title: BCL6 can repress transcription from the human immunodeficiency virus type I promoter/enhancer region.
abstract: The gene BCL6 encodes a zinc finger protein with similarities to transcription factors. We previously reported that a number of viral genomes, including human immunodeficiency virus type I (HIV-1), contain sequences which are similar to the BCL6 DNA-binding consensus in their promoter regions. Electrophoretic mobility shift assays showed that the full-length BCL6 protein extracted from transfected COS cells and a bacterially expressed truncated protein containing the BCL6 zinc fingers can bind specifically to DNA from the U3 promoter/enhancer region of HIV-1. Transient transfections were performed to analyze the effects of the BCL6 protein on luciferase expression driven by the HIV-1 long terminal repeat (LTR) sequences. Full-length BCL6 significantly repressed luciferase activity compared with multiple controls. We conclude that the BCL6 protein can bind to the HIV-1 promoter-enhancer region and contains a domain upstream of its zinc fingers that can repress transcription from the HIV-1 LTR.
authors.affiliation: Department of Pathology, University of Chicago, Illinois 60637, USA.
authors.forename: B W
authors.initials: BW
authors.lastname: Baron
authors.forename: M
authors.initials: M
authors.lastname: Desai
authors.forename: L J
authors.initials: LJ
authors.lastname: Baber
authors.forename: L
authors.initials: L
authors.lastname: Paras
authors.forename: Q
authors.initials: Q
authors.lastname: Zhang
authors.forename: A
authors.initials: A
authors.lastname: Sadhu
authors.forename: S
authors.initials: S
authors.lastname: Duguay
authors.forename: G
authors.initials: G
authors.lastname: Nucifora
authors.forename: T W
authors.initials: TW
authors.lastname: McKeithan
authors.forename: N
authors.initials: N
authors.lastname: Zeleznik-Le
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D015153:Blotting, Western; D019556:COS Cells; D016384:Consensus Sequence; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D004591:Electrophoresis, Polyacrylamide Gel; D015967:Gene Expression Regulation, Viral; D017930:Genes, Reporter; D016322:HIV Enhancer; D015497:HIV-1 / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D008156:Luciferases / Q000235:genetics; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology*; D051560:Proto-Oncogene Proteins c-bcl-6; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic; D016335:Zinc Fingers
chemical_list: D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D051560:Proto-Oncogene Proteins c-bcl-6; D014157:Transcription Factors; D004247:DNA; D008156:Luciferases