| Structural highlights
Function
[UBP28_HUMAN] Deubiquitinase involved in DNA damage response checkpoint and MYC proto-oncogene stability. Involved in DNA damage induced apoptosis by specifically deubiquitinating proteins of the DNA damage pathway such as CLSPN. Also involved in G2 DNA damage checkpoint, by deubiquitinating CLSPN, and preventing its degradation by the anaphase promoting complex/cyclosome (APC/C). In contrast, it does not deubiquitinate PLK1. Specifically deubiquitinates MYC in the nucleoplasm, leading to prevent MYC degradation by the proteasome: acts by specifically interacting with isoform 1 of FBXW7 (FBW7alpha) in the nucleoplasm and counteracting ubiquitination of MYC by the SCF(FBW7) complex. In contrast, it does not interact with isoform 4 of FBXW7 (FBW7gamma) in the nucleolus, allowing MYC degradation and explaining the selective MYC degradation in the nucleolus.[1] [2] [3] [4]
Publication Abstract from PubMed
The evolutionarily related deubiquitinating enzymes (DUBs) USP25 and USP28 comprise an identical overall domain architecture but are functionally non-redundant: USP28 stabilizes c-MYC and other nuclear proteins, and USP25 regulates inflammatory TRAF signaling. We here compare molecular features of USP25 and USP28. Active enzymes form distinctively shaped dimers, with a dimerizing insertion spatially separating independently active catalytic domains. In USP25, but not USP28, two dimers can form an autoinhibited tetramer, where a USP25-specific, conserved insertion sequence blocks ubiquitin binding. In full-length enzymes, a C-terminal domain with a previously unknown fold has no impact on oligomerization, but N-terminal regions affect the dimer-tetramer equilibrium in vitro. We confirm oligomeric states of USP25 and USP28 in cells and show that modulating oligomerization affects substrate stabilization in accordance with in vitro activity data. Our work highlights how regions outside of the catalytic domain enable a conceptually intriguing interplay of DUB oligomerization and activity.
Distinct USP25 and USP28 Oligomerization States Regulate Deubiquitinating Activity.,Gersch M, Wagstaff JL, Toms AV, Graves B, Freund SMV, Komander D Mol Cell. 2019 Mar 21. pii: S1097-2765(19)30141-8. doi:, 10.1016/j.molcel.2019.02.030. PMID:30926242[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Zhang D, Zaugg K, Mak TW, Elledge SJ. A role for the deubiquitinating enzyme USP28 in control of the DNA-damage response. Cell. 2006 Aug 11;126(3):529-42. PMID:16901786 doi:http://dx.doi.org/10.1016/j.cell.2006.06.039
- ↑ Popov N, Wanzel M, Madiredjo M, Zhang D, Beijersbergen R, Bernards R, Moll R, Elledge SJ, Eilers M. The ubiquitin-specific protease USP28 is required for MYC stability. Nat Cell Biol. 2007 Jul;9(7):765-74. Epub 2007 Jun 10. PMID:17558397 doi:http://dx.doi.org/10.1038/ncb1601
- ↑ Popov N, Herold S, Llamazares M, Schulein C, Eilers M. Fbw7 and Usp28 regulate myc protein stability in response to DNA damage. Cell Cycle. 2007 Oct 1;6(19):2327-31. Epub 2007 Jul 26. PMID:17873522
- ↑ Bassermann F, Frescas D, Guardavaccaro D, Busino L, Peschiaroli A, Pagano M. The Cdc14B-Cdh1-Plk1 axis controls the G2 DNA-damage-response checkpoint. Cell. 2008 Jul 25;134(2):256-67. doi: 10.1016/j.cell.2008.05.043. PMID:18662541 doi:http://dx.doi.org/10.1016/j.cell.2008.05.043
- ↑ Gersch M, Wagstaff JL, Toms AV, Graves B, Freund SMV, Komander D. Distinct USP25 and USP28 Oligomerization States Regulate Deubiquitinating Activity. Mol Cell. 2019 Mar 21. pii: S1097-2765(19)30141-8. doi:, 10.1016/j.molcel.2019.02.030. PMID:30926242 doi:http://dx.doi.org/10.1016/j.molcel.2019.02.030
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