title: HIV integration targeting: a pathway involving Transportin-3 and the nuclear pore protein RanBP2.
abstract: Genome-wide siRNA screens have identified host cell factors important for efficient HIV infection, among which are nuclear pore proteins such as RanBP2/Nup358 and the karyopherin Transportin-3/TNPO3. Analysis of the roles of these proteins in the HIV replication cycle suggested that correct trafficking through the pore may facilitate the subsequent integration step. Here we present data for coupling between these steps by demonstrating that depletion of Transportin-3 or RanBP2 altered the terminal step in early HIV replication, the selection of chromosomal sites for integration. We found that depletion of Transportin-3 and RanBP2 altered integration targeting for HIV. These knockdowns reduced HIV integration frequency in gene-dense regions and near gene-associated features, a pattern that differed from that reported for depletion of the HIV integrase binding cofactor Psip1/Ledgf/p75. MLV integration was not affected by the Transportin-3 knockdown. Using siRNA knockdowns and integration targeting analysis, we also implicated several additional nuclear proteins in proper target site selection. To map viral determinants of integration targeting, we analyzed a chimeric HIV derivative containing MLV gag, and found that the gag replacement phenocopied the Transportin-3 and RanBP2 knockdowns. Thus, our data support a model in which Gag-dependent engagement of the proper transport and nuclear pore machinery mediate trafficking of HIV complexes to sites of integration.
authors.affiliation: Department of Microbiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA.
authors.forename: Karen E
authors.initials: KE
authors.lastname: Ocwieja
authors.forename: Troy L
authors.initials: TL
authors.lastname: Brady
authors.forename: Keshet
authors.initials: K
authors.lastname: Ronen
authors.forename: Alyssa
authors.initials: A
authors.lastname: Huegel
authors.forename: Shoshannah L
authors.initials: SL
authors.lastname: Roth
authors.forename: Torsten
authors.initials: T
authors.lastname: Schaller
authors.forename: Leo C
authors.initials: LC
authors.lastname: James
authors.forename: Greg J
authors.initials: GJ
authors.lastname: Towers
authors.forename: John A T
authors.initials: JA
authors.lastname: Young
authors.forename: Sumit K
authors.initials: SK
authors.lastname: Chanda
authors.forename: Renate
authors.initials: R
authors.lastname: König
authors.forename: Nirav
authors.initials: N
authors.lastname: Malani
authors.forename: Charles C
authors.initials: CC
authors.lastname: Berry
authors.forename: Frederic D
authors.initials: FD
authors.lastname: Bushman
mesh_terms: D015967:Gene Expression Regulation, Viral; D055785:Gene Knockdown Techniques; D057809:HEK293 Cells; D006678:HIV / Q000502:physiology*; D054884:Host-Pathogen Interactions / Q000502:physiology*; D006801:Humans; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism*; D028861:Nuclear Pore Complex Proteins / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D014779:Virus Replication; D028961:beta Karyopherins / Q000235:genetics / Q000378:metabolism*; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000235:genetics / Q000378:metabolism
chemical_list: D018832:Molecular Chaperones; D028861:Nuclear Pore Complex Proteins; D034741:RNA, Small Interfering; C546476:TNPO3 protein, human; D028961:beta Karyopherins; D054301:gag Gene Products, Human Immunodeficiency Virus; C094493:ran-binding protein 2