MARCH9 is a member of the MARCH family of membrane-bound E3 ubiquitin ligases (EC 6.3.2.19). MARCH enzymes add ubiquitin (see MIM 191339) to target lysines in substrate proteins, thereby signaling their vesicular transport between membrane compartments. MARCH9 induces internalization of several membrane glycoproteins and directs them to the endosomal compartment (Bartee et al., 2004 [PubMed 14722266]; Hoer et al., 2007 [PubMed 17174307]).[supplied by OMIM, Apr 2010].