The integrase interactor 1 (INI1) proteins facilitate Tat-mediated human immunodeficiency virus type 1 transcription.
Integration of human immunodeficiency virus type 1 (HIV-1) into the host genome is catalyzed by the viral integrase (IN) and preferentially occurs within transcriptionally active genes. During the early phase of HIV-1 infection, the incoming viral preintegration complex (PIC) recruits the integrase interactor 1 (INI1)/hSNF5, a chromatin remodeling factor which directly binds to HIV-1 IN. The impact of this event on viral replication is so far unknown, although it has been hypothesized that it could tether the preintegration complex to transcriptionally active genes, thus contributing to the bias of HIV integration for these regions of the genome. Here, we demonstrate that while INI1 is dispensable for HIV-1 transduction, it can facilitate HIV-1 transcription by enhancing Tat function. INI1 bound to Tat and both the repeat (Rpt) 1 and Rpt 2 domains of INI1 were required for efficient activation of Tat-mediated transcription. These results suggest that the incoming PICs might recruit INI1 to facilitate proviral transcription.
Ariumi
Yasuo
Y
Department of Microbiology and Molecular Medicine, University of Geneva and Frontiers in Genetics National Center for Competence in Research, Switzerland. ariumi@md.okayama-u.ac.jp
Serhan
Fatima
F
Turelli
Priscilla
P
Telenti
Amalio
A
Trono
Didier
D
D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D015696:Gene Products, tat / Q000235:genetics* / Q000378:metabolism; D019427:HIV Integrase / Q000378:metabolism; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D000071796:SMARCB1 Protein; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D016662:Virus Integration; D054322:tat Gene Products, Human Immunodeficiency Virus
D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D015696:Gene Products, tat; D000071796:SMARCB1 Protein; C513266:SMARCB1 protein, human; D014157:Transcription Factors; D054322:tat Gene Products, Human Immunodeficiency Virus; D019427:HIV Integrase