Maedi-Visna Virus and Caprine Arthritis Encephalitis Virus Genomes Encode a Vpr-Like but No Tat Protein
| Autor: | Baya Amel Bouzar, Thierry Morin, Gérard Verdier, Catherine Legras, Stephanie Villet, Y. Chebloune |
|---|---|
| Přispěvatelé: | Rétrovirus et Pathologie Comparée (RPC), Institut National de la Recherche Agronomique (INRA)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Ecole Nationale Vétérinaire de Lyon (ENVL) |
| Rok vydání: | 2003 |
| Předmět: |
Visna-maedi virus
viruses LONG TERMINAL REPEAT ACTIVATION INFECTION ARRESTS Cells Cultured BASIC DOMAIN 0303 health sciences biology Goats virus diseases Transfection Long terminal repeat 3. Good health Gene Products tat [SDV.MP.VIR]Life Sciences [q-bio]/Microbiology and Parasitology/Virology Lentivirus Subcellular Fractions G2 Phase Arthritis-Encephalitis Virus Caprine Genes vpr Immunology Replication Genome Viral Microbiology Virus Open Reading Frames 03 medical and health sciences Virology Animals Humans CELL-CYCLE Caprine arthritis encephalitis virus TYPE-1 030304 developmental biology Base Sequence 030306 microbiology Gene Products vpr HIV-1 PREINTEGRATION COMPLEX TRANSACTIVATION biology.organism_classification Molecular biology Open reading frame Genes tat Insect Science DNA Viral Nuclear localization sequence HeLa Cells |
| Zdroj: | Journal of Virology Journal of Virology, American Society for Microbiology, 2003, 77 (17), pp.9632-9638. ⟨10.1128/JVI.77.17.9632-9638.2003⟩ |
| ISSN: | 1098-5514 0022-538X |
| Popis: | A small open reading frame (ORF) in maedi-visna virus (MVV) and caprine arthritis encephalitis virus (CAEV) was initially named “ tat ” by analogy with a similarly placed ORF in the primate lentiviruses. The encoded “Tat” protein was ascribed the function of up regulation of the viral transcription from the long terminal repeat (LTR) promoter, but we have recently reported that MVV and CAEV Tat proteins lack trans -activation function activity under physiological conditions (S. Villet, C. Faure, B. Bouzar, G. Verdien, Y. Chebloune, and C. Legras, Virology 307:317-327, 2003). In the present work, we show that MVV Tat localizes to the nucleus of transfected cells, probably through the action of a nuclear localization signal in its C-terminal portion. We also show that, unlike the human immunodeficiency virus (HIV) Tat protein, MVV Tat was not secreted into the medium by transfected human or caprine cells in the absence of cell lysis but that, like the primate accessory protein Vpr, MVV and CAEV Tat proteins were incorporated into viral particles. In addition, analysis of the primary protein structures showed that small-ruminant lentivirus (SRLV) Tat proteins are more similar to the HIV type 1 (HIV-1) Vpr protein than to HIV-1 Tat. We also demonstrate a functional similarity between the SRLV Tat proteins and the HIV-1 Vpr product in the induction of a specific G 2 arrest of the cell cycle in MVV Tat-transfected cells, which increases the G 2 /G 1 ratio 2.8-fold. Together, these data strongly suggest that the tat ORF in the SRLV genomes does not code for a regulatory transactivator of the LTR but, rather, for a Vpr-like accessory protein. |
| Databáze: | OpenAIRE |
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