6h4i
Usp28 catalytic domain apo
Structural highlights
FunctionUBP28_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 PubMedDeubiquitinases have emerged as promising drug targets for cancer therapy. The two DUBs USP25 and USP28 share high similarity but vary in their cellular functions. USP28 is known for its tumor-promoting role, whereas USP25 is a regulator of the innate immune system and, recently, a role in tumorigenesis was proposed. We solved the structures of the catalytic domains of both proteins and established substantial differences in their activities. While USP28 is a constitutively active dimer, USP25 presents an auto-inhibited tetramer. Our data indicate that the activation of USP25 is not achieved through substrate or ubiquitin binding. USP25 cancer-associated mutations lead to activation in vitro and in vivo, thereby providing a functional link between auto-inhibition and the cancer-promoting role of the enzyme. Our work led to the identification of significant differences between USP25 and USP28 and provided the molecular basis for the development of new and highly specific anti-cancer drugs. Differential Oligomerization of the Deubiquitinases USP25 and USP28 Regulates Their Activities.,Sauer F, Klemm T, Kollampally RB, Tessmer I, Nair RK, Popov N, Kisker C Mol Cell. 2019 Mar 22. pii: S1097-2765(19)30140-6. doi:, 10.1016/j.molcel.2019.02.029. PMID:30926243[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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