Use1/UBE2Z: ProductsUba6-specific E2 Conjugating Enzyme 1 (Use1), also known as Ubiquitin-conjugating Enzyme E2Z (UBE2Z), is a member of the Ubiquitin-conjugating (E2) enzyme family that is highly expressed in human placenta, pancreas, spleen, and testis. Use1/UBE2Z has a predicted molecular weight of 38 kDa. The human enzyme shares 98% amino acid sequence identity with its mouse and rat orthologs. It has an E2 catalytic core domain that contains an active site cysteine residue that is required for the formation of a thioester bond with Ubiquitin. Use1/UBE2Z functions specifically with the UBE1L2/UBA6 Ubiquitin-activating (E1) enzyme, rather than the UBE1 E1 enzyme, for Ubiquitin conjugation. Use1/UBE2Z expression is enriched in the cytoplasm where it mediates the ubiquitination of RGS4 and RGS5 via the N-end rule proteolytic pathway. Use1/UBE2Z also functions with UBE1L2/UBA6 to mediate the conjugation of HLA F-associated Transcript 10 (FAT10), a Ubiquitin-like protein, and is auto-FAT10ylated in response to TNF-alpha and IFN-gamma.