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5ohp
From Proteopedia
Crystal structure of USP30 (C77A) in complex with Lys6-linked diubiquitin
Structural highlights
FunctionUBP30_HUMAN Deubiquitinating enzyme tethered to the mitochondrial outer membrane that acts as a key inhibitor of mitophagy by counteracting the action of parkin (PRKN): hydrolyzes ubiquitin attached by parkin on target proteins, such as RHOT1/MIRO1 and TOMM20, thereby blocking parkin's ability to drive mitophagy (PubMed:18287522, PubMed:24896179, PubMed:25527291, PubMed:25621951). Preferentially cleaves 'Lys-6'- and 'Lys-11'-linked polyubiquitin chains, 2 types of linkage that participate to mitophagic signaling (PubMed:25621951). Does not cleave efficiently polyubiquitin phosphorylated at 'Ser-65' (PubMed:25527291). Acts as negative regulator of mitochondrial fusion by mediating deubiquitination of MFN1 and MFN2 (By similarity).[UniProtKB:Q3UN04][1] [2] [3] [4] Publication Abstract from PubMedDamaged mitochondria undergo mitophagy, a specialized form of autophagy that is initiated by the protein kinase PINK1 and the ubiquitin E3 ligase Parkin. Ubiquitin-specific protease USP30 antagonizes Parkin-mediated ubiquitination events on mitochondria and is a key negative regulator of mitophagy. Parkin and USP30 both show a preference for assembly or disassembly, respectively, of Lys6-linked polyubiquitin, a chain type that has not been well studied. Here we report crystal structures of human USP30 bound to monoubiquitin and Lys6-linked diubiquitin, which explain how USP30 achieves Lys6-linkage preference through unique ubiquitin binding interfaces. We assess the interplay between USP30, PINK1 and Parkin and show that distally phosphorylated ubiquitin chains impair USP30 activity. Lys6-linkage-specific affimers identify numerous mitochondrial substrates for this modification, and we show that USP30 regulates Lys6-polyubiquitinated TOM20. Our work provides insights into the architecture, activity and regulation of USP30, which will aid drug design against this and related enzymes. Mechanism and regulation of the Lys6-selective deubiquitinase USP30.,Gersch M, Gladkova C, Schubert AF, Michel MA, Maslen S, Komander D Nat Struct Mol Biol. 2017 Sep 25. doi: 10.1038/nsmb.3475. PMID:28945249[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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