title: Identification of posttranscriptionally active inhibitory sequences in human immunodeficiency virus type 1 RNA: novel level of gene regulation.
abstract: cis-acting inhibitory region (IR) sequences were identified within the gag/pol gene of the human immunodeficiency virus type 1 (HIV-1) by using a novel feedback-stimulated, rev-independent tat reporter gene to screen HIV-1 sequences in transient expression assays. Two regions, a 1,295-nucleotide segment in the gag gene (IR-1) and a 1,932-nucleotide segment of the pol gene (IR-2), each inhibited reporter gene expression 10- to 20-fold. IR-1 and IR-2 both contained subsequences which inhibited reporter gene expression. Introduction of IR sequences into a heterologous reporter plasmid, pCMV-CAT, resulted in decreased chloramphenicol acetyltransferase expression, suggesting that the inhibitory effect was not restricted to a reporter gene under the control of the HIV-1 promoter. The presence of HIV IR sequences in cis did not alter relative levels of reporter gene RNA; however, fractionation studies revealed IR-containing RNA accumulated in the nucleus. These findings demonstrate that IR sequences within the gag/pol region affect gene expression by altering the cellular distribution of viral RNA.
authors.affiliation: Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.
authors.forename: F
authors.initials: F
authors.lastname: Maldarelli
authors.forename: M A
authors.initials: MA
authors.lastname: Martin
authors.forename: K
authors.initials: K
authors.lastname: Strebel
mesh_terms: D001483:Base Sequence; D015152:Blotting, Northern; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D002872:Chromosome Deletion; D004251:DNA Transposable Elements; D004279:DNA, Viral / Q000235:genetics*; D015967:Gene Expression Regulation, Viral; D015750:Genes, gag; D015751:Genes, pol; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D015345:Oligonucleotide Probes; D010957:Plasmids; D012323:RNA Processing, Post-Transcriptional; D012367:RNA, Viral / Q000235:genetics*; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D004251:DNA Transposable Elements; D004279:DNA, Viral; D009838:Oligodeoxyribonucleotides; D015345:Oligonucleotide Probes; D012367:RNA, Viral; D008156:Luciferases; D015500:Chloramphenicol O-Acetyltransferase