1
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Arkinson C, Dong KC, Gee CL, Costello SM, Marqusee S, Martin A. Nub1 traps unfolded FAT10 for ubiquitin-independent degradation by the 26S proteasome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.12.598715. [PMID: 38915702 PMCID: PMC11195292 DOI: 10.1101/2024.06.12.598715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
The ubiquitin-like modifier FAT10 targets hundreds of proteins in the mammalian immune system to the 26S proteasome for degradation. This degradation pathway requires the cofactor Nub1, yet the underlying mechanisms remain unknown. Here, we reconstituted a minimal in vitro system and revealed that Nub1 utilizes FAT10's intrinsic instability to trap its N-terminal ubiquitin-like domain in an unfolded state and deliver it to the 26S proteasome for engagement, allowing the degradation of FAT10-ylated substrates in a ubiquitin- and p97-independent manner. Through hydrogen-deuterium exchange, structural modeling, and site-directed mutagenesis, we identified the formation of a peculiar complex with FAT10 that activates Nub1 for docking to the 26S proteasome, and our cryo-EM studies visualized the highly dynamic Nub1 complex bound to the proteasomal Rpn1 subunit during FAT10 delivery and the early stages of ATP-dependent degradation. These studies thus identified a novel mode of cofactor-mediated, ubiquitin-independent substrate delivery to the 26S proteasome that relies on trapping partially unfolded states for engagement by the proteasomal ATPase motor.
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Affiliation(s)
- Connor Arkinson
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, CA94720, USA
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA94720, USA
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, CA94720, USA
| | - Ken C. Dong
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, CA94720, USA
| | - Christine L. Gee
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, CA94720, USA
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA94720, USA
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, CA94720, USA
| | - Shawn M. Costello
- Biophysics Graduate Program, University of California, Berkeley, CA, USA
| | - Susan Marqusee
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, CA94720, USA
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA94720, USA
- Department of Chemistry, University of California, Berkeley, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Andreas Martin
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, CA94720, USA
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA94720, USA
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, CA94720, USA
- Lead contact
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Wen P, Sun Y, Jiang TX, Qiu XB. PA200-Mediated Proteasomal Protein Degradation and Regulation of Cellular Senescence. Int J Mol Sci 2024; 25:5637. [PMID: 38891826 PMCID: PMC11171664 DOI: 10.3390/ijms25115637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 06/21/2024] Open
Abstract
Cellular senescence is closely related to DNA damage, proteasome inactivity, histone loss, epigenetic alterations, and tumorigenesis. The mammalian proteasome activator PA200 (also referred to as PSME4) or its yeast ortholog Blm10 promotes the acetylation-dependent degradation of the core histones during transcription, DNA repair, and spermatogenesis. According to recent studies, PA200 plays an important role in senescence, probably because of its role in promoting the degradation of the core histones. Loss of PA200 or Blm10 is a major cause of the decrease in proteasome activity during senescence. In this paper, recent research progress on the association of PA200 with cellular senescence is summarized, and the potential of PA200 to serve as a therapeutic target in age-related diseases is discussed.
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Affiliation(s)
- Pei Wen
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China; (P.W.); (Y.S.)
| | - Yan Sun
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China; (P.W.); (Y.S.)
| | - Tian-Xia Jiang
- Ministry of Education Key Laboratory of Cell Proliferation & Regulation Biology, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing 100875, China
| | - Xiao-Bo Qiu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 211198, China; (P.W.); (Y.S.)
- Ministry of Education Key Laboratory of Cell Proliferation & Regulation Biology, College of Life Sciences, Beijing Normal University, 19 Xinjiekouwai Avenue, Beijing 100875, China
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3
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Rong Q, Xi Z, Guo D, Xu W, Zhang L, Wu Q. Regulation of ubiquitination and antiviral activity of Cactin by deubiquitinase Usp14 in Drosophila. J Virol 2024; 98:e0017724. [PMID: 38563731 PMCID: PMC11092352 DOI: 10.1128/jvi.00177-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 03/10/2024] [Indexed: 04/04/2024] Open
Abstract
Cactin, a highly conserved protein, plays a crucial role in various physiological processes in eukaryotes, including innate immunity. Recently, the function of Cactin in the innate immunity of Drosophila has been explored, revealing that Cactin regulates a non-canonical signaling pathway associated with the Toll and Imd pathways via the Cactin-Deaf1 axis. In addition, Cactin exhibits specific antiviral activity against the Drosophila C virus (DCV) in Drosophila, with an unknown mechanism. During DCV infection, it has been confirmed that the protein level and antiviral activity of Cactin are regulated by ubiquitination. However, the precise ubiquitination and deubiquitination mechanisms of Cactin in Drosophila remain unexplored. In this study, we identified ubiquitin-specific protease 14 (Usp14) as a major deubiquitinase for Cactin through comprehensive deubiquitinase screening. Our results demonstrate that Usp14 interacts with the C_Cactus domain of Cactin via its USP domain. Usp14 efficiently removes K48- and K63-linked polyubiquitin chains from Cactin, thereby preventing its degradation through the ubiquitin-proteasome pathway. Usp14 significantly inhibits DCV replication in Drosophila cells by stabilizing Cactin. Moreover, Usp14-deficient fruit flies exhibit increased susceptibility to DCV infection compared to wild-type flies. Collectively, our findings reveal the regulation of ubiquitination and antiviral activity of Cactin by the deubiquitinase Usp14, providing valuable insights into the modulation of Cactin-mediated antiviral activity in Drosophila.IMPORTANCEViral infections pose a severe threat to human health, marked by high pathogenicity and mortality rates. Innate antiviral pathways, such as Toll, Imd, and JAK-STAT, are generally conserved across insects and mammals. Recently, the multi-functionality of Cactin in innate immunity has been identified in Drosophila. In addition to regulating a non-canonical signaling pathway through the Cactin-Deaf1 axis, Cactin exhibits specialized antiviral activity against the Drosophila C virus (DCV) with an unknown mechanism. A previous study emphasized the significance of the Cactin level, regulated by the ubiquitin-proteasome pathway, in modulating antiviral signaling. However, the regulatory mechanisms governing Cactin remain unexplored. In this study, we demonstrate that Usp14 stabilizes Cactin by preventing its ubiquitination and subsequent degradation. Furthermore, Usp14 plays a crucial role in regulating the antiviral function mediated by Cactin. Therefore, our findings elucidate the regulatory mechanism of Cactin in Drosophila, offering a potential target for the prevention and treatment of viral infections.
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Affiliation(s)
- Qiqi Rong
- Department of Pharmacy, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
- Key Laboratory of Anhui Province for Emerging and Reemerging Infectious Diseases, University of Science and Technology of China, Hefei, China
| | - Zhichong Xi
- Department of Pharmacy, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
| | - Dongyang Guo
- Department of Pharmacy, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
- Key Laboratory of Anhui Province for Emerging and Reemerging Infectious Diseases, University of Science and Technology of China, Hefei, China
| | - Wen Xu
- Department of Pharmacy, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
- Anhui Provincial Key Laboratory of Precision Pharmaceutical Preparations and Clinical Pharmacy, Hefei, Anhui, China
| | - Liqin Zhang
- Department of Pharmacy, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
- Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, China
| | - Qingfa Wu
- Department of Pharmacy, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, China
- Division of Molecular Medicine, CAS Key Laboratory of Innate Immunity and Chronic Disease, University of Science and Technology of China, Hefei, Anhui, China
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4
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Salomonsson J, Wallner B, Sjöstrand L, D'Arcy P, Sunnerhagen M, Ahlner A. Transient interdomain interactions in free USP14 shape its conformational ensemble. Protein Sci 2024; 33:e4975. [PMID: 38588275 PMCID: PMC11001199 DOI: 10.1002/pro.4975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 02/16/2024] [Accepted: 03/13/2024] [Indexed: 04/10/2024]
Abstract
The deubiquitinase (DUB) ubiquitin-specific protease 14 (USP14) is a dual domain protein that plays a regulatory role in proteasomal degradation and has been identified as a promising therapeutic target. USP14 comprises a conserved USP domain and a ubiquitin-like (Ubl) domain separated by a 25-residue linker. The enzyme activity of USP14 is autoinhibited in solution, but is enhanced when bound to the proteasome, where the Ubl and USP domains of USP14 bind to the Rpn1 and Rpt1/Rpt2 units, respectively. No structure of full-length USP14 in the absence of proteasome has yet been presented, however, earlier work has described how transient interactions between Ubl and USP domains in USP4 and USP7 regulate DUB activity. To better understand the roles of the Ubl and USP domains in USP14, we studied the Ubl domain alone and in full-length USP14 by nuclear magnetic resonance spectroscopy and used small angle x-ray scattering and molecular modeling to visualize the entire USP14 protein ensemble. Jointly, our results show how transient interdomain interactions between the Ubl and USP domains of USP14 predispose its conformational ensemble for proteasome binding, which may have functional implications for proteasome regulation and may be exploited in the design of future USP14 inhibitors.
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Affiliation(s)
| | - Björn Wallner
- Department of Physics, Chemistry and BiologyLinköping UniversityLinköpingSweden
| | - Linda Sjöstrand
- Department of Biomedical and Clinical SciencesLinköping UniversityLinköpingSweden
| | - Pádraig D'Arcy
- Department of Biomedical and Clinical SciencesLinköping UniversityLinköpingSweden
| | - Maria Sunnerhagen
- Department of Physics, Chemistry and BiologyLinköping UniversityLinköpingSweden
| | - Alexandra Ahlner
- Department of Physics, Chemistry and BiologyLinköping UniversityLinköpingSweden
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5
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Yang M, Chen S, Lim SL, Yang L, Zhong JY, Chan KC, Zhao Z, Wong KB, Wang J, Lim BL. A converged ubiquitin-proteasome pathway for the degradation of TOC and TOM tail-anchored receptors. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2024; 66:1007-1023. [PMID: 38501483 DOI: 10.1111/jipb.13645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 02/27/2024] [Indexed: 03/20/2024]
Abstract
In plants, thousands of nucleus-encoded proteins translated in the cytosol are sorted to chloroplasts and mitochondria by binding to specific receptors of the TOC (translocon on the outer chloroplast membrane) and the TOM (translocon on the outer mitochondrial membrane) complexes for import into those organelles. The degradation pathways for these receptors are unclear. Here, we discovered a converged ubiquitin-proteasome pathway for the degradation of Arabidopsis thaliana TOC and TOM tail-anchored receptors. The receptors are ubiquitinated by E3 ligase(s) and pulled from the outer membranes by the AAA+ adenosine triphosphatase CDC48, after which a previously uncharacterized cytosolic protein, transmembrane domain (TMD)-binding protein for tail-anchored outer membrane proteins (TTOP), binds to the exposed TMDs at the C termini of the receptors and CDC48, and delivers these complexes to the 26S proteasome.
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Affiliation(s)
- Meijing Yang
- School of Biological Sciences, University of Hong Kong, Pokfulam, 999077, Hong Kong, China
- Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Shuai Chen
- School of Biomedical Engineering, Shenzhen University, Shenzhen, 518060, China
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, 999077, Hong Kong, China
| | - Shey-Li Lim
- School of Biological Sciences, University of Hong Kong, Pokfulam, 999077, Hong Kong, China
| | - Lang Yang
- School of Biological Sciences, University of Hong Kong, Pokfulam, 999077, Hong Kong, China
- Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Jia Yi Zhong
- School of Biological Sciences, University of Hong Kong, Pokfulam, 999077, Hong Kong, China
| | - Koon Chuen Chan
- School of Biological Sciences, University of Hong Kong, Pokfulam, 999077, Hong Kong, China
| | - Zhizhu Zhao
- School of Biological Sciences, University of Hong Kong, Pokfulam, 999077, Hong Kong, China
| | - Kam-Bo Wong
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, 999077, Hong Kong, China
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, 999077, Hong Kong, China
| | - Junqi Wang
- Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Boon Leong Lim
- School of Biological Sciences, University of Hong Kong, Pokfulam, 999077, Hong Kong, China
- State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, 999077, Hong Kong, China
- HKU Shenzhen Institute of Research and Innovation, Shenzhen, 518052, China
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6
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Fabijan A, Polis B, Zawadzka-Fabijan A, Korabiewska I, Zakrzewski K, Nowosławska E, Chojnacki M. Domains in Action: Understanding Ddi1's Diverse Functions in the Ubiquitin-Proteasome System. Int J Mol Sci 2024; 25:4080. [PMID: 38612889 PMCID: PMC11012796 DOI: 10.3390/ijms25074080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/01/2024] [Accepted: 04/03/2024] [Indexed: 04/14/2024] Open
Abstract
The ubiquitin-proteasome system (UPS) is a pivotal cellular mechanism responsible for the selective degradation of proteins, playing an essential role in proteostasis, protein quality control, and regulating various cellular processes, with ubiquitin marking proteins for degradation through a complex, multi-stage process. The shuttle proteins family is a very unique group of proteins that plays an important role in the ubiquitin-proteasome system. Ddi1, Dsk2, and Rad23 are shuttle factors that bind ubiquitinated substrates and deliver them to the 26S proteasome. Besides mediating the delivery of ubiquitinated proteins, they are also involved in many other biological processes. Ddi1, the least-studied shuttle protein, exhibits unique physicochemical properties that allow it to play non-canonical functions in the cells. It regulates cell cycle progression and response to proteasome inhibition and defines MAT type of yeast cells. The Ddi1 contains UBL and UBA domains, which are crucial for binding to proteasome receptors and ubiquitin respectively, but also an additional domain called RVP. Additionally, much evidence has been provided to question whether Ddi1 is a classical shuttle protein. For many years, the true nature of this protein remained unclear. Here, we highlight the recent discoveries, which shed new light on the structure and biological functions of the Ddi1 protein.
