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Shi P, Du Y, Zhang Y, Yang B, Guan Q, Jing Y, Tang H, Tang J, Yang C, Ge X, Shen S, Li L, Wu C. Ubiquitin-independent degradation of Bim blocks macrophage pyroptosis in sepsis-related tissue injury. Cell Death Dis 2024; 15:703. [PMID: 39349939 PMCID: PMC11442472 DOI: 10.1038/s41419-024-07072-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 09/04/2024] [Accepted: 09/12/2024] [Indexed: 10/04/2024]
Abstract
Pyroptosis, a typical inflammatory cell death mode, has been increasingly demonstrated to have therapeutic value in inflammatory diseases such as sepsis. However, the mechanisms and therapeutic targets of sepsis remain elusive. Here, we reported that REGγ inhibition promoted pyroptosis by regulating members of the gasdermin family in macrophages. Mechanistically, REGγ directly degraded Bim, a factor of the Bcl-2 family that can inhibit the cleavage of GSDMD/E, ultimately preventing the occurrence of pyroptosis. Furthermore, cecal ligation and puncture (CLP)-induced sepsis model mice showed downregulation of REGγ at both the RNA and protein levels. Gasdermin-mediated pyroptosis was augmented in REGγ-knockout mice, and these mice exhibited more severe sepsis-related tissue injury. More importantly, we found that REGγ expression was downregulated in clinical sepsis samples, such as those from patients with Pseudomonas aeruginosa (PA) infection. Finally, PA-infected mice showed decreased REGγ levels in the lung. In summary, our study reveals that the REGγ-Bim-GSDMD/E pathway is a novel regulatory mechanism of pyroptosis in sepsis-related tissue injury.
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Affiliation(s)
- Peilin Shi
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, East China Normal University, Shanghai, 200241, China
| | - Yingying Du
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, East China Normal University, Shanghai, 200241, China
| | - Yunyan Zhang
- Department of Respiratory and Critical Care Medicine, Changzheng Hospital, Naval Military Medical University, Shanghai, 200003, China
| | - Bo Yang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, East China Normal University, Shanghai, 200241, China
| | - Qiujing Guan
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, East China Normal University, Shanghai, 200241, China
| | - Yiming Jing
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, East China Normal University, Shanghai, 200241, China
| | - Hao Tang
- Department of Respiratory and Critical Care Medicine, Changzheng Hospital, Naval Military Medical University, Shanghai, 200003, China
| | - Jianguo Tang
- Joint Center for Translational Medicine, Shanghai Fifth People's Hospital, Fudan University and School of Life Science, East China Normal University, Shanghai, 200011, China
- Department of Trauma-Emergency and Critical Care Medicine Center (TECCMC), Shanghai Fifth People's Hospital, Fudan University, Shanghai, 200240, China
| | - Chunhui Yang
- Joint Center for Translational Medicine, Shanghai Fifth People's Hospital, Fudan University and School of Life Science, East China Normal University, Shanghai, 200011, China
- Department of Trauma-Emergency and Critical Care Medicine Center (TECCMC), Shanghai Fifth People's Hospital, Fudan University, Shanghai, 200240, China
| | - Xiaoli Ge
- Department of Emergency, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
| | - Shihui Shen
- Joint Center for Translational Medicine, Shanghai Fifth People's Hospital, Fudan University and School of Life Science, East China Normal University, Shanghai, 200011, China.
| | - Lei Li
- Joint Center for Translational Medicine, Shanghai Fifth People's Hospital, Fudan University and School of Life Science, East China Normal University, Shanghai, 200011, China.
| | - Chunrong Wu
- Joint Center for Translational Medicine, Shanghai Fifth People's Hospital, Fudan University and School of Life Science, East China Normal University, Shanghai, 200011, China.
- Department of Trauma-Emergency and Critical Care Medicine Center (TECCMC), Shanghai Fifth People's Hospital, Fudan University, Shanghai, 200240, China.
- Department of Emergency Medicine, Xinhua Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200092, China.
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Kasai H, Yamashita A, Akaike Y, Tanaka T, Matsuura Y, Moriishi K. HCV infection activates the proteasome via PA28γ acetylation and heptamerization to facilitate the degradation of RNF2, a catalytic component of polycomb repressive complex 1. mBio 2024:e0169124. [PMID: 39329491 DOI: 10.1128/mbio.01691-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Accepted: 08/26/2024] [Indexed: 09/28/2024] Open
Abstract
We previously reported that hepatitis C virus (HCV) infection or HCV core protein expression induces HOX gene expression by impairing histone H2A monoubiquitination via a proteasome-dependent reduction in the level of RNF2, a key catalytic component of polycomb repressive complex 1 (H. Kasai, K. Mochizuki, T. Tanaka, A. Yamashita, et al., J Virol 95:e01784-20, 2021, https://doi.org/10.1128/jvi.01784-20). In this study, we aimed to investigate the mechanism by which HCV infection accelerates RNF2 degradation. Yeast two-hybrid screening and an immunoprecipitation assay revealed that RNF2 is a PA28γ-binding protein. The proteasome activator PA28γ destabilized the RNF2 protein in a proteasome-dependent manner, since RNF2 degradation was impaired by PA28γ knockout or MG132 treatment. HCV infection or core protein expression reduced the levels of RNF2 and histone H2A K119 monoubiquitination and induced the expression of HOX genes in the presence of PA28γ, while PA28γ knockout reversed these changes. Treatment with a lysine acetyltransferase inhibitor inhibited the acetylation of PA28γ at K195 and the degradation of the RNF2 protein, while treatment with a lysine deacetylase inhibitor accelerated these events in a PA28γ-dependent manner. RNF2 protein degradation was increased by expression of the acetylation mimetic PA28γ mutant but not by expression of the acetylation-defective mutant or the proteasome activation-defective mutant. Furthermore, HCV infection or core protein expression facilitated the interaction between PA28γ and the lysine acetyltransferase CBP/p300 and then accelerated PA28γ acetylation and heptazmerization to promote RNF2 degradation. These data suggest that HCV infection accelerates the acetylation-dependent heptamerization of PA28γ to increase the proteasomal targeting of RNF2.IMPORTANCEHCV is a causative agent of HCV-related liver diseases, including hepatic steatosis, cirrhosis, and hepatocellular carcinoma. PA28γ, which, in heptameric form, activates the 20S core proteasome for the degradation of PA28γ-binding proteins, is responsible for HCV-related liver diseases. HCV core protein expression or HCV infection accelerates RNF2 degradation, leading to the induction of HOX gene expression via a decrease in the level of H2Aub on HOX gene promoters. However, the mechanism of RNF2 degradation in HCV-infected cells has not been clarified. The data presented in this study suggest that PA28γ acetylation and heptamerization are promoted by HCV infection or by core protein expression to activate the proteasome for the degradation of RNF2 and are responsible for HCV propagation. This study provides novel insights valuable for the development of therapies targeting both HCV propagation and HCV-related diseases.
