Influenza A virus Matrix protein 2 extracellular domain (M2e) (M2e)

The Influenza A Matrix protein 2 (M2) is a multifunctional homotetrameric integral membrane protein essential for the viral life cycle. Its extracellular domain, known as M2e, consists of approximately 24 amino acids and is highly conserved across nearly all human Influenza A strains, making it a primary candidate for 'universal' influenza vaccines. Beyond its role as a proton-selective ion channel that facilitates viral uncoating in the endosome, the M2 protein's cytoplasmic tail and assembly interfaces are critical for viral budding and the scission of new virions from the host cell membrane. Unlike the rapidly mutating hemagglutinin and neuraminidase proteins, M2e remains relatively stable, providing a consistent target for monoclonal antibodies and vaccine-induced immunity. Therapeutic strategies targeting M2e often rely on immune-mediated clearance of infected cells rather than direct neutralization of free virus particles. Research into the assembly interfaces of M2 also explores how disrupting protein-protein interactions can inhibit the formation of infectious progeny.

Other names

M2 ectodomainMatrix protein 2 extracellular domainInfluenza A M2eM2-associated assembly interfaces

Monoclonal antibodies targeting M2e primarily work through antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) to eliminate infected cells, while small molecules like amantadine block the M2 proton channel to prevent viral uncoating.