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Affiliation(s)
- Artur Fabijan
- Department of Neurosurgery, Polish-Mother’s Memorial Hospital Research Institute, 93-338 Lodz, Poland; (B.P.); (K.Z.); (E.N.)
| | - Bartosz Polis
- Department of Neurosurgery, Polish-Mother’s Memorial Hospital Research Institute, 93-338 Lodz, Poland; (B.P.); (K.Z.); (E.N.)
| | - Agnieszka Zawadzka-Fabijan
- Department of Rehabilitation Medicine, Faculty of Health Sciences, Medical University of Lodz, 90-419 Lodz, Poland;
| | - Izabela Korabiewska
- Department of Rehabilitation, Faculty of Dental Medicine, Medical University of Warsaw, 02-091 Warsaw, Poland;
| | - Krzysztof Zakrzewski
- Department of Neurosurgery, Polish-Mother’s Memorial Hospital Research Institute, 93-338 Lodz, Poland; (B.P.); (K.Z.); (E.N.)
| | - Emilia Nowosławska
- Department of Neurosurgery, Polish-Mother’s Memorial Hospital Research Institute, 93-338 Lodz, Poland; (B.P.); (K.Z.); (E.N.)
| | - Michał Chojnacki
- Department of Medical Biochemistry, Medical University of Lodz, 92-215 Lodz, Poland;
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7
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Li H, Ji Z, Paulo JA, Gygi SP, Rapoport TA. Bidirectional substrate shuttling between the 26S proteasome and the Cdc48 ATPase promotes protein degradation. Mol Cell 2024; 84:1290-1303.e7. [PMID: 38401542 DOI: 10.1016/j.molcel.2024.01.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 12/12/2023] [Accepted: 01/31/2024] [Indexed: 02/26/2024]
Abstract
Most eukaryotic proteins are degraded by the 26S proteasome after modification with a polyubiquitin chain. Substrates lacking unstructured segments cannot be degraded directly and require prior unfolding by the Cdc48 ATPase (p97 or VCP in mammals) in complex with its ubiquitin-binding partner Ufd1-Npl4 (UN). Here, we use purified yeast components to reconstitute Cdc48-dependent degradation of well-folded model substrates by the proteasome. We show that a minimal system consists of the 26S proteasome, the Cdc48-UN ATPase complex, the proteasome cofactor Rad23, and the Cdc48 cofactors Ubx5 and Shp1. Rad23 and Ubx5 stimulate polyubiquitin binding to the 26S proteasome and the Cdc48-UN complex, respectively, allowing these machines to compete for substrates before and after their unfolding. Shp1 stimulates protein unfolding by the Cdc48-UN complex rather than substrate recruitment. Experiments in yeast cells confirm that many proteins undergo bidirectional substrate shuttling between the 26S proteasome and Cdc48 ATPase before being degraded.
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Affiliation(s)
- Hao Li
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Zhejian Ji
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA
| | - Tom A Rapoport
- Howard Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, MA 02115, USA.
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8
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Waite KA, Vontz G, Lee SY, Roelofs J. Proteasome condensate formation is driven by multivalent interactions with shuttle factors and ubiquitin chains. Proc Natl Acad Sci U S A 2024; 121:e2310756121. [PMID: 38408252 DOI: 10.1073/pnas.2310756121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 01/26/2024] [Indexed: 02/28/2024] Open
Abstract
Stress conditions can cause the relocalization of proteasomes to condensates in yeast and mammalian cells. The interactions that facilitate the formation of proteasome condensates, however, are unclear. Here, we show that the formation of proteasome condensates in yeast depends on ubiquitin chains together with the proteasome shuttle factors Rad23 and Dsk2. These shuttle factors colocalize to these condensates. Strains deleted for the third shuttle factor gene, DDI1, show proteasome condensates in the absence of cellular stress, consistent with the accumulation of substrates with long K48-linked ubiquitin chains that accumulate in this mutant. We propose a model where the long K48-linked ubiquitin chains function as a scaffold for the ubiquitin-binding domains of the shuttle factors and the proteasome, allowing for the multivalent interactions that further drive condensate formation. Indeed, we determined different intrinsic ubiquitin receptors of the proteasome-Rpn1, Rpn10, and Rpn13-and the Ubl domains of Rad23 and Dsk2 are critical under different condensate-inducing conditions. In all, our data support a model where the cellular accumulation of substrates with long ubiquitin chains, potentially due to reduced cellular energy, allows for proteasome condensate formation. This suggests that proteasome condensates are not simply for proteasome storage, but function to sequester soluble ubiquitinated substrates together with inactive proteasomes.
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Affiliation(s)
- Kenrick A Waite
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160
| | - Gabrielle Vontz
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160
| | - Stella Y Lee
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160
| | - Jeroen Roelofs
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160
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9
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Pan C, Zhang C, Lin Z, Liang Z, Cui Y, Shang Z, Wei Y, Chen F. Disulfidptosis-related Protein RPN1 may be a Novel Anti-osteoporosis Target of Kaempferol. Comb Chem High Throughput Screen 2024; 27:1611-1628. [PMID: 38213143 DOI: 10.2174/0113862073273655231213070619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 10/07/2023] [Accepted: 10/13/2023] [Indexed: 01/13/2024]
Abstract
BACKGROUND Osteoporosis (OP) is an age-related skeletal disease. Kaempferol can regulate bone mesenchymal stem cells (BMSCs) osteogenesis to improve OP, but its mechanism related to disulfidptosis, a newly discovered cell death mechanism, remains unclear. OBJECTIVE The study aimed to investigate the biological function and immune mechanism of disulfidptosis- related ribophorin I (RPN1) in OP and to experimentally confirm that RPN1 is the target for the treatment of OP with kaempferol. METHODS Differential expression analysis was conducted on disulfide-related genes extracted from the GSE56815 and GSE7158 datasets. Four machine learning algorithms identified disease signature genes, with RPN1 identified as a significant risk factor for OP through the nomogram. Validation of RPN1 differential expression in OP patients was performed using the GSE56116 dataset. The impact of RPN1 on immune alterations and biological processes was explored. Predictive ceRNA regulatory networks associated with RPN1 were generated via miRanda, miRDB, and TargetScan databases. Molecular docking estimated the binding model between kaempferol and RPN1. The targeting mechanism of kaempferol on RPN1 was confirmed through pathological HE staining and immunohistochemistry in ovariectomized (OVX) rats. RESULTS RPN1 was abnormally overexpressed in the OP cohort, associated with TNF signaling, hematopoietic cell lineage, and NF-kappa B pathway. Immune infiltration analysis showed a positive correlation between RPN1 expression and CD8+ T cells and resting NK cells, while a negative correlation with CD4+ naive T cells, macrophage M1, T cell gamma delta, T cell follicular helper cells, activated mast cells, NK cells, and dendritic cells, was found. Four miRNAs and 17 lncRNAs associated with RPN1 were identified. Kaempferol exhibited high binding affinity (-7.2 kcal/mol) and good stability towards the RPN1. The experimental results verified that kaempferol could improve bone microstructure destruction and reverse the abnormally high expression of RPN1 in the femur of ovariectomized rats. CONCLUSION RPN1 may be a new diagnostic biomarker in patients with OP, and may serve as a new target for kaempferol to improve OP.
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Affiliation(s)
- Chengzhen Pan
- Ruikang Hospital Affiliated with Guangxi University of Chinese Medicine, Nanning, Guangxi, China
| | - Chi Zhang
- Ruikang Hospital Affiliated with Guangxi University of Chinese Medicine, Nanning, Guangxi, China
| | - Zonghan Lin
- Ruikang Hospital Affiliated with Guangxi University of Chinese Medicine, Nanning, Guangxi, China
| | - Zhou Liang
- Yulin Orthopedic Hospital of Integrated Traditional Chinese and Western Medicine, Yulin, Guangxi, China
| | - Yinhang Cui
- Ruikang Hospital Affiliated with Guangxi University of Chinese Medicine, Nanning, Guangxi, China
| | - Zhihao Shang
- Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China
| | - Yuanxun Wei
- Ruikang Hospital Affiliated with Guangxi University of Chinese Medicine, Nanning, Guangxi, China
| | - Feng Chen
- Ruikang Hospital Affiliated with Guangxi University of Chinese Medicine, Nanning, Guangxi, China
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10
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Li H, Ji Z, Paulo JA, Gygi SP, Rapoport TA. Bidirectional substrate shuttling between the 26S proteasome and the Cdc48 ATPase promotes protein degradation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.20.572403. [PMID: 38187576 PMCID: PMC10769200 DOI: 10.1101/2023.12.20.572403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Most eukaryotic proteins are degraded by the 26S proteasome after modification with a polyubiquitin chain. Substrates lacking unstructured segments cannot be degraded directly and require prior unfolding by the Cdc48 ATPase (p97 or VCP in mammals) in complex with its ubiquitin-binding partner Ufd1-Npl4 (UN). Here, we use purified yeast components to reconstitute Cdc48-dependent degradation of well-folded model substrates by the proteasome. We show that a minimal system consists of the 26S proteasome, the Cdc48-UN ATPase complex, the proteasome cofactor Rad23, and the Cdc48 cofactors Ubx5 and Shp1. Rad23 and Ubx5 stimulate polyubiquitin binding to the 26S proteasome and the Cdc48-UN complex, respectively, allowing these machines to compete for substrates before and after their unfolding. Shp1 stimulates protein unfolding by the Cdc48-UN complex, rather than substrate recruitment. In vivo experiments confirm that many proteins undergo bidirectional substrate shuttling between the 26S proteasome and Cdc48 ATPase before being degraded.
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11
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Mebratu YA, Jones JT, Liu C, Negasi ZH, Rahman M, Rojas-Quintero J, O’Connor GT, Gao W, Dupuis J, Cho MH, Litonjua AA, Randell S, Tesfaigzi Y. Bik promotes proteasomal degradation to control low-grade inflammation. J Clin Invest 2023; 134:e170594. [PMID: 38113109 PMCID: PMC10866658 DOI: 10.1172/jci170594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 12/13/2023] [Indexed: 12/21/2023] Open
Abstract
Although chronic low-grade inflammation does not cause immediate clinical symptoms, over the longer term, it can enhance other insults or age-dependent damage to organ systems and thereby contribute to age-related disorders, such as respiratory disorders, heart disease, metabolic disorders, autoimmunity, and cancer. However, the molecular mechanisms governing low-level inflammation are largely unknown. We discovered that Bcl-2-interacting killer (Bik) deficiency causes low-level inflammation even at baseline and the development of spontaneous emphysema in female but not male mice. Similarly, a single nucleotide polymorphism that reduced Bik levels was associated with increased inflammation and enhanced decline in lung function in humans. Transgenic expression of Bik in the airways of Bik-deficient mice inhibited allergen- or LPS-induced lung inflammation and reversed emphysema in female mice. Bik deficiency increased nuclear but not cytosolic p65 levels because Bik, by modifying the BH4 domain of Bcl-2, interacted with regulatory particle non-ATPase 1 (RPN1) and RPN2 and enhanced proteasomal degradation of nuclear proteins. Bik deficiency increased inflammation primarily in females because Bcl-2 and Bik levels were reduced in lung tissues and airway cells of female compared with male mice. Therefore, controlling low-grade inflammation by modifying the unappreciated role of Bik and Bcl-2 in facilitating proteasomal degradation of nuclear proteins may be crucial in treating chronic age-related diseases.
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Affiliation(s)
- Yohannes A. Mebratu
- Brigham and Women’s Hospital, Division of Pulmonary and Critical Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Jane T. Jones
- University Geisel School of Medicine, Department of Microbiology and Immunology, Dartmouth, Hanover, New Hampshire, USA
| | - Congjian Liu
- Brigham and Women’s Hospital, Division of Pulmonary and Critical Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Zerihun H. Negasi
- Brigham and Women’s Hospital, Division of Pulmonary and Critical Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Mizanur Rahman
- Brigham and Women’s Hospital, Division of Pulmonary and Critical Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Joselyn Rojas-Quintero
- Brigham and Women’s Hospital, Division of Pulmonary and Critical Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - George T. O’Connor
- Pulmonary Center, Boston University School of Medicine, Boston, Massachusetts, USA
- National Heart, Lung, and Blood Institute’s (NHLBI’s) Framingham Heart Study, Framingham, Massachusetts, USA
| | - Wei Gao
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts, USA
| | - Josée Dupuis
- Department of Biostatistics, Boston University School of Public Health, Boston, Massachusetts, USA
- Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Canada
| | - Michael H. Cho
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, USA
| | - Augusto A. Litonjua
- Division of Pediatric Pulmonary Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Scott Randell
- Marsico Lung Institute, UNC School of Medicine, Chapel Hill, North Carolina, USA
| | - Yohannes Tesfaigzi
- Brigham and Women’s Hospital, Division of Pulmonary and Critical Medicine, Harvard Medical School, Boston, Massachusetts, USA
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12
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Chen X, Walters KJ. 1H, 15N, 13C resonance assignments for proteasome shuttle factor hHR23a. BIOMOLECULAR NMR ASSIGNMENTS 2023; 17:287-291. [PMID: 37812322 DOI: 10.1007/s12104-023-10157-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 10/04/2023] [Indexed: 10/10/2023]
Abstract
hHR23a (human homolog of Rad23 a) functions in nucleotide excision repair and proteasome-mediated protein degradation. It contains an N-terminal ubiquitin-like (UBL) domain, an xeroderma pigmentosum C (XPC)-binding domain, and a ubiquitin-associated (UBA) domain preceding and following the XPC-binding domain. Each of the four structural domains are connected by flexible linker regions. We report in this NMR study, the 1H, 15N and 13C resonance assignments for the backbone and sidechain atoms of the hHR23a full-length protein with BioMagResBank accession number 52059. Assignments are 97% and 87% for the backbone (NH, N, C', Cα, and Hα) and sidechain atoms of the hHR23a structured regions. The secondary structural elements predicted from the NMR data fit well to the hHR23a NMR structure. The assignments described in this manuscript can be used to apply NMR for studies of hHR23a with its binding partners.