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Affiliation(s)
- Hirotake Kasai
- Department of Microbiology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, University of Yamanashi, Yamanashi, Japan
| | - Atsuya Yamashita
- Department of Microbiology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, University of Yamanashi, Yamanashi, Japan
| | - Yasunori Akaike
- Department of Microbiology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, University of Yamanashi, Yamanashi, Japan
| | - Tomohisa Tanaka
- Department of Microbiology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, University of Yamanashi, Yamanashi, Japan
- Division of Hepatitis Virology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Yoshiharu Matsuura
- Laboratory of Virus Control, Research Institute for Microbial Diseases (RIMD), Osaka University, Osaka, Japan
- Center for Infectious Diseases Education and Research (CiDER), Osaka University, Osaka, Japan
| | - Kohji Moriishi
- Department of Microbiology, Faculty of Medicine, Graduate Faculty of Interdisciplinary Research, University of Yamanashi, Yamanashi, Japan
- Division of Hepatitis Virology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
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Li Z, Sun S, Wang Y, Hua Y, Liu M, Zhou Y, Zhong L, Li T, Zhao H, Zhou X, Zeng X, Chen Q, Li J. PA28γ coordinates the cross-talk between cancer-associated fibroblasts and tumor cells to promote OSCC progression via HDAC1/E2F3/IGF2 signaling. Cancer Lett 2024; 594:216962. [PMID: 38768680 DOI: 10.1016/j.canlet.2024.216962] [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: 02/05/2024] [Revised: 05/09/2024] [Accepted: 05/10/2024] [Indexed: 05/22/2024]
Abstract
PA28γ overexpression is aberrant and accompanied by poor patient prognosis in various cancers, the precise regulatory mechanism of this crucial gene in the tumor microenvironment remains incompletely understood. In this study, using oral squamous cell carcinoma as a model, we demonstrated that PA28γ exhibits high expression in cancer-associated fibroblasts (CAFs), and its expression significantly correlates with the severity of clinical indicators of malignancy. Remarkably, we found that elevated levels of secreted IGF2 from PA28γ+ CAFs can enhance stemness maintenance and promote tumor cell aggressiveness through the activation of the MAPK/AKT pathway in a paracrine manner. Mechanistically, PA28γ upregulates IGF2 expression by stabilizing the E2F3 protein, a transcription factor of IGF2. Further mechanistic insights reveal that HDAC1 predominantly mediates the deacetylation and subsequent ubiquitination and degradation of E2F3. Notably, PA28γ interacts with HDAC1 and accelerates its degradation via a 20S proteasome-dependent pathway. Additionally, PA28γ+ CAFs exert an impact on the tumor immune microenvironment by secreting IGF2. Excitingly, our study suggests that targeting PA28γ+ CAFs or secreted IGF2 could increase the efficacy of PD-L1 therapy. Thus, our findings reveal the pivotal role of PA28γ in cell interactions in the tumor microenvironment and propose novel strategies for augmenting the effectiveness of immune checkpoint blockade in oral squamous cell carcinoma.
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Affiliation(s)
- Zaiye Li
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management & Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Silu Sun
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management & Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Ying Wang
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management & Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Yufei Hua
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management & Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Ming Liu
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management & Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Yu Zhou
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management & Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Liang Zhong
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management & Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Taiwen Li
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management & Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Hang Zhao
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management & Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Xikun Zhou
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, China
| | - Xin Zeng
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management & Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Qianming Chen
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management & Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China.
| | - Jing Li
- State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Research Unit of Oral Carcinogenesis and Management & Chinese Academy of Medical Sciences, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, Sichuan, China.
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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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García‐Gomis D, López J, Calderón A, Andrés M, Ponte I, Roque A. Proteasome-dependent degradation of histone H1 subtypes is mediated by its C-terminal domain. Protein Sci 2024; 33:e4970. [PMID: 38591484 PMCID: PMC11002908 DOI: 10.1002/pro.4970] [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: 09/27/2023] [Revised: 02/29/2024] [Accepted: 03/10/2024] [Indexed: 04/10/2024]
Abstract
Histone H1 is involved in chromatin compaction and dynamics. In human cells, the H1 complement is formed by different amounts of somatic H1 subtypes, H1.0-H1.5 and H1X. The amount of each variant depends on the cell type, the cell cycle phase, and the time of development and can be altered in disease. However, the mechanisms regulating H1 protein levels have not been described. We have analyzed the contribution of the proteasome to the degradation of H1 subtypes in human cells using two different inhibitors: MG132 and bortezomib. H1 subtypes accumulate upon treatment with both drugs, indicating that the proteasome is involved in the regulation of H1 protein levels. Proteasome inhibition caused a global increase in cytoplasmatic H1, with slight changes in the composition of H1 bound to chromatin and chromatin accessibility and no alterations in the nucleosome repeat length. The analysis of the proteasome degradation pathway showed that H1 degradation is ubiquitin-independent. The whole protein and its C-terminal domain can be degraded directly by the 20S proteasome in vitro. Partial depletion of PA28γ revealed that this regulatory subunit contributes to H1 degradation within the cell. Our study shows that histone H1 protein levels are under tight regulation to prevent its accumulation in the nucleus. We revealed a new regulatory mechanism for histone H1 degradation, where the C-terminal disordered domain is responsible for its targeting and degradation by the 20S proteasome, a process enhanced by the regulatory subunit PA28γ.
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Affiliation(s)
- D. García‐Gomis
- Biochemistry and Molecular Biology Department, Biosciences FacultyUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - J. López
- Biochemistry and Molecular Biology Department, Biosciences FacultyUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - A. Calderón
- Biochemistry and Molecular Biology Department, Biosciences FacultyUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - M. Andrés
- Biochemistry and Molecular Biology Department, Biosciences FacultyUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - I. Ponte
- Biochemistry and Molecular Biology Department, Biosciences FacultyUniversitat Autònoma de BarcelonaBarcelonaSpain
| | - A. Roque
- Biochemistry and Molecular Biology Department, Biosciences FacultyUniversitat Autònoma de BarcelonaBarcelonaSpain
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6
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Dong C, Guo Y, Yang Y, Ge X. Comprehensive analysis of PSME3: from pan-cancer analysis to experimental validation. Front Immunol 2024; 15:1295693. [PMID: 38312840 PMCID: PMC10834762 DOI: 10.3389/fimmu.2024.1295693] [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: 09/17/2023] [Accepted: 01/03/2024] [Indexed: 02/06/2024] Open
Abstract
PSME3 plays a significant role in tumor progression. However, the prognostic value of PSME3 in pan-cancer and its involvement in tumor immunity remain unclear. We conducted a comprehensive study utilizing extensive RNA sequencing data from the TCGA (The Cancer Genome Atlas) and GTEx (Genotype-Tissue Expression) databases. Our research revealed abnormal expression levels of PSME3 in various cancer types and unveiled a correlation between high PSME3 expression and adverse clinical outcomes, especially in cancers like liver cancer (LIHC) and lung adenocarcinoma (LUAD). Functional enrichment analysis highlighted multiple biological functions of PSME3, including its involvement in protein degradation, immune responses, and stem cell regulation. Moreover, PSME3 showed associations with immune infiltration and immune cells in the tumor microenvironment, indicating its potential role in shaping the cancer immune landscape. The study also unveiled connections between PSME3 and immune checkpoint expression, with experimental validation demonstrating that PSME3 positively regulates CD276. This suggests that PSME3 could be a potential therapeutic target in immunotherapy. Additionally, we predicted sensitive drugs targeting PSME3. Finally, we confirmed in both single-factor Cox and multiple-factor Cox regression analyses that PSME3 is an independent prognostic factor. We also conducted preliminary validations of the impact of PSME3 on cell proliferation and wound healing in liver cancer. In summary, our study reveals the multifaceted role of PSME3 in cancer biology, immune regulation, and clinical outcomes, providing crucial insights for personalized cancer treatment strategies and the development of immunotherapy.
