 ... | 1996 | 8917513 |
| bovine papillomavirus oncoprotein e5 induces the nf kappa b activation through superoxide radicals. | bovine papillomavirus type 1 (bpv-1) open reading frame e5 encodes the smallest known oncoprotein. this protein is involved in transforming cells during the early stage of infection. nuclear factor kappa b (nf kappa b) is activated in the host cells as a result of different virus infections. it has been shown that reactive oxygen intermediates activate nf kappa b which leads the activation of several cellular genes. we studied the effect of bpv-1 es protein on nf kappa b activation. we found tha ... | 1996 | 8950027 |
| conditional requirement for sequences distinct from the replication origin during episomal establishment of the bpv1 genome. | removal from bpv1 dna of a short segment (nt. 4786-5045) that contains several protein binding sites and is required for efficient replication in short term assays prevents its autonomous maintenance in cell lines established by selection in g418 medium after cotransfer of neo(r). in contrast, transformed cell lines established from foci, which express the viral genes at higher levels, maintain extrachromosomal copies of the deleted dna. two modes of maintenance of the viral genome are thus dist ... | 1996 | 8954917 |
| phenotypical characterization of lymphocytes infiltrating regressing papillomas. | papillomavirus-induced lesions often regress spontaneously in both humans and animals. papilloma regression is deemed to be due to a cell-mediated immune response, the nature of which is still ill defined, and is accompanied by immune cell infiltrates. to gain further information on the nature and role of the immune cells present in regressing papillomas, we have analyzed biopsies of papillomas induced in the soft palate of cattle by bovine papillomavirus type 4 (bpv-4) and have phenotypically c ... | 1996 | 8970967 |
| the bovine papillomavirus type 4 e8 protein binds to ductin and causes loss of gap junctional intercellular communication in primary fibroblasts. | the e8 open reading frame of bovine papillomavirus type 4 encodes a small hydrophobic polypeptide which contributes to cell transformation by conferring anchorage-independent growth. using an in vitro translation system, we show that the e8 polypeptide binds to ductin, the 16-kda proteolipid that forms transmembrane channels in both gap junctions and vacuolar h+-atpase. this association is not due to nonspecific hydrophobic interactions. ppa1, a saccharomyces cerevisiae polypeptide homologous (w ... | 1996 | 8971040 |
| e2 represses the late gene promoter of human papillomavirus type 8 at high concentrations by interfering with cellular factors. | the late gene promoter p7535 of the epidermodysplasia verruciformis-associated human papillomavirus type 8 (hpv8) is regulated by the viral e2 protein. transfection experiments performed with the human skin keratinocyte cell line rts3b and p7535 reporter plasmids revealed transactivation at low amounts and a repression of basal promoter activity at high amounts of e2 expression vector. this repression was promoter specific and correlated with the amount of transiently expressed e2 protein. mutat ... | 1996 | 8523515 |
| amino acids critical for the functions of the bovine papillomavirus type 1 e2 transactivator. | the n-terminal domain of the bovine papillomavirus type 1 e2 protein is important for viral dna replication, for transcriptional transactivation, and for interaction with the e1 protein. to determine which residues of this 200-amino-acid domain are important for these activities, single conservative amino acid substitutions have been generated in 17 residues that are invariant among all papillomavirus e2 proteins. the resulting mutated e2 proteins were tested for the ability to support viral dna ... | 1996 | 8523530 |
| the bovine papillomavirus type 1 e2 transactivator and repressor proteins use different nuclear localization signals. | the e2 gene of bovine papillomavirus type 1 encodes at least three nuclear phosphoproteins that regulate viral transcription and dna replication. all three proteins have a common c-terminal domain that has dna-binding and dimerization activities. a basic region in this domain forms an alpha helix which makes direct contact with the dna target. in this study, it is shown that in addition to its role in dna binding, this basic region functions as a nuclear localization signal both in the e2 dna-bi ... | 1996 | 8551571 |
| cis and trans requirements for stable episomal maintenance of the bpv-1 replicator. | papillomavirus genomes are maintained as multicopy nuclear plasmids in transformed cells. to address the mechanisms by which the viral dna is stably propagated in the transformed cells, we have constructed a cell line ch04.15 expressing constitutively the viral proteins e1 and e2, that are required for initiation of viral dna replication. we show that these viral proteins are necessary and sufficient for stable extrachromosomal replication. using the cell line ch04.15, we have shown that the bov ... | 1996 | 8598191 |
