Identification of a novel human immunodeficiency virus type 1 integrase interactor, Gemin2, that facilitates efficient viral cDNA synthesis in vivo.
Retroviral integrase (IN) catalyzes the integration of viral cDNA into a host chromosome. Additional roles have been suggested for IN, including uncoating, reverse transcription, and nuclear import of the human immunodeficiency virus type 1 (HIV-1) genome. However, the underlying mechanism is largely unknown. Here, using a yeast two-hybrid system, we identified a survival motor neuron (SMN)-interacting protein 1 (Gemin2) that binds to HIV-1 IN. Reduction of Gemin2 with small interfering RNA duplexes (siGemin2) dramatically reduced HIV-1 infection in human primary monocyte-derived macrophages and also reduced viral cDNA synthesis. In contrast, siGemin2 did not affect HIV-1 expression from the integrated proviral DNA. Although Gemin2 was undetectable in cell-free viral particles, coimmunoprecipitation experiments using FLAG-tagged Gemin2 strongly suggested that Gemin2 interacts with the incoming viral genome through IN. Further experiments reducing SMN or other SMN-interacting proteins suggested that Gemin2 might act on HIV-1 either alone or with unknown proteins to facilitate efficient viral cDNA synthesis soon after infection. Thus, we provide the evidence for a novel host protein that binds to HIV-1 IN and facilitates viral cDNA synthesis and subsequent steps that precede integration in vivo.
Hamamoto
Seiji
S
Department of Immunotherapeutics, Tokyo Medical and Dental University, Tokyo 113-8519, Japan.
Nishitsuji
Hironori
H
Amagasa
Teruo
T
Kannagi
Mari
M
Masuda
Takao
T
D002478:Cells, Cultured; D018076:DNA, Complementary / Q000096:biosynthesis; D019427:HIV Integrase / Q000378:metabolism; D015497:HIV-1 / Q000201:enzymology / Q000502:physiology*; D006801:Humans; D008264:Macrophages / Q000821:virology; D009419:Nerve Tissue Proteins / Q000378:metabolism* / Q000502:physiology; D011485:Protein Binding; D016601:RNA-Binding Proteins / Q000378:metabolism* / Q000502:physiology; D012191:Retroviridae Proteins / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D016662:Virus Integration
D018076:DNA, Complementary; C108381:GEMIN2 protein, human; D009419:Nerve Tissue Proteins; D016601:RNA-Binding Proteins; D012191:Retroviridae Proteins; D019427:HIV Integrase