pinecone/core-2020-05-10-deduplication huggingface dataset:
Human Herpesvirus-8 Glycoprotein B Interacts with Epstein–Barr Virus (EBV) Glycoprotein 110 but Fails to Complement the Infectivity of EBV Mutants

AbstractTo characterize human herpesvirus 8 (HHV-8) gB, the open reading frame was PCR amplified from the HHV-8-infected cell line BCBL-1 and cloned into an expression vector. To facilitate detection of expressed HHV-8 gB, the cytoplasmic tail of the glycoprotein was tagged with the influenza hemagglutinin (HA) epitope. Expression of tagged HHV-8 gB (gB-HA), as well as the untagged form, was readily detected in CHO-K1 cells and several lymphoblastoid cell lines (LCLs). HHV-8 gB-HA was sensitive to endoglycosidase H treatment, and immunofluorescence revealed that HHV-8 gB-HA was detectable in the perinuclear region of CHO-K1 cells. These observations suggest that HHV-8 gB is not processed in the Golgi and localizes to the endoplasmic reticulum or nuclear membrane. Because both HHV-8 and EBV are γ-herpesviruses, the ability of HHV-8 gB to interact with and functionally complement EBV gp110 was examined. HHV-8 gB-HA and EBV gp110 co-immunoprecipitated, indicating formation of hetero-oligomers. However, HHV-8 gB-HA and HHV-8 gB failed to restore the infectivity of gp110-negative EBV mutants. These findings indicate that although HHV-8 gB and EBV gp110 have similar patterns of intracellular localization and can interact, there is not sufficient functional homology to allow efficient complementation
Recombinant Human Respiratory Syncytial Virus (RSV) from cDNA and Construction of Subgroup A and B Chimeric RSV

AbstractInfectious human respiratory syncytial virus (RSV) was produced from a cDNA clone that contains 15,222 nucleotides of RSV genome derived from the A2 strain of subgroup A. Recovery of infectious RSV from cDNA required cotransfection of only three expression plasmids encoding the nucleoprotein (N), the phosphoprotein (P), and the major polymerase protein (L). Inclusion of the M2–1 plasmid was not required in the transfection reaction and if included did not significantly increase the rescue efficiency. However, a single nucleotide substitution in the RSV leader region (C to G at position 4 in the antigenomic sense), greatly increased the amount of infectious virus recovered from cDNA. A recombinant RSVA2 virus that expresses an additional structural G protein derived from a subgroup B RSV was also obtained. Both A2 and B strain G glycoproteins were expressed in cells infected with the chimeric RSV. A chimeric RSV that expresses a heterologous subgroup antigen in a live attenuated vaccine candidate may be important for prevention of diseases associated with both RSV subgroup A and subgroup B infection
Characterization of the Acidic Domain of the IE1 Regulatory Protein fromOrgyia pseudotsugataMulticapsid Nucleopolyhedrovirus

AbstractThis study presents a detailed analysis of the acidic N-terminal region of theOrgyia pseudotsugatamulticapsid nucleopolyhedrovirus (OpMNPV) transactivator IE1. The N-terminal region of IE1 is rich in acidic amino acids and has been hypothesized to be an acidic activation domain. Removal of the N-terminal 126 amino acids containing the acidic domain of IE1 resulted in complete loss of transactivation activity, indicating that this region is essential for transactivation. The OpMNPV acidic domain was replaced with the archetype acidic activation domain from VP16 and the acid-rich region ofAutographa californicamulticapsid NPV (AcMNPV) IE1. These chimeric constructs were fully capable of transactivation in transient assays. The chimeric OpMNPV IE1s containing the herpes simplex virus VP16 and AcMNPV IE1 acidic activation domains consistently transactivated a reporter gene to higher levels than the OpMNPV IE1 acidic activation domain. Transactivation by the chimeric constructs is enhanced synergistically when cotransfected with IE2 intoLymantria disparandSpodoptera frugiperdacells. Both N- to C-terminal and C- to N-terminal deletions of the OpMNPV acidic activation domain were constructed to define functional domains within the OpMNPV IE1 acidic activation domain. At least two potential activation domains were identified. Within each of these domains, two core regions at amino acids 28–43 and amino acids 113–124 were identified that were similar to core regions of VP16 and GAL4, which contain predominately acidic and bulky hydrophobic amino acids
Characterization of Transformation Function of Cottontail Rabbit Papillomavirus E5 and E8 Genes