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Affiliation(s)
- Chengyuan Dong
- Department of Clinical Medicine, Shanghai Tenth People’s Hospital, School of Medicine, Tongji University, Shanghai, China
- School of Medicine, Anhui University of Science and Technology, Huainan, China
| | - Yadong Guo
- Department of Urology, Shanghai Tenth People’s Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Yanrong Yang
- Tongji University Cancer Center, School of Medicine, Tongji University, Shanghai, China
| | - Xin Ge
- Department of Clinical Medicine, Shanghai Tenth People’s Hospital, School of Medicine, Tongji University, Shanghai, China
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Barman P, Chakraborty P, Bhaumik R, Bhaumik SR. UPS writes a new saga of SAGA. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194981. [PMID: 37657588 PMCID: PMC10843445 DOI: 10.1016/j.bbagrm.2023.194981] [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: 06/15/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 09/03/2023]
Abstract
SAGA (Spt-Ada-Gcn5-Acetyltransferase), an evolutionarily conserved transcriptional co-activator among eukaryotes, is a large multi-subunit protein complex with two distinct enzymatic activities, namely HAT (Histone acetyltransferase) and DUB (De-ubiquitinase), and is targeted to the promoter by the gene-specific activator proteins for histone covalent modifications and PIC (Pre-initiation complex) formation in enhancing transcription (or gene activation). Targeting of SAGA to the gene promoter is further facilitated by the 19S RP (Regulatory particle) of the 26S proteasome (that is involved in targeted degradation of protein via ubiquitylation) in a proteolysis-independent manner. Moreover, SAGA is also recently found to be regulated by the 26S proteasome in a proteolysis-dependent manner via the ubiquitylation of its Sgf73/ataxin-7 component that is required for SAGA's integrity and DUB activity (and hence transcription), and is linked to various diseases including neurodegenerative disorders and cancer. Thus, SAGA itself and its targeting to the active gene are regulated by the UPS (Ubiquitin-proteasome system) with implications in diseases.
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Affiliation(s)
- Priyanka Barman
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale IL-62901, USA
| | - Pritam Chakraborty
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale IL-62901, USA
| | - Rhea Bhaumik
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale IL-62901, USA
| | - Sukesh R Bhaumik
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale IL-62901, USA.
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Thomas T, Salcedo-Tacuma D, Smith DM. Structure, Function, and Allosteric Regulation of the 20S Proteasome by the 11S/PA28 Family of Proteasome Activators. Biomolecules 2023; 13:1326. [PMID: 37759726 PMCID: PMC10526260 DOI: 10.3390/biom13091326] [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: 07/17/2023] [Revised: 08/24/2023] [Accepted: 08/24/2023] [Indexed: 09/29/2023] Open
Abstract
The proteasome, a complex multi-catalytic protease machinery, orchestrates the protein degradation essential for maintaining cellular homeostasis, and its dysregulation also underlies many different types of diseases. Its function is regulated by many different mechanisms that encompass various factors such as proteasome activators (PAs), adaptor proteins, and post-translational modifications. This review highlights the unique characteristics of proteasomal regulation through the lens of a distinct family of regulators, the 11S, REGs, or PA26/PA28. This ATP-independent family, spanning from amoebas to mammals, exhibits a common architectural structure; yet, their cellular biology and criteria for protein degradation remain mostly elusive. We delve into their evolution and cellular biology, and contrast their structure and function comprehensively, emphasizing the unanswered questions regarding their regulatory mechanisms and broader roles in proteostasis. A deeper understanding of these processes will illuminate the roles of this regulatory family in biology and disease, thus contributing to the advancement of therapeutic strategies.
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Affiliation(s)
- Taylor Thomas
- Department of Biochemistry and Molecular Medicine, School of Medicine, West Virginia University, 64 Medical Center Drive, Morgantown, WV 26506, USA
| | - David Salcedo-Tacuma
- Department of Biochemistry and Molecular Medicine, School of Medicine, West Virginia University, 64 Medical Center Drive, Morgantown, WV 26506, USA
| | - David M. Smith
- Department of Biochemistry and Molecular Medicine, School of Medicine, West Virginia University, 64 Medical Center Drive, Morgantown, WV 26506, USA
- Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University, Morgantown, WV 26506, USA
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9
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Makaros Y, Raiff A, Timms RT, Wagh AR, Gueta MI, Bekturova A, Guez-Haddad J, Brodsky S, Opatowsky Y, Glickman MH, Elledge SJ, Koren I. Ubiquitin-independent proteasomal degradation driven by C-degron pathways. Mol Cell 2023; 83:1921-1935.e7. [PMID: 37201526 PMCID: PMC10237035 DOI: 10.1016/j.molcel.2023.04.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 03/13/2023] [Accepted: 04/25/2023] [Indexed: 05/20/2023]
Abstract
Although most eukaryotic proteins are targeted for proteasomal degradation by ubiquitination, a subset have been demonstrated to undergo ubiquitin-independent proteasomal degradation (UbInPD). However, little is known about the molecular mechanisms driving UbInPD and the degrons involved. Utilizing the GPS-peptidome approach, a systematic method for degron discovery, we found thousands of sequences that promote UbInPD; thus, UbInPD is more prevalent than currently appreciated. Furthermore, mutagenesis experiments revealed specific C-terminal degrons required for UbInPD. Stability profiling of a genome-wide collection of human open reading frames identified 69 full-length proteins subject to UbInPD. These included REC8 and CDCA4, proteins which control proliferation and survival, as well as mislocalized secretory proteins, suggesting that UbInPD performs both regulatory and protein quality control functions. In the context of full-length proteins, C termini also play a role in promoting UbInPD. Finally, we found that Ubiquilin family proteins mediate the proteasomal targeting of a subset of UbInPD substrates.
