Membrane glycoprotein of SARS-CoV-2 (M protein)

The membrane glycoprotein (M protein) of SARS-CoV-2 is the most abundant structural protein in the viral envelope, comprising three transmembrane domains with a short N-terminal region exposed outside the virion and a large C-terminal region inside. It forms homodimers and organizes the assembly of new virions by directing interactions with other viral structural proteins—spike (S), nucleocapsid (N), and envelope (E)—as well as with viral RNA. Unlike the spike glycoprotein (which mediates viral entry), the membrane glycoprotein functions primarily as a scaffold for viral packaging, morphogenesis, and budding, strongly influencing the shape and integrity of the virus particle. The M protein is evolutionarily related to the SemiSWEET family of sugar transporters but is unique in its structural features in coronaviruses. Its glycosylation patterns vary among coronavirus subgroups, and it can act as a target for patient antibodies and experimental vaccine approaches, although the spike protein remains the primary immunogen in most current vaccine designs.

Other names

Membrane proteinM proteinMatrix proteinE1 protein

Inhibition of protein-protein interactions (between M and other structural proteins) for viral assembly; Blocking immune evasion mechanisms (by preventing antibody recognition or assembly)