AbstractCottontail rabbit papillomavirus (CRPV) induces rabbit skin papillomas, which progress to invasive carcinoma in some animals. Two early genes, E7 and E6, have been demonstrated previously to be oncogenes. In this study, we identified two additional transforming genes, E8 and E5. Both E8 and E5 stimulated C127 and BALB/c A31 (A31) cell proliferation and affected cell cycle transition. The E8 and E5 transfectants lost cell contact inhibition, reaching a high saturation density when cultured up to 2 weeks. E8–C127 transfectants formed colonies in soft agar in the presence of platelet-derived growth factor (PDGF) while E5–C127 transfectants formed colonies without the requirement for PDGF. E8–C127 transfectants were highly tumorigenic whereas E5–C127 transfectants showed a weak tumorigenicity in nude mice. Both E8 and E5 A31 transfectants failed to form colonies in soft agar even in the presence of platelet-derived growth factor (PDGF) and did not develop tumors in nude mice. These results clearly showed that CRPVE8 and E5 are oncogenes and that the PDGF β-receptor signaling pathway may be involved in E8-mediated C127 cell transformation. The difference in colony formation in soft agar and tumorigenicity in nude mice between C127 and A31 cell lines indicates that additional alterations in cellular gene expression are needed for E5- and E8-transfected cells to acquire a malignant phenotype
Human Papillomavirus-Induced Carcinogenesis with p53 Deficiency in Mouse: Novel Lymphomagenesis in HPV16E6E7 Transgenic Mice Mimicking p53 Defect

AbstractTo investigate the transforming activity of human papillomavirus (HPV) E6 and E7 genesin vivo, we previously established transgenic mouse lines containing HPV16E6E7, in which male mice develop a Leydig cell tumors with a very high incidence. Because HPV-induced carcinogenesis is highly related to p53, we changed the dose of p53 gene in the transgenic lines by the mice crossing with p53-disrupted mice. The transgenic mice with homozygous wild-type p53 alleles developed only the testicular tumor, whereas novel T cell lymphomagenesis occurred in the heterozygous p53–disrupted E6E7 (p53+/−E6E7) transgenic mice. In this tumor and even in the normal spleen, the absence of p53 protein was observed, whereas the p53 mRNA was expressed with a normal size, suggesting the degradation of p53 protein in these tissues. These results suggest that HPV16E6 could stimulate p53 protein degradation in mouse cells and induced the lymphomagenesis in a manner indistinguishable from p53 deficiency
Nucleotide Sequence and Transcription Map of Porcine Adenovirus Type 3

AbstractThe complete nucleotide sequence of porcine adenovirus type 3 was determined and a transcriptional map for the genome was constructed. The size of the genome is 34094 bp in length with an unusually high G + C content (63.7%), the highest thus far reported for any adenovirus. Overall organization of the genome is similar to that for previously sequenced adenoviral DNAs, but there also were distinct differences. The late regions genes are organized into six families, instead of five as they are in human adenovirus type 2. In contrast to bovine adenovirus type 3 and ovine adenovirus, which lack virion-associated RNA genes, the nucleotide sequence analysis of the viral genome indicates that it encodes one short VA RNA species. With the exception of the fiber and a 33-kDa nonstructural protein, the predicted amino acid sequences of the open reading frames in the late regions and the E2 region and IVa2 exhibited a high level of homology, whereas the deduced amino acid sequences of ORFs in E1, E3, and E4 regions, and the pIX showed a lesser homology with the corresponding proteins of other adenoviruses. The proteins V, VII, and IX are unusually long, and the protein VII lacks the consensus protease cleavage site. Genomic and cDNA sequence analysis has identified promoters, cap sites, intron–exon boundaries, polyadenylation signals, and polyadenylation sites in the viral genome
Detection and Quantitation of Human Respiratory Syncytial Virus (RSV) Using Minigenome cDNA and a Sindbis Virus Replicon: A Prototype Assay for Negative-Strand RNA Viruses