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Affiliation(s)
- Xiang Chen
- Protein Processing Section, Center for Structural Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, 21702, USA
| | - Kylie J Walters
- Protein Processing Section, Center for Structural Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, 21702, USA.
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13
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Padhy AA, Mavor D, Sahoo S, Bolon DNA, Mishra P. Systematic profiling of dominant ubiquitin variants reveals key functional nodes contributing to evolutionary selection. Cell Rep 2023; 42:113064. [PMID: 37656625 DOI: 10.1016/j.celrep.2023.113064] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 06/30/2023] [Accepted: 08/21/2023] [Indexed: 09/03/2023] Open
Abstract
Dominant-negative mutations can help to investigate the biological mechanisms and to understand the selective pressures for multifunctional proteins. However, most studies have focused on recessive mutant effects that occur in the absence of a second functional gene copy, which overlooks the fact that most eukaryotic genomes contain more than one copy of many genes. We have identified dominant effects on yeast growth rate among all possible point mutations in ubiquitin expressed alongside a wild-type allele. Our results reveal more than 400 dominant-negative mutations, indicating that dominant-negative effects make a sizable contribution to selection acting on ubiquitin. Cellular and biochemical analyses of individual ubiquitin variants show that dominant-negative effects are explained by varied accumulation of polyubiquitinated cellular proteins and/or defects in conjugation of ubiquitin variants to ubiquitin ligases. Our approach to identify dominant-negative mutations is general and can be applied to other proteins of interest.
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Affiliation(s)
- Amrita Arpita Padhy
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Telangana 500046, India
| | - David Mavor
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Subhashree Sahoo
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Telangana 500046, India
| | - Daniel N A Bolon
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
| | - Parul Mishra
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Telangana 500046, India.
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14
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Bialek W, Collawn JF, Bartoszewski R. Ubiquitin-Dependent and Independent Proteasomal Degradation in Host-Pathogen Interactions. Molecules 2023; 28:6740. [PMID: 37764516 PMCID: PMC10536765 DOI: 10.3390/molecules28186740] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/18/2023] [Accepted: 09/19/2023] [Indexed: 09/29/2023] Open
Abstract
Ubiquitin, a small protein, is well known for tagging target proteins through a cascade of enzymatic reactions that lead to protein degradation. The ubiquitin tag, apart from its signaling role, is paramount in destabilizing the modified protein. Here, we explore the complex role of ubiquitin-mediated protein destabilization in the intricate proteolysis process by the 26S proteasome. In addition, the significance of the so-called ubiquitin-independent pathway and the role of the 20S proteasome are considered. Next, we discuss the ubiquitin-proteasome system's interplay with pathogenic microorganisms and how the microorganisms manipulate this system to establish infection by a range of elaborate pathways to evade or counteract host responses. Finally, we focus on the mechanisms that rely either on (i) hijacking the host and on delivering pathogenic E3 ligases and deubiquitinases that promote the degradation of host proteins, or (ii) counteracting host responses through the stabilization of pathogenic effector proteins.
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Affiliation(s)
- Wojciech Bialek
- Department of Biophysics, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - James F. Collawn
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35233, USA;
| | - Rafal Bartoszewski
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35233, USA;
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15
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Gao H, Yin J, Ji C, Yu X, Xue J, Guan X, Zhang S, Liu X, Xing F. Targeting ubiquitin specific proteases (USPs) in cancer immunotherapy: from basic research to preclinical application. J Exp Clin Cancer Res 2023; 42:225. [PMID: 37658402 PMCID: PMC10472646 DOI: 10.1186/s13046-023-02805-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 08/21/2023] [Indexed: 09/03/2023] Open
Abstract
Tumors have evolved in various mechanisms to evade the immune system, hindering the antitumor immune response and facilitating tumor progression. Immunotherapy has become a potential treatment strategy specific to different cancer types by utilizing multifarious molecular mechanisms to enhance the immune response against tumors. Among these mechanisms, the ubiquitin-proteasome system (UPS) is a significant non-lysosomal pathway specific to protein degradation, regulated by deubiquitinating enzymes (DUBs) that counterbalance ubiquitin signaling. Ubiquitin-specific proteases (USPs), the largest DUB family with the strongest variety, play critical roles in modulating immune cell function, regulating immune response, and participating in antigen processing and presentation during tumor progression. According to recent studies, the expressions of some USP family members in tumor cells are involved in tumor immune escape and immune microenvironment. This review explores the potential of targeting USPs as a new approach for cancer immunotherapy, highlighting recent basic and preclinical studies investigating the applications of USP inhibitors. By providing insights into the structure and function of USPs in cancer immunity, this review aims at assisting in developing new therapeutic approaches for enhancing the immunotherapy efficacy.
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Affiliation(s)
- Hongli Gao
- Department of Oncology, Shengjing Hospital of China Medical University, Shenyang, 110004, China
| | - Jianqiao Yin
- Department of Oncology, Shengjing Hospital of China Medical University, Shenyang, 110004, China
| | - Ce Ji
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, 110004, China
| | - Xiaopeng Yu
- Department of Oncology, Shengjing Hospital of China Medical University, Shenyang, 110004, China
| | - Jinqi Xue
- Department of Oncology, Shengjing Hospital of China Medical University, Shenyang, 110004, China
| | - Xin Guan
- Department of Gastroenterology, Shengjing Hospital of China Medical University, Shenyang, 110004, China
| | - Shuang Zhang
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, 110004, China
| | - Xun Liu
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, 110004, China.
| | - Fei Xing
- Department of Oncology, Shengjing Hospital of China Medical University, Shenyang, 110004, China.
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16
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Chen X, Walters K. 1H, 15N, 13C resonance assignments for proteasome shuttle factor hHR23a. RESEARCH SQUARE 2023:rs.3.rs-3256627. [PMID: 37645848 PMCID: PMC10462248 DOI: 10.21203/rs.3.rs-3256627/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
hHR23a (human homolog of Rad23 a) functions in nucleotide excision repair and proteasome-mediated protein degradation. It contains an N-terminal ubiquitin-like (UBL) domain, an xeroderma pigmentosum C (XPC)-binding domain, and a ubiquitin-associated (UBA) domain preceding and following the XPC-binding domain. Each of the four structural domains are connected by flexible linker regions. We report in this NMR study, the 1H, 15N and 13C resonance assignments for the backbone and sidechain atoms of the hHR23a full-length protein with BioMagResBank accession number 52059. Assignments are 97% and 87% for the backbone (NH, N, C', Cα, and Hα) and sidechain atoms of the hHR23a structured regions. The secondary structural elements predicted from the NMR data fit well to the hHR23a NMR structure. The assignments described in this manuscript can be used to apply NMR for studies of hHR23a with its binding partners.
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17
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Lee D, Zhu Y, Colson L, Wang X, Chen S, Tkacik E, Huang L, Ouyang Q, Goldberg AL, Lu Y. Molecular mechanism for activation of the 26S proteasome by ZFAND5. Mol Cell 2023; 83:2959-2975.e7. [PMID: 37595557 PMCID: PMC10523585 DOI: 10.1016/j.molcel.2023.07.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 05/07/2023] [Accepted: 07/24/2023] [Indexed: 08/20/2023]
Abstract
Various hormones, kinases, and stressors (fasting, heat shock) stimulate 26S proteasome activity. To understand how its capacity to degrade ubiquitylated proteins can increase, we studied mouse ZFAND5, which promotes protein degradation during muscle atrophy. Cryo-electron microscopy showed that ZFAND5 induces large conformational changes in the 19S regulatory particle. ZFAND5's AN1 Zn-finger domain interacts with the Rpt5 ATPase and its C terminus with Rpt1 ATPase and Rpn1, a ubiquitin-binding subunit. Upon proteasome binding, ZFAND5 widens the entrance of the substrate translocation channel, yet it associates only transiently with the proteasome. Dissociation of ZFAND5 then stimulates opening of the 20S proteasome gate. Using single-molecule microscopy, we showed that ZFAND5 binds ubiquitylated substrates, prolongs their association with proteasomes, and increases the likelihood that bound substrates undergo degradation, even though ZFAND5 dissociates before substrate deubiquitylation. These changes in proteasome conformation and reaction cycle can explain the accelerated degradation and suggest how other proteasome activators may stimulate proteolysis.
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Affiliation(s)
- Donghoon Lee
- Department of Cell Biology, Harvard Medical School, Boston, MA USA
| | - Yanan Zhu
- Department of Systems Biology, Harvard Medical School, Boston, MA USA; Center for Quantitative Biology, Peking University, Beijing, China; State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing, China
| | - Louis Colson
- Department of Systems Biology, Harvard Medical School, Boston, MA USA
| | - Xiaorong Wang
- School of Medicine, University of California Irvine, Irvine, Irvine, CA USA
| | - Siyi Chen
- Department of Systems Biology, Harvard Medical School, Boston, MA USA
| | - Emre Tkacik
- Department of Systems Biology, Harvard Medical School, Boston, MA USA
| | - Lan Huang
- School of Medicine, University of California Irvine, Irvine, Irvine, CA USA
| | - Qi Ouyang
- Center for Quantitative Biology, Peking University, Beijing, China; State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing, China; Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | | | - Ying Lu
- Department of Systems Biology, Harvard Medical School, Boston, MA USA.
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18
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Davis C, Spaller BL, Choi E, Kurrasch J, Chong H, Elsasser S, Finley D, Matouschek A. A strict requirement in proteasome substrates for spacing between ubiquitin tag and degradation initiation elements. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.08.552540. [PMID: 37609285 PMCID: PMC10441315 DOI: 10.1101/2023.08.08.552540] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Proteins are typically targeted to the proteasome for degradation through the attachment of ubiquitin chains and the proteasome initiates degradation at a disordered region within the target protein. Yet some proteins with ubiquitin chains and disordered regions escape degradation. Here we investigate how the position of the ubiquitin chain on the target protein relative to the disordered region modulates degradation and show that the distance between the two determines whether a protein is degraded efficiently. This distance depends on the type of the degradation tag and is likely a result of the separation on the proteasome between the receptor that binds the tag and the site that engages the disordered region.
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19
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Betancourt D, Lawal T, Tomko RJ. Wiggle and Shake: Managing and Exploiting Conformational Dynamics during Proteasome Biogenesis. Biomolecules 2023; 13:1223. [PMID: 37627288 PMCID: PMC10452565 DOI: 10.3390/biom13081223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/01/2023] [Accepted: 08/03/2023] [Indexed: 08/27/2023] Open
Abstract
The 26S proteasome is the largest and most complicated protease known, and changes to proteasome assembly or function contribute to numerous human diseases. Assembly of the 26S proteasome from its ~66 individual polypeptide subunits is a highly orchestrated process requiring the concerted actions of both intrinsic elements of proteasome subunits, as well as assistance by extrinsic, dedicated proteasome assembly chaperones. With the advent of near-atomic resolution cryo-electron microscopy, it has become evident that the proteasome is a highly dynamic machine, undergoing numerous conformational changes in response to ligand binding and during the proteolytic cycle. In contrast, an appreciation of the role of conformational dynamics during the biogenesis of the proteasome has only recently begun to emerge. Herein, we review our current knowledge of proteasome assembly, with a particular focus on how conformational dynamics guide particular proteasome biogenesis events. Furthermore, we highlight key emerging questions in this rapidly expanding area.
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Affiliation(s)
| | | | - Robert J. Tomko
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32306, USA; (D.B.); (T.L.)
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20
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Brockmann F, Catone N, Wünsch C, Offensperger F, Scheffner M, Schmidtke G, Aichem A. FAT10 and NUB1L cooperate to activate the 26S proteasome. Life Sci Alliance 2023; 6:e202201463. [PMID: 37188463 PMCID: PMC10185811 DOI: 10.26508/lsa.202201463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/02/2023] [Accepted: 05/03/2023] [Indexed: 05/17/2023] Open
Abstract
The interaction of the 19S regulatory particle of the 26S proteasome with ubiquitylated proteins leads to gate opening of the 20S core particle and increases its proteolytic activity by binding of the ubiquitin chain to the inhibitory deubiquitylation enzyme USP14 on the 19S regulatory subunit RPN1. Covalent modification of proteins with the cytokine inducible ubiquitin-like modifier FAT10 is an alternative signal for proteasomal degradation. Here, we report that FAT10 and its interaction partner NUB1L facilitate the gate opening of the 20S proteasome in an ubiquitin- and USP14-independent manner. We also show that FAT10 is capable to activate all peptidolytic activities of the 26S proteasome, however only together with NUB1L, by binding to the UBA domains of NUB1L and thereby interfering with NUB1L dimerization. The binding of FAT10 to NUB1L leads to an increased affinity of NUB1L for the subunit RPN1. In conclusion, the herein described cooperation of FAT10 and NUB1L is a substrate-induced mechanism to activate the 26S proteasome.