| the bpv-1 e2 dna-contact helix cysteine is required for transcriptional activation but not replication in mammalian cells. | the papillomavirus e2 protein contains an amino-terminal region thought necessary and sufficient to support transcriptional activation and a carboxy-terminal region shown to direct sequence-specific dna binding and dimerization. a cysteine residue in the center of the e2 dna recognition helix is highly conserved among papillomavirus e2 proteins. mutations of this cysteine in bovine papillomavirus type 1 e2 to serine and glycine resulted in proteins which failed to activate e2-dependent promoters ... | 1996 | 8599215 |
| stable expression of the reovirus mu2 protein in mouse l cells complements the growth of a reovirus ts mutant with a defect in its m1 gene. | reovirus mu2 protein was constitutively expressed in mammalian cells transfected with dicistronic constructs in which the reovirus m1 gene and the selectable neomycin-resistant gene (neo) were both driven by the same phosphoglycerate kinase promoter. translation of neo was initiated with the cap-independent translation initiation element from encephalomyocarditis virus. expression of mu2 protein was detected by mu2-specific antibody produced through immunization of rabbits with trp-e-mu2 fusion ... | 1996 | 8599234 |
| pituitary-specific chromatin structure of the rat prolactin distal enhancer element. | the location of target dna sequences within chromatin may affect the ability of trans-acting factors to bind cis-elements and regulate gene transcription. to examine the effect of chromatin structure on the ability of the estrogen-estrogen receptor complex (e2r) to bind its respective dna binding element within the rat prolactin (rprl) gene and modulate rprl gene expression, we have developed cell lines derived from the rprl-expressing (rprl+) rat pituitary cell line gh3 and the rprl-non- expres ... | 1996 | 8604340 |
| mapping of hpv-11 e1 binding site and determination of other important cis elements for replication of the origin. | the viral proteins e1 and e2 are essential for the replication of the hpv-11 origin. we have now mapped the e1 binding site (e1bs) and show by mutation analysis that the e1bs and an adjoining poly(a)-rich region are necessary for efficient replication of the origin. we have also shown, using suboptimal levels of e1 protein, that enhancement of e1 binding by e2 partially protects the e1bs. finally, we show that e1 can enhance the binding of e2 even in the absence of the e1bs. | 1996 | 8614991 |
| arsenic and chromium enhance transformation of bovine papillomavirus dna-transfected c3h/10t1/2 cells. | tumor promoters such as phorbol esters, teleocidin and okadaic acid increase the numbers of multilayered, transformed foci produced by bpv dna-transfected c3h/10t1/2 cells. we questioned whether arsenic and chromium, which are known human carcinogens also enhance transformation of bpv dna-transfected c3h/10t1/2 cells. cr(iii) potassium sulfate at 100 microm enhanced transformation by 1.4-fold, but cr(vi) as potassium chromate did not enhance transformation, although toxicity of potassium chromat ... | 1996 | 8616810 |
| perturbation of the host cell cycle and dna replication by the bovine papillomavirus replication protein e1. | a stable cell line expressing the bovine papillomavirus e1 protein (c2e1) was compared with an e1 minus control line (cneo) to study the effects of e1 protein on host cell growth. c2e1 and cneo cells were synchronized either at mitosis or at the g1/s boundary by the cell cycle inhibitors nocodazole and mimosine, respectively. after release from the drug-induced cell cycle block, the progression through the succeeding stages of the cell cycle was temporally monitored using flow cytometry. in addi ... | 1996 | 8623531 |
| virus-like particles of bovine papillomavirus type 4 in prophylactic and therapeutic immunization. | virus-like particles were produced in insect cells containing either the l1 and l2 capsid proteins of bovine papillomavirus type 4 (bpv-4) or only the l1 protein. both preparations of vlps proved to be extremely effective prophylactic vaccines. thirteen of 15 calves immunised with either l1-l2 vlps or l1-vlps were refractory to experimental challenge with high doses of bpv-4 and did not develop papillomas, while 9 of 10 control animals developed multiple oral papillomas. vlps were not efficient ... | 1996 | 8623552 |
| antigenicity of bovine papillomavirus type 1 (bpv-1) l1 virus-like particles compared with that of intact bpv-1 virions. | virus-like-particles (vlps) of various papillomavirus (pv) types have been produced by expressing recombinant l1 proteins in eukaryotic cells. although vlps have the same ultrastructural appearance as native virions and their immunogenicity appears to be similar, their antigenicity has not been carefully evaluated. for this reason, the antigenicity of intact bovine pv type 1 (bpv-1) virions was compared with that of bpv-1 recombinant l1 vlps by elisa using a well-characterized panel of polyclona ... | 1996 | 8627221 |
| sp1 is critical for basal and e2-transactivated transcription from the bovine papillomavirus type 1 p89 promoter. | the bovine papillomavirus type 1 (bpv-1) long control region (lcr) contains at least three consensus binding sites for the transcription factor sp1 at nucleotides (nt) 7800, 7833 and 7854. a high basal-level p89 expression vector consisting of an origin-deleted lcr fused to the chloramphenicol acetyltransferase (cat) gene was utilized to determine the role of these sp1 sites in the regulation of transcription from the bpv-1 p89 promoter. the three sp1 sites were capable of binding sp1 in vitro. ... | 1996 | 8627222 |
