title: The cytoplasmic domain of influenza M2 protein interacts with caveolin-1.
abstract: The cytoplasmic domain of influenza M2 protein (M2c) consists of 54 amino acid (aa) residues from aa44 to aa97. In this paper, M2c and its deletion mutant M2c(delta47-55) were expressed using prokaryotic expression system. First, glutaraldehyde crosslinking assay showed that M2c had multimerization potential mediated by aa47-55. Then, M2c, instead of M2c(delta47-55), directed eGFP from the whole cell localization to a predominately perinuclear region in CHO cells, which indicated that aa47-55 of M2c mediated the localization. Moreover, M2c colocalized with caveolin-1 (Cav) when CHO cells were cotransfected with Cav. A caveolin-1 binding motif phixxxxphixxphi (phi represents aromatic amino acid residues) in aa47-55 of M2c was found by sequence alignment and analysis. Further overlay ELISA result showed that M2c, but not M2c(delta47-55), bound to prokaryotically expressed cholesterol-free Cav(2-101), which illustrated the interaction could be cholesterol-independent. That was the first report of cellular protein bound to M2c.
authors.affiliation: Department of Biology, Tsinghua University, Beijing, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zou
authors.forename: Fan
authors.initials: F
authors.lastname: Wu
authors.forename: Lu
authors.initials: L
authors.lastname: Lu
authors.forename: Jing-He
authors.initials: JH
authors.lastname: Huang
authors.forename: Ying-Hua
authors.initials: YH
authors.lastname: Chen
mesh_terms: D001665:Binding Sites; D051242:Caveolin 1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers; D005784:Gene Amplification; D009980:Influenza A virus / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D008958:Models, Molecular; D016133:Polymerase Chain Reaction; D011487:Protein Conformation; D014162:Transfection; D014763:Viral Matrix Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000737:chemistry / Q000378:metabolism; D000086082:Viroporin Proteins
chemical_list: D051242:Caveolin 1; D017931:DNA Primers; D014763:Viral Matrix Proteins; D014764:Viral Proteins; C488937:M2 protein, Influenza A virus; D000086082:Viroporin Proteins