title: The BET bromodomain inhibitor JQ1 activates HIV latency through antagonizing Brd4 inhibition of Tat-transactivation.
abstract: Latent HIV reservoirs are the primary hurdle to eradication of infection. Identification of agents, pathways and molecular mechanisms that activate latent provirus may, in the presence of highly active antiretroviral therapy, permit clearance of infected cells by the immune system. Promoter-proximal pausing of RNA polymerase (Pol) II is a major rate-limiting step in HIV gene expression. The viral Tat protein recruits human Super Elongation Complex (SEC) to paused Pol II to overcome this limitation. Here, we identify the bromodomain protein Brd4 and its inhibition of Tat-transactivation as a major impediment to latency reactivation. Brd4 competitively blocks the Tat-SEC interaction on HIV promoter. The BET bromodomain inhibitor JQ1 dissociates Brd4 from the HIV promoter to allow Tat recruitment of SEC to stimulate HIV elongation. JQ1 synergizes with another latency activator prostratin, which promotes Pol II loading onto the viral promoter. Because JQ1 activates viral latency without inducing global T cell activation, this and other closely related compounds and their antagonization of Brd4 to promote Tat-SEC interaction merit further investigations as effective agents/strategies for eliminating latent HIV.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
authors.forename: Zichong
authors.initials: Z
authors.lastname: Li
authors.forename: Jia
authors.initials: J
authors.lastname: Guo
authors.forename: Yuntao
authors.initials: Y
authors.lastname: Wu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhou
mesh_terms: D019380:Anti-HIV Agents / Q000494:pharmacology*; D001381:Azepines / Q000494:pharmacology*; D018797:Cell Cycle Proteins; D042863:Cyclin-Dependent Kinase 9 / Q000378:metabolism; D006678:HIV / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D019169:Jurkat Cells; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010703:Phorbol Esters / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D042925:Positive Transcriptional Elongation Factor B / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012319:RNA Polymerase II / Q000378:metabolism; D017411:Ribonucleoproteins, Small Nuclear / Q000378:metabolism; D014157:Transcription Factors / Q000037:antagonists & inhibitors* / Q000378:metabolism; D015533:Transcriptional Activation / Q000187:drug effects*; D035602:Transcriptional Elongation Factors / Q000037:antagonists & inhibitors / Q000378:metabolism; D014230:Triazoles / Q000494:pharmacology*; D017735:Virus Latency / Q000187:drug effects* / Q000235:genetics; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000092468:Bromodomain Containing Proteins
chemical_list: D019380:Anti-HIV Agents; D001381:Azepines; D018797:Cell Cycle Proteins; D042863:Cyclin-Dependent Kinase 9; D009687:Nuclear Proteins; D010703:Phorbol Esters; D042925:Positive Transcriptional Elongation Factor B; D012319:RNA Polymerase II; D017411:Ribonucleoproteins, Small Nuclear; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; D014230:Triazoles; D054322:tat Gene Products, Human Immunodeficiency Virus; C561695:(+)-JQ1 compound; C441289:BRD4 protein, human; D000092468:Bromodomain Containing Proteins; C447613:ELL2 protein, human; C070999:prostratin