Differential Phosphorylation of the Nucleoprotein of Influenza A Viruses

• Published in: Journal of general virology Vol. 70; no. 9; pp. 2421 - 2431
• Main Authors: Kistner, O, Muller, Karin, Scholtissek, C
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.09.1989; Society for General Microbiology
• Subjects: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; Amino Acids - analysis; Animals; Biological and medical sciences; Chick Embryo; Fundamental and applied biological sciences. Psychology; influenza A virus; Influenza A virus - analysis; Influenza A virus - metabolism; Influenza A virus - physiology; Isoquinolines - pharmacology; Microbiology; Morphology, structure, chemical composition, physicochemical properties; Nucleoproteins - isolation & purification; Nucleoproteins - metabolism; Peptide Mapping; Phosphopeptides - isolation & purification; Phosphoproteins - biosynthesis; Phosphoproteins - isolation & purification; Phosphorylation; Piperazines - pharmacology; Protein Kinase C - metabolism; Species Specificity; Tetradecanoylphorbol Acetate - pharmacology; Virology; Virus Replication; Virus; Proteins; Phosphorylation; Nucleocapside; Fingerprint method; Orthomyxoviridae; Virus replication cycle; Influenzavirus; Strain
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-70-9-2421

Institut für Virologie, Justus-Liebig-Universität Giessen, Frankfurter Strasse 107, D-6300 Giessen, F.R.G. An analysis of the nucleoprotein (NP) of 29 different influenza A viruses by phosphopeptide fingerprinting revealed three prototype patterns. The first, which was a complex pattern consisting of six to seven phosphopeptides, another which was relatively simple consisted of two or three phosphopeptides, and a third one which was complex but was missing the main phosphopeptide shared by the two other patterns. Phosphoserine was the only labelled phosphamino acid detected. A tentative deduction of two of the phosphate attachment sites (serine residues at positions 3 and 473) could be made by comparison of the known amino acid sequences of the NPs of 25 strains. No correlation was found between species specificity or subtype or year of isolation of the strains. During the infectious cycle the fingerprint underwent significant changes, indicating subtle phosphorylation and dephosphorylation of the NP at various stages during viral multiplication. Most of the phosphopeptides were metabolically stable; however one major phosphopeptide, which was not found in the NP of mature virions, exhibited a high turnover (presumably serine at position 3). The phosphopeptide fingerprint could be significantly influenced in vivo by the specific stimulation of cellular protein kinase C by the phorbol ester 12- O -tetradecanolyphorbol 13-acetate or by its inhibition with the isoquinoline sulphonamide H7. H7 specifically inhibited the replication of influenza A viruses by deregulation of viral protein synthesis without interfering with the multiplication of a parainfluenza virus (Newcastle disease virus), an alphavirus (Semliki Forest virus) or a flavivirus (West Nile). Therefore the correct phosphorylation of the NP of influenza viruses appears to be essential for influenza virus replication. Keywords: influenza A viruses, nucleoprotein, phosphopeptide fingerprints Received 22 December 1988; accepted 17 May 1989.