title: Parainfluenza virus 5 m protein interaction with host protein 14-3-3 negatively affects virus particle formation.
abstract: Paramyxovirus matrix (M) proteins organize virus assembly, linking viral glycoproteins and viral ribonucleoproteins together at virus assembly sites on cellular membranes. Using a yeast two-hybrid screening approach, we identified 14-3-3 as a binding partner for the M protein of parainfluenza virus 5 (PIV5). Binding in both transfected and PIV5-infected cells was confirmed by coimmunoprecipitation and was mapped to a C-terminal region within the M protein, namely, 366-KTKSLP-371. This sequence resembles known 14-3-3 binding sites, in which the key residue for binding is a phosphorylated serine residue. Mutation of S369 within the PIV5 M protein disrupted 14-3-3 binding and improved the budding of both virus-like particles (VLPs) and recombinant viruses, suggesting that 14-3-3 binding impairs virus budding. 14-3-3 protein overexpression reduced the budding of VLPs. Using (33)P labeling, phosphorylated M protein was detected in PIV5-infected cells, and this phosphorylation was nearly absent in cells infected with a recombinant virus harboring an S369A mutation within the M protein. Assembly of the M protein into clusters and filaments at infected cell surfaces was enhanced in cells infected with a recombinant virus defective in 14-3-3 binding. These findings support a model in which a portion of M protein within PIV5-infected cells is phosphorylated at residue S369, binds the 14-3-3 protein, and is held away from sites of virus budding.
authors.affiliation: Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Zifei
authors.initials: Z
authors.lastname: Pei
authors.forename: Megan S
authors.initials: MS
authors.lastname: Harrison
authors.forename: Anthony P
authors.initials: AP
authors.lastname: Schmitt
mesh_terms: D048948:14-3-3 Proteins / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D002460:Cell Line; D015536:Down-Regulation; D006801:Humans; D008969:Molecular Sequence Data; D045402:Parainfluenza Virus 5 / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D010766:Phosphorylation; D011485:Protein Binding; D019351:Rubulavirus Infections / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D016415:Sequence Alignment; D014763:Viral Matrix Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014771:Virion / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D019065:Virus Assembly
chemical_list: D048948:14-3-3 Proteins; D014763:Viral Matrix Proteins; C482982:YWHAB protein, human