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Affiliation(s)
- Florian Brockmann
- Division of Immunology, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Nicola Catone
- Biotechnology Institute Thurgauhttps://ror.org/0546hnb39 at the University of Konstanz, Kreuzlingen, Switzerland
| | - Christine Wünsch
- Division of Immunology, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Fabian Offensperger
- Division of Biochemistry, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Martin Scheffner
- Division of Biochemistry, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Gunter Schmidtke
- Division of Immunology, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Annette Aichem
- Division of Immunology, Department of Biology, University of Konstanz, Konstanz, Germany
- Biotechnology Institute Thurgauhttps://ror.org/0546hnb39 at the University of Konstanz, Kreuzlingen, Switzerland
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21
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Negi H, Osei-Amponsa V, Ibrahim B, Evans CN, Sullenberger C, Loncarek J, Chari R, Walters KJ. An engineered cell line with a hRpn1-attached handle to isolate proteasomes. J Biol Chem 2023; 299:104948. [PMID: 37354974 PMCID: PMC10372910 DOI: 10.1016/j.jbc.2023.104948] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 06/08/2023] [Accepted: 06/12/2023] [Indexed: 06/26/2023] Open
Abstract
Regulated protein degradation in eukaryotes is performed by the 26S proteasome, which contains a 19-subunit regulatory particle (RP) that binds, processes, and translocates substrates to a 28-subunit hollow core particle (CP) where proteolysis occurs. In addition to its intrinsic subunits, myriad proteins interact with the proteasome transiently, including factors that assist and/or regulate its degradative activities. Efforts to identify proteasome-interacting components and/or to solve its structure have relied on over-expression of a tagged plasmid, establishing stable cell lines, or laborious purification protocols to isolate native proteasomes from cells. Here, we describe an engineered human cell line, derived from colon cancer HCT116 cells, with a biotin handle on the RP subunit hRpn1/PSMD2 (proteasome 26S subunit, non-ATPase 2) for purification of 26S proteasomes. A 75-residue sequence from Propionibacterium shermanii that is biotinylated in mammalian cells was added following a tobacco etch virus protease cut site at the C terminus of hRpn1. We tested and found that 26S proteasomes can be isolated from this modified HCT116 cell line by using a simple purification protocol. More specifically, biotinylated proteasomes were purified from the cell lysates by using neutravidin agarose resin and released from the resin following incubation with tobacco etch virus protease. The purified proteasomes had equivalent activity in degrading a model ubiquitinated substrate, namely ubiquitinated p53, compared to commercially available bovine proteasomes that were purified by fractionation. In conclusion, advantages of this approach to obtain 26S proteasomes over others is the simple purification protocol and that all cellular proteins, including the tagged hRpn1 subunit, remain at endogenous stoichiometry.
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Affiliation(s)
- Hitendra Negi
- Protein Processing Section, Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA
| | - Vasty Osei-Amponsa
- Protein Processing Section, Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA
| | - Bishoy Ibrahim
- Protein Processing Section, Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA
| | - Christine N Evans
- Genome Modification Core, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Catherine Sullenberger
- Cancer Innovation Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA
| | - Jadranka Loncarek
- Cancer Innovation Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA
| | - Raj Chari
- Genome Modification Core, Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Kylie J Walters
- Protein Processing Section, Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA.
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22
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Waite KA, Vontz G, Lee SY, Roelofs J. Proteasome condensate formation is driven by multivalent interactions with shuttle factors and K48-linked ubiquitin chains. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.25.546446. [PMID: 37425862 PMCID: PMC10326979 DOI: 10.1101/2023.06.25.546446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Stress conditions can cause the relocalization of proteasomes to condensates in yeast and mammalian cells. The interactions that facilitate the formation of proteasome condensates, however, are unclear. Here, we show that the formation of proteasome condensates in yeast depends on long K48-linked ubiquitin chains together with the proteasome shuttle factors Rad23 and Dsk2. These shuttle factors colocalize to these condensates. Strains deleted for the third shuttle factor gene, DDI1 , show proteasome condensates in the absence of cellular stress, consistent with the accumulation of substrates with long K48-linked ubiquitin chains that accumulate in this mutant. We propose a model where the long K48-linked ubiquitin chains function as a scaffold for the ubiquitin binding domains of the shuttle factors and the proteasome, allowing for the multivalent interactions that further drive condensate formation. Indeed, we determined different intrinsic ubiquitin receptors of the proteasome (Rpn1, Rpn10, and Rpn13) are critical under different condensate inducing conditions. In all, our data support a model where the cellular accumulation of substrates with long ubiquitin chains, potentially due to reduced cellular energy, allows for proteasome condensate formation. This suggests that proteasome condensates are not simply for proteasome storage, but function to sequester soluble ubiquitinated substrates together with inactive proteasomes. Significance Stress conditions can cause the relocalization of proteasomes to condensates in yeast as well as mammalian cells. Our work shows that the formation of proteasome condensates in yeast depends on long K48-linked ubiquitin chains, the proteasome binding shuttle factors Rad23 and Dsk2 and proteasome intrinsic ubiquitin receptors. Here, different receptors are critical for different condensate inducers. These results indicate distinct condensates can form with specific functionality. Our identification of key factors involved in the process is crucial for understanding the function of proteasome relocalization to condensates. We propose that cellular accumulation of substrates with long ubiquitin chains results in the formation of condensates comprising those ubiquitinated substrates, proteasomes, and proteasome shuttle factors, where the ubiquitin chains serve as the scaffold for condensate formation.
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23
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Du T, Song Y, Ray A, Wan X, Yao Y, Samur MK, Shen C, Penailillo J, Sewastianik T, Tai YT, Fulciniti M, Munshi NC, Wu H, Carrasco RD, Chauhan D, Anderson KC. Ubiquitin receptor PSMD4/Rpn10 is a novel therapeutic target in multiple myeloma. Blood 2023; 141:2599-2614. [PMID: 36630605 PMCID: PMC10273170 DOI: 10.1182/blood.2022017897] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 12/12/2022] [Accepted: 12/29/2022] [Indexed: 01/13/2023] Open
Abstract
PSMD4/Rpn10 is a subunit of the 19S proteasome unit that is involved with feeding target proteins into the catalytic machinery of the 26S proteasome. Because proteasome inhibition is a common therapeutic strategy in multiple myeloma (MM), we investigated Rpn10 and found that it is highly expressed in MM cells compared with normal plasma cells. Rpn10 levels inversely correlated with overall survival in patients with MM. Inducible knockout or knockdown of Rpn10 decreased MM cell viability both in vitro and in vivo by triggering the accumulation of polyubiquitinated proteins, cell cycle arrest, and apoptosis associated with the activation of caspases and unfolded protein response-related pathways. Proteomic analysis revealed that inhibiting Rpn10 increased autophagy, antigen presentation, and the activation of CD4+ T and natural killer cells. We developed an in vitro AlphaScreen binding assay for high-throughput screening and identified a novel Rpn10 inhibitor, SB699551 (SB). Treating MM cell lines, leukemic cell lines, and primary cells from patients with MM with SB decreased cell viability without affecting the viability of normal peripheral blood mononuclear cells. SB inhibited the proliferation of MM cells even in the presence of the tumor-promoting bone marrow milieu and overcame proteasome inhibitor (PI) resistance without blocking the 20S proteasome catalytic function or the 19S deubiquitinating activity. Rpn10 blockade by SB triggered MM cell death via similar pathways as the genetic strategy. In MM xenograft models, SB was well tolerated, inhibited tumor growth, and prolonged survival. Our data suggest that inhibiting Rpn10 will enhance cytotoxicity and overcome PI resistance in MM, providing the basis for further optimization studies of Rpn10 inhibitors for clinical application.
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Affiliation(s)
- Ting Du
- Department of Medical Oncology, LeBow Institute for Myeloma Therapeutics and Jerome Lipper Myeloma Center, Dana-Farber Cancer Institute, Harvard Medical School, Harvard University, Boston, MA
| | - Yan Song
- Department of Medical Oncology, LeBow Institute for Myeloma Therapeutics and Jerome Lipper Myeloma Center, Dana-Farber Cancer Institute, Harvard Medical School, Harvard University, Boston, MA
| | - Arghya Ray
- Department of Medical Oncology, LeBow Institute for Myeloma Therapeutics and Jerome Lipper Myeloma Center, Dana-Farber Cancer Institute, Harvard Medical School, Harvard University, Boston, MA
| | - Xueping Wan
- Department of Medical Oncology, LeBow Institute for Myeloma Therapeutics and Jerome Lipper Myeloma Center, Dana-Farber Cancer Institute, Harvard Medical School, Harvard University, Boston, MA
| | - Yao Yao
- Department of Medical Oncology, LeBow Institute for Myeloma Therapeutics and Jerome Lipper Myeloma Center, Dana-Farber Cancer Institute, Harvard Medical School, Harvard University, Boston, MA
| | - Mehmet K. Samur
- Department of Medical Oncology, LeBow Institute for Myeloma Therapeutics and Jerome Lipper Myeloma Center, Dana-Farber Cancer Institute, Harvard Medical School, Harvard University, Boston, MA
- Department of Biostatistics and Computational Biology, Harvard T.H. Chan School of Public Health, Harvard Medical School, Harvard University, Boston, MA
| | - Chen Shen
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, MA
- Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Boston, MA
| | - Johany Penailillo
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Harvard University, Boston, MA
| | - Tomasz Sewastianik
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Harvard University, Boston, MA
- Department of Experimental Hematology, Institute of Hematology and Transfusion Medicine, Warsaw, Poland
| | - Yu-Tzu Tai
- Department of Medical Oncology, LeBow Institute for Myeloma Therapeutics and Jerome Lipper Myeloma Center, Dana-Farber Cancer Institute, Harvard Medical School, Harvard University, Boston, MA
| | - Mariateresa Fulciniti
- Department of Medical Oncology, LeBow Institute for Myeloma Therapeutics and Jerome Lipper Myeloma Center, Dana-Farber Cancer Institute, Harvard Medical School, Harvard University, Boston, MA
| | - Nikhil C. Munshi
- Department of Medical Oncology, LeBow Institute for Myeloma Therapeutics and Jerome Lipper Myeloma Center, Dana-Farber Cancer Institute, Harvard Medical School, Harvard University, Boston, MA
- VA Boston Healthcare System, Boston, MA
| | - Hao Wu
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University, Boston, MA
- Program in Cellular and Molecular Medicine, Boston Children’s Hospital, Boston, MA
| | - Ruben D. Carrasco
- Department of Oncologic Pathology, Dana-Farber Cancer Institute, Harvard Medical School, Harvard University, Boston, MA
- Department of Pathology, Brigham and Women’s Hospital, Harvard Medical School, Harvard University, Boston, MA
| | - Dharminder Chauhan
- Department of Medical Oncology, LeBow Institute for Myeloma Therapeutics and Jerome Lipper Myeloma Center, Dana-Farber Cancer Institute, Harvard Medical School, Harvard University, Boston, MA
| | - Kenneth C. Anderson
- Department of Medical Oncology, LeBow Institute for Myeloma Therapeutics and Jerome Lipper Myeloma Center, Dana-Farber Cancer Institute, Harvard Medical School, Harvard University, Boston, MA
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Lee D, Zhu Y, Colson L, Wang X, Chen S, Tkacik E, Huang L, Ouyang Q, Goldberg AL, Lu Y. Molecular mechanisms for activation of the 26S proteasome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.09.540094. [PMID: 37214989 PMCID: PMC10197607 DOI: 10.1101/2023.05.09.540094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Various hormones, kinases, and stressors (fasting, heat shock) stimulate 26S proteasome activity. To understand how its capacity to degrade ubiquitylated protein can increase, we studied ZFAND5, which promotes protein degradation during muscle atrophy. Cryo-electron microscopy showed that ZFAND5 induces large conformational changes in the 19S regulatory particle. ZFAND5's AN1 Zn finger interacts with the Rpt5 ATPase and its C-terminus with Rpt1 ATPase and Rpn1, a ubiquitin-binding subunit. Surprisingly, these C-terminal interactions are sufficient to activate proteolysis. With ZFAND5 bound, entry into the proteasome's protein translocation channel is wider, and ZFAND5 dissociation causes opening of the 20S gate for substrate entry. Using single-molecular microscopy, we showed that ZFAND5 binds ubiquitylated substrates, prolongs their association with proteasomes, and increases the likelihood that bound substrates undergo degradation, even though ZFAND5 dissociates before substrate deubiquitylation. These changes in proteasome conformation and reaction cycle can explain the accelerated degradation and suggest how other proteasome activators may stimulate proteolysis.
