Matrix protein 2 protein of Influenza A virus (M2)

Matrix protein 2 (M2) of Influenza A virus is a small integral membrane protein (viroporin) comprised of about 97 amino acids, organized as a tetramer that forms a proton-selective ion channel in the viral envelope[1][2][3][6][7]. Its N-terminal extracellular domain (M2e) is highly conserved and a target for universal influenza A vaccine development[1][4]. The channel is activated by low endosomal pH after viral entry and is essential for proton influx into the viral particle, which dissociates viral ribonucleoprotein from matrix protein 1 and enables genome release into the host cell[1][2][3]. The M2 channel's activity is also crucial for viral assembly, budding, and modulation of host cellular processes such as autophagy and immune response[3][4]. The M2 protein is the target of adamantane antiviral drugs, but widespread resistance has diminished their efficacy[2][3]. Its unique structural and functional features make M2 both a therapeutic and vaccine target in influenza A infection.

Other names

Matrix-2 proteinM2 proton channelAM2Influenza A virus M2 proteinViroporin M2

Blockade of the M2 proton channel inhibits proton conductance, thereby preventing acidification of the viral particle interior, which inhibits viral uncoating and genome release into the host cell[2][3][6][7].