Membrane Associated Ring Finger Protein 3 (MARCH3)

MARCH3 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. MARCH3 appears to function in the endosomal recycling pathway. Overexpression of March3 in HeLa cells caused mislocalization of TGN46 (TGOLN2), an endosome protein that normally cycles between the plasma membrane and the trans-Golgi network (TGN), from the TGN to peripheral vesicles. Overexpression of March3 also interfered with uptake of transferrin (TF) through the endosomal recycling pathway. Immunoprecipitation analysis showed that epitope-tagged March3 interacted with March2 and with syntaxin-6 (STX6).