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Affiliation(s)
- Yaara Makaros
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Anat Raiff
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Richard T Timms
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, Cambridge, Cambridgeshire CB2 0AW, UK
| | - Ajay R Wagh
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 3525433, Israel
| | - Mor Israel Gueta
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Aizat Bekturova
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Julia Guez-Haddad
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Sagie Brodsky
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yarden Opatowsky
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Michael H Glickman
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 3525433, Israel
| | - Stephen J Elledge
- Department of Genetics, Harvard Medical School, Division of Genetics, Brigham and Women's Hospital, Howard Hughes Medical Institute, Boston, MA 02115, USA
| | - Itay Koren
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
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Govatati S, Pichavaram P, Kumar R, Rao GN. Blockade of CD47 function attenuates restenosis by promoting smooth muscle cell efferocytosis and inhibiting their migration and proliferation. J Biol Chem 2023; 299:104594. [PMID: 36898577 PMCID: PMC10124914 DOI: 10.1016/j.jbc.2023.104594] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 03/04/2023] [Accepted: 03/06/2023] [Indexed: 03/10/2023] Open
Abstract
Cluster of differentiation 47 (CD47) plays an important role in the pathophysiology of various diseases including atherosclerosis, but its role in neointimal hyperplasia which contributes to restenosis, has not been studied. Using molecular approaches in combination with a mouse vascular endothelial denudation model, we studied the role of CD47 in injury-induced neointimal hyperplasia. We determined that thrombin induced CD47 expression both in human and mouse aortic smooth muscle cells (HASMCs and MASMCs). In exploring the mechanisms, we found that the protease-activated receptor 1 (PAR1)-Gα protein q/11 (Gαq/11)-phospholipase Cβ3 (PLCβ3)-nuclear factor of activated T cells c1 (NFATc1) signaling axis regulates thrombin-induced CD47 expression in HASMCs. Depletion of CD47 levels using its siRNA or interference of its function by its blocking antibody (bAb) blunted thrombin-induced migration and proliferation of HASMCs and MASMCs. In addition, we found that thrombin-induced HASMC migration requires CD47 interaction with integrin β3. On the other hand, thrombin-induced HASMC proliferation was dependent on CD47's role in nuclear export and degradation of CDK-interacting protein 1 (p21Cip1). In addition, suppression of CD47 function by its bAb rescued HASMC efferocytosis from inhibition by thrombin. We also found that vascular injury induces CD47 expression in intimal SMCs and that inhibition of CD47 function by its bAb, while alleviating injury-induced inhibition of SMC efferocytosis, attenuated SMC migration and proliferation resulting in reduced neointima formation. Thus, these findings reveal a pathological role for CD47 in neointimal hyperplasia.
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Affiliation(s)
- Suresh Govatati
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Prahalathan Pichavaram
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Raj Kumar
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Gadiparthi N Rao
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
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11
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Son SH, Kim MY, Lim YS, Jin HC, Shin JH, Yi JK, Choi S, Park MA, Chae JH, Kang HC, Lee YJ, Uversky VN, Kim CG. SUMOylation-mediated PSME3-20 S proteasomal degradation of transcription factor CP2c is crucial for cell cycle progression. SCIENCE ADVANCES 2023; 9:eadd4969. [PMID: 36706181 PMCID: PMC9882985 DOI: 10.1126/sciadv.add4969] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 12/27/2022] [Indexed: 06/18/2023]
Abstract
Transcription factor CP2c (also known as TFCP2, α-CP2, LSF, and LBP-1c) is involved in diverse ubiquitous and tissue/stage-specific cellular processes and in human malignancies such as cancer. Despite its importance, many fundamental regulatory mechanisms of CP2c are still unclear. Here, we uncover an unprecedented mechanism of CP2c degradation via a previously unidentified SUMO1/PSME3/20S proteasome pathway and its biological meaning. CP2c is SUMOylated in a SUMO1-dependent way, and SUMOylated CP2c is degraded through the ubiquitin-independent PSME3 (also known as REGγ or PA28)/20S proteasome system. SUMOylated PSME3 could also interact with CP2c to degrade CP2c via the 20S proteasomal pathway. Moreover, precisely timed degradation of CP2c via the SUMO1/PSME3/20S proteasome axis is required for accurate progression of the cell cycle. Therefore, we reveal a unique SUMO1-mediated uncanonical 20S proteasome degradation mechanism via the SUMO1/PSME3 axis involving mutual SUMO-SIM interaction of CP2c and PSME3, providing previously unidentified mechanistic insights into the roles of dynamic degradation of CP2c in cell cycle progression.
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Affiliation(s)
- Seung Han Son
- Department of Life Science and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
| | - Min Young Kim
- Department of Life Science and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
| | - Young Su Lim
- Department of Life Science and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
| | - Hyeon Cheol Jin
- Department of Life Science and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
| | - June Ho Shin
- Department of Life Science and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
| | - Jae Kyu Yi
- Department of Life Science and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
| | - Sungwoo Choi
- Department of Life Science and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
| | - Mi Ae Park
- Department of Life Science and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
| | - Ji Hyung Chae
- Department of Life Science and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
| | - Ho Chul Kang
- Department of Life Science and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
| | - Young Jin Lee
- Department of Life Science and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
| | - Vladimir N. Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer’s Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, USA
| | - Chul Geun Kim
- Department of Life Science and Research Institute for Natural Sciences, College of Natural Sciences, Hanyang University, Seoul 04763, Korea
- CGK Biopharma Co. Ltd., Seoul 04763, Korea
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12
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Reciprocal REG γ-Nrf2 Regulation Promotes Long Period ROS Scavenging in Oxidative Stress-Induced Cell Aging. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2023; 2023:4743885. [PMID: 36659906 PMCID: PMC9845040 DOI: 10.1155/2023/4743885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 11/18/2022] [Accepted: 12/28/2022] [Indexed: 01/12/2023]
Abstract
Increased accumulation of reactive oxygen species (ROS) and decline of adaptive response of antioxidants to oxidative stimuli has been implicated in the aging process. Nuclear factor erythroid 2-related factor 2 (Nrf2) activation is a core event in attenuating oxidative stress-associated aging. The activity is modulated by a more complex regulatory network. In this study, we demonstrate the proteasome activator REGγ function as a new regulator of Nrf2 activity upon oxidative stress in cell aging model induced by hydrogen peroxide (H2O2). REGγ deficiency promotes cell senescence in primary MEF cells after H2O2 treatment. Accordingly, ROS scavenging is accelerated in WT cells but blunted in REGγ lacking cells during 12-hour recovery from a 1-hour H2O2 treatment, indicating long-lasting antioxidant buffering capacity of REGγ. Mechanistically, through GSK-3β inhibition, REGγ enhances the nuclear distribution and transcriptional activity of Nrf2, which is surveyed by induction of phase II enzymes including Ho1 and Nqo1. Meanwhile, Nrf2 mediates the transcriptional activation of REGγ upon H2O2 stimulation. More interestingly, short-term exposure to H2O2 leads to transiently upregulation and gradually descent of REGγ transcription, however sustained higher REGγ protein level even in the absence of H2O2 for 24 hours. Thus, our results establish a positive feedback loop between REGγ and Nrf2 and a new layer of adaptive response after oxidative stimulation that is the REGγ-GSK-3β-Nrf2 pathway.
