| Structural highlights
Function
[ADRM1_HUMAN] Functions as a proteasomal ubiquitin receptor. Recruits the deubiquitinating enzyme UCHL5 at the 26S proteasome and promotes its activity.[1] [2] [3] [4] [5]
Publication Abstract from PubMed
Uch37 is a de-ubiquitinating enzyme that is activated by Rpn13 and involved in the proteasomal degradation of proteins. The full-length Uch37 was shown to exhibit low iso-peptidase activity and is thought to be auto-inhibited. Structural comparisons revealed that within a homo-dimer of Uch37, each of the catalytic domains was blocking the other's ubiquitin (Ub)-binding site. This blockage likely prevented Ub from entering the active site of Uch37 and might form the basis of auto-inhibition. To understand the mode of auto-inhibition clearly and shed light on the activation mechanism of Uch37 by Rpn13, we investigated the Uch37-Rpn13 complex using a combination of mutagenesis, biochemical, NMR, and small-angle X-ray scattering (SAXS) techniques. Our results also proved that Uch37 oligomerized in solution and had very low activity against the fluorogenic substrate ubiquitin-7-amino-4-methylcoumarin (Ub-AMC) of de-ubiquitinating enzymes. Uch37Delta(Hb,Hc,KEKE), a truncation removal of the C-terminal extension region (residues 256-329) converted oligomeric Uch37 into a monomeric form that exhibited iso-peptidase activity comparable to that of a truncation-containing the Uch37 catalytic domain only. We also demonstrated that Rpn13C (Rpn13 residues 270-407) could disrupt the oligomerization of Uch37 by sequestering Uch37 and forming a Uch37-Rpn13 complex. Uch37 was activated in such a complex, exhibiting 12-fold-higher activity than Uch37 alone. Time-resolved SAXS (TR-SAXS) and FRET experiments supported the proposed mode of auto-inhibition and the activation mechanism of Uch37 by Rpn13. Rpn13 activated Uch37 by forming a 1:1 stoichiometric complex in which the active site of Uch37 was accessible to Ub.
Mechanism of the Rpn13-induced activation of Uch37.,Jiao L, Ouyang S, Shaw N, Song G, Feng Y, Niu F, Qiu W, Zhu H, Hung LW, Zuo X, Eleonora Shtykova V, Zhu P, Dong YH, Xu R, Liu ZJ Protein Cell. 2014 Aug;5(8):616-30. doi: 10.1007/s13238-014-0046-z. Epub 2014 Apr, 22. PMID:24752541[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Hamazaki J, Iemura S, Natsume T, Yashiroda H, Tanaka K, Murata S. A novel proteasome interacting protein recruits the deubiquitinating enzyme UCH37 to 26S proteasomes. EMBO J. 2006 Oct 4;25(19):4524-36. Epub 2006 Sep 21. PMID:16990800 doi:http://dx.doi.org/10.1038/sj.emboj.7601338
- ↑ Qiu XB, Ouyang SY, Li CJ, Miao S, Wang L, Goldberg AL. hRpn13/ADRM1/GP110 is a novel proteasome subunit that binds the deubiquitinating enzyme, UCH37. EMBO J. 2006 Dec 13;25(24):5742-53. Epub 2006 Nov 30. PMID:17139257 doi:http://dx.doi.org/7601450
- ↑ Jorgensen JP, Lauridsen AM, Kristensen P, Dissing K, Johnsen AH, Hendil KB, Hartmann-Petersen R. Adrm1, a putative cell adhesion regulating protein, is a novel proteasome-associated factor. J Mol Biol. 2006 Jul 28;360(5):1043-52. Epub 2006 Jun 21. PMID:16815440 doi:http://dx.doi.org/S0022-2836(06)00703-0
- ↑ Yao T, Song L, Xu W, DeMartino GN, Florens L, Swanson SK, Washburn MP, Conaway RC, Conaway JW, Cohen RE. Proteasome recruitment and activation of the Uch37 deubiquitinating enzyme by Adrm1. Nat Cell Biol. 2006 Sep;8(9):994-1002. Epub 2006 Aug 13. PMID:16906146 doi:ncb1460
- ↑ Husnjak K, Elsasser S, Zhang N, Chen X, Randles L, Shi Y, Hofmann K, Walters KJ, Finley D, Dikic I. Proteasome subunit Rpn13 is a novel ubiquitin receptor. Nature. 2008 May 22;453(7194):481-8. PMID:18497817 doi:10.1038/nature06926
- ↑ Jiao L, Ouyang S, Shaw N, Song G, Feng Y, Niu F, Qiu W, Zhu H, Hung LW, Zuo X, Eleonora Shtykova V, Zhu P, Dong YH, Xu R, Liu ZJ. Mechanism of the Rpn13-induced activation of Uch37. Protein Cell. 2014 Aug;5(8):616-30. doi: 10.1007/s13238-014-0046-z. Epub 2014 Apr, 22. PMID:24752541 doi:http://dx.doi.org/10.1007/s13238-014-0046-z
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