| activation of the endogenous p53 growth inhibitory pathway in hela cervical carcinoma cells by expression of the bovine papillomavirus e2 gene. | we previously showed that expression of the bovine papillomavirus (bpv) e2 gene results in a dramatic inhibition of the proliferation of several human cervical carcinoma cell lines, including hela cells which contain human papillomavirus (hpv) type 18 dna. we have assessed the status of endogenous g1 cell cycle regulatory proteins, including the tumor suppressor proteins, p53 and p105rb, in order to investigate growth regulatory pathways in hela cells following e2 expression. the p53 tumor suppr ... | 1996 | 8632901 |
| status and transcriptional activity of a bovine-papillomavirus-i-based expression vector in a recombinant production cell lines. | 1996 | 8639276 | |
| e5 oncoprotein transmembrane mutants dissociate fibroblast transforming activity from 16-kilodalton protein binding and platelet-derived growth factor receptor binding and phosphorylation. | the e5 oncoprotein of bovine papillomavirus type 1 is a 44-amino-acid, hydrophobic polypeptide which localizes predominantly in golgi membranes and appears to transform cells through the activation of tyrosine kinase growth factor receptors. in fibroblasts, e5 interacts with both the 16-kilodalton vacuolar atpase subunit and the platelet-derived growth factor receptor (pdgf-r) via its hydrophobic transmembrane domain and induces autophosphorylation of the receptor. to further analyze the correla ... | 1996 | 8642670 |
| the human t-cell leukemia/lymphotropic virus type 1 p12i proteins bind the interleukin-2 receptor beta and gammac chains and affects their expression on the cell surface. | p12i is a small hydrophobic protein encoded by the human t-cell leukemia/lymphotropic virus type 1 (htlv-1) that interacts with the 16-kda component of the h+ vacuolar atpase and cooperates with bovine papillomavirus 1 e5 oncoprotein in cell transformation. just as an important step in e5 action appears to be its binding to the platelet-derived growth factor receptor, it was found that p12i binds specifically to both the beta and gamma(c) chains of the interleukin-2 receptor (il-2r). the il-2r b ... | 1996 | 8648694 |
| solution structure of the dna-binding domain of a human papillomavirus e2 protein: evidence for flexible dna-binding regions. | the three-dimensional structure of the dna-binding domain of the e2 protein from human papillomavirus-31 was determined by using multidimensional heteronuclear nuclear magnetic resonance (nmr) spectroscopy. a total of 1429 nmr-derived distance and dihedral angle restraints were obtained for each of the 83-residue subunits of this symmetric dimer. the average root mean square deviations of 20 structures calculated using a distance geometry-simulated annealing protocol are 0.59 and 0.90 angstroms ... | 1996 | 8652551 |
| conserved features in papillomavirus and polyomavirus capsids. | 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 ... | 1996 | 8656427 |
| genetic analysis of the bovine papillomavirus e2 transcriptional activation domain. | the bovine papillomavirus type 1 e2 transactivator has a large amino-terminal 215-residue transcriptional activation domain (tad) that is active in saccharomyces cerevisiae and higher eukaryotic cells. comparison to other transcriptional activators suggests that its functions may be mediated in part through two acidic regions, a1 and a2, in this domain. we have characterized the functional elements within the e2 tad using lexa-e2 fusions and by screening randomly generated libraries of e2 mutati ... | 1996 | 8661412 |
| the transactivation and dna binding domains of the bpv-1 e2 protein have different roles in cooperative origin binding with the e1 protein. | the bovine papillomavirus e2 transactivator protein enhances the ability of the e1 protein to bind to the viral origin of replication which contains an e1 binding site flanked by two e2 binding sites. to determine which regions and functions of the e2 protein are important for this cooperative interaction, a series of mutated e2 proteins were assayed for their ability to enhance e1 origin-specific binding. cooperative origin binding required at least one e2 dna binding site, an intact functional ... | 1996 | 8661413 |
| swelling and ca2+-activated anion conductances in c127 epithelial cells expressing wt and delta f508-cftr. | cftr is a chloride channel that is required for fluid secretion and salt absorption in many exocrine epithelia. mutations in cftr cause cystic fibrosis. cftr expression influences some ion channels, but the range of channels influenced, the mechanism of the interaction and the significance for cystic fibrosis are not known. possible interactions between cftr and other ion channels were studied in c127 mouse mammary epithelial cell lines stably transfected with cftr, delta f508-cftr, or vector. c ... | 1996 | 8661514 |
