Wolff T, O'Neill R E, Palese P
Department of Microbiology, Mount Sinai School of Medicine, New York 10029, USA.
J Virol. 1996 Aug;70(8):5363-72. doi: 10.1128/JVI.70.8.5363-5372.1996.
The yeast interaction trap system was used to identify, NS1-I (for NS1 interactor), which is a human protein that binds to the nonstructural NS1 protein of the influenza A virus. NS1-I is a human homolog of the porcine 17beta-estradiol dehydrogenase precursor protein, to which it is 84% identical. We detected only one NS1-I mRNA species, of about 3.0 kb, in HeLa cells, and the NS1-I cDNA was found to have a coding capacity for a 79.6-kDa protein. However, immunoblot analysis detected predominantly a 55-kDa protein in human cells, suggesting that NS1-I, like the porcine 17beta-estradiol dehydrogenase, is posttranslationally processed. Using an in vitro coprecipitation assay, we showed that NS1-I interacts with NS1 proteins from extracts of cells infected with five different influenza A virus strains as well as with the NS1 of an influenza B virus. The fact that influenza A and influenza B virus NS1 proteins bind to NS1-I suggests that this cellular protein plays a role in the influenza virus life cycle.
酵母相互作用陷阱系统用于鉴定NS1-I（NS1相互作用蛋白），它是一种与甲型流感病毒非结构NS1蛋白结合的人类蛋白。NS1-I是猪17β-雌二醇脱氢酶前体蛋白的人类同源物，二者的同源性为84%。我们在HeLa细胞中仅检测到一种约3.0 kb的NS1-I mRNA，并且发现NS1-I cDNA编码一种79.6 kDa的蛋白。然而，免疫印迹分析在人类细胞中主要检测到一种55 kDa的蛋白，这表明NS1-I与猪17β-雌二醇脱氢酶一样，经过了翻译后加工。通过体外共沉淀试验，我们发现NS1-I与感染五种不同甲型流感病毒株的细胞提取物中的NS1蛋白以及乙型流感病毒的NS1相互作用。甲型和乙型流感病毒NS1蛋白均与NS1-I结合，这一事实表明这种细胞蛋白在流感病毒生命周期中发挥作用。
