Virology
Feline immunodeficiency virus (FIV) establishes persistent infections in cats inducing an acquired immunodeficiency syndrome. Differences in cell tropism have been observed among isolates of FIV (T. R. Phillips et al., J. Virol. 64, 46054613, 1990). The progeny of the infectious molecular clone of FIV p34TF10 was able to productively infect a feline fibroblast cell line, Crandell feline kidney cell,...
We previously demonstrated that a 23-mer peptide (DB3) derived from the V3 loop of the surface glycoprotein of HIV-1 MN strain was able to bind to soluble CD4 and enhance HIV-1 infection. The mechanism and structural features required for these biological activities were studied by using shortened DB3 derivatives and DB3 analogs carrying single amino acid substitutions. We found that peptides in which...
Regulation of splicing of Rous sarcoma virus (RSV) RNA primary transcripts is necessary, as with other retroviruses, to allow for the accumulation of unspliced RNA and approximately equivalent amounts of spliced env and src mRNAs. Previous studies have indicated that the env 3' splice site is suboptimal because it has a nonconsensus branchpoint sequence and that this suboptimal splice site is required...
We present an immunological characterization of the Ty1 virus-like particle (VLP). A panel of monoclonal and polyclonal antibodies were raised against the TYA particle-forming protein. Using these antibodies in epitope availability assays two N-terminal regions of the TYA protein were mapped projecting from or at the surface of the proteinaceous shell of the VLP. Two different C-termini of the TYA...
A comparative sequence analysis of part of the RNA genome containing the poly(A) signal of different groups of immunodeficiency viruses, including human types 1 and 2, simian types mandrill, african green monkey, and sykes, reveals the conservation of certain structural features despite the divergence in sequence. In all cases, the AAUAAA signal was found to be flanked by nucleotide segments that...
The sequences of the genes encoding the putative attachment (G) proteins of pathogenic (strain J3666) mouse lung-passaged and nonpathogenic (strain 15) tissue culture-passaged strains of pneumonia virus of mice (PVM) have been determined. In both cases the major polypeptide was synthesised from the second open reading frame (ORF), a feature also found in the G gene of respiratory syncytial (RS) virus,...
Bipartite geminiviruses such as squash leaf curl virus (SqLCV) encode two movement proteins (MPs), BR1 and BL1, that are essential for virus movement and systemic infection of host plants. BR1 has been implicated in the host range properties of the virus, and BL1 in viral pathogenic properties. To more precisely examine the roles of each MP, we have introduced missense and deletion mutations into...
The first open reading frame of the blueberry scorch carlavirus (BBScV) genome encodes a putative replication-associated protein of 223 kDa (p223). A pulse-chase analysis of viral RNA translated in vitro in rabbit reticulocyte lysate revealed that p223 was proteolytically processed. Using a full-length ORF 1 cDNA clone in a coupled in vitro transcription/translation reaction, we confirmed that the...
Gag-Pol frameshift translational products of avian retroviruses (e.g., myeloblastosis associated virus, MAV) contain a putative proteinase species of 131 amine acids that maps between the NC/PR and the PR/RT processing sites. Expression in Escherichia coli of an in-frame PR precursor that contains the natural NC/PR processing site and is translationally terminated at the PR/RT site leads to formation...
Segmented genomes of RNA viruses are thought to evolve and be maintained in analogy to sexual recombination and reassortment in eukaryotic systems. If reassortment among genomes is an important event in cucumoviral evolution, then such events should be detectable among extant viruses. In this study, phylogenetic analyses of cucumoviruses were performed using aligned amino acid sequences. The results...
The DNA sequence of a 4.792-kb fragment comprising 3.176 kb of the long unique region (U L ) and 1.605 kb of the internal repeat (IR L ) flanking U L of herpesvirus of turkeys (HVT) was determined. Three potential open reading frames (ORFs) and an origin of replication have been identified. ORF 1, which maps entirely within UL, has the capacity to code for an 82K protein, 731...
An RNA-dependent RNA polymerase activity was found associated with virions of tomato spotted wilt virus (TSWV), a plant- and insect-infecting member of the family Bunyaviridae. Radiolabeled nucleoside triphosphates were incorporated into trichloroacetic acid-precipitable products by detergent-disrupted, purified TSWV virions. Incorporation was reduced to near-background levels when RNase was present...
The control of the ICP0 and ICP4 immediate early genes of herpes simplex virus (HSV) can critically determine the course of viral lytic or latent infections. Their promoters contain so-called TAATGARAT motifs that are activated via a multiprotein complex which includes cellular proteins Oct-1 and HCF and the viral activator VP16 (=Vmw65, αTIF). Relative to the ICP4 promoter TAATGAGAT sequence, the...
The human colon epithelial line HT29 represents a semipermisive cellular system for human immunodeficiency virus type 1 (HIV-1). It could be productively infected with HIV-1 NDK, a Zairian virus isolate highly cytopathic for CD4 positive lymphocytes, whereas infection with the prototype virus HIV-1 LAV was nonproductive. Recombinant viruses derived from HIV-1 LAV and HIV-1 NDK were used to determine...
Two highly degenerate primers for sequence-specific amplification and cloning of a 510-nucleotide-long segment of RNA-dependent RNA-polymerase (RdRp) genes were selected and synthesized on the basis of available plant carmovirus-like viral RdRp sequences. These primers were shown to be efficient in PCR screening of different RdRp genes including those of carmoviruses, dianthoviruses, and tombusviruses...
A chimeric construct (VCD) consisting of parts from viral jun, chicken c-jun, and chicken junD was cloned into the replication-competent retroviral RCAS vector. This construct, RCAS-VCD, was found to have a higher focus forming potential in quail fibroblasts than the equivalent construct RCAS-VJ-1, expressing viral jun. DNAs from RCAS-VCD and RCAS-VJ-1 were transfected into primary quail embryo fibroblasts...
A 65-kDa protein has been detected in mouse hepatitis virus A59 (MHV-A59)-infected DBT cells using polyclonal antibodies directed against polypeptides encoded by the 5' 1.8 kb of gene 1. The presence of this 65-kDa protein (p65) was previously predicted from immunoprecipitation studies of gene 1 expression in MHV-A59-infected DBT cells with other antisera (1). p65 was rapidly labeled in virus-infected...
The simian varicella virus (SVV) genome is a linear DNA molecule consisting of a unique short (U S ) and a unique long (U L ) region. The U S is bounded by internal (IR) and terminal inverted repeats and inverts such that virion DNA contains equimolar amounts of two genome isomers. We have sequenced the right and leftward termini and the U L -IR junction region of the...
In order to define the mechanism used by the adeno-associated virus replication (rep) gene to mediate inhibition of cell proliferation, we have studied its effects on SV40 and cellular DNA replication. SV40 DNA replication was inhibited by the presence of the rep gene in human 293 cells, and the inhibition was not linked to suppression of SV40 early gene expression, Using double-immunofluorescence...