The function of ENSG00000170142 (UBE2E1, ubiquitin conjugating enzyme E2 E1) is as follows. Accepts ubiquitin from the E1 complex and catalyzes its covalent attachment to other proteins. Catalyzes the covalent attachment of ISG15 to other proteins. Mediates the selective degradation of short-lived and abnormal proteins. In vitro also catalyzes 'Lys-48'-linked polyubiquitination. Catalyzes monoubiquitination of other proteins in both an E3-dependent and E3- independent manner (PubMed:27237050). {ECO:0000269|PubMed:16428300, ECO:0000269|PubMed:20061386, ECO:0000269|PubMed:27237050}.