| [specific serologic studies with a novel authentic hpv antigen (virus-like particles) for hpv-6 antibodies in gynecologic patient samples]. | a serological assay for genital hpv infection would provide important additional information to hpv dna diagnostic methods, since it would evaluate prior exposure to the viruses, detect significant systemic immunologic response to virus infection, and could be performed in most clinical laboratories. | 1995 | 8672922 |
| co-operative interaction between the initiator e1 and the transcriptional activator e2 is required for replicator specific dna replication of bovine papillomavirus in vivo and in vitro. | the e1 polypeptide from bovine papillomavirus binds to the origin of replication (ori) and possesses the activities attributed to initiator proteins. e1 is also the only viral protein required for replication in a cell-free replication system. replication in vivo, however, absolutely requires in addition the viral transcription factor e2. we demonstrate that the basis for this distinction between in vitro and in vivo requirements is the limited sequence specificity of the e1 protein. e1 and e2, ... | 1995 | 8557041 |
| bpv e1 protein alters the kinetics of cell cycle entry of serum starved mouse fibroblasts. | a stable bovine papillomavirus e1 expressing cell line (c2e1) was used to investigate the effects of e1 protein on the requirement for growth factors during serum-induced reentry from quiescence to proliferation. flow cytometric bivariate dna/pcna analysis was utilized to study the expression of proliferating cell nuclear antigen (pcna) concomitant with this transition. c2e1 cells, unlike the control cells (cneo), were able to reenter the cell cycle when stimulated with low serum (1%). stimulati ... | 1995 | 8582248 |
| [bovine papillomavirus vector]. | 1995 | 8584697 | |
| early phase in the infection of cultured cells with papillomavirus virions. | the fate of full bovine papillomavirus (bpv) virions and virus-like particles after binding to c127 or cv-1 cells was studied by electron microscopy and indirect immunofluorescence. after incubation at 4 degrees for 1 hr, bpv virions were found to be bound to the plasma membrane, and most viruses were absorbed by the cells after 30 min incubation at 37 degrees. ninety minutes after the virions had been bound to the plasma membrane, the uptake of the virions was completed and most of the antigen ... | 1995 | 8525612 |
| bovine papillomavirus type 4 in australia. | 1995 | 8534233 | |
| the atp-binding and atpase activities of human papillomavirus type 16 e1 are significantly weakened by the absence of prolines in its atp-binding domain. | the e1 protein of human papillomavirus (hpv) type 16 is the only known papillomavirus e1 which does not contain any proline residues in the phosphate-loop (p-loop) of its atp-binding site. to ascertain whether this feature influences the activities of hpv-16 e1, we generated a mutant hpv-16 e1 (e1pro) in which prolines are inserted in place of alanines in this site, making the p-loop identical to its bovine papillomavirus type 1 counterpart. glutathione s-transferase (gst) fusion proteins (gste1 ... | 1995 | 8847499 |
| mutations in the human papillomavirus type 16 e2 protein identify a region of the protein involved in binding to e1 protein. | papillomavirus dna replication is primarily dependent upon two viral gene products, e1 and e2. work with bovine papillomavirus has shown that the e2 protein can bind directly to the e1 protein and enhance the binding of e1 to the viral origin of replication. however, little is known about the mechanism of interaction between e1 and e2 proteins. in this study we have analysed in detail the association between human papillomavirus type 16 (hpv-16) e1 and e2 proteins. using a purified glutathione s ... | 1995 | 9049327 |
| transgenic models for papillomavirus-associated multistep carcinogenesis. | to investigate the physiological and pathological in vivo functions of molecularly cloned genes, the transgenic mouse is one of the most useful experimental animal systems. many kinds of transgenic mice carrying papillomavirus genes have been produced, and the studies have revealed several new aspects in the field of papillomaviral oncology. among these transgenic mice, the mechanism of skin carcinogenis in the bovine papillomavirus (bpv) transgenic mouse has been well characterized, demonstrati ... | 1995 | 8682614 |
| a high capacity assay for inhibitors of human papillomavirus dna replication. | the discovery of antiviral compounds against human papillomaviruses (hpv) has been hindered by the difficulties in culturing virus in vitro or assaying stable hpv dna replication. however, plasmids containing the hpv replication origin replicate transiently upon co-transfection with hpv e1 and e2 expression vectors. we have adapted this assay using secreted alkaline phosphatase (sap) as a reporter for rapid analysis of dna copy number. use of the sv40 early promoter in controlling sap expression ... | 1995 | 9636294 |
