Structural highlights
Function
UBP4_HUMAN Hydrolase that deubiquitinates target proteins such as the receptor ADORA2A, PDPK1 and TRIM21. Deubiquitination of ADORA2A increases the amount of functional receptor at the cell surface. Plays a role in the regulation of quality control in the ER.[1] [2] [3] [4]
Publication Abstract from PubMed
Ubiquitin-specific protease USP4 is emerging as an important regulator of cellular pathways, including the TGF-beta response, NF-kappaB signalling and splicing, with possible roles in cancer. Here we show that USP4 has its catalytic triad arranged in a productive conformation. Nevertheless, it requires its N-terminal DUSP-Ubl domain to achieve full catalytic turnover. Pre-steady-state kinetics measurements reveal that USP4 catalytic domain activity is strongly inhibited by slow dissociation of ubiquitin after substrate hydrolysis. The DUSP-Ubl domain is able to enhance ubiquitin dissociation, hence promoting efficient turnover. In a mechanism that requires all USP4 domains, binding of the DUSP-Ubl domain promotes a change of a switching loop near the active site. This 'allosteric regulation of product discharge' provides a novel way of regulating deubiquitinating enzymes that may have relevance for other enzyme classes.
The DUSP-Ubl domain of USP4 enhances its catalytic efficiency by promoting ubiquitin exchange.,Clerici M, Luna-Vargas MP, Faesen AC, Sixma TK Nat Commun. 2014 Nov 18;5:5399. doi: 10.1038/ncomms6399. PMID:25404403[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Gray DA, Inazawa J, Gupta K, Wong A, Ueda R, Takahashi T. Elevated expression of Unph, a proto-oncogene at 3p21.3, in human lung tumors. Oncogene. 1995 Jun 1;10(11):2179-83. PMID:7784062
- ↑ Wada K, Tanji K, Kamitani T. Oncogenic protein UnpEL/Usp4 deubiquitinates Ro52 by its isopeptidase activity. Biochem Biophys Res Commun. 2006 Jan 20;339(3):731-6. PMID:16316627 doi:10.1016/j.bbrc.2005.11.076
- ↑ Wada K, Kamitani T. UnpEL/Usp4 is ubiquitinated by Ro52 and deubiquitinated by itself. Biochem Biophys Res Commun. 2006 Mar 31;342(1):253-8. Epub 2006 Feb 6. PMID:16472766 doi:10.1016/j.bbrc.2006.01.144
- ↑ Milojevic T, Reiterer V, Stefan E, Korkhov VM, Dorostkar MM, Ducza E, Ogris E, Boehm S, Freissmuth M, Nanoff C. The ubiquitin-specific protease Usp4 regulates the cell surface level of the A2A receptor. Mol Pharmacol. 2006 Apr;69(4):1083-94. Epub 2005 Dec 9. PMID:16339847 doi:10.1124/mol.105.015818
- ↑ Clerici M, Luna-Vargas MP, Faesen AC, Sixma TK. The DUSP-Ubl domain of USP4 enhances its catalytic efficiency by promoting ubiquitin exchange. Nat Commun. 2014 Nov 18;5:5399. doi: 10.1038/ncomms6399. PMID:25404403 doi:http://dx.doi.org/10.1038/ncomms6399
