| 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
The 26S proteasome is a large cellular assembly that mediates the selective degradation of proteins in the nucleus and cytosol and is an established target for anti-cancer therapeutics. Protein substrates are typically targeted to the proteasome through modification with a polyubiquitin chain, which can be recognized by several proteasome-associated ubiquitin receptors. One of these receptors, RPN13/ADRM1, is recruited to the proteasome through direct interaction with the large scaffolding protein RPN2 within the 19S regulatory particle. To better understand the interactions between RPN13, RPN2, and ubiquitin, we used human proteins to map the RPN13-binding epitope to the C-terminal 14 residues of RPN2, which, like ubiquitin, binds the N-terminal PRU domain of RPN13. We also report crystal structures of the RPN13 PRU domain in complex with peptides corresponding to the RPN2 C-terminus and ubiquitin. Through mutational analysis, we validated the RPN2 binding interface revealed by our structures and quantified binding interactions with surface plasmon resonance and fluorescence polarization. In contrast to a previous report, we find that RPN13 binds ubiquitin with an affinity similar to that of other proteasome-associated ubiquitin receptors and that RPN2, ubiquitin, and the deubiquitylase UCH37 bind to RPN13 with independent energetics. These findings provide a detailed characterization of interactions that are important for proteasome function, indicate ubiquitin affinities that are consistent with the role of RPN13 as a proteasomal ubiquitin receptor, and have major implications for the development of novel anticancer therapeutics.
Structure and energetics of pairwise interactions between proteasome subunits RPN2, RPN13, and ubiquitin clarify a substrate recruitment mechanism.,VanderLinden RT, Hemmis CW, Yao T, Robinson H, Hill CP J Biol Chem. 2017 Apr 25. pii: jbc.M117.785287. doi: 10.1074/jbc.M117.785287. PMID:28442575[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
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
- ↑ VanderLinden RT, Hemmis CW, Yao T, Robinson H, Hill CP. Structure and energetics of pairwise interactions between proteasome subunits RPN2, RPN13, and ubiquitin clarify a substrate recruitment mechanism. J Biol Chem. 2017 Apr 25. pii: jbc.M117.785287. doi: 10.1074/jbc.M117.785287. PMID:28442575 doi:http://dx.doi.org/10.1074/jbc.M117.785287
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