| disparate replication properties of integrated and extrachromosomal forms of bovine papilloma virus in id13 cells. | bovine papillomavirus (bpv) previously has been reported to exist in transformed rodent cell lines as both chromosomally integrated and extrachromosomal forms. in the bpv-transformed mouse cell line id13, extrachromosomal bpv molecules replicate throughout s phase of the cell cycle in a random choice mode. we report here that these replication properties were altered for chromosomally integrated bpv dna in five independent id13 subclones. in all of the subclones, the integrated bpv sequences, wh ... | 1995 | 7490737 |
| transformed mouse cell lines that consist predominantly of cells maintaining bovine papilloma virus at high copy number. | rare cells that contain large amounts of bovine papilloma virus (bpv) dna have been observed in populations of bpv-transformed mouse id13 cells. the viral dna molecules in these "jackpot cells" have been thought to have switched from the controlled replication typical of latent bpv infection to the uncontrolled "runaway" prelytic replication characteristic of terminal stage infection of bovine epidermal cells. by sequential subcloning of high-bpv derivatives of id13, we isolated stable cell line ... | 1995 | 7491777 |
| replication efficiency of bovine papillomavirus type 1 dna depends on cis-acting sequences distinct from the replication origin. | the viral elements required for the initiation of replication of bovine papillomavirus type 1 dna include the origin region and two trans-acting factors, the e1 and e2 proteins. we now report that the replication efficiency of a dna molecule which contains these three elements is modulated by other viral sequences. by measuring the extent of replication of deleted viral genomes in transfected mouse cells, we identified sequences required for maximal efficiency. addition of these sequences to a c ... | 1995 | 7494277 |
| suppression of cellular proliferation by the papillomavirus e2 protein. | carcinogenic progression of a human papillomavirus (hpv)-infected cell is often associated with integration of the viral genome in a manner which results in the loss of expression of the viral regulatory protein e2. one function of e2 is the regulation of expression of the viral oncogenes, e6 and e7. introduction of the bovine papillomavirus type 1 (bpv-1) e2 transactivator (e2-ta) in hela cells, an hpv type 18 (hpv-18)-positive cervical carcinoma cell line results in growth arrest. in this stud ... | 1995 | 7494290 |
| cellular factors required for papillomavirus dna replication. | in vitro replication of papillomavirus dna has been carried out with a combination of purified proteins and partially purified extracts made from human cells. dna synthesis requires the viral e1 protein and the papillomavirus origin of replication. the e2 protein stimulates dna synthesis in a binding site-independent manner. papillomavirus dna replication is also dependent on the cellular factors replication protein a, replication factor c, and proliferating-cell nuclear antigen as well as a pho ... | 1995 | 7494298 |
| antibodies against linear and conformational epitopes of human papillomavirus type 16 that independently associate with incident cervical cancer. | in a seroepidemiological study of incident cervical cancer, 94 cases and 188 population-based controls were used to evaluate the disease-association of igg and iga antibody responses against 6 human papillomavirus (hpv) type-16 antigens. nine of the tested antibody responses were positively associated with cervical cancer, with odds ratios (ors) ranging from 2.5 to 15.0. the antibody responses most strongly associated with cervical cancer were iga against e6:10, an epitope derived from the carbo ... | 1995 | 7530234 |
| t cell responses to bpv-4 e7 during infection and mapping of t cell epitopes. | vaccination of cattle with the recombinant e7 protein of bovine papillomavirus type 4 (bpv-4) prior to bpv-4 infection has been shown to retard development of papillomas and accelerate their regression. to understand the mechanism of regression we have measured proliferation of peripheral blood mononuclear cells (pbm) to e7 in vitro during the course of bpv-4 infection in both vaccinated and nonvaccinated cattle. in vaccinated cattle, t cells specific for e7 could be detected at high levels shor ... | 1995 | 7530395 |
| association of serum immunoglobulin g antibodies against human papillomavirus type 16 capsids with anal epidermoid carcinoma. | anal epidermoid carcinoma is a relatively rare tumor, but its incidence has been increasing rapidly during the past few years. genetic material from the major oncogenic types of human papillomavirus (hpv), types 16 and 18, has regularly been demonstrated in a substantial proportion of anal cancers, suggesting an etiologic role of hpv infection. recently, serum antibodies against hpv type 16 capsids were shown to be a serologic measure of hpv16 infection. | 1995 | 7532227 |
| human papillomavirus type 16 capsids expose multiple type-restricted and type-common antigenic epitopes. | the study of viral infectivity and detection of viral capsid antigens of the major cervical cancer-associated human papillomavirus (hpv) type, hpv-16, requires knowledge of which epitopes are exposed in clinical specimens of infected tissue or on intact capsids. to define the antigenic epitopes of hpv-16, antisera to 66 overlapping synthetic peptides corresponding to the hpv-16 capsid proteins l1 and l2 and to seven peptide analogues were tested in immunoperoxidase stainings of consecutive secti ... | 1995 | 7537325 |
