The cleavage of spike protein НА0→НА1/HA2 by trypsin permits activation of the M2 channel without its proteolytic cleavage in the influenza A virus

Virology. 2021 Jul:559:86-88. doi: 10.1016/j.virol.2021.03.016. Epub 2021 Apr 1.

Abstract

M2 plays numerous regulatory roles in influenza A virus infection confirming the old adage: "a little body often harbors a great sense". The comment here demonstrates that a small viral protein M2, having 14 kD m.w. and situating in the virion at a minor amount of only about 40 molecules per virus particle is resistant to trypsin at concentrations initiating the HA0 cleavage and virus infectivity activation. A mechanism involving a programmed disassembly by cascade-type transmembrane signaling of the HA-M2-M1-RNP cooperation during virus entry into the infected cell is proposed.

Keywords: Acidification; Cleavage; HA; Influenza virus; M2.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Dogs
  • Hemagglutinin Glycoproteins, Influenza Virus / genetics*
  • Hemagglutinin Glycoproteins, Influenza Virus / metabolism*
  • Humans
  • Influenza A Virus, H3N2 Subtype / chemistry
  • Influenza A Virus, H3N2 Subtype / drug effects
  • Influenza A Virus, H3N2 Subtype / genetics
  • Influenza A Virus, H3N2 Subtype / metabolism*
  • Madin Darby Canine Kidney Cells
  • Peptide Hydrolases / metabolism
  • Proteolysis
  • Signal Transduction
  • Trypsin / metabolism*
  • Trypsin / pharmacology
  • Viral Matrix Proteins / genetics*
  • Viroporin Proteins / genetics*
  • Virus Activation*
  • Virus Internalization

Substances

  • Hemagglutinin Glycoproteins, Influenza Virus
  • M2 protein, Influenza A virus
  • Viral Matrix Proteins
  • Viroporin Proteins
  • Peptide Hydrolases
  • Trypsin