Sp100与HIV-1整合酶互作并抑制其介导的病毒整合(英文)

Sp100 Interacts With HIV-1 Integrase and Inhibits Viral Integration

Sp100是核颗粒ND10的组成蛋白,在哺乳动物细胞中广泛存在.Sp100参与多种细胞生理病理过程,如转录调控、细胞内抗病毒免疫等.利用酵母双杂交系统,我们发现了Sp100的互作蛋白HIV-1整合酶,免疫共沉淀实验进一步证实了Sp100与HIV-1整合酶的互作,细胞内荧光共定位实验也证实了二者在细胞内部分共定位.此外,突变体实验表明,Sp100的C端300～480氨基酸和HIV-1的催化结构域是两个蛋白质的互作区域.利用siRNA降低细胞内Sp100的表达量,可以增加HIV-1整合酶介导的病毒的整合,反之,细胞内过表达Sp100则会降低HIV-1整合酶介导的病毒的整合.这是首次发现Sp100可以和HIV-1整合酶发生相互作用,并进而抑制病毒的整合.我们发现了Sp100作为HIV-1整合酶互作蛋白的新功能,并扩展了细胞防御病毒感染的相关研究.

Sp100 is a constitutive protein of nuclear domain 10 （NDIO） and is ubiquitous in mammal cells. It is involved in many cellular processes such as transcriptional regulation and the cellular intrinsic immune response against viral infection. Using a yeast mating assay, we found that Sp100 can interact with HIV-I integrase （HIV-I IN）. This interaction was verified by co-immunoprecipitation, and intracellular imaging revealed that Spl00 and HIV-I IN partially colocalized. Furthermore, mutant variants assay indicated that the C-terminal 300～480 residues of Sp100 and the catalytic domain of HIV-1 IN were responsible for this interaction. Knocking down endogenous Sp100 with Sp100-specific siRNA increased HIV-1 1N-mediated integration. Conversely,overexpression of Sp100 by transient transfection decreased HIV-1 IN-mediated integration. This is the first time that Sp100 has been found to interact with HIV-I IN and inhibit lentiviral vector integration. It reveals a new function of Sp100 as a HIV-1 IN-interacting protein and expands knowledge of the cellular defensive response to viral infection.