| papillomavirus l1 capsids agglutinate mouse erythrocytes through a proteinaceous receptor. | virus-like particles (vlps) composed of l1 derived from bovine papillomavirus type 1 (bpv-1), several human papillomavirus types, or cottontail rabbit papillomavirus (crpv) agglutinated mouse but not human or rat erythrocytes. treatment of mouse erythrocytes with trypsin prevented hemagglutination (ha) by bpv-1. sera from rabbits immunized with native crpv vlps, which protect against experimental crpv infection, exhibited high titers of antibodies that inhibited crpv vlp ha activity, while sera ... | 1995 | 7541848 |
| induction of neutralizing antibodies to papillomaviruses by anti-idiotypic antibodies. | anti-idiotypic antibodies (anti-ids) were generated against three mouse monoclonal antibodies (mabs) which neutralized three different papillomaviruses. the neutralizing mabs (n-mabs) were generated against infectious human papillomavirus type 11 (hpv-11), cottontail rabbit papillomavirus (crpv), and bovine papillomavirus type 1 (bpv-1), and all recognized surface conformational epitopes that were lost upon denaturation of the virions. the polyclonal anti-ids were screened in an elisa using a pa ... | 1995 | 7542415 |
| serum igg, igm, and iga reactivity to human papillomavirus types 11 and 6 virus-like particles in different gynecologic patient groups. | serum samples from several groups of patients attending a gynecology clinic were analyzed by elisa for specific antibodies recognizing surface epitopes on intact human papillomavirus (hpv) types 6 and 11 l1 virus-like particles (vlps) that were synthesized in vitro. in these samples, positive igg and igm reactivities to hpv-11 l1 vlps were, respectively, 12% and 6% for 87 controls, 46% and 67% for 79 condyloma patients, 30% and 64% for 72 cervical intraepithelial neoplasia patients, 16% and 19% ... | 1995 | 7542685 |
| mutational analysis of the interaction between the bovine papillomavirus e5 transforming protein and the endogenous beta receptor for platelet-derived growth factor in mouse c127 cells. | the bovine papillomavirus e5 protein is a 44-amino-acid membrane-associated protein that forms a stable complex with the endogenous platelet-derived growth factor (pdgf) beta receptor in rodent and bovine fibroblasts, resulting in sustained receptor activation and cell transformation. we report here that high-level expression of the e5 protein caused a reduction in the level of the mature form of the pdgf beta receptor in acutely and stably transformed mouse c127 cells. to explore in more detail ... | 1995 | 7543592 |
| vaccination of cattle with the n-terminus of l2 is necessary and sufficient for preventing infection by bovine papillomavirus-4. | we have previously shown that cattle vaccinated with l2, the minor structural protein of bovine papillomavirus-4 (bpv-4), do not develop alimentary papillomas upon challenge with bpv-4. analysis of the b and t cell response in l2-vaccinated animals showed that the majority of the response was directed against the n-terminus and c-terminus of l2 with little response against the middle portion. cattle were vaccinated with the n-terminus or the c-terminus of l2. the animals vaccinated with the n-te ... | 1995 | 7544045 |
| organization of the major and minor capsid proteins in human papillomavirus type 33 virus-like particles. | the organization of the major (l1) and minor (l2) proteins in the human papillomavirus capsid is still largely unknown. in this study we analysed the disulphide bonding between l1 proteins and the association of l2 proteins with capsomers using virus-like particles obtained in insect cells by co-expression of the l1 and l2 genes of human papillomavirus type 33. about 50% of the l1 protein molecules in these particles (1.29 g/cm3) formed disulphide-bonded trimers. reduction of the intermolecular ... | 1995 | 7561785 |
| association of serum antibodies against defined epitopes of human papillomavirus l1, e2, and e7 antigens and of hpv dna with incident cervical cancer. | in order to provide a large-scale evaluation of the association with cervical cancer of antibodies against human papillomavirus (hpv) antigens, sera from 233 patients with primary, untreated cervical cancer and from 157 healthy age- and sex-matched blood donors were analyzed for igg and iga antibodies against hpv-derived peptide antigens and against bovine papillomavirus. several serological responses were strongly associated with cervical cancer, notably the igg response against the hpv 16 epit ... | 1995 | 7585724 |
| the functions of human papillomavirus type 11 e1, e2, and e2c proteins in cell-free dna replication. | we examined the functions of human papillomavirus type 11 (hpv-11) e1 and e2 proteins purified from sf9 cells infected with recombinant baculoviruses in cell-free hpv-11 origin (ori) replication. the e1 protein binds specifically to a wild type but not to a mutated sequence in the ori spanning nucleotide position 1. it also has a relatively strong affinity for nonspecific dna. a neutralizing antiserum directed against the amino-terminal one-third of the e1 protein totally abolishes initiation an ... | 1995 | 7592989 |
