Lin, Chou-WenEngelman, Alan2019-10-052003Lin, C.-W., and A. Engelman. 2003. “The Barrier-to-Autointegration Factor Is a Component of Functional Human Immunodeficiency Virus Type 1 Preintegration Complexes.” Journal of Virology 77 (8): 5030–36. https://doi.org/10.1128/jvi.77.8.5030-5036.2003.0022-538X1070-63211098-5514http://nrs.harvard.edu/urn-3:HUL.InstRepos:41483065Retroviral integration in vivo is mediated by preintegration complexes (PICs) derived from infectious virions. In addition to the integrase enzyme and cDNA substrate, PICs contain a variety of viral and host cell proteins. Whereas two different cell proteins, high-mobility group protein A1 (HMGA1) and the barrier-to-autointegration factor (BAF), were identified as integration cofactors based on activities in in vitro PIC assays, only HMGA1 was previously identified as a PIC component. By using antibodies against known viral and cellular PIC components, we demonstrate here functional coimmunoprecipitation of endogenous BAF protein with human immunodeficiency virus type 1 (HIV-1) PICs. Since integrase protein and integration activity were also coimmunoprecipitated by anti-BAF antibodies, we conclude that BAF is a component of HIV-1 PICs. These data are consistent with the model that BAF functions as an integration cofactor in vivo.en-USJournal Article2019-10-0510.1128/JVI.77.8.5030-5036.2003