title: Inhibition of early steps of HIV-1 replication by SNF5/Ini1.
abstract: To replicate, human immunodeficiency virus, type 1 (HIV-1) needs to integrate a cDNA copy of its RNA genome into a chromosome of the host cell, a step controlled by the viral integrase (IN) protein. Viral integration involves the participation of several cellular proteins. SNF5/Ini1, a subunit of the SWI/SNF chromatin remodeling complex, was the first cofactor identified to interact with IN. We report here that SNF5/Ini1 interferes with early steps of HIV-1 replication. Inhibition of SNF5/Ini1 expression by RNA interference increases HIV-1 replication. Using quantitative PCR, we show that both the 2-long terminal repeat circle and integrated DNA forms accumulate upon SNF5/Ini1 knock down. By yeast two-hybrid assay, we screened a library of HIV-1 IN random mutants obtained by PCR random mutagenesis using SNF5/Ini1 as prey. Two different mutants of interaction, IN E69G and IN K71R, were impaired for SNF5/Ini1 interaction. The E69G substitution completely abolished integrase catalytic activity, leading to a replication-defective virus. On the contrary, IN K71R retained in vitro integrase activity. K71R substitution stimulates viral replication and results in higher infectious titers. Taken together, these results suggest that, by interacting with IN, SNF5/Ini1 interferes with early steps of HIV-1 infection.
authors.affiliation: Institut Cochin, Département Maladies Infectieuses, F-75014 Paris, Inserm, U567, F-75014 Paris, France.
authors.forename: Marlène
authors.initials: M
authors.lastname: Maroun
authors.forename: Olivier
authors.initials: O
authors.lastname: Delelis
authors.forename: Gaël
authors.initials: G
authors.lastname: Coadou
authors.forename: Thomas
authors.initials: T
authors.lastname: Bader
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Ségéral
authors.forename: Gladys
authors.initials: G
authors.lastname: Mbemba
authors.forename: Caroline
authors.initials: C
authors.lastname: Petit
authors.forename: Pierre
authors.initials: P
authors.lastname: Sonigo
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Rain
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Mouscadet
authors.forename: Richard
authors.initials: R
authors.lastname: Benarous
authors.forename: Stéphane
authors.initials: S
authors.lastname: Emiliani
mesh_terms: D002384:Catalysis; D049109:Cell Proliferation; D002868:Chromosomal Proteins, Non-Histone; D004247:DNA / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000502:physiology*; D015497:HIV-1 / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D009154:Mutation; D011485:Protein Binding; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D011995:Recombination, Genetic; D000071796:SMARCB1 Protein; D014157:Transcription Factors / Q000502:physiology*; D020798:Two-Hybrid System Techniques; D014779:Virus Replication
chemical_list: D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D034741:RNA, Small Interfering; D000071796:SMARCB1 Protein; C513266:SMARCB1 protein, human; D014157:Transcription Factors; D004247:DNA