| e5 oncoprotein retained in the endoplasmic reticulum/cis golgi still induces pdgf receptor autophosphorylation but does not transform cells. | the e5 oncoprotein encoded by bovine papillomavirus type 1 is a homodimeric, hydrophobic polypeptide which is localized predominantly in golgi membranes and which transforms several cell types apparently by inducing tyrosine phosphorylation of the platelet-derived growth factor receptor (pdgf-r). while the precise mechanism of receptor activation is unknown, e5 associates with several cellular proteins, including pdgf-r and the 16k v-atpase protein, and induces the preferential phosphorylation o ... | 1995 | 7621820 |
| interaction of papillomavirus e6 oncoproteins with a putative calcium-binding protein. | human papillomaviruses (hpvs) are associated with the majority of cervical cancers and encode a transforming protein, e6, that interacts with the tumor suppressor protein p53. because e6 has p53-independent transforming activity, the yeast two-hybrid system was used to search for other e6-binding proteins. one such protein, e6bp, interacted with cancer-associated hpv e6 and with bovine papillomavirus type 1 (bpv-1) e6. the transforming activity of bpv-1 e6 mutants correlated with their e6bp-bind ... | 1995 | 7624774 |
| sequence similarities between latent membrane protein lmp-1 of epstein-barr virus, integral membrane protein p12i of human t cell leukemia/lymphotropic virus type 1, e5 transformation protein of bovine papillomavirus, and the transmembrane proteins of slowly transforming retroviruses. | 1995 | 7632458 | |
| the synergism between bovine papillomavirus type 4 and quercetin is dependent on the timing of exposure. | exposure to the flavonoid quercetin and transfection with bovine papillomavirus type 4 (bpv-4) dna lead to oncogenic transformation of primary bovine cells. here we show that the synergism between quercetin and bpv-4 (or its e7 oncogene) is stronger the shorter the interval between the two treatments. quercetin immortalizes transformed cells, confers anchorage-independent growth and induces tumorigenicity in cells transfected only with the e7 oncogene. | 1995 | 7634432 |
| mapping of the intermolecular association of human t cell leukaemia/lymphotropic virus type i p12i and the vacuolar h+-atpase 16 kda subunit protein. | the p12i protein, a small hydrophobic protein encoded by the human t cell leukaemia/lymphotropic virus type i px region, contains a proline-rich region located between two putative transmembrane (tm) domains. the p12i protein is associated with cellular endomembranes, and physically binds to the 16 kda subunit of the vacuolar h+-atpase proton pump. to investigate the nature of the 16 kda and p12i interaction and to determine the oncogenic domain of p12i, we constructed p12i mutant proteins in wh ... | 1995 | 7636472 |
| failure of the bovine papillomavirus to transform mouse embryo fibroblasts with a targeted disruption of the insulin-like growth factor i receptor genes. | mouse embryo cells with a targeted disruption of the insulin-like growth factor i receptor (igf-ir) genes (r- cells) are refractory to transformation by the simian virus 40 large t antigen and/or an activated and overexpressed ras, both of which readily transform cells from wild-type littermate embryos and other 3t3-like cells. r- cells are also refractory to transformation induced by overexpressed epidermal growth factor receptor and platelet-derived growth factor receptor beta. since the plate ... | 1995 | 7636972 |
| domains of the bpv-1 e1 replication protein required for origin-specific dna binding and interaction with the e2 transactivator. | the viral e1 and e2 proteins are required for replication of bovine papillomavirus type 1 dna. both proteins bind as a complex to the replication origin, which consists of an e1 binding site flanked on either side by e2 binding sites. the e1 protein has properties common to replication initiator proteins such as sequence-specific origin binding and dna helicase activities. the e2 protein is a transcriptional transactivator that forms a complex with the e1 protein and enhances binding of e1 to th ... | 1995 | 7645243 |
| transitional cell carcinoma of the bladder: low incidence of human papillomavirus dna detected by the polymerase chain reaction and in situ hybridization. | viral studies on mammalian urothelium have shown an association between the bovine papillomavirus and cancer of the bladder in cattle. however, the evidence for human papillomavirus (hpv) involvement in urinary bladder in man is less clear. the aim of this study was to investigate the association between hpv dna and transitional cell carcinoma of the bladder, using the highly sensitive polymerase chain reaction (pcr) and non-isotopic dna in situ hybridization of formalin-fixed paraffin-embedded ... | 1995 | 7665148 |
