Polyubiquitin chains target protein substrates to the 26S proteasome, where they are removed by the deubiquitinase Rpn11 to allow efficient substrate degradation. Despite Rpn11's essential function during substrate processing, its detailed structural and biochemical characterization has been hindered by difficulties in purifying the isolated enzyme. Here we report the 2.0-Å crystal structures of Zn(2+)-free and Zn(2+)-bound Saccharomyces cerevisiae Rpn11 in an MPN-domain heterodimer with Rpn8. The Rpn11-Rpn8 interaction occurs via two distinct interfaces that may be conserved in related MPN-domain complexes. Our structural and mutational studies reveal that Rpn11 lacks a conserved surface to bind the ubiquitin Ile44 patch, does not interact with the moiety on the proximal side of the scissile isopeptide bond and exhibits no linkage specificity for ubiquitin cleavage. These findings explain how Rpn11 functions as a promiscuous deubiquitinase for cotranslocational substrate deubiquitination during proteasomal degradation.
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http://dx.doi.org/10.1038/nsmb.2771 | DOI Listing |
Acta Pharmacol Sin
January 2025
Department of Cardiology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325035, China.
Increased level of angiotensin II (Ang II) plays a central role in the development of hypertensive vascular remodeling. In this study, we identified the deubiquitinating enzyme Josephin domain-containing protein 2 (JOSD2) as a protective factor and investigated its molecular mechanism in Ang II-induced vascular remodeling. First, we found that JOSD2 was upregulated in aortic smooth muscle cells, but not in endothelial cells of Ang II-challenged mouse vascular tissues.
View Article and Find Full Text PDFCell Death Differ
January 2025
Department of Endocrinology, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China.
Recent studies have implicated altered ubiquitination/de-ubiquitination pathway in the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD). Here, we investigated the potential role of a deubiquitinase, ubiquitin-specific peptidase 25 (USP25), in MASLD. Analysis of mRNA profiling data showed that both human and mouse MASLD are associated with reduced expression of USP25 in hepatocytes.
View Article and Find Full Text PDFJ Proteome Res
January 2025
Target Discovery Institute, Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, U.K.
Inhibition of the mitochondrial deubiquitinating (DUB) enzyme USP30 is neuroprotective and presents therapeutic opportunities for the treatment of idiopathic Parkinson's disease and mitophagy-related disorders. We integrated structural and quantitative proteomics with biochemical assays to decipher the mode of action of covalent USP30 inhibition by a small-molecule containing a cyanopyrrolidine reactive group, . The inhibitor demonstrated high potency and selectivity for endogenous USP30 in neuroblastoma cells.
View Article and Find Full Text PDFZhong Nan Da Xue Xue Bao Yi Xue Ban
August 2024
School of Economics and Management, Beijing Forestry University, Beijing 100083, China.
OTU domain-containing protein 3 (OTUD3) is a crucial deubiquitinase that exhibits significant expression differences across various disease models. OTUD3 plays a role in regulating biological functions such as apoptosis, inflammatory responses, cell cycle, proliferation, and invasion in different cell types. By deubiquitinating key substrate proteins, OTUD3 is involved in essential physiological and pathological processes, including innate antiviral immunity, neural development, neurodegenerative diseases, and cancer.
View Article and Find Full Text PDFBiomedicines
December 2024
Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN 55905, USA.
Background/objectives: The enzyme ubiquitin-specific protease 44 (USP44) is a deubiquitinating enzyme with identified physiological roles as a tumor suppressor and an oncogene. While some binding partners and substrates are known for USP44, the identification of other interactions may improve our understanding of its role in cancer. We therefore performed a proximity biotinylation study that identified products of several known cancer genes that are associated with USP44, including a novel interaction between BRCA2 and USP44.
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