E3 ubiquitin-protein ligase involved in ER-associated protein degradation, preferentially associates with the E2 enzyme UBE2J2. Exploited by viral US11 proteins to mediate HLA class I proteins degradation. . This is the function of TMEM129 (transmembrane protein 129, E3 ubiquitin ligase, Ensembl gene identifier ENSG00000168936).