RING finger, HC subclass, found in peroxin-2 (PEX2) and similar proteins
PEX2, also known as peroxisome biogenesis factor 2, 35 kDa peroxisomal membrane protein, peroxisomal membrane protein 3, peroxisome assembly factor 1 (PAF-1), or RING finger protein 72 (RNF72), is an integral peroxisomal membrane protein with two transmembrane regions and a C3HC4-type RING-HC finger within its cytoplasmically exposed C-terminus. It may be involved in the biogenesis of peroxisomes, as well as in peroxisomal matrix protein import. Mutations in the PEX2 gene are the primary defect in a subset of patients with Zellweger syndrome and related peroxisome biogenesis disorders. Moreover, PEX2 functions as an E3-ubiquitin ligase that mediates the UBC4-dependent polyubiquitination of PEX5, a key player in peroxisomal matrix protein import, to control PEX5 receptor recycling or degradation.