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13
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Xie Y, Gao R, Gao Y, Dong Z, Ge J. 11S Proteasome Activator REGγ Promotes Aortic Dissection by Inhibiting RBM3 (RNA Binding Motif Protein 3) Pathway. Hypertension 2023; 80:125-137. [PMID: 36330811 DOI: 10.1161/hypertensionaha.122.19618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Aortic dissection (AD) is a life-threatening cardiovascular disorder with high mortality and lacking underlying mechanisms or effective treatments. REGγ, the 11S proteasome activator known to promote the degradation of cellular proteins in a ubiquitin- and ATP-independent manner, emerges as a new regulator in the cardiovascular system. METHODS Using β-aminopropionitrile (BAPN)-subjected REGγ knockout AD mice and Ang II (angiotensin II)-treated REGγ deficiency vascular smooth muscle cells (VSMCs) to explore the effect of REGγ in AD progression. RESULTS REGγ was upregulated in mouse aorta of β-aminopropionitrile-induced AD model in vivo and Ang II-treated VSMCs in vitro. REGγ deficiency ameliorated AD progression in β-aminopropionitrile-induced mice by protecting against the switch in VSMCs from contractile to synthetic phenotype through suppressing RBM3 (RNA-binding motif protein 3) decay. Mechanically, REGγ interacted with and degraded the RNA-binding protein RBM3 directly, leading to decreased mRNA stability, lowered expression and transcriptional activity of transcription factor SRF (serum response factor), subsequently reduced transcription of VSMCs-specific contractile genes, α-SMA (alpha-smooth muscle actin) and SM22α (smooth muscle 22 alpha), caused the switch in VSMCs from contractile to synthetic phenotype and associated AD progression. Ablation of endogenous SRF or RBM3, or overexpressing exogenous RBM3 in VSMCs significantly blocked or reestablished the REGγ-dependent action on VSMCs phenotypic switch of Ang II stimulation in vitro. Furthermore, exogenously introducing RBM3 improved the switch in VSMCs from contractile to synthetic phenotype and associated AD features caused by REGγ in vivo. CONCLUSIONS Our results demonstrated that REGγ promoted the switch in VSMCs from contractile to synthetic phenotype and AD progression by inhibiting RBM3-SRF pathway, indicated that modulating REGγ-proteasome activity may be a potential therapeutic approach for AD-associated cardiovascular dysfunction.
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Affiliation(s)
- Yifan Xie
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, China (Y.X., R.G., Y.G., Z.D., J.G.).,Shanghai Institute of Cardiovascular Diseases' Shanghai' China (Y.X., R.G., Y.G., Z.D., J.G.).,Institutes of Biomedical Science, Fudan University, Shanghai, China (Y.X., J.G.)
| | - Rifeng Gao
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, China (Y.X., R.G., Y.G., Z.D., J.G.).,Shanghai Institute of Cardiovascular Diseases' Shanghai' China (Y.X., R.G., Y.G., Z.D., J.G.)
| | - Yang Gao
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, China (Y.X., R.G., Y.G., Z.D., J.G.).,Shanghai Institute of Cardiovascular Diseases' Shanghai' China (Y.X., R.G., Y.G., Z.D., J.G.)
| | - Zheng Dong
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, China (Y.X., R.G., Y.G., Z.D., J.G.).,Shanghai Institute of Cardiovascular Diseases' Shanghai' China (Y.X., R.G., Y.G., Z.D., J.G.)
| | - Junbo Ge
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai, China (Y.X., R.G., Y.G., Z.D., J.G.).,Shanghai Institute of Cardiovascular Diseases' Shanghai' China (Y.X., R.G., Y.G., Z.D., J.G.).,Institutes of Biomedical Science, Fudan University, Shanghai, China (Y.X., J.G.)
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14
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Tu J, Zhang H, Yang T, Liu Y, Kibreab S, Zhang Y, Gao L, Moses RE, O'Malley BW, Xiao J, Li X. Aging-associated REGγ proteasome decline predisposes to tauopathy. J Biol Chem 2022; 298:102571. [PMID: 36209822 PMCID: PMC9647549 DOI: 10.1016/j.jbc.2022.102571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 09/20/2022] [Accepted: 09/25/2022] [Indexed: 11/09/2022] Open
Abstract
The REGγ-20S proteasome is an ubiquitin- and ATP-independent degradation system, targeting selective substrates, possibly helping to regulate aging. The studies we report here demonstrate that aging-associated REGγ decline predisposes to decreasing tau turnover, as in a tauopathy. The REGγ proteasome promotes degradation of human and mouse tau, notably phosphorylated tau and toxic tau oligomers that shuttle between the cytoplasm and nuclei. REGγ-mediated proteasomal degradation of tau was validated in 3- to 12-month-old REGγ KO mice, REGγ KO;PS19 mice, and PS19 mice with forebrain conditional neuron-specific overexpression of REGγ (REGγ OE) and behavioral abnormalities. Coupled with tau accumulation, we found with REGγ-deficiency, neuron loss, dendrite reduction, tau filament accumulation, and microglial activation are much more prominent in the REGγ KO;PS19 than the PS19 model. Moreover, we observed that the degenerative neuronal lesions and aberrant behaviors were alleviated in REGγ OE;PS19 mice. Memory and other behavior analysis substantiate the role of REGγ in prevention of tauopathy-like symptoms. In addition, we investigated the potential mechanism underlying aging-related REGγ decline. This study provides valuable insights into the novel regulatory mechanisms and potential therapeutic targets for tau-related neurodegenerative diseases.
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15
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Atomic resolution Cryo-EM structure of human proteasome activator PA28γ. Int J Biol Macromol 2022; 219:500-507. [PMID: 35932807 DOI: 10.1016/j.ijbiomac.2022.07.246] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 07/18/2022] [Accepted: 07/31/2022] [Indexed: 11/21/2022]
Abstract
The PA28 family proteasome activators play important roles in regulating proteasome activities. Though the three paralogs (PA28α, PA28β, and PA28γ) are similar in terms of primary sequence, they show significant difference in expression pattern, cellular localization and most importantly, biological functions. While PA28αβ is responsible for promoting peptidase activity of proteasome to facilitate MHC-I antigen processing, but unable to promote protein degradation, PA28γ is well-known to not only promote peptidase activity, but also proteolytic activity of proteasome. However, why this paralog has the unique function remains elusive. Previous structural studies have mainly focused on mammalian PA28α, PA28β and PA28αβ heptamers, while structural studies on mammalian PA28γ of atomic resolution are still absent to date. In the present work, we determined the Cryo-EM structure of the human PA28γ heptamer at atomic resolution, revealing interesting unique structural features that may hint our understanding the functional mechanisms of this proteasome activator.
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16
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Thomas TA, Smith DM. Proteasome activator 28γ (PA28γ) allosterically activates trypsin-like proteolysis by binding to the α-ring of the 20S proteasome. J Biol Chem 2022; 298:102140. [PMID: 35714770 PMCID: PMC9287138 DOI: 10.1016/j.jbc.2022.102140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 06/06/2022] [Accepted: 06/08/2022] [Indexed: 11/21/2022] Open
Abstract
Proteasome activator 28γ (PA28γ/REGγ) is a member of the 11S family of proteasomal regulators that is constitutively expressed in the nucleus and implicated in various diseases, including certain cancers and systemic lupus erythematosus. Despite years of investigation, how PA28γ functions to stimulate proteasomal protein degradation remains unclear. Alternative hypotheses have been proposed for the molecular mechanism of PA28γ, including the following: (1) substrate selection, (2) allosteric upregulation of the trypsin-like (T-L) site, (3) allosteric inhibition of the chymotrypsin-like (CT-L) and caspase-like (C-L) sites, (4) conversion of the CT-L or C-L sites to new T-L sites, and (5) gate opening alone or in combination with a previous hypothesis. Here, by mechanistically decoupling gating effects from active site effects, we unambiguously demonstrate that WT PA28γ allosterically activates the T-L site. We show PA28γ binding increases the Kcat/Km by 13-fold for T-L peptide substrates while having little-to-no effect on hydrolysis kinetics for CT-L or C-L substrates. Furthermore, mutagenesis and domain swaps of PA28γ reveal that it does not select for T-L peptide substrates through either the substrate entry pore or the distal intrinsically disordered region. We also show that a previously reported point mutation can functionally switch PA28γ from a T-L activating to a gate-opening activator in a mutually exclusive fashion. Finally, using cryogenic electron microscopy, we visualized the PA28γ-proteasome complex at 4.3 Å and confirmed its expected quaternary structure. The results of this study provide unambiguous evidence that PA28γ can function by binding the 20S proteasome to allosterically activate the T-L proteolytic site.