AbstractWe describe here a novel approach for detecting and quantitating human respiratory syncytial virus (RSV) based on expression of a reporter gene from an RSV minigenome. BHK cells were cytoplasmically transformed with a noncytopathic Sindbis virus replicon expressing T7 RNA polymerase. These cells were then cotransfected with T7 expression plasmids that contain the cDNA of an RSV minigenome and the genes for RSV nucleocapsid proteins N, P, and L. The minigenome contains a reporter gene such aslacZorCATflanked bycis-acting RSV transcription signals. Subsequent infection of these cells with RSV resulted in a high level of reporter gene expression which could be inhibited by ribavirin. Mock-infected cells exhibited background levels of expression. This assay can be used to quantitate RSV and titer neutralizing antibody and may be a valuable tool for screening compounds for anti-RSV activity. It serves as a prototype for other negative-strand RNA viruses
Deletion of Internal Sequences Results in Tobacco Mosaic Virus Defective RNAs That Accumulate to High Levels without Interfering with Replication of the Helper Virus

AbstractDeletion of certain internal sequences of the tobacco mosaic tobamovirus (TMV) genome was required to create replication-defective RNAs (dRNA) that were replicatedin transby TMV. All dRNAs that accumulated to detectable levels were missing nucleotides 3420–4902, which appeared to constitute a core region that inhibited replicationin trans.Deletion of additional sequences resulted in dRNAs that varied tremendously in ability to be replicated from none to levels exceeding that of the helper viral RNA. Accumulation of dRNA negative- and positive-stranded RNAs of each dRNA paralleled those of the helper virus. Negative-stranded RNA accumulation of both helper and dRNA ceased at the same early time in the infection while synthesis of both positive-stranded RNAs continued, suggesting that both dRNAs and helper virus RNAs were synthesized from the same pool of replicase complexes. Positive- to negative-stranded RNA ratios for the dRNAs were similar to, or slightly greater than the wild-type helper virus. Full-length dRNAs were not supportedin transby a replication-competent helper virus. Even though some of the artificially constructed dRNAs accumulated to levels exceeding the level of the helper virus, none appreciably affected the replication of the helper virus, suggesting that the dRNAs are produced from “excess” replicase capacity
Molecular Studies on Bromovirus Capsid Protein V. Evidence for the Specificity of Brome Mosaic Virus Encapsidation Using RNA3 Chimera of Brome Mosaic and Cucumber Mosaic Viruses Expressing Heterologous Coat Proteins

AbstractBrome mosaic bromovirus (BMV) and cucumber mosaic cucumovirus (CMV) are structurally and genetically very similar. The specificity of the BMV and CMV coat proteins (CPs) duringin vivoencapsidation was studied using two RNA3 chimera in which the respective CP genes were exchanged. The replicative competence of each chimera was analyzed inNicotiana benthamianaprotoplasts, and their ability to cause infections was examined in two common permissive hosts,Chenopodium quinoaandN. benthamiana.Each RNA3 chimera replicated to near wild-type (wt) levels and synthesized CPs of expected parental origin when co-inoculated with their respective genomic wt RNAs 1 and 2. However, inoculum containing each chimera was noninfectious in the common permissive hosts tested. Encapsidation assays inN. benthamianaprotoplasts revealed that CMV CP expressed from chimeric BMV RNA3 was capable of packaging heterologous BMV RNA, however, at a lower efficiency than parental BMV CP. By contrast, BMV CP expressed from chimeric CMV RNA3 was unable to package heterologous CMV RNA. These observations demonstrate that BMV CP, but not CMV CP, exhibits a high degree of specificity duringin vivopackaging. The reasons for the noninfectious nature of each chimera in the host plants tested and factors likely to affect encapsidationin vivoare discussed
Characterization of Cucumber Mosaic Virus VI. Generation of Deletions in Defective RNA 3s during Passage in Transgenic Tobacco Expressing the 3a Gene

AbstractDefective mutants of cucumber mosaic virus (CMV) RNA 3, containing deletions in the 3a gene were passaged in transgenic tobacco plants expressing the CMV 3a gene. After six passages, the various progeny RNA 3 were characterized. In all but one case, the size of the deletion increased. For theNheI-fs RNA 3 mutant of the Fny-strain of CMV (with an 8 nucleotide deletion), the deletion increased in the progeny viral RNA 3 to 570 nucleotides. For a similar frameshift mutant in RNA 3 of the M strain of CMV, either single RNA 3 species (with deletions of 579 or 627 nucleotides) or mixtures of RNA 3 deletion variants were observed in different plants. The ΔE-Hmutant (with a deletion of 202 nucleotides) of Fny-CMV RNA 3 underwent further deletion resulting in the loss of the entire 3a gene and flanking sequences. The ΔKpnI mutant (deletion of 501 nucleotides) of Fny-CMV RNA 3 underwent a further deletion of 30 nucleotides. Except for the deletion progeny of the ΔE-HRNA 3 mutant, the other defective RNA 3s all contained inframe deletions. It is proposed that the various deletions were created by different types of recombination and that packaging may be an important factor in the selection of particular defective RNA 3 variants
Genetic Determinants of Host-Specificity in Bipartite Geminivirus DNA A Components