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Shi X, Xiong Y, Zhang K, Zhang Y, Zhang J, Zhang L, Xiao Y, Wang GL, Liu W. The ANIP1-OsWRKY62 module regulates both basal defense and Pi9-mediated immunity against Magnaporthe oryzae in rice. MOLECULAR PLANT 2023; 16:739-755. [PMID: 36872602 DOI: 10.1016/j.molp.2023.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 01/16/2023] [Accepted: 03/01/2023] [Indexed: 06/09/2023]
Abstract
During effector-triggered immunity (ETI) against the devastating rice blast pathogen Magnaporthe oryzae, Pi9 functions as an intracellular resistance protein sensing the pathogen-secreted effector AvrPi9 in rice. Importantly, the underlying recognition mechanism(s) between Pi9 and AvrPi9 remains elusive. In this study, we identified a rice ubiquitin-like domain-containing protein (UDP), AVRPI9-INTERACTING PROTEIN 1 (ANIP1), which is directly targeted by AvrPi9 and also binds to Pi9 in plants. Phenotypic analysis of anip1 mutants and plants overexpressing ANIP1 revealed that ANIP1 negatively modulates rice basal defense against M. oryzae. ANIP1 undergoes 26S proteasome-mediated degradation, which can be blocked by both AvrPi9 and Pi9. Moreover, ANIP1 physically associates with the rice WRKY transcription factor OsWRKY62, which also interacts with AvrPi9 and Pi9 in plants. In the absence of Pi9, ANIP1 negatively regulates OsWRKY62 abundance, which can be promoted by AvrPi9. Accordingly, knocking out of OsWRKY62 in a non-Pi9 background decreased immunity against M. oryzae. However, we also observed that OsWRKY62 plays negative roles in defense against a compatible M. oryzae strain in Pi9-harboring rice. Pi9 binds to ANIP1 and OsWRKY62 to form a complex, which may help to keep Pi9 in an inactive state and weaken rice immunity. Furthermore, using competitive binding assays, we showed that AvrPi9 promotes Pi9 dissociation from ANIP1, which could be an important step toward ETI activation. Taken together, our results reveal an immune strategy whereby a UDP-WRKY module, targeted by a fungal effector, modulates rice immunity in distinct ways in the presence or absence of the corresponding resistance protein.
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Affiliation(s)
- Xuetao Shi
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
| | - Yehui Xiong
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Kai Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yinshan Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Junqi Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Lili Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yutao Xiao
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen 518120, China
| | - Guo-Liang Wang
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, USA
| | - Wende Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
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Liu Y, Wu M, Xu S, Niu X, Liu W, Miao C, Lin A, Xu Y, Yu L. PSMD2 contributes to the progression of esophageal squamous cell carcinoma by repressing autophagy. Cell Biosci 2023; 13:67. [PMID: 36998052 DOI: 10.1186/s13578-023-01016-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 03/16/2023] [Indexed: 04/01/2023] Open
Abstract
BACKGROUND The ubiquitin-proteasome and autophagy-lysosomal systems collaborate in regulating the levels of intracellular proteins. Dysregulation of protein homeostasis is a central feature of malignancy. The gene encoding 26S proteasome non-ATPase regulatory subunit 2 (PSMD2) of the ubiquitin-proteasome system is an oncogene in various types of cancer. However, the detailed role of PSMD2 in autophagy and its relationship to tumorigenesis in esophageal squamous cell carcinoma (ESCC) remain unknown. In the present study, we have investigated the tumor-promoting roles of PSMD2 in the context of autophagy in ESCC. METHODS Molecular approaches including DAPgreen staining, 5-Ethynyl-2'-deoxyuridine (EdU), cell counting kit 8 (CCK8), colony formation, transwell assays, and cell transfection, xenograft model, immunoblotting and Immunohistochemical analysis were used to investigate the roles of PSMD2 in ESCC cells. Data-independent acquisition (DIA) quantification proteomics analysis and rescue experiments were used to study the roles of PSMD2 in ESCC cells. RESULTS We demonstrate that the overexpression of PSMD2 promotes ESCC cell growth by inhibiting autophagy and is correlated with tumor progression and poor prognosis of ESCC patients. DIA quantification proteomics analysis shows a significant positive correlation between argininosuccinate synthase 1 (ASS1) and PSMD2 levels in ESCC tumors. Further studies indicate that PSMD2 activates the mTOR pathway by upregulating ASS1 to inhibit autophagy. CONCLUSIONS PSMD2 plays an important role in repressing autophagy in ESCC, and represents a promising biomarker to predict prognosis and a therapeutic target of ESCC patients.
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Affiliation(s)
- Yachen Liu
- Department of Thoracic Surgery, Fudan University Shanghai Cancer Center, Shanghai, China
- Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
- Department of Etiology and Carcinogenesis, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Meng Wu
- Department of Cardiology, Cardiovascular Key Lab of Zhejiang Province, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
- Department of Medical Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Shuxiang Xu
- Department of Cardiology, Cardiovascular Key Lab of Zhejiang Province, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China
| | - Xiangjie Niu
- Department of Etiology and Carcinogenesis, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Weiling Liu
- Department of Etiology and Carcinogenesis, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Chuanwang Miao
- Department of Etiology and Carcinogenesis, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Ai Lin
- Department of Etiology and Carcinogenesis, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, People's Republic of China
| | - Yang Xu
- Department of Cardiology, Cardiovascular Key Lab of Zhejiang Province, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China.
| | - Lili Yu
- Department of Medical Oncology, Key Laboratory of Cancer Prevention and Intervention, Ministry of Education, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310009, China.
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Buneeva OA, Kopylov AT, Medvedev AE. Proteasome Interactome and Its Role in the Mechanisms of Brain Plasticity. BIOCHEMISTRY (MOSCOW) 2023; 88:319-336. [PMID: 37076280 DOI: 10.1134/s0006297923030033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/28/2023]
Abstract
Abstract
Proteasomes are highly conserved multienzyme complexes responsible for proteolytic degradation of the short-lived, regulatory, misfolded, and damaged proteins. They play an important role in the processes of brain plasticity, and decrease in their function is accompanied by the development of neurodegenerative pathology. Studies performed in different laboratories both on cultured mammalian and human cells and on preparations of the rat and rabbit brain cortex revealed a large number of proteasome-associated proteins. Since the identified proteins belong to certain metabolic pathways, multiple enrichment of the proteasome fraction with these proteins indicates their important role in proteasome functioning. Extrapolation of the experimental data, obtained on various biological objects, to the human brain suggests that the proteasome-associated proteins account for at least 28% of the human brain proteome. The proteasome interactome of the brain contains a large number of proteins involved in the assembly of these supramolecular complexes, regulation of their functioning, and intracellular localization, which could be changed under different conditions (for example, during oxidative stress) or in different phases of the cell cycle. In the context of molecular functions of the Gene Ontology (GO) Pathways, the proteins of the proteasome interactome mediate cross-talk between components of more than 30 metabolic pathways annotated in terms of GO. The main result of these interactions is binding of adenine and guanine nucleotides, crucial for realization of the nucleotide-dependent functions of the 26S and 20S proteasomes. Since the development of neurodegenerative pathology is often associated with regioselective decrease in the functional activity of proteasomes, a positive therapeutic effect would be obviously provided by the factors increasing proteasomal activity. In any case, pharmacological regulation of the brain proteasomes seems to be realized through the changes in composition and/or activity of the proteins associated with proteasomes (deubiquitinase, PKA, CaMKIIα, etc.).
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Affiliation(s)
- Olga A Buneeva
- Institute of Biomedical Chemistry, Moscow, 119121, Russia
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Grønbæk-Thygesen M, Kampmeyer C, Hofmann K, Hartmann-Petersen R. The moonlighting of RAD23 in DNA repair and protein degradation. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194925. [PMID: 36863450 DOI: 10.1016/j.bbagrm.2023.194925] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 02/20/2023] [Accepted: 02/23/2023] [Indexed: 03/04/2023]
Abstract
A moonlighting protein is one, which carries out multiple, often wholly unrelated, functions. The RAD23 protein is a fascinating example of this, where the same polypeptide and the embedded domains function independently in both nucleotide excision repair (NER) and protein degradation via the ubiquitin-proteasome system (UPS). Hence, through direct binding to the central NER component XPC, RAD23 stabilizes XPC and contributes to DNA damage recognition. Conversely, RAD23 also interacts directly with the 26S proteasome and ubiquitylated substrates to mediate proteasomal substrate recognition. In this function, RAD23 activates the proteolytic activity of the proteasome and engages specifically in well-characterized degradation pathways through direct interactions with E3 ubiquitin-protein ligases and other UPS components. Here, we summarize the past 40 years of research into the roles of RAD23 in NER and the UPS.
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Affiliation(s)
- Martin Grønbæk-Thygesen
- The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Denmark.
| | - Caroline Kampmeyer
- The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Denmark
| | - Kay Hofmann
- Institute for Genetics, University of Cologne, Germany
| | - Rasmus Hartmann-Petersen
- The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Denmark.
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Sekaran S, Park S. The penultimate step of proteasomal ATPase assembly is mediated by a switch dependent on the chaperone Nas2. J Biol Chem 2023; 299:102870. [PMID: 36621624 PMCID: PMC9922823 DOI: 10.1016/j.jbc.2023.102870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 12/21/2022] [Accepted: 12/28/2022] [Indexed: 01/07/2023] Open
Abstract
The proteasome holoenzyme is a complex molecular machine that degrades most proteins. In the proteasome holoenzyme, six distinct ATPase subunits (Rpt1 through Rpt6) enable protein degradation by injecting protein substrates into it. Individual Rpt subunits assemble into a heterohexameric "Rpt ring" in a stepwise manner, by binding to their cognate chaperones. Completion of the heterohexameric Rpt ring correlates with release of a specific chaperone, Nas2; however, it is unclear whether and how this event may ensure proper Rpt ring assembly. Here, we examined the action of Nas2 by capturing the poorly characterized penultimate step of heterohexameric Rpt ring assembly. For this, we used a heterologous Escherichia coli system coexpressing all Rpt subunits and assembly chaperones as well as Saccharomyces cerevisiae to track Nas2 actions during endogenous Rpt ring assembly. We show that Nas2 uses steric hindrance to block premature progression of the penultimate step into the final step of Rpt ring assembly. Importantly, Nas2 can activate an assembly checkpoint via its steric activity, when the last ATPase subunit, Rpt1, cannot be added in a timely manner. This checkpoint can be relieved via Nas2 release, when Nas2 recognizes proper addition of Rpt1 to one side of its cognate Rpt5, and ATP hydrolysis by Rpt4 on the other side of Rpt5, allowing completion of Rpt ring assembly. Our findings reveal dual criteria for Nas2 release, as a mechanism to ensure both the composition and functional competence of a newly assembled proteasomal ATPase, to generate the proteasome holoenzyme.
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Affiliation(s)
- Suganya Sekaran
- Department of Molecular Cellular and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA
| | - Soyeon Park
- Department of Molecular Cellular and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, USA.
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The Ubiquitin-26S Proteasome Pathway and Its Role in the Ripening of Fleshy Fruits. Int J Mol Sci 2023; 24:ijms24032750. [PMID: 36769071 PMCID: PMC9917055 DOI: 10.3390/ijms24032750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 01/17/2023] [Accepted: 01/20/2023] [Indexed: 02/04/2023] Open
Abstract
The 26S proteasome is an ATP-dependent proteolytic complex in eukaryotes, which is mainly responsible for the degradation of damaged and misfolded proteins and some regulatory proteins in cells, and it is essential to maintain the balance of protein levels in the cell. The ubiquitin-26S proteasome pathway, which targets a wide range of protein substrates in plants, is an important post-translational regulatory mechanism involved in various stages of plant growth and development and in the maturation process of fleshy fruits. Fleshy fruit ripening is a complex biological process, which is the sum of a series of physiological and biochemical reactions, including the biosynthesis and signal transduction of ripening related hormones, pigment metabolism, fruit texture changes and the formation of nutritional quality. This paper reviews the structure of the 26S proteasome and the mechanism of the ubiquitin-26S proteasome pathway, and it summarizes the function of this pathway in the ripening process of fleshy fruits.
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Yu P, Hua Z. To Kill or to Be Killed: How Does the Battle between the UPS and Autophagy Maintain the Intracellular Homeostasis in Eukaryotes? Int J Mol Sci 2023; 24:ijms24032221. [PMID: 36768543 PMCID: PMC9917186 DOI: 10.3390/ijms24032221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 01/27/2023] Open
Abstract
The ubiquitin-26S proteasome system and autophagy are two major protein degradation machineries encoded in all eukaryotic organisms. While the UPS is responsible for the turnover of short-lived and/or soluble misfolded proteins under normal growth conditions, the autophagy-lysosomal/vacuolar protein degradation machinery is activated under stress conditions to remove long-lived proteins in the forms of aggregates, either soluble or insoluble, in the cytoplasm and damaged organelles. Recent discoveries suggested an integrative function of these two seemly independent systems for maintaining the proteome homeostasis. One such integration is represented by their reciprocal degradation, in which the small 76-amino acid peptide, ubiquitin, plays an important role as the central signaling hub. In this review, we summarized the current knowledge about the activity control of proteasome and autophagosome at their structural organization, biophysical states, and turnover levels from yeast and mammals to plants. Through comprehensive literature studies, we presented puzzling questions that are awaiting to be solved and proposed exciting new research directions that may shed light on the molecular mechanisms underlying the biological function of protein degradation.
