title: Interaction cloning of NS1-I, a human protein that binds to the nonstructural NS1 proteins of influenza A and B viruses.
abstract: 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.
authors.affiliation: Department of Microbiology, Mount Sinai School of Medicine, New York 10029, USA.
authors.forename: T
authors.initials: T
authors.lastname: Wolff
authors.forename: R E
authors.initials: RE
authors.lastname: O'Neill
authors.forename: P
authors.initials: P
authors.lastname: Palese
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004960:Estradiol Dehydrogenases / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D009980:Influenza A virus / Q000378:metabolism*; D009981:Influenza B virus / Q000378:metabolism*; D007251:Influenza, Human / Q000378:metabolism / Q000821:virology*; D008969:Molecular Sequence Data; D011485:Protein Binding; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae; D017421:Sequence Analysis; D017361:Viral Nonstructural Proteins / Q000378:metabolism*
chemical_list: C085820:INS1 protein, influenza virus; D011506:Proteins; D017361:Viral Nonstructural Proteins; D004960:Estradiol Dehydrogenases