title: Recruitment of TFIIH to the HIV LTR is a rate-limiting step in the emergence of HIV from latency.
abstract: Latently infected cells rapidly initiate HIV transcription after exposure to signals that induce NF-kappaB. To investigate the role of TFIIH during HIV reactivation in vivo, we developed a population of Jurkat cells containing integrated, but transcriptionally silent, HIV proviruses. Surprisingly, the HIV promoter in unactivated Jurkat T cells is partially occupied and carries Mediator containing the CDK8 repressive module, TFIID and RNAP II that is hypophosphorylated and confined to the promoter region. Significantly, the promoter is devoid of TFIIH. Upon stimulation of the cells by TNF-alpha, NF-kappaB and TFIIH are rapidly recruited to the promoter together with additional Mediator and RNAP II, but CDK8 is lost. Detailed time courses show that the levels of TFIIH at the promoter fluctuate in parallel with NF-kappaB recruitment to the promoter. Similarly, recombinant p65 activates HIV transcription in vitro and stimulates phosphorylation of the RNAP II CTD by the CDK7 kinase module of TFIIH. We conclude that the recruitment and activation of TFIIH represents a rate-limiting step for the emergence of HIV from latency.
authors.affiliation: Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.
authors.forename: Young Kyeung
authors.initials: YK
authors.lastname: Kim
authors.forename: Cyril F
authors.initials: CF
authors.lastname: Bourgeois
authors.forename: Richard
authors.initials: R
authors.lastname: Pearson
authors.forename: Mudit
authors.initials: M
authors.lastname: Tyagi
authors.forename: Michelle J
authors.initials: MJ
authors.lastname: West
authors.forename: Julian
authors.initials: J
authors.lastname: Wong
authors.forename: Shwu-Yuan
authors.initials: SY
authors.lastname: Wu
authors.forename: Cheng-Ming
authors.initials: CM
authors.lastname: Chiang
authors.forename: Jonathan
authors.initials: J
authors.lastname: Karn
mesh_terms: D015967:Gene Expression Regulation, Viral; D006678:HIV / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D016325:HIV Long Terminal Repeat; D006801:Humans; D019169:Jurkat Cells; D008954:Models, Biological; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D051758:Transcription Factor TFIIH / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D017735:Virus Latency / Q000235:genetics*
chemical_list: D016328:NF-kappa B; D051758:Transcription Factor TFIIH; D012319:RNA Polymerase II