UBE2J1: ProductsUbiquitin-conjugating Enzyme E2, J1 (UBE2J1), also known as HsUbc6e, is a 318 amino acid (aa) member of the Ubiquitin-conjugating (E2) enzyme family with a predicted molecular weight of approximately 35 kDa. The human protein shares 92% and 85% aa sequence identity with the mouse and rat orthologs, respectively. UBE2J1 has an E2 catalytic core domain with an active site cysteine residue that is required for the formation of a thioester bond with Ubiquitin. It localizes to endoplasmic reticulum (ER) membranes where it participates in ER-associated degradation (ERAD) of misfolded proteins. In response to ER stress, UBE2J1 is phosphorylated on Ser184 in a PERK-dependent manner. It has also been shown to function with the HRD1 Ubiquitin ligase (E3) to promote the ubiquitination and degradation of misfolded MHC class I heavy chain via ERAD. Additionally, UBE2J1 may have a preventative role in early-onset systemic amyloidosis. It has a redundant role, along with the UBE2G2 E2 enzyme, in promoting the degradation of a mutant form of Transthyretin that is associated with this disease.