Short report
The integrase interactor 1 (INI1) proteins facilitate Tat-mediated human immunodeficiency virus type 1 transcription
-
* Corresponding author: Didier Trono didier.trono@epfl.ch
1 Department of Microbiology and Molecular Medicine, University of Geneva and 'Frontiers in Genetics' National Center for Competence in Research, Switzerland
2 Department of Molecular Biology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
3 Institute of Microbiology, CHUV, University of Lausanne, Lausanne, Switzerland
4 School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
Retrovirology 2006, 3:47 doi:10.1186/1742-4690-3-47
Published: 5 August 2006Abstract
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.