AbstractGeminiviruses are small, ssDNA-containing plant viruses. Bean golden mosaic virus (BGMV) and tomato golden mosaic virus (TGMV) have bipartite genomes, the components of which are designated A and B. Although they are closely related, BGMV and TGMV nevertheless exhibit distinct host-specific phenotypes, with BGMV being well adapted to beans and TGMV being well adapted toNicotiana benthamiana.A previous study showed that the two open reading frames (ORFs) of DNA B only partially determine the host-adapted phenotypes of BGMV and TGMV. We have now investigated the contributions of A component ORFs to host adaptation. Co-inoculated TGMV DNA A enhances the accumulation of BGMV inN. benthamiana.Using mutant and hybrid TGMV A components, the determinant of this phenotype was mapped to a region encompassing the overlappingAL2andAL3ORFs (AL23). BGMV- and TGMV-based hybrid A components containing the heterologousAL23region each displayed host-specific gain-of-function phenotypes, which indicates that these sequences contribute to host adaptation in both viruses. InN. benthamiana, al2andal3mutants of either virus can be complementedin transby the heterologous A component, so adaptation of theAL23region to this host is likely mediated through a virus nonspecific,trans-acting factor. In beans, however, co-inoculated BGMV A does not affect the accumulation of TGMV, and TGMV did not complement BGMVal2oral3mutants. Thus host-adaptation of theAL23region may have a different mechanistic basis in beans than it does inN. benthamiana.Although our experiments did not reveal significant host adaptation of the coat protein, which is encoded by theAR1ORF, a virus-specific effect on viral ssDNA accumulation was observed
Construction of Pathogenic Molecular Clones of Aleutian Mink Disease Parvovirus that Replicate Bothin Vivoandin Vitro

AbstractThe ADV-G isolate of Aleutian mink disease parvovirus (ADV) replicates permissively in Crandell feline kidney (CRFK) cells but is nonpathogenic for mink, whereas the highly pathogenic ADV-Utah isolate is nonviable in CRFK cells. To assign control of host range in CRFK cells and pathogenicity to specific regions of the ADV genome, we constructed a full-length molecular clone chimeric between ADV-G and ADV-Utah. If either the map unit (MU) 54–65 (clone G/U-5) or MU 65–88 (clone G/U-7) sections were ADV-Utah, viability in CRFK cells was abolished, thus indicating thatin vitrohost range was controlled by two independent determinants: A in the MU 54–65 segment and B in the MU 65–88 segment. Determinant B could be divided into two subregions, B1 (MU 65–69) and B2 (MU 73–88), neither of which alone could inhibit replication in CRFK cells, an observation suggesting that expression of the B determinant required interaction between noncontiguous sequences. Adult mink of Aleutian genotype inoculated with G/U-8 or G/U-10 developed viremia, antiviral antibody, and histopathological changes characteristic of progressive Aleutian disease. The capsid sequences of G/U-8 and G/U-10 differed from ADV-G at five and four amino acid residues, respectively. Our results suggested that the host range and pathogenicity of ADV are regulated by sequences in the capsid protein gene
The Host Range of Chronic Wasting Disease Is Altered on Passage in Ferrets

AbstractChronic wasting disease (CWD), a member of the transmissible spongiform encephalopathies (TSEs), was first identified in captive mule and black-tail deer in 1967. Due to the failure to transmit CWD to rodents, we investigated the use of ferrets (Mustela putorius furo) as a small animal model of CWD. The inoculation of CWD into ferrets resulted in an incubation period of 17–21 months on primary passage that shortened to 5 months by the third ferret passage. The brain tissue of animals inoculated with ferret-passaged CWD exhibited spongiform degeneration and reactive astrocytosis. Western blot analysis of ferret-passaged CWD demonstrated the presence of PrP-res. Unlike mule deer CWD, ferret-passaged CWD was transmissible to Syrian golden hamsters (Mesocricetus auratus). Increasing the passage number of CWD in ferrets increased the pathogenicity of the agent for hamsters. This increase in host range of a field isolate on interspecies transmission emphasizes the need for caution when assessing the potential risk of transmission of TSEs, such as bovine spongiform encephalopathy, to new host species
Expression of a Uracil DNA Glycosylase (UNG) Inhibitor in Mammalian Cells: Varicella-Zoster Virus Can Replicatein Vitroin the Absence of Detectable UNG Activity

