InterPro domain: IPR044635

This entry represents ubiquitin carboxyl-terminal hydrolase 14 (UBP14) and its homologues, such as Ubp6 from fungi and Ubp6/7 from Arabidopsis. They are ubiquitin-specific proteases responsible for disassembling ubiquitin chains at the proteasome, cleaving ubiquitin precursors, and editing ubiquitin side chains [ 1 ]. It has been shown that an N-terminal ubiquitin-like (UBL) domain of USP14 associates with the base of the 26S proteasome and the interaction of USP14 with the proteasome activates the catalytic activity of USP14 [ 2 , 2 ]. It has also be shown that Ubp6 has both deubiquitinating activity and proteasome-inhibitory activity [ 3 ].

1. USP14 inhibits ER-associated degradation via interaction with IRE1alpha. Biochem. Biophys. Res. Commun. 379, 995-1000
2. Structure and mechanisms of the proteasome-associated deubiquitinating enzyme USP14. EMBO J. 24, 3747-56
3. Deubiquitinating enzyme Ubp6 functions noncatalytically to delay proteasomal degradation. Cell 127, 99-111