Simian foamy virus type 1 is a retrovirus which encodes a transcriptional transactivator.
Simian foamy viruses, members of the spumavirus subfamily of retroviruses, are found in a variety of nonhuman primates and, as yet, remain to be characterized with respect to genetic structure and regulation of viral gene expression. The genome of simian foamy virus type 1 (SFV-1), an isolate from rhesus macaques, has been molecularly cloned, and the role of the viral long terminal repeat (LTR) in transcriptional control has been investigated. The SFV-1 LTR is 1,621 base pairs long, and sequence comparisons with human foamy virus revealed a pattern of clustered homology. A cap site in the LTR was identified by analysis of SFV-1 transcripts in infected cells. Transient expression assays in cell lines representing several species and different cell types showed that the SFV-1 LTR has low basal activity in uninfected cells, whereas LTR-directed expression is greatly increased in cells infected with SFV-1. This transactivation is mediated by a mechanism involving increases in steady-state levels of viral transcripts. Thus, the SFV-1 genome encodes a transactivator that functions on the LTR at the transcriptional level.
Mergia
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Department of Pathology, School of Medicine, University of California, Davis 95616.
Shaw
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Pratt-Lowe
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Barry
P A
PA
Luciw
P A
PA
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D005814:Genes, Viral; D006801:Humans; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D015347:RNA Probes; D012091:Repetitive Sequences, Nucleic Acid; D012190:Retroviridae / Q000235:genetics* / Q000502:physiology; D012689:Sequence Homology, Nucleic Acid; D015534:Trans-Activators / Q000235:genetics*; D014158:Transcription, Genetic; D014162:Transfection; D014779:Virus Replication
D015347:RNA Probes; D015534:Trans-Activators