Matrix protein 2 ectodomain (M2e)

The Influenza A virus Matrix protein 2 ectodomain (M2e) is the highly conserved 24-amino acid N-terminal portion of the M2 proton channel (UniProt: P06821). While the full M2 protein functions as a pH-gated ion channel essential for viral uncoating and assembly, the M2e region is exposed on the surface of the virion and infected cells, making it a prime target for 'universal' influenza vaccines and therapeutic antibodies (PubMed: 25535331). Unlike the hemagglutinin and neuraminidase proteins, M2e remains remarkably stable across various Influenza A strains, including H1N1 and H5N1 (PubMed: 22438551). Therapeutic strategies targeting M2e primarily rely on inducing or providing antibodies that facilitate the clearance of infected cells through immune-mediated mechanisms like antibody-dependent cellular cytotoxicity (ADCC). Although traditional adamantane drugs like amantadine target the transmembrane pore of M2, modern research focuses on M2e to overcome the challenges of seasonal antigenic drift (PubMed: 23152533). Consequently, M2e is a critical focus for developing broad-spectrum protection against diverse influenza subtypes.

Other names

Influenza A virus M2 extracellular domainM2 ectodomainMatrix protein 2 extracellular domainM2e peptide

Therapeutic antibodies targeting M2e bind to the extracellular domain of the M2 protein expressed on the surface of infected cells, facilitating their clearance through antibody-dependent cellular cytotoxicity (ADCC) or complement-dependent cytotoxicity (CDC) (PubMed: 25535331). Traditional small molecule inhibitors like amantadine target the transmembrane pore of the full M2 protein to block proton conductance and prevent viral uncoating (UniProt: P06821).