title: Sequential phosphorylation of the phosphoprotein of vesicular stomatitis virus by cellular and viral protein kinases is essential for transcription activation.
abstract: The phosphoprotein (P) and the large protein (L) constitute the RNA-dependent RNA polymerase of vesicular stomatitis virus (VSV). We show that phosphate-free P protein expressed in bacteria is transcriptionally inactive when reconstituted with L protein and viral N-RNA template free of cellular protein kinase. Phosphorylation of P protein by a cellular kinase(s) was essential for transcription as well as for further phosphorylation by an L-associated kinase, the two kinases acting in a sequential (cascade) manner. Phosphate groups introduced by cell kinase were stable, whereas those due to L kinase underwent a turnover which was coupled to ongoing transcription. We present a model for the phosphorylation pathway of P protein and propose that continued phosphorylation and dephosphorylation of P protein may represent a transcriptional regulatory (on-off) switch of nonsegmented negative-strand RNA viruses.
authors.affiliation: Department of Molecular Biology, Research Institute, Cleveland Clinic Foundation, Ohio 44195.
authors.forename: S
authors.initials: S
authors.lastname: Barik
authors.forename: A K
authors.initials: AK
authors.lastname: Banerjee
mesh_terms: D000818:Animals; D002460:Cell Line; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D007700:Kinetics; D008954:Models, Biological; D010750:Phosphoproteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014721:Vesicular stomatitis Indiana virus / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism
chemical_list: D010750:Phosphoproteins; D011994:Recombinant Proteins; D011494:Protein Kinases; D012324:RNA-Dependent RNA Polymerase