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Affiliation(s)
- Taylor A Thomas
- Department of Biochemistry, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, West Virginia, USA
| | - David M Smith
- Department of Biochemistry, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, West Virginia, USA; Department of Neuroscience, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, West Virginia, USA; WVU Rockefeller Neuroscience Institute, Morgantown, West Virginia, USA; WVU Cancer Institute, Morgantown, West Virginia, USA.
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17
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The proteasome activator REGγ promotes diabetic endothelial impairment by inhibiting HMGA2-GLUT1 pathway. Transl Res 2022; 246:33-48. [PMID: 35367424 DOI: 10.1016/j.trsl.2022.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 03/16/2022] [Accepted: 03/18/2022] [Indexed: 11/22/2022]
Abstract
Diabetic vascular endothelial impairment is one of the main causes of death in patients with diabetes lacking adequately defined mechanisms or effective treatments. REGγ, the 11S proteasome activator known to promote the degradation of cellular proteins in a ubiquitin- and ATP-independent manner, emerges as a new regulator in the cardiovascular system. Here, we found that REGγ was upregulated in streptozocin (STZ)-induced diabetic mouse aortic endothelium in vivo and high glucose (HG)-treated vascular endothelial cells (ECs) in vitro. REGγ deficiency ameliorated endothelial impairment in STZ-induced diabetic mice by protecting against a decline in cellular glucose uptake and associated vascular ECs dysfunction by suppressing high mobility group AT-hook 2 (HMGA2) decay. Mechanically, REGγ interacted with and degraded the transcription factor HMGA2 directly, leading to decreased HMGA2 transcriptional activity, subsequently lowered expression of glucose transporter type 1 (GLUT1), and reduced cellular glucose uptake, vascular endothelial dysfunction, and impaired diabetic endothelium. Ablation of endogenous GLUT1 or HMGA2 or overexpressing exogenous HMGA2 in vascular ECs significantly blocked or reestablished the REGγ-dependent action on cellular glucose uptake and vascular endothelial functions of HG stimulation in vitro. Furthermore, exogenously introducing HMGA2 improved diabetic mice endothelial impairment features caused by REGγ in vivo, thereby substantiating a REGγ-HMGA2-GLUT1 pathway in diabetic endothelial impairment. Our findings indicate that modulating REGγ-proteasome activity may be a potential therapeutic approach for diabetic disorders with endothelial impairment.
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18
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Regulation of Life & Death by REGγ. Cells 2022; 11:cells11152281. [PMID: 35892577 PMCID: PMC9330691 DOI: 10.3390/cells11152281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/17/2022] [Accepted: 07/20/2022] [Indexed: 01/27/2023] Open
Abstract
REGγ, a proteasome activator belonging to the 11S (otherwise known as REG, PA28, or PSME) proteasome activator family, is widely present in many eukaryotes. By binding to the 20S catalytic core particle, REGγ acts as a molecular sieve to selectively target proteins for degradation in an ATP- and ubiquitin-independent manner. This non-canonical proteasome pathway directly regulates seemingly unrelated cellular processes including cell growth and proliferation, apoptosis, DNA damage response, immune response, and metabolism. By affecting different pathways, REGγ plays a vital role in the regulation of cellular life and death through the maintenance of protein homeostasis. As a promoter of cellular growth and a key regulator of several tumor suppressors, many recent studies have linked REGγ overexpression with tumor formation and suggested the REGγ-proteasome as a potential target of new cancer-drug development. This review will present an overview of the major functions of REGγ as it relates to the regulation of cellular life and death, along with new mechanistic insights into the regulation of REGγ.
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19
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Xie K, Yang Q, Yan Z, Gao X, Huang X, Wang P, Zhang J, Yang J, Li J, Gun S. miR-30d Inhibition Protects IPEC-J2 Cells Against Clostridium perfringens Beta2 Toxin-Induced Inflammatory Injury. Front Vet Sci 2022; 9:909500. [PMID: 35799836 PMCID: PMC9253665 DOI: 10.3389/fvets.2022.909500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/19/2022] [Indexed: 11/23/2022] Open
Abstract
Clostridium perfringens beta2 (CPB2) toxin, one of the virulence factors of Clostridium perfringens (C. perfringens), can cause necrotizing enterocolitis in piglets. Accumulating pieces of evidence indicate that microRNAs (miRNAs) refer to the regulation of inflammatory processes. Previously, we have discovered that miR-30d was differentially expressed between the ileum of normal piglets and C. perfringens type C-infected diarrheal piglets. Here, we found that miR-30d expression was lowered in CPB2 toxin-treated intestinal porcine epithelial cells (IPEC-J2) at different time points. Subsequently, we determined that miR-30d inhibitor attenuated CPB2 toxin revulsive inflammatory damage in IPEC-J2 cells and promoted cell proliferation and cell cycle progression, whereas miR-30d mimic had opposite results. In addition, we confirmed that Proteasome activator subunit 3 (PSME3) was a downstream target gene of miR-30d via a dual luciferase reporter assay, qPCR, and western blot. We also found that overexpression of PSME3 suppressed CPB2 toxin-induced inflammatory damage and promoted cell proliferation and cycle progression. Our results demonstrate that miR-30d aggravates CPB2 toxin revulsive IPEC-J2 cells inflammatory injury via targeting PSME3, thereby providing a novel perspective for the prevention and treatment of piglet diarrhea at the molecular level.