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Affiliation(s)
- Peifeng Yu
- Department of Environmental and Plant Biology, Ohio University, Athens, OH 45701, USA
- Interdisciplinary Program in Molecular and Cellular Biology, Ohio University, Athens, OH 45701, USA
| | - Zhihua Hua
- Department of Environmental and Plant Biology, Ohio University, Athens, OH 45701, USA
- Interdisciplinary Program in Molecular and Cellular Biology, Ohio University, Athens, OH 45701, USA
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32
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Targeted degradation via direct 26S proteasome recruitment. Nat Chem Biol 2023; 19:55-63. [PMID: 36577875 PMCID: PMC9797404 DOI: 10.1038/s41589-022-01218-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 10/25/2022] [Indexed: 12/29/2022]
Abstract
Engineered destruction of target proteins by recruitment to the cell's degradation machinery has emerged as a promising strategy in drug discovery. The majority of molecules that facilitate targeted degradation do so via a select number of ubiquitin ligases, restricting this therapeutic approach to tissue types that express the requisite ligase. Here, we describe a new strategy of targeted protein degradation through direct substrate recruitment to the 26S proteasome. The proteolytic complex is essential and abundantly expressed in all cells; however, proteasomal ligands remain scarce. We identify potent peptidic macrocycles that bind directly to the 26S proteasome subunit PSMD2, with a 2.5-Å-resolution cryo-electron microscopy complex structure revealing a binding site near the 26S pore. Conjugation of this macrocycle to a potent BRD4 ligand enabled generation of chimeric molecules that effectively degrade BRD4 in cells, thus demonstrating that degradation via direct proteasomal recruitment is a viable strategy for targeted protein degradation.
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Xie G, Dong KC, Worden EJ, Martin A. High-Throughput Assay for Characterizing Rpn11 Deubiquitinase Activity. Methods Mol Biol 2023; 2591:79-100. [PMID: 36350544 PMCID: PMC11111417 DOI: 10.1007/978-1-0716-2803-4_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Rpn11 is an essential metalloprotease responsible for the en bloc removal of ubiquitin chains from protein substrates that are targeted for degradation by the 26S proteasome. A unique feature of Rpn11 is that its deubiquitinase (DUB) activity is greatly stimulated by the mechanical translocation of the substrate into the proteasomal AAA+ (ATPase Associated with diverse cellular Activities) motor, which delivers the scissile isopeptide bond between a substrate lysine and the proximal moiety of an attached ubiquitin chain to the DUB catalytic active site. As a consequence, Rpn11 cleaves at the base of ubiquitin chains and lacks selectivity towards specific ubiquitin-chain linkage types, which is in contrast to other DUBs, including the related AMSH that selectively cleaves Lys63-linked chains. Prevention of Rpn11's deubiquitinase activity leads to inhibition of proteasomal degradation by stalling substrate translocation. With the proteasome as an approved anticancer target, Rpn11 is therefore an attractive point of attack for the development of new inhibitors, which requires robust biochemical assays to measure DUB activity. Here we describe a method for the purification of the Rpn8/Rpn11 heterodimer and ubiquitin-GC-TAMRA, a model substrate that can be used to characterize the DUB activity of Rpn11 in isolation without the need of purifying 26S proteasomes. This assay thus enables a high-throughput screening platform for Rpn11-targeted small-molecule discovery.
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Affiliation(s)
- Gang Xie
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, USA
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, CA, USA
| | - Ken C Dong
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, USA
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, CA, USA
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, CA, USA
| | | | - Andreas Martin
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA, USA.
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, CA, USA.
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, CA, USA.
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34
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Jonsson E, Htet ZM, Bard JA, Dong KC, Martin A. Ubiquitin modulates 26 S proteasome conformational dynamics and promotes substrate degradation. SCIENCE ADVANCES 2022; 8:eadd9520. [PMID: 36563145 PMCID: PMC9788759 DOI: 10.1126/sciadv.add9520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 10/27/2022] [Indexed: 06/17/2023]
Abstract
The 26S proteasome recognizes thousands of appropriate protein substrates in eukaryotic cells through attached ubiquitin chains and uses its adenosine triphosphatase (ATPase) motor for mechanical unfolding and translocation into a proteolytic chamber. Here, we used single-molecule Förster resonance energy transfer measurements to monitor the conformational dynamics of the proteasome, observe individual substrates during their progression toward degradation, and elucidate how these processes are regulated by ubiquitin chains. Rapid transitions between engagement- and processing-competent proteasome conformations control substrate access to the ATPase motor. Ubiquitin chain binding functions as an allosteric regulator to slow these transitions, stabilize the engagement-competent state, and aid substrate capture to accelerate degradation initiation. Upon substrate engagement, the proteasome remains in processing-competent states for translocation and unfolding, except for apparent motor slips when encountering stably folded domains. Our studies revealed how ubiquitin chains allosterically regulate degradation initiation, which ensures substrate selectivity in a crowded cellular environment.
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Affiliation(s)
- Erik Jonsson
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, CA 94720, USA
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, CA 94720, USA
| | - Zaw Min Htet
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, CA 94720, USA
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, CA 94720, USA
| | | | - Ken C. Dong
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, CA 94720, USA
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, CA 94720, USA
| | - Andreas Martin
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA
- California Institute for Quantitative Biosciences, University of California at Berkeley, Berkeley, CA 94720, USA
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, CA 94720, USA
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35
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Weinberg J, Gaur M, Swaroop A, Taylor A. Proteostasis in aging-associated ocular disease. Mol Aspects Med 2022; 88:101157. [PMID: 36459837 PMCID: PMC9742340 DOI: 10.1016/j.mam.2022.101157] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 11/15/2022] [Indexed: 11/30/2022]
Abstract
Vision impairment has devastating consequences for the quality of human life. The cells and tissues associated with the visual process must function throughout one's life span and maintain homeostasis despite exposure to a variety of insults. Maintenance of the proteome is termed proteostasis, and is vital for normal cellular functions, especially at an advanced age. Here we describe basic aspects of proteostasis, from protein synthesis and folding to degradation, and discuss the current status of the field with a particular focus on major age-related eye diseases: age-related macular degeneration, cataract, and glaucoma. Our intent is to allow vision scientists to determine where and how to harness the proteostatic machinery for extending functional homeostasis in the aging retina, lens, and trabecular meshwork. Several common themes have emerged despite these tissues having vastly different metabolisms. Continued exposure to insults, including chronic stress with advancing age, increases proteostatic burden and reduces the fidelity of the degradation machineries including the ubiquitin-proteasome and the autophagy-lysosome systems that recognize and remove damaged proteins. This "double jeopardy" results in an exponential accumulation of cytotoxic proteins with advancing age. We conclude with a discussion of the challenges in maintaining an appropriate balance of protein synthesis and degradation pathways, and suggest that harnessing proteostatic capacities should provide new opportunities to design interventions for attenuating age-related eye diseases before they limit sight.
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Affiliation(s)
- Jasper Weinberg
- Laboratory for Nutrition and Vision Research, USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, 02111, USA
| | - Mohita Gaur
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Anand Swaroop
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Allen Taylor
- Laboratory for Nutrition and Vision Research, USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, 02111, USA.
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Sparks A, Kelly CJ, Saville MK. Ubiquitin receptors play redundant roles in the proteasomal degradation of the p53 repressor MDM2. FEBS Lett 2022; 596:2746-2767. [PMID: 35735670 PMCID: PMC9796813 DOI: 10.1002/1873-3468.14436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/01/2022] [Accepted: 06/05/2022] [Indexed: 01/07/2023]
Abstract
Much remains to be determined about the participation of ubiquitin receptors in proteasomal degradation and their potential as therapeutic targets. Suppression of the ubiquitin receptor S5A/PSMD4/hRpn10 alone stabilises p53/TP53 but not the key p53 repressor MDM2. Here, we observed S5A and the ubiquitin receptors ADRM1/PSMD16/hRpn13 and RAD23A and B functionally overlap in MDM2 degradation. We provide further evidence that degradation of only a subset of ubiquitinated proteins is sensitive to S5A knockdown because ubiquitin receptor redundancy is commonplace. p53 can be upregulated by S5A modulation while degradation of substrates with redundant receptors is maintained. Our observations and analysis of Cancer Dependency Map (DepMap) screens show S5A depletion/loss substantially reduces cancer cell line viability. This and selective S5A dependency of proteasomal substrates make S5A a target of interest for cancer therapy.
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Affiliation(s)
| | - Christopher J. Kelly
- School of MedicineUniversity of DundeeUK,Institute of Infection, Immunity and InflammationUniversity of GlasgowUK
| | - Mark K. Saville
- School of MedicineUniversity of DundeeUK,Silver River EditingDundeeUK
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Osei-Amponsa V, Walters KJ. Proteasome substrate receptors and their therapeutic potential. Trends Biochem Sci 2022; 47:950-964. [PMID: 35817651 PMCID: PMC9588529 DOI: 10.1016/j.tibs.2022.06.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/02/2022] [Accepted: 06/14/2022] [Indexed: 11/22/2022]
Abstract
The ubiquitin-proteasome system (UPS) is critical for protein quality control and regulating protein lifespans. Following ubiquitination, UPS substrates bind multidomain receptors that, in addition to ubiquitin-binding sites, contain functional domains that bind to deubiquitinating enzymes (DUBs) or the E3 ligase E6AP/UBE3A. We provide an overview of the proteasome, focusing on its receptors and DUBs. We highlight the key role of dynamics and importance of the substrate receptors having domains for both binding and processing ubiquitin chains. The UPS is rich with therapeutic opportunities, with proteasome inhibitors used clinically and ongoing development of small molecule proteolysis targeting chimeras (PROTACs) for the degradation of disease-associated proteins. We discuss the therapeutic potential of proteasome receptors, including hRpn13, for which PROTACs have been developed.
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Affiliation(s)
- Vasty Osei-Amponsa
- Protein Processing Section, Center for Structural Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Kylie J Walters
- Protein Processing Section, Center for Structural Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA.
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Pu M, Tai Y, Yuan L, Zhang Y, Guo H, Hao Z, Chen J, Qi X, Wang G, Tao Z, Ren J. The contribution of proteasomal impairment to autophagy activation by C9orf72 poly-GA aggregates. Cell Mol Life Sci 2022; 79:501. [PMID: 36036324 DOI: 10.1007/s00018-022-04518-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 07/18/2022] [Accepted: 08/08/2022] [Indexed: 11/26/2022]
Abstract
BACKGROUND Poly-GA, a dipeptide repeat protein unconventionally translated from GGGGCC (G4C2) repeat expansions in C9orf72, is abundant in C9orf72-related amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) (C9orf72-ALS/FTD). Although the poly-GA aggregates have been identified in C9orf72-ALS/FTD neurons, the effects on UPS (ubiquitin-proteasome system) and autophagy and their exact molecular mechanisms have not been fully elucidated. RESULTS Herein, our in vivo experiments indicate that the mice expressing ploy-GA with 150 repeats instead of 30 repeats exhibit significant aggregates in cells. Mice expressing 150 repeats ploy-GA shows behavioral deficits and activates autophagy in the brain. In vitro findings suggest that the poly-GA aggregates influence proteasomal by directly binding proteasome subunit PSMD2. Subsequently, the poly-GA aggregates activate phosphorylation and ubiquitination of p62 to recruit autophagosomes. Ultimately, the poly-GA aggregates lead to compensatory activation of autophagy. In vivo studies further reveal that rapamycin (autophagy activator) treatment significantly improves the degenerative symptoms and alleviates neuronal injury in mice expressing 150 repeats poly-GA. Meanwhile, rapamycin administration to mice expressing 150 repeats poly-GA reduces neuroinflammation and aggregates in the brain. CONCLUSION In summary, we elucidate the relationship between poly-GA in the proteasome and autophagy: when poly-GA forms complexes with the proteasome, it recruits autophagosomes and affects proteasome function. Our study provides support for further promoting the comprehension of the pathogenesis of C9orf72, which may bring a hint for the exploration of rapamycin for the treatment of ALS/FTD.
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Affiliation(s)
- Mei Pu
- Center for Drug Safety Evaluation and Research, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yusi Tai
- Center for Drug Safety Evaluation and Research, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Luyang Yuan
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yu Zhang
- Key Laboratory of Receptor Research, Department of Neuropharmacology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Huijie Guo
- Center for Drug Safety Evaluation and Research, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zongbing Hao
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Neuropsychiatric Diseases and Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China
| | - Jing Chen
- Center for Drug Safety Evaluation and Research, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai, China
| | - Xinming Qi
- Center for Drug Safety Evaluation and Research, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai, China
| | - Guanghui Wang
- Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Neuropsychiatric Diseases and Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China.
| | - Zhouteng Tao
- Center for Drug Safety Evaluation and Research, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai, China.
- State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, China.
| | - Jin Ren
- Center for Drug Safety Evaluation and Research, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai, China.
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
- University of Chinese Academy of Sciences, Beijing, China.
- School of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China.
