title: HIV-1 tat trans-activation requires the loop sequence within tar.
abstract: Human immunodeficiency virus (HIV-1) is the primary retroviral agent responsible for AIDS and related disorders worldwide. One of its identified gene products, tat protein, stimulates in trans the expression of all HIV-1 genes by several orders of magnitude. Cells infected with HIV-1 require tat protein to produce virus, suggesting that trans-activation is crucial for viral replication. The essential cis-acting site for trans-activation, termed tar, resides within the R region of the HIV-1 long terminal repeat (LTR), between -17 and +54 with respect to the initiation site of viral transcription. It is striking that the RNA encoded between +1 and +59 has the potential to form an extensive stem-loop secondary structure which, as a portion of the untranslated leader RNA, would be common to all HIV-1 mRNAs. We now present the results of nucleotide substitution experiments which suggest that tat trans-activation requires presentation of the sequence +30CUGGG+34 in tar within the loop of a RNA hairpin structure.
authors.affiliation: Department of Biochemistry, Stanford University Medical Center, California 94305.
authors.forename: S
authors.initials: S
authors.lastname: Feng
authors.forename: E C
authors.initials: EC
authors.lastname: Holland
mesh_terms: D004252:DNA Mutational Analysis; D005786:Gene Expression Regulation; D006678:HIV / Q000235:genetics*; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D012191:Retroviridae Proteins / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology
chemical_list: D012367:RNA, Viral; D012191:Retroviridae Proteins; D014157:Transcription Factors