Membrane Associated Ring Finger Protein 1 (MARCH1)

MARCH1 is a member of the MARCH family of membrane-bound E3 ubiquitin ligases (EC 6.3.2.19). MARCH proteins add ubiquitin to target lysines in substrate proteins, thereby signaling their vesicular transport between membrane compartments. MARCH1 downregulates the surface expression of major histocompatibility complex (MHC) class II molecules  and other glycoproteins by directing them to the late endosomal/lysosomal compartment .The deduced MARCH1 protein contains a short N terminus, followed by a RING-CH domain and 2 transmembrane domains. MARCH1 shares over 90% identity with MARCH8 in the RING-CH and transmembrane domains. Real-time PCR analysis detected highest MARCH1 expression in lymph node, followed by spleen and lung.