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RPNs Levels Are Prognostic and Diagnostic Markers for Hepatocellular Carcinoma. JOURNAL OF ONCOLOGY 2022; 2022:7270541. [PMID: 36072976 PMCID: PMC9444382 DOI: 10.1155/2022/7270541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 05/04/2022] [Accepted: 05/23/2022] [Indexed: 11/17/2022]
Abstract
The ribophorin family (RPN) is an essential regulatory subunit of the proteasome. By influencing the ubiquitin-proteasome system activity, ribophorins (RPNs) are responsible for almost all physiology and pathology processes of mammalian cells. Nevertheless, little is known about the role of RPNs in HCC. In this work, we first evaluated the transcriptional levels and the prognostic and diagnostic value of RPNs based on the public database. Firstly, we found all RPNs were surprisingly consistently upregulated in HCC tissues. Moreover, the RPNs' expression pattern is correlated with HCC tumor grade. The TCGA HCC platforms' data indicated that RPN2, RPN3, RPN6, RPN9, RPN10, RPN11, and RPN12 have robust diagnosis values. Then, survival analysis revealed that the high expression of RPN1, RPN2, RPN4, RPN5, RPN6, RPN9, and RPN11 was correlated with unfavourable HCC overall survival. Then, genetic alteration, immune infiltration feature, gene-genes network, and functional enrichment for RPNs indicated that RPNs have many potential biosynthesis activities expert for UPS functions. Moreover, western blot and qRT-PCR results confirmed these results. The silencing of RPN6 and RPN9 significantly reduced HCC cells' proliferation, migration, and invasion ability in vitro. An in vivo tumor model further validated the oncogene effect of RPN6 on HCC cell growth. Moreover, RPN6 and RPN9 could promote cell migratory and invasive potential by affecting the epithelial-mesenchymal transition (EMT) process. In summary, this study suggests that the RPN family has the potential to be potential biomarkers and targets for HCC.
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Dreier JE, Prestel A, Martins JM, Brøndum SS, Nielsen O, Garbers AE, Suga H, Boomsma W, Rogers JM, Hartmann-Petersen R, Kragelund BB. A context-dependent and disordered ubiquitin-binding motif. Cell Mol Life Sci 2022; 79:484. [PMID: 35974206 PMCID: PMC9381478 DOI: 10.1007/s00018-022-04486-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 07/06/2022] [Accepted: 07/14/2022] [Indexed: 02/07/2023]
Abstract
Ubiquitin is a small, globular protein that is conjugated to other proteins as a posttranslational event. A palette of small, folded domains recognizes and binds ubiquitin to translate and effectuate this posttranslational signal. Recent computational studies have suggested that protein regions can recognize ubiquitin via a process of folding upon binding. Using peptide binding arrays, bioinformatics, and NMR spectroscopy, we have uncovered a disordered ubiquitin-binding motif that likely remains disordered when bound and thus expands the palette of ubiquitin-binding proteins. We term this motif Disordered Ubiquitin-Binding Motif (DisUBM) and find it to be present in many proteins with known or predicted functions in degradation and transcription. We decompose the determinants of the motif showing it to rely on features of aromatic and negatively charged residues, and less so on distinct sequence positions in line with its disordered nature. We show that the affinity of the motif is low and moldable by the surrounding disordered chain, allowing for an enhanced interaction surface with ubiquitin, whereby the affinity increases ~ tenfold. Further affinity optimization using peptide arrays pushed the affinity into the low micromolar range, but compromised context dependence. Finally, we find that DisUBMs can emerge from unbiased screening of randomized peptide libraries, featuring in de novo cyclic peptides selected to bind ubiquitin chains. We suggest that naturally occurring DisUBMs can recognize ubiquitin as a posttranslational signal to act as affinity enhancers in IDPs that bind to folded and ubiquitylated binding partners.
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Affiliation(s)
- Jesper E Dreier
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.,REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Andreas Prestel
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - João M Martins
- Department of Computer Science, University of Copenhagen, Universitetsparken 1, 2100, Copenhagen Ø, Denmark
| | - Sebastian S Brøndum
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Olaf Nielsen
- Functional Genomics, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Anna E Garbers
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.,REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark
| | - Hiroaki Suga
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Wouter Boomsma
- Department of Computer Science, University of Copenhagen, Universitetsparken 1, 2100, Copenhagen Ø, Denmark
| | - Joseph M Rogers
- Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, 2100, Copenhagen Ø, Denmark
| | - Rasmus Hartmann-Petersen
- REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark. .,The Linderstrøm Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark. .,REPIN, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark. .,The Linderstrøm Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, 2200, Copenhagen N, Denmark.
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Yeast PI31 inhibits the proteasome by a direct multisite mechanism. Nat Struct Mol Biol 2022; 29:791-800. [PMID: 35927584 PMCID: PMC9399903 DOI: 10.1038/s41594-022-00808-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 06/24/2022] [Indexed: 02/06/2023]
Abstract
Proteasome inhibitors are widely used as therapeutics and research tools, and typically target one of the three active sites, each present twice in the proteasome complex. An endogeneous proteasome inhibitor, PI31, was identified 30 years ago, but its inhibitory mechanism has remained unclear. Here, we identify the mechanism of Saccharomyces cerevisiae PI31, also known as Fub1. Using cryo-electron microscopy (cryo-EM), we show that the conserved carboxy-terminal domain of Fub1 is present inside the proteasome's barrel-shaped core particle (CP), where it simultaneously interacts with all six active sites. Targeted mutations of Fub1 disrupt proteasome inhibition at one active site, while leaving the other sites unaffected. Fub1 itself evades degradation through distinct mechanisms at each active site. The gate that allows substrates to access the CP is constitutively closed, and Fub1 is enriched in mutant CPs with an abnormally open gate, suggesting that Fub1 may function to neutralize aberrant proteasomes, thereby ensuring the fidelity of proteasome-mediated protein degradation.
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42
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Buneeva OA, Kopylov AT, Medvedev AE. [The key role of the regulatory 19S subunit in changes in the brain proteasome subproteome induced by the neuroprotector isatin]. BIOMEDITSINSKAIA KHIMIIA 2022; 68:250-262. [PMID: 36005843 DOI: 10.18097/pbmc20226804250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Isatin (indole-2,3-dione) is an endogenous regulator exhibiting various effects mediated by numerous isatin-binding proteins localized in different compartments of cells of the brain and peripheral tissues. It attenuates manifestations of experimental parkinsonism induced by administration of the MPTP neurotoxin and reduces the movement disorders characteristic of this disease. The molecular mechanisms of the neuroprotective action of isatin include its direct interaction with proteasomes, intracellular supramolecular complexes responsible for the targeted elimination of proteins. Incubation of fractions of 26S and 20S rabbit brain proteasomes, containing the whole spectrum of proteasomal subunits, as well as a number of proteasome-associated proteins, with isatin (100 μM) had a significant impact on the profile of released proteins. In the case of 26S proteasomes containing, in addition to the core part (20S proteasome), 19S regulatory subparticles, incubation with isatin resulted in a more than threefold increase in the number of dissociated proteins. In the case of 20S proteasomes (containing only the 20S core particle), incubation with isatin resulted in a significant decrease in the number of dissociated proteins compared to the control. Our results indicate an important role of the regulatory 19S subunit components in the formation of the proteasome subproteome and the sensitivity of these supramolecular complexes to isatin.
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Affiliation(s)
- O A Buneeva
- Institute of Biomedical Chemistry, Moscow, Russia
| | - A T Kopylov
- Institute of Biomedical Chemistry, Moscow, Russia
| | - A E Medvedev
- Institute of Biomedical Chemistry, Moscow, Russia
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43
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Zhao J, Guo J, Wang Y, Ma Q, Shi Y, Cheng F, Lu Q, Fu W, Ouyang G, Zhang J, Xu Q, Hu X. Research Progress of DUB Enzyme in Hepatocellular Carcinoma. Front Oncol 2022; 12:920287. [PMID: 35875077 PMCID: PMC9303014 DOI: 10.3389/fonc.2022.920287] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 05/24/2022] [Indexed: 11/13/2022] Open
Abstract
According to GLOBOCAN 2021 cancer incidence and mortality statistics compiled by the International Agency for Research on Cancer, hepatocellular carcinoma (HCC) is the most common malignancy in the human liver and one of the leading causes of cancer death worldwide. Although there have been great advances in the treatment of HCC, such as regofenib, sorafenib, and lomvatinib, which have been developed and approved for the clinical treatment of advanced or metastatic HCC. However, they only prolong survival by a few months, and patients with advanced liver cancer are susceptible to tumor invasion metastasis and drug resistance. Ubiquitination modification is a type of post-translational modification of proteins. It can affect the physiological activity of cells by regulating the localization, stability and activity of proteins, such as: gene transcription, DNA damage signaling and other pathways. The reversible process of ubiquitination is called de-ubiquitination: it is the process of re-releasing ubiquitinated substrates with the participation of de-ubiquitinases (DUBs) and other active substances. There is growing evidence that many dysregulations of DUBs are associated with tumorigenesis. Although dysregulation of deuquitinase function is often found in HCC and other cancers, The mechanisms of action of many DUBs in HCC have not been elucidated. In this review, we focused on several deubiquitinases (DUBs) associated with hepatocellular carcinoma, including their structure, function, and relationship to hepatocellular carcinoma. hepatocellular carcinoma was highlighted, as well as the latest research reports. Among them, we focus on the USP family and OTU family which are more studied in the HCC. In addition, we discussed the prospects and significance of targeting DUBs as a new strategy for the treatment of hepatocellular carcinoma. It also briefly summarizes the research progress of some DUB-related small molecule inhibitors and their clinical application significance as a treatment for HCC in the future.
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Affiliation(s)
- Jie Zhao
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
- Laboratory of Tumor Molecular Diagnosis and Individualized Medicine of Zhejiang Province, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Hangzhou, China
| | - Jinhui Guo
- Qingdao Medical College, Qingdao University, Qingdao, China
| | - Yanan Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Qiancheng Ma
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Yu Shi
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Feng Cheng
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Qiliang Lu
- Qingdao Medical College, Qingdao University, Qingdao, China
| | - Wen Fu
- Qingdao Medical College, Qingdao University, Qingdao, China
| | | | - Ji Zhang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Qiuran Xu
- Laboratory of Tumor Molecular Diagnosis and Individualized Medicine of Zhejiang Province, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Hangzhou, China
- *Correspondence: Xiaoge Hu, ; Qiuran Xu,
| | - Xiaoge Hu
- Department of Hepatobiliary and Pancreatic Surgery, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical CollegeHangzhou, China
- The Key Laboratory of Tumor Molecular Diagnosis and Individualized Medicine of Zhejiang Province, Zhejiang Provincial People’s Hospital, Affiliated People’s Hospital, Hangzhou Medical College, Hangzhou, China
- *Correspondence: Xiaoge Hu, ; Qiuran Xu,
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Nahar A, Sokolova V, Sekaran S, Orth JD, Park S. Assembly checkpoint of the proteasome regulatory particle is activated by coordinated actions of proteasomal ATPase chaperones. Cell Rep 2022; 39:110918. [PMID: 35675778 PMCID: PMC9214829 DOI: 10.1016/j.celrep.2022.110918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 03/14/2022] [Accepted: 05/12/2022] [Indexed: 11/26/2022] Open
Abstract
The proteasome holoenzyme regulates the cellular proteome via degrading most proteins. In its 19-subunit regulatory particle (RP), a heterohexameric ATPase enables protein degradation by injecting protein substrates into the core peptidase. RP assembly utilizes “checkpoints,” where multiple dedicated chaperones bind to specific ATPase subunits and control the addition of other subunits. Here, we find that the RP assembly checkpoint relies on two common features of the chaperones. Individual chaperones can distinguish an RP, in which their cognate ATPase persists in the ATP-bound state. Chaperones then together modulate ATPase activity to facilitate RP subunit rearrangements for switching to an active, substrate-processing state in the resulting proteasome holoenzyme. Thus, chaperones may sense ATP binding and hydrolysis as a readout for the quality of the RP complex to generate a functional proteasome holoenzyme. Our findings provide a basis to potentially exploit the assembly checkpoints in situations with known deregulation of proteasomal ATPase chaperones. Nahar et al. report that cells build functional proteasomes by utilizing an assembly checkpoint, which is activated by a common feature of multiple dedicated chaperones; they can distinguish the nucleotide state of proteasomal ATPases and help facilitate proper subunit rearrangement to ensure efficient protein degradation by the proteasome.
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Affiliation(s)
- Asrafun Nahar
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, 1945 Colorado Avenue, Boulder, CO 80309, USA
| | - Vladyslava Sokolova
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, 1945 Colorado Avenue, Boulder, CO 80309, USA
| | - Suganya Sekaran
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, 1945 Colorado Avenue, Boulder, CO 80309, USA
| | - James D Orth
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, 1945 Colorado Avenue, Boulder, CO 80309, USA
| | - Soyeon Park
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, 1945 Colorado Avenue, Boulder, CO 80309, USA.
