title: Coordination of transcription factor phosphorylation and histone methylation by the P-TEFb kinase during human immunodeficiency virus type 1 transcription.
abstract: The human immunodeficiency virus type 1 (HIV-1) Tat protein recruits positive transcription elongation factor b (P-TEFb) to the transactivation response (TAR) RNA structure to facilitate formation of processive transcription elongation complexes (TECs). Here we examine the role of the Tat/TAR-specified cyclin-dependent kinase 9 (CDK9) kinase activity in regulation of HIV-1 transcription elongation and histone methylation. In HIV-1 TECs, P-TEFb phosphorylates the RNA polymerase II (RNAP II) carboxyl-terminal domain (CTD) and the transcription elongation factors SPT5 and Tat-SF1 in a Tat/TAR-dependent manner. Using in vivo chromatin immunoprecipitation analysis, we demonstrate the following distinct properties of the HIV-1 transcription complexes. First, the RNAP II CTD is phosphorylated at Ser 2 and Ser 5 near the promoter and at downstream coding regions. Second, the stable association of SPT5 with the TECs is dependent upon P-TEFb kinase activity. Third, P-TEFb kinase activity is critical for the induction of methylation of histone H3 at lysine 4 and lysine 36 on HIV-1 genes. Flavopiridol, a potent P-TEFb kinase inhibitor, inhibits CTD phosphorylation, stable SPT5 binding, and histone methylation, suggesting that its potent antiviral activity is due to its ability to inhibit several critical and unique steps in HIV-1 transcription elongation.
authors.affiliation: Department of Biochemistry and Molecular Biology, The George Washington University School of Medicine, Washington, DC 20037, USA.
authors.forename: Meisheng
authors.initials: M
authors.lastname: Zhou
authors.forename: Longwen
authors.initials: L
authors.lastname: Deng
authors.forename: Vincent
authors.initials: V
authors.lastname: Lacoste
authors.forename: Hyeon Ung
authors.initials: HU
authors.lastname: Park
authors.forename: Anne
authors.initials: A
authors.lastname: Pumfery
authors.forename: Fatah
authors.initials: F
authors.lastname: Kashanchi
authors.forename: John N
authors.initials: JN
authors.lastname: Brady
authors.forename: Ajit
authors.initials: A
authors.lastname: Kumar
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D042863:Cyclin-Dependent Kinase 9 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019175:DNA Methylation; D005419:Flavonoids / Q000494:pharmacology; D015696:Gene Products, tat / Q000235:genetics / Q000378:metabolism; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism*; D006801:Humans; D010766:Phosphorylation; D010880:Piperidines / Q000494:pharmacology; D042925:Positive Transcriptional Elongation Factor B / Q000378:metabolism; D012319:RNA Polymerase II / Q000378:metabolism; D018411:Spodoptera; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D035602:Transcriptional Elongation Factors / Q000378:metabolism*; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D005419:Flavonoids; D015696:Gene Products, tat; C101819:HTATSF1 protein, human; D006657:Histones; D010880:Piperidines; D015534:Trans-Activators; D035602:Transcriptional Elongation Factors; D054322:tat Gene Products, Human Immunodeficiency Virus; C069940:SPT5 transcriptional elongation factor; C077990:alvocidib; D042925:Positive Transcriptional Elongation Factor B; D042863:Cyclin-Dependent Kinase 9; D012319:RNA Polymerase II