Evidence that the CM2 protein of influenza C virus can modify the pH of the exocytic pathway of transfected cells.
The 115 residue CM2 protein of influenza C virus is a structural homologue of the M2 protein of influenza A virus. Expression of the CM2 protein in Xenopus oocytes showed that it can form a voltage-activated ion channel permeable to Cl-. To investigate whether the CM2 protein has pH modulating activity comparable to that of the M2 protein, CM2 was co-expressed with a pH-sensitive haemagglutinin (HA) from influenza A virus. The results indicate that, like the M2 protein, the CM2 protein has a capacity to reduce the acidity of the exocytic pathway and reduce conversion of the pH-sensitive HA to its low pH conformation during transport to the cell surface. By contrast, the NB protein of influenza B virus has no detectable activity. Although, the pH modulating activity of the CM2 protein was substantially less than that of the M2 protein, these observations provide support for a role in virus uncoating analogous to that of M2.
Betakova
Tatiana
T
National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK.|Institute of Virology - Slovaks Academy of Sciences, Dubravska cesta 9, 845 05 Bratislava, Slovak Republic.
Hay
Alan J
AJ
National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK.
D000143:Acids / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D009982:Gammainfluenzavirus / Q000737:chemistry*; D014162:Transfection; D014763:Viral Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism
D000143:Acids; C090877:CM2 protein, Influenza C virus; D019267:Hemagglutinin Glycoproteins, Influenza Virus; C051094:NB glycoprotein, Influenza B virus; D014763:Viral Matrix Proteins; D014764:Viral Proteins