title: Naturally occurring genotypes of the human immunodeficiency virus type 1 long terminal repeat display a wide range of basal and Tat-induced transcriptional activities.
abstract: The primary body of information on the structure of human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR)/gag leader genotypes has been determined from the analysis of cocultivated isolates. Functional studies of this regulatory portion of the provirus have been derived from the study of in vitro-generated mutations of laboratory-adapted molecular clones of HIV-1. We have performed a longitudinal analysis of molecular clones from the LTR/gag leader region amplified directly from the peripheral blood of four patients over three years. We have found a remarkable number of point mutations and length polymorphisms in cis- and trans-acting regulatory elements within this cohort. Most of the length polymorphisms were associated with duplications of Sp1 and TCF-1 alpha sequences. These mutations were associated with a wide range of transcriptional activities for these genotypes in a reporter gene assay. Mutations in conserved Sp1 sequences correlated with a diminished capacity of such genotypes to bind purified Sp1 protein. Although no generalized trend in transcriptional activity was seen, a single patient accumulated mutations in NF-kappa B, Sp1, and TAR elements over this period. The analysis of naturally occurring mutations of LTR genotypes provides a means to study the molecular genetic consequences of virus-host interactions and to assess the functional impact of HIV therapeutics.
authors.affiliation: Division of Retrovirology, Walter Reed Army Institute of Research, Rockville, Maryland.
authors.forename: N L
authors.initials: NL
authors.lastname: Michael
authors.forename: L
authors.initials: L
authors.lastname: D'Arcy
authors.forename: P K
authors.initials: PK
authors.lastname: Ehrenberg
authors.forename: R R
authors.initials: RR
authors.lastname: Redfield
mesh_terms: D001483:Base Sequence; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000378:metabolism; D015696:Gene Products, tat / Q000494:pharmacology*; D017930:Genes, Reporter; D015750:Genes, gag / Q000235:genetics; D005838:Genotype; D015658:HIV Infections / Q000097:blood*; D016325:HIV Long Terminal Repeat / Q000235:genetics*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000382:microbiology; D051821:Lymphoid Enhancer-Binding Factor 1; D008969:Molecular Sequence Data; D017354:Point Mutation; D012150:Polymorphism, Restriction Fragment Length; D011485:Protein Binding; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D016329:Sp1 Transcription Factor / Q000378:metabolism; D051822:T Cell Transcription Factor 1; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D004268:DNA-Binding Proteins; D015696:Gene Products, tat; D051821:Lymphoid Enhancer-Binding Factor 1; D016329:Sp1 Transcription Factor; D051822:T Cell Transcription Factor 1; C497576:TCF7 protein, human; D014157:Transcription Factors; D054322:tat Gene Products, Human Immunodeficiency Virus