UBX Domain Protein 4 (UBXN4)

UBXD2 is an integral membrane protein of the endoplasmic reticulum (ER) that binds valosin-containing protein (VCP) and promotes ER-associated protein degradation (ERAD).The deduced 508-amino acid protein contains a putative coiled-coil region, a UBX domain, and a hydrophobic domain. UBXD2 shares 93% amino acid identity to the mouse homolog. Northern blot analysis detected a 3.9-kb transcript in all human tissues examined. Western blot analysis identified a major 64-kD band in all human cell lines tested with highest expression in HEK293 cells. Ubxd2 protein was detected in all mouse tissues examined with highest expression in brain. Immunofluorescence studies of HEK293 and HeLa cells showed that UBXD2 had a reticular staining pattern in the cytoplasm.