MARCH3 is a member of the MARCH family of membrane-bound E3 ubiquitin ligases (EC 6.3.2.19). MARCH proteins add ubiquitin (see MIM 191339) to target lysines in substrate proteins, thereby signaling their vesicular transport between membrane compartments. MARCH3 appears to function in the endosomal recycling pathway (Fukuda et al., 2006 [PubMed 16428329]).