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Affiliation(s)
- Kaihui Xie
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Qiaoli Yang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Zunqiang Yan
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Xiaoli Gao
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Xiaoyu Huang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Pengfei Wang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Juanli Zhang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Jiaojiao Yang
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Jie Li
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
| | - Shuangbao Gun
- College of Animal Science and Technology, Gansu Agricultural University, Lanzhou, China
- Gansu Research Center for Swine Production Engineering and Technology, Lanzhou, China
- *Correspondence: Shuangbao Gun
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20
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Frayssinhes JYA, Cerruti F, Laulin J, Cattaneo A, Bachi A, Apcher S, Coux O, Cascio P. PA28γ-20S proteasome is a proteolytic complex committed to degrade unfolded proteins. Cell Mol Life Sci 2021; 79:45. [PMID: 34913092 PMCID: PMC11071804 DOI: 10.1007/s00018-021-04045-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/15/2021] [Accepted: 11/17/2021] [Indexed: 02/07/2023]
Abstract
PA28γ is a nuclear activator of the 20S proteasome that, unlike the 19S regulatory particle, stimulates hydrolysis of several substrates in an ATP- and ubiquitin-independent manner and whose exact biological functions and molecular mechanism of action still remain elusive. In an effort to shed light on these important issues, we investigated the stimulatory effect of PA28γ on the hydrolysis of different fluorogenic peptides and folded or denatured full-length proteins by the 20S proteasome. Importantly, PA28γ was found to dramatically enhance breakdown rates by 20S proteasomes of several naturally or artificially unstructured proteins, but not of their native, folded counterparts. Furthermore, these data were corroborated by experiments in cell lines with a nucleus-tagged myelin basic protein. Finally, mass spectrometry analysis of the products generated during proteasomal degradation of two proteins demonstrated that PA28γ does not increase, but rather decreases, the variability of peptides that are potentially suitable for MHC class I antigen presentation. These unexpected findings indicate that global stimulation of the degradation of unfolded proteins may represent a more general feature of PA28γ and suggests that this proteasomal activator might play a broader role in the pathway of protein degradation than previously believed.
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Affiliation(s)
| | - Fulvia Cerruti
- Department of Veterinary Sciences, University of Turin, Largo P. Braccini 2, 10095, Grugliasco, Turin, Italy
| | - Justine Laulin
- Université Paris-Saclay, Institut Gustave Roussy, Inserm, Immunologie Des Tumeurs et Immunothérapie, Villejuif, France
| | | | - Angela Bachi
- The FIRC Institute of Molecular Oncology (IFOM), 20139, Milan, Italy
| | - Sebastien Apcher
- Université Paris-Saclay, Institut Gustave Roussy, Inserm, Immunologie Des Tumeurs et Immunothérapie, Villejuif, France
| | - Olivier Coux
- Centre de Recherche de Biologie Cellulaire de Montpellier (CRBM), CNRS UMR 5237, Université de Montpellier, 1919 Route de Mende, 34293, Montpellier, France
| | - Paolo Cascio
- Department of Veterinary Sciences, University of Turin, Largo P. Braccini 2, 10095, Grugliasco, Turin, Italy.
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21
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Ghafouri-Fard S, Khanbabapour Sasi A, Abak A, Shoorei H, Khoshkar A, Taheri M. Contribution of miRNAs in the Pathogenesis of Breast Cancer. Front Oncol 2021; 11:768949. [PMID: 34804971 PMCID: PMC8602198 DOI: 10.3389/fonc.2021.768949] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/18/2021] [Indexed: 12/16/2022] Open
Abstract
Breast cancer is the most frequently diagnosed cancer among females. Gene expression profiling methods have shown the deregulation of several genes in breast cancer samples and have confirmed the heterogeneous nature of breast cancer at the genomic level. microRNAs (miRNAs) are among the recently appreciated contributors in breast carcinogenic processes. These small-sized transcripts have been shown to partake in breast carcinogenesis through modulation of apoptosis, autophagy, and epithelial-mesenchymal transition. Moreover, they can confer resistance to chemotherapy. Based on the contribution of miRNAs in almost all fundamental aspects of breast carcinogenesis, therapeutic intervention with their expression might affect the course of this disorder. Moreover, the presence of miRNAs in the peripheral blood of patients potentiates these transcripts as tools for non-invasive diagnosis of breast cancer.
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Affiliation(s)
- Soudeh Ghafouri-Fard
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ali Khanbabapour Sasi
- Biochemistry Group, School of Medicine, Golestan University of Medical Science, Gorgan, Iran
| | - Atefe Abak
- Men's Health and Reproductive Health Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamed Shoorei
- Department of Anatomical Sciences, Faculty of Medicine, Birjand University of Medical Sciences, Birjand, Iran
| | - Ali Khoshkar
- Department of Surgery, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Taheri
- Skull Base Research Center, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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22
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Han J, Kim H, Jeong H, Yoon H, Jang KL. Proteasomal activator 28 gamma stabilizes hepatitis B virus X protein by competitively inhibiting the Siah-1-mediated proteasomal degradation. Biochem Biophys Res Commun 2021; 578:97-103. [PMID: 34555669 DOI: 10.1016/j.bbrc.2021.09.028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 09/14/2021] [Indexed: 12/17/2022]
Abstract
Proteasomal activator 28 gamma (PA28γ) upregulates the levels of HBx, a regulatory protein of hepatitis B virus (HBV) to stimulate HBV replication; however, the detailed mechanism remains unknown. Here, we found that PA28γ impaired the ability of seven in absentia homolog 1 (Siah-1) as an E3 ubiquitin ligase of HBx. PA28γ competitively inhibited the binding of Siah-1 to HBx in human hepatoma cells. Accordingly, PA28γ increased the stability of HBx and decreased HBx ubiquitination, abolishing the potential of Siah-1 to downregulate HBx levels. PA28γ also executed its role as an antagonist of Siah-1 during HBV replication, as demonstrated by an in vitro HBV replication system. The present study may provide insights into the mechanisms underlying the regulation of HBV replication.
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Affiliation(s)
- Jiwoo Han
- Department of Microbiology, College of Natural Science, Pusan National University, Busan, 46241, Republic of Korea
| | - Haeji Kim
- Department of Microbiology, College of Natural Science, Pusan National University, Busan, 46241, Republic of Korea
| | - Hyerin Jeong
- Department of Microbiology, College of Natural Science, Pusan National University, Busan, 46241, Republic of Korea
| | - Hyunyoung Yoon
- Department of Microbiology, College of Natural Science, Pusan National University, Busan, 46241, Republic of Korea
| | - Kyung Lib Jang
- Department of Microbiology, College of Natural Science, Pusan National University, Busan, 46241, Republic of Korea; Microbiological Resource Research Institute, Pusan National University, Busan, 46241, Republic of Korea.
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23
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REGγ regulates circadian clock by modulating BMAL1 protein stability. Cell Death Discov 2021; 7:335. [PMID: 34741025 PMCID: PMC8571338 DOI: 10.1038/s41420-021-00704-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 09/17/2021] [Accepted: 10/08/2021] [Indexed: 11/09/2022] Open
Abstract
Endogenous clocks generate rhythms in gene expression, which facilitates the organisms to cope through periodic environmental variations in accordance with 24-h light/dark time. A core question that needs to be elucidated is how such rhythms proliferate throughout the cells and regulate the dynamic physiology. In this study, we demonstrate the role of REGγ as a new regulator of circadian clock in mice, primary MEF, and SY5Y cells. Assessment of circadian conduct reveals a difference in circadian period, wheel mode, and the ability to acclimate the external light stimulus between WT and KO littermates. Compared to WT mice, REGγ KO mice attain the phase delay behavior upon light shock at early night. During the variation of 12/12 h light/dark (LD) exposure, levels of Per1, Per2, Cry1, Clock, Bmal1, and Rorα circadian genes in suprachiasmatic nucleus are significantly higher in REGγ KO than in WT mice, concomitant with remarkable changes in BMAL1 and PER2 proteins. In cultured cells depleted of REGγ, serum shock induces early response of the circadian genes Per1 and Per2 with the cyclic rhythm maintained. Mechanistic study indicates that REGγ directly degrades BMAL1 by the non-canonical proteasome pathway independent of ATP and ubiquitin. Silencing BMAL1 abrogates the changes in circadian genes in REGγ-deficient cells. However, inhibition of GSK-3β, a known promoter for degradation of BMAL1, exacerbates the action of REGγ depletion. In conclusion, our findings define REGγ as a new factor, which functions as a rheostat of circadian rhythms to mitigate the levels of Per1 and Per2 via proteasome-dependent degradation of BMAL1.