| both viral e2 protein and the cellular factor pebp2 regulate transcription via e2 consensus sites within the bovine papillomavirus type 4 long control region. | the bovine papillomavirus type 4 (bpv4) long control region (lcr) contains three consensus binding sites, e2(1), e2(2), and e2(3) (accn6ggt), for the viral e2 transcription factor and a fourth degenerate site, de2 (atcn6ggt), which lies 3 bp upstream of e2(3). the e2(2) site was found to bind the cellular transcription factor pebp2, and mutations at this site reduced basal promoter activity by as much as 60%, indicating an important role for pebp2 in lcr function. mutation of the e2(3) or de2 si ... | 1995 | 7666508 |
| bovine papillomavirus type 1 e2 transcriptional regulators directly bind two cellular transcription factors, tfiid and tfiib. | the bovine papillomavirus type 1 (bpv-1) e2 translational open reading frame encodes three proteins that regulate viral transcription and dna replication: the e2 transcriptional activator (e2ta), the e2 transcriptional repressor (e2tr) and the e8/e2 transcriptional repressor (e8/e2tr). e2ta is a strong activator of papillomaviral promoters and is required for viral dna replication. e2tr and e8/e2tr inhibit the activities of e2ta but also possess weak transactivational properties of their own. tw ... | 1995 | 7666533 |
| mutational analysis of the beta-type platelet-derived growth factor receptor defines the site of interaction with the bovine papillomavirus type 1 e5 transforming protein. | the e5 polypeptide of bovine papillomavirus type 1 is a small membrane-bound protein which induces the transformation of immortalized fibroblasts, apparently via the formation of a ternary complex with the platelet-derived growth factor receptor (pdgfr) and the 16-kda v-atpase protein. this interaction seems to be mediated, at least in part, by their respective transmembrane domains. e5 also cooperates with transfected beta pdgfr to induce interleukin-3 (il-3)-independent growth of a mouse myelo ... | 1995 | 7666552 |
| mutational analysis of the 18-base-pair inverted repeat element at the bovine papillomavirus origin of replication: identification of critical sequences for e1 binding and in vivo replication. | replication of bovine papillomavirus requires two viral proteins, e1 and e2-ta. previously we demonstrated that sequences within an imperfect 18-bp inverted repeat (ir) element were sufficient to confer specific binding of the e1 protein to the origin region (s. e. holt, g. schuller, and v. g. wilson, j. virol. 68:1094-1102, 1994). to identify critical nucleotides for e1 binding and origin function, a series of individual point mutations was constructed at each nucleotide position in the 18-bp i ... | 1995 | 7666554 |
| differentiation-specific alternative splicing of bovine papillomavirus late mrnas. | activation of the late promoter (pl) of bovine papillomavirus type 1 (bpv-1) is dependent on the differentiation state of keratinocytes and occurs in the upper layers of the bovine fibropapilloma. in this study, we show by in situ hybridization that a differentiation-specific pattern of bpv-1 late rna splicing is also seen in the fibropapilloma. rnas containing the 7385/3605 and 3764/5609 splice junctions were confined to the granular cell layer. in contrast, rnas containing the 7385/3225 splice ... | 1995 | 7666558 |
| bovine papillomavirus e1 protein can, by itself, efficiently drive multiple rounds of dna synthesis in vitro. | bovine papillomavirus e1 protein was found to be as efficient as the simian virus 40 large t antigen in initiating dna synthesis in a cell-free system derived from cos1 cells. multiple rounds of dna synthesis occur, initiated at the bovine papillomavirus type 1 origin. therefore, e1 functions in vitro as a lytic virus initiator. | 1995 | 7707551 |
| inactivation of papillomavirus by low concentrations of povidone-iodine. | a recent report by hermonat et al showed that nonoxynol 9 is completely inactive against bovine papillomavirus, which is very closely related to human papillomavirus. finding a vaginal microbicide active against human papillomavirus to reduce the risk of sexual transmission of human papillomavirus would be desirable. | 1995 | 7709321 |
| dna polymerase delta holoenzyme: action on single-stranded dna and on double-stranded dna in the presence of replicative dna helicases. | dna polymerase delta requires proliferating cell nuclear antigen and replication factor c to form a holoenzyme efficient in dna synthesis. we have analyzed three different aspects of calf thymus dna polymerase delta holoenzyme: (i) analysis of pausing during dna synthesis, (ii) replication of double-stranded dna in the absence of additional factors, and (iii) replication of double-stranded dna in the presence of the two known replicative dna helicases from simian virus 40 and bovine papilloma vi ... | 1995 | 7711022 |
| bovine papillomavirus type 1 e1 atpase activity does not depend on binding to dna nor to viral e2 protein. | replication of bovine papillomavirus type 1 (bpv-1) dna has been shown to require two viral proteins known to interact in a molecular complex: e2, a transcription activator, and e1, another nuclear phosphoprotein, which binds to the replication origin and for which helicase/atpase activities have previously been reported. here we characterize the bpv-1 e1 atpase activity. in contrast to seo et al. (proceedings of the national academy of sciences, usa, 90, 702-706, 1993), we were able to detect t ... | 1995 | 7730798 |