Axotrophin (AXOT)

MARCH7 is a member of the MARCH family of membrane-bound E3 ubiquitin ligases. MARCH proteins add ubiquitin to target lysines in substrate proteins, thereby signaling their vesicular transport between membrane compartments.

Poxviruses and gamma-2 herpesviruses express ubiquitin ligases called K3 proteins that inhibit the surface expression of glycoproteins, including major histocompatibility complex class I molecules. The deduced MARCH7 protein has a 500-amino acid N-terminal domain, followed by a RING-CH domain and 2 transmembrane domains. Other MARCH proteins lack the N-terminal extension, and the RING-CH domain of MARCH7 is only distantly related to those of other MARCH proteins.