AbstractUracil DNA glycosylase (UNG) functions as a DNA repair or proofreading enzyme. The UNG gene is present in nearly all prokaryotes and eukaryotes screened to date and is found in herpesviruses and poxviruses. Prior studies showed that viral UNG is essential for poxvirus replication. Although viral UNG is not required for herpesvirus replication, cellular UNG was thought to be essential for virus replication. To study the role of UNG in herpesvirus replication, we first showed that varicella-zoster virus (VZV) ORF59 encodes a functional UNG. We then constructed a VZV mutant with a deletion in the UNG gene and showed that the mutant was unimpaired for replicationin vitro. Because cultured cells express their own endogenous UNG, we next inserted a bacteriophage UNG inhibitor UGI gene into the VZV genome. Infection of cells with VZV lacking viral UNG and expressing UGI completely abrogated detectable cellular UNG activityin vitro. Parental VZV, VZV lacking viral UNG, and VZV expressing UGI all grew to similar titers in cell culture, indicating that VZV can replicatein vitroin the absence of detectable viral or cellular UNG activity
A Plasma Membrane Localization Signal in the HIV-1 Envelope Cytoplasmic Domain Prevents Localization at Sites of Vesicular Stomatitis Virus Budding and Incorporation into VSV Virions

AbstractPrevious studies showed that the HIV-1 envelope (Env) protein was not incorporated into vesicular stomatitis virus (VSV) virions unless its cytoplasmic tail was replaced with that of the VSV glycoprotein (G). To determine whether the G tail provided a positive incorporation signal for Env, or if sequences in the Env tail prevented incorporation, we generated mutants of Env with its 150-amino-acid tail shortened to 29, 10, or 3 amino acids (Envtr mutants). Cells infected with VSV recombinants expressing these proteins or an Env-G tail hybrid showed similar amounts of Env protein at the surface. The Env-G tail hybrid or the Envtr3 mutant were incorporated at the highest levels into budding VSV virions. In contrast, the Envtr29 or Envtr10 mutants were incorporated poorly. These results defined a signal preventing incorporation within the 10 membrane-proximal amino acids of the Env tail. Confocal microscopy revealed that this signal functioned by causing localization of human immunodeficiency virus type 1 Env to plasma membrane domains distinct from the VSV budding sites, where VSV proteins were concentrated
Association between HTLV-1 Tax and IκBα Is Dependent on the IκBα Phosphorylation State

AbstractBiological, molecular, and epidemiological data have demonstrated that human T cell leukemia virus type 1 (HTLV-1) encoded Tax protein plays a central role in the initiation of T cell malignancy. The 40-kDa Tax oncoprotein serves as a potent transcriptional activator that induces viral gene expression driven by the HTLV-1 long terminal repeats and also stimulates multiple cellular genes involved in T cell activation, cell cycle regulation, and gene activation. Since Tax has been shown to interact directly and indirectly with the NF-κB/IκB regulatory proteins, we examined the significance of anin vivoassociation between Tax and the IκBα inhibitor. Using GST affinity chromatography, Tax was shown to interact with the IκBα ankyrin repeats which are essential for interaction with the NF-κB/Rel proteins.In vivo,using IκBα mutants and co-immunoprecipitation, a preferential interaction between HTLV-1 Tax and N-terminally hypophosphorylated IκBα was detected. Tax also enhanced binding of IκBα to the proteasome subunit HsN3, resulting in a Tax-enhanced, constitutive degradation of wild-type and mutated forms of IκBα in the absence of phosphorylation and ubiquitination. Binding of IκBα to proteasome subunit HC9 was also observed, but this interaction occurred independently of Tax. Taken together, these results suggest a role for Tax as a viral chaperone resulting in the enhanced constitutive turnover of IκBα. The association of Tax with hypophosphorylated IκBα may prevent IκBα from binding to NF-κB and also target IκBα to the proteasome for degradation via a phosphorylation-independent pathway