title: Identification of cellular proteins interacting with influenza A virus  PB1-F2 protein.
abstract: The influenza A virus (IAV) protein PB1-F2, which is encoded by an alternative ORF of the PB1 polymerase gene, has been implicated as an important virulence factor and apoptosis inducer. However, the molecular mechanism of PB1-F2 function remains elusive. In this study, eight cellular proteins were identified as potential PB1-F2 interacting partners using the yeast two-hybrid system. Two positive candidate proteins, guanine nucleotide binding protein (G protein) beta polypeptide 2 (Gβ2) and macrophage migration inhibitory factor (MIF), were selected to be further characterized. The interaction of MIF and Gβ2 with PB1-F2 was confirmed by both GST pull-down and co-immunoprecipitation assays. Confocal laser microscopy showed that the interaction between PB1-F2 and the two cellular proteins occurred in the cytoplasm. The novel interactions between PB1-F2 and host proteins provide further pieces of evidence in the investigation of the pathogenic mechanism of IAV.
  
  
  BACKGROUND
  influenza A virus; PB1-F2; yeast two-hybrid; protein-protein interaction.
authors.affiliation: Key Laboratory of Zoonosis Ministry of Education, Institute of Zoonosis, Jilin University, 130062 Changchun, P. R. China. guanzh@jlu.edu.cn
authors.forename: Z H
authors.initials: ZH
authors.lastname: Guan
authors.forename: M L
authors.initials: ML
authors.lastname: Zhang
authors.forename: P L
authors.initials: PL
authors.lastname: Hou
authors.forename: M
authors.initials: M
authors.lastname: Duan
authors.forename: Y M
authors.initials: YM
authors.lastname: Cui
authors.forename: X R
authors.initials: XR
authors.lastname: Wang
mesh_terms: D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000378:metabolism*; D007251:Influenza, Human / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D019746:Intramolecular Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D008263:Macrophage Migration-Inhibitory Factors / Q000235:genetics / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C578133:GNB2 protein, human; D008263:Macrophage Migration-Inhibitory Factors; D009363:Neoplasm Proteins; C442816:PB1-F2 protein, Influenza A virus; C419368:RACK1 protein, human; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface; D014764:Viral Proteins; D019204:GTP-Binding Proteins; D019746:Intramolecular Oxidoreductases; C515598:MIF protein, human