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HECT ubiquitin ligases as accessory proteins of the plant proteasome. Essays Biochem 2022; 66:135-145. [PMID: 35635104 PMCID: PMC9400063 DOI: 10.1042/ebc20210064] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 04/21/2022] [Accepted: 04/29/2022] [Indexed: 12/31/2022]
Abstract
The proteasome plays vital roles in eukaryotic cells by orchestrating the regulated degradation of large repertoires of substrates involved in numerous biological processes. Proteasome dysfunction is associated with a wide variety of human pathologies and in plants severely affects growth, development and responses to stress. The activity of E3 ubiquitin ligases marks proteins fated for degradation with chains of the post-translational modifier, ubiquitin. Proteasomal processing of ubiquitinated substrates involves ubiquitin chain recognition, deubiquitination, ATP-mediated unfolding and translocation, and proteolytic digestion. This complex series of steps is made possible not only by the many specialised subunits of the 1.5 MDa proteasome complex but also by a range of accessory proteins that are recruited to the proteasome. A surprising class of accessory proteins are members of the HECT-type family of ubiquitin ligases that utilise a unique mechanism for post-translational attachment of ubiquitin to their substrates. So why do proteasomes that already contain all the necessary machinery to recognise ubiquitinated substrates, harbour HECT ligase activity? It is now clear that some ubiquitin ligases physically relay their substrates to proteasome-associated HECT ligases, which prevent substrate stalling at the proteasome. Moreover, HECT ligases ubiquitinate proteasome subunits, thereby modifying the proteasome's ability to recognise substrates. They may therefore enable proteasomes to be both non-specific and extraordinarily selective in a complex substrate environment. Understanding the relationship between the proteasome and accessory HECT ligases will reveal how the proteasome controls so many diverse plant developmental and stress responses.
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46
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Enenkel C, Kang RW, Wilfling F, Ernst OP. Intracellular localization of the proteasome in response to stress conditions. J Biol Chem 2022; 298:102083. [PMID: 35636514 PMCID: PMC9218506 DOI: 10.1016/j.jbc.2022.102083] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 12/15/2022] Open
Abstract
The ubiquitin–proteasome system fulfills an essential role in regulating protein homeostasis by spatially and temporally controlling proteolysis in an ATP- and ubiquitin-dependent manner. However, the localization of proteasomes is highly variable under diverse cellular conditions. In yeast, newly synthesized proteasomes are primarily localized to the nucleus during cell proliferation. Yeast proteasomes are transported into the nucleus through the nuclear pore either as immature subcomplexes or as mature enzymes via adapter proteins Sts1 and Blm10, while in mammalian cells, postmitotic uptake of proteasomes into the nucleus is mediated by AKIRIN2, an adapter protein essentially required for nuclear protein degradation. Stressful growth conditions and the reversible halt of proliferation, that is quiescence, are associated with a decline in ATP and the reorganization of proteasome localization. Cellular stress leads to proteasome accumulation in membraneless granules either in the nucleus or in the cytoplasm. In quiescence, yeast proteasomes are sequestered in an ubiquitin-dependent manner into motile and reversible proteasome storage granules in the cytoplasm. In cancer cells, upon amino acid deprivation, heat shock, osmotic stress, oxidative stress, or the inhibition of either proteasome activity or nuclear export, reversible proteasome foci containing polyubiquitinated substrates are formed by liquid–liquid phase separation in the nucleus. In this review, we summarize recent literature revealing new links between nuclear transport, ubiquitin signaling, and the intracellular organization of proteasomes during cellular stress conditions.
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Affiliation(s)
- Cordula Enenkel
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
| | - Ryu Won Kang
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Florian Wilfling
- Mechanisms of Cellular Quality Control, Max-Planck-Institute of Biophysics, Frankfurt, Germany
| | - Oliver P Ernst
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
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47
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Demange P, Joly E, Marcoux J, Zanon PRA, Listunov D, Rullière P, Barthes C, Noirot C, Izquierdo JB, Rozié A, Pradines K, Hee R, de Brito MV, Marcellin M, Serre RF, Bouchez O, Burlet-Schiltz O, Oliveira MCF, Ballereau S, Bernardes-Génisson V, Maraval V, Calsou P, Hacker SM, Génisson Y, Chauvin R, Britton S. SDR enzymes oxidize specific lipidic alkynylcarbinols into cytotoxic protein-reactive species. eLife 2022; 11:73913. [PMID: 35535493 PMCID: PMC9090334 DOI: 10.7554/elife.73913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 04/19/2022] [Indexed: 11/21/2022] Open
Abstract
Hundreds of cytotoxic natural or synthetic lipidic compounds contain chiral alkynylcarbinol motifs, but the mechanism of action of those potential therapeutic agents remains unknown. Using a genetic screen in haploid human cells, we discovered that the enantiospecific cytotoxicity of numerous terminal alkynylcarbinols, including the highly cytotoxic dialkynylcarbinols, involves a bioactivation by HSD17B11, a short-chain dehydrogenase/reductase (SDR) known to oxidize the C-17 carbinol center of androstan-3-alpha,17-beta-diol to the corresponding ketone. A similar oxidation of dialkynylcarbinols generates dialkynylketones, that we characterize as highly protein-reactive electrophiles. We established that, once bioactivated in cells, the dialkynylcarbinols covalently modify several proteins involved in protein-quality control mechanisms, resulting in their lipoxidation on cysteines and lysines through Michael addition. For some proteins, this triggers their association to cellular membranes and results in endoplasmic reticulum stress, unfolded protein response activation, ubiquitin-proteasome system inhibition and cell death by apoptosis. Finally, as a proof-of-concept, we show that generic lipidic alkynylcarbinols can be devised to be bioactivated by other SDRs, including human RDH11 and HPGD/15-PGDH. Given that the SDR superfamily is one of the largest and most ubiquitous, this unique cytotoxic mechanism-of-action could be widely exploited to treat diseases, in particular cancer, through the design of tailored prodrugs.
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Affiliation(s)
- Pascal Demange
- Institut de Pharmacologie et de Biologie Structurale, IPBS, CNRS, Université de Toulouse, Toulouse, France
| | - Etienne Joly
- Institut de Pharmacologie et de Biologie Structurale, IPBS, CNRS, Université de Toulouse, Toulouse, France
| | - Julien Marcoux
- Institut de Pharmacologie et de Biologie Structurale, IPBS, CNRS, Université de Toulouse, Toulouse, France
| | - Patrick R A Zanon
- Leiden Institute of Chemistry, Leiden University, Leiden, Netherlands.,Department of Chemistry, Technical University of Munich, Garching, Germany
| | - Dymytrii Listunov
- SPCMIB, UMR5068, CNRS, Université de Toulouse, UPS, Toulouse, France.,LCC-CNRS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Pauline Rullière
- SPCMIB, UMR5068, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Cécile Barthes
- LCC-CNRS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Céline Noirot
- INRAE, UR 875 Unité de Mathématique et Informatique Appliquées, Genotoul Bioinfo Auzeville, Castanet-Tolosan, France
| | - Jean-Baptiste Izquierdo
- Institut de Pharmacologie et de Biologie Structurale, IPBS, CNRS, Université de Toulouse, Toulouse, France
| | - Alexandrine Rozié
- Institut de Pharmacologie et de Biologie Structurale, IPBS, CNRS, Université de Toulouse, Toulouse, France.,Equipe labellisée la Ligue contre le Cancer 2018, Toulouse, France
| | - Karen Pradines
- Institut de Pharmacologie et de Biologie Structurale, IPBS, CNRS, Université de Toulouse, Toulouse, France.,Equipe labellisée la Ligue contre le Cancer 2018, Toulouse, France
| | - Romain Hee
- Institut de Pharmacologie et de Biologie Structurale, IPBS, CNRS, Université de Toulouse, Toulouse, France.,Equipe labellisée la Ligue contre le Cancer 2018, Toulouse, France
| | - Maria Vieira de Brito
- LCC-CNRS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Department of Organic and Inorganic Chemistry, Science Center, Federal University of Ceará, Fortaleza, Brazil
| | - Marlène Marcellin
- Institut de Pharmacologie et de Biologie Structurale, IPBS, CNRS, Université de Toulouse, Toulouse, France
| | | | | | - Odile Burlet-Schiltz
- Institut de Pharmacologie et de Biologie Structurale, IPBS, CNRS, Université de Toulouse, Toulouse, France
| | | | | | | | - Valérie Maraval
- LCC-CNRS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Patrick Calsou
- Institut de Pharmacologie et de Biologie Structurale, IPBS, CNRS, Université de Toulouse, Toulouse, France.,Equipe labellisée la Ligue contre le Cancer 2018, Toulouse, France
| | - Stephan M Hacker
- Leiden Institute of Chemistry, Leiden University, Leiden, Netherlands.,Department of Chemistry, Technical University of Munich, Garching, Germany
| | - Yves Génisson
- SPCMIB, UMR5068, CNRS, Université de Toulouse, UPS, Toulouse, France
| | - Remi Chauvin
- LCC-CNRS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Sébastien Britton
- Institut de Pharmacologie et de Biologie Structurale, IPBS, CNRS, Université de Toulouse, Toulouse, France.,Equipe labellisée la Ligue contre le Cancer 2018, Toulouse, France
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48
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Kandolf S, Grishkovskaya I, Belačić K, Bolhuis DL, Amann S, Foster B, Imre R, Mechtler K, Schleiffer A, Tagare HD, Zhong ED, Meinhart A, Brown NG, Haselbach D. Cryo-EM structure of the plant 26S proteasome. PLANT COMMUNICATIONS 2022; 3:100310. [PMID: 35576154 PMCID: PMC9251434 DOI: 10.1016/j.xplc.2022.100310] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/01/2022] [Accepted: 03/04/2022] [Indexed: 05/17/2023]
Abstract
Targeted proteolysis is a hallmark of life. It is especially important in long-lived cells that can be found in higher eukaryotes, like plants. This task is mainly fulfilled by the ubiquitin-proteasome system. Thus, proteolysis by the 26S proteasome is vital to development, immunity, and cell division. Although the yeast and animal proteasomes are well characterized, there is only limited information on the plant proteasome. We determined the first plant 26S proteasome structure from Spinacia oleracea by single-particle electron cryogenic microscopy at an overall resolution of 3.3 Å. We found an almost identical overall architecture of the spinach proteasome compared with the known structures from mammals and yeast. Nevertheless, we noticed a structural difference in the proteolytic active β1 subunit. Furthermore, we uncovered an unseen compression state by characterizing the proteasome's conformational landscape. We suspect that this new conformation of the 20S core protease, in correlation with a partial opening of the unoccupied gate, may contribute to peptide release after proteolysis. Our data provide a structural basis for the plant proteasome, which is crucial for further studies.
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Affiliation(s)
- Susanne Kandolf
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-BioCenter 1, 1030 Vienna, Austria
| | - Irina Grishkovskaya
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-BioCenter 1, 1030 Vienna, Austria
| | - Katarina Belačić
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-BioCenter 1, 1030 Vienna, Austria; Vienna BioCenter PhD Program, Doctoral School of the University at Vienna and Medical University of Vienna, Vienna BioCenter (VBC), Vienna, Austria
| | - Derek L Bolhuis
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Sascha Amann
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-BioCenter 1, 1030 Vienna, Austria; Vienna BioCenter PhD Program, Doctoral School of the University at Vienna and Medical University of Vienna, Vienna BioCenter (VBC), Vienna, Austria
| | - Brent Foster
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06510, USA
| | - Richard Imre
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-BioCenter 1, 1030 Vienna, Austria
| | - Karl Mechtler
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-BioCenter 1, 1030 Vienna, Austria
| | - Alexander Schleiffer
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-BioCenter 1, 1030 Vienna, Austria
| | - Hemant D Tagare
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06510, USA
| | - Ellen D Zhong
- Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Anton Meinhart
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-BioCenter 1, 1030 Vienna, Austria
| | - Nicholas G Brown
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - David Haselbach
- Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-BioCenter 1, 1030 Vienna, Austria; Institute of Physical Chemistry, University of Freiburg, Albertstraße 21, Freiburg 79104, Germany; CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
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49
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USP14-regulated allostery of the human proteasome by time-resolved cryo-EM. Nature 2022; 605:567-574. [PMID: 35477760 PMCID: PMC9117149 DOI: 10.1038/s41586-022-04671-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 03/22/2022] [Indexed: 01/19/2023]
Abstract
Proteasomal degradation of ubiquitylated proteins is tightly regulated at multiple levels1-3. A primary regulatory checkpoint is the removal of ubiquitin chains from substrates by the deubiquitylating enzyme ubiquitin-specific protease 14 (USP14), which reversibly binds the proteasome and confers the ability to edit and reject substrates. How USP14 is activated and regulates proteasome function remain unknown4-7. Here we present high-resolution cryo-electron microscopy structures of human USP14 in complex with the 26S proteasome in 13 distinct conformational states captured during degradation of polyubiquitylated proteins. Time-resolved cryo-electron microscopy analysis of the conformational continuum revealed two parallel pathways of proteasome state transitions induced by USP14, and captured transient conversion of substrate-engaged intermediates into substrate-inhibited intermediates. On the substrate-engaged pathway, ubiquitin-dependent activation of USP14 allosterically reprograms the conformational landscape of the AAA-ATPase motor and stimulates opening of the core particle gate8-10, enabling observation of a near-complete cycle of asymmetric ATP hydrolysis around the ATPase ring during processive substrate unfolding. Dynamic USP14-ATPase interactions decouple the ATPase activity from RPN11-catalysed deubiquitylation11-13 and kinetically introduce three regulatory checkpoints on the proteasome, at the steps of ubiquitin recognition, substrate translocation initiation and ubiquitin chain recycling. These findings provide insights into the complete functional cycle of the USP14-regulated proteasome and establish mechanistic foundations for the discovery of USP14-targeted therapies.
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50
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Assembly and function of branched ubiquitin chains. Trends Biochem Sci 2022; 47:759-771. [DOI: 10.1016/j.tibs.2022.04.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/23/2022] [Accepted: 04/05/2022] [Indexed: 12/11/2022]
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