title: Phosphorylation of the human respiratory syncytial virus P protein mediates M2-2 regulation of viral RNA synthesis, a process that involves two P proteins.
abstract: The M2-2 protein regulates the balance between human respiratory syncytial virus (HRSV) transcription and replication. Here it is shown that M2-2 mediated transcriptional inhibition is managed through P protein phosphorylation. Transcription inhibition by M2-2 of the HRSV based minigenome pRSVluc, required P protein phosphorylation at serines (S) in positions 116, 117, 119 and increased inhibition is observed if S232 or S237 is also phosphorylated. Phosphorylation of these residues is required for viral particle egression from infected cells. Viral RNA synthesis complementation assays between P protein variants, suggest that two types of P proteins participate in the process as components of RNA dependent RNA polymerase (RdRp). Type I is only functional when, as a homotetramer, it is bound to N and L proteins through residues 203-241. Type II is functionally independent of these interactions and binds to N protein at a region outside residues 232-241. P protein type I phosphorylation at S116, S117 and S119, did not affect the activity of RdRp but this phosphorylation in type II avoids its interaction with N protein and impairs RdRp functionality for transcription and replication. Structural changes in the RdRp, mediated by phosphorylation turnover at the indicated residues, in the two types of P proteins, may result in a fine adjustment, late in the infectious cycle, of transcription, replication and progression in the morphogenetic process that ends in egression of the viral particles from infected cells.
authors.affiliation: Centro Nacional de Microbiología (CNM) Instituto de Salud Carlos III(ISCIII), Ctra. Majadahonda-Pozuelo Km 2., Majadahonda, Madrid 28220, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Asenjo
authors.affiliation: Centro Nacional de Microbiología (CNM) Instituto de Salud Carlos III(ISCIII), Ctra. Majadahonda-Pozuelo Km 2., Majadahonda, Madrid 28220, Spain. Electronic address: nvilla@isciii.es.
authors.forename: Nieves
authors.initials: N
authors.lastname: Villanueva
mesh_terms: D020816:Amino Acid Motifs; D015967:Gene Expression Regulation, Viral; D006801:Humans; D010766:Phosphorylation; D012367:RNA, Viral / Q000096:biosynthesis* / Q000235:genetics; D018357:Respiratory Syncytial Virus Infections / Q000821:virology*; D018113:Respiratory Syncytial Virus, Human / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism; D015678:Viral Structural Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: C507355:M2-2 protein, respiratory syncytial virus; C529603:P protein, human respiratory syncytial virus; D012367:RNA, Viral; D014764:Viral Proteins; D015678:Viral Structural Proteins
keywords: M2-2 protein; P protein phosphorylation; Replication; Transcription; Viral RNA synthesis