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24
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Concept and application of circulating proteasomes. Exp Mol Med 2021; 53:1539-1546. [PMID: 34707192 PMCID: PMC8568939 DOI: 10.1038/s12276-021-00692-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 08/27/2021] [Accepted: 09/06/2021] [Indexed: 12/26/2022] Open
Abstract
Proteostasis is primarily a function of protein synthesis and degradation. Although the components and processes involved in intracellular proteostasis have been studied extensively, it is apparent that extracellular proteostasis is equitably crucial for the viability of organisms. The 26S proteasome, a unique ATP-dependent proteolytic complex in eukaryotic cells, contributes to the majority of intracellular proteolysis. Accumulating evidence suggests the presence of intact 20S proteasomes in the circulatory system (c-proteasomes), and similar to other plasma proteins, the levels of these c-proteasomes may vary, potentially reflecting specific pathophysiological conditions. Under normal conditions, the concentration of c-proteasomes has been reported to be in the range of ~0.2-2 μg/mL, which is ~2-4-fold lower than that of functional plasma proteins but markedly higher than that of signaling proteins. The characterization of c-proteasomes, such as their origin, structure, role, and clearance, has been delayed mainly due to technical limitations. In this review, we summarize the current perspectives pertaining to c-proteasomes, focusing on the methodology, including our experimental understanding. We believe that once the pathological relevance of c-proteasomes is revealed, these unique components may be utilized in the diagnosis and prognosis of diverse human diseases.
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25
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Liu W, Li T, Hu W, Ji Q, Hu F, Wang Q, Yang X, Qi D, Chen H, Zhang X. Hematopoietic cell kinase enhances osteosarcoma development via the MEK/ERK pathway. J Cell Mol Med 2021; 25:8789-8795. [PMID: 34363435 PMCID: PMC8435456 DOI: 10.1111/jcmm.16836] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 07/06/2021] [Accepted: 07/16/2021] [Indexed: 01/13/2023] Open
Abstract
Osteosarcoma (OS) is a sarcoma with high rates of pulmonary metastases and mortality. The mechanisms underlying tumour generation and development in OS are not well‐understood. Haematopoietic cell kinase (HCK), a vital member of the Src family of kinase proteins, plays crucial roles in cancer progression and may act as an anticancer target; however, the mechanism by which HCK enhances OS development remains unexplored. Therefore, we investigated the role of HCK in OS development in vitro and in vivo. Downregulation of HCK attenuated OS cell proliferation, migration and invasion and increased OS cell apoptosis, whereas overexpression of HCK enhanced these processes. Mechanistically, HCK expression enhanced OS tumorigenesis via the mitogen‐activated protein kinase (MEK)/extracellular signal‐regulated kinase (ERK) pathway; HCK upregulation increased the phosphorylation of MEK and ERK and promoted epithelial‐mesenchymal transition, with a reduction in E‐cadherin in vitro. Furthermore, HCK downregulation decreased the tumour volume and weight in mice transplanted with OS cells. In conclusion, HCK plays a crucial role in OS tumorigenesis, progression and metastasis via the MEK/ERK pathway, suggesting that HCK is a potential target for developing treatments for OS.
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Affiliation(s)
- Weibo Liu
- Department of Orthopaedics, The Fourth Medical Centre, Chinese PLA General Hospital, Beijing, China
| | - Teng Li
- Department of Orthopaedics, The Fourth Medical Centre, Chinese PLA General Hospital, Beijing, China
| | - Wenhao Hu
- Department of Orthopaedics, The Fourth Medical Centre, Chinese PLA General Hospital, Beijing, China
| | - Quanbo Ji
- Department of Orthopaedics, The Fourth Medical Centre, Chinese PLA General Hospital, Beijing, China
| | - Fanqi Hu
- Department of Orthopaedics, The Fourth Medical Centre, Chinese PLA General Hospital, Beijing, China
| | - Qi Wang
- Department of Orthopaedics, The Fourth Medical Centre, Chinese PLA General Hospital, Beijing, China
| | - Xiaoqing Yang
- Department of Orthopaedics, The Fourth Medical Centre, Chinese PLA General Hospital, Beijing, China
| | - Dengbin Qi
- Department of Orthopaedics, The Fourth Medical Centre, Chinese PLA General Hospital, Beijing, China
| | - Hui Chen
- College of Life Sciences, East China Normal University, Shanghai, China
| | - Xuesong Zhang
- Department of Orthopaedics, The Fourth Medical Centre, Chinese PLA General Hospital, Beijing, China
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26
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The Involvement of Ubiquitination Machinery in Cell Cycle Regulation and Cancer Progression. Int J Mol Sci 2021; 22:ijms22115754. [PMID: 34072267 PMCID: PMC8198665 DOI: 10.3390/ijms22115754] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/12/2021] [Accepted: 05/26/2021] [Indexed: 02/07/2023] Open
Abstract
The cell cycle is a collection of events by which cellular components such as genetic materials and cytoplasmic components are accurately divided into two daughter cells. The cell cycle transition is primarily driven by the activation of cyclin-dependent kinases (CDKs), which activities are regulated by the ubiquitin-mediated proteolysis of key regulators such as cyclins, CDK inhibitors (CKIs), other kinases and phosphatases. Thus, the ubiquitin-proteasome system (UPS) plays a pivotal role in the regulation of the cell cycle progression via recognition, interaction, and ubiquitination or deubiquitination of key proteins. The illegitimate degradation of tumor suppressor or abnormally high accumulation of oncoproteins often results in deregulation of cell proliferation, genomic instability, and cancer occurrence. In this review, we demonstrate the diversity and complexity of the regulation of UPS machinery of the cell cycle. A profound understanding of the ubiquitination machinery will provide new insights into the regulation of the cell cycle transition, cancer treatment, and the development of anti-cancer drugs.
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27
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Jia R, Sui Z, Zhang H, Yu Z. Identification and Validation of Immune-Related Gene Signature for Predicting Lymph Node Metastasis and Prognosis in Lung Adenocarcinoma. Front Mol Biosci 2021; 8:679031. [PMID: 34109216 PMCID: PMC8182055 DOI: 10.3389/fmolb.2021.679031] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 05/10/2021] [Indexed: 12/15/2022] Open
Abstract
Lung cancer is a serious malignancy, and lung adenocarcinoma (LUAD) is the most common pathological subtype. Immune-related factors play an important role in lymph node metastasis. In this study, we obtained gene expression profile data for LUAD and normal tissues from the TCGA database and analyzed their immune-related genes (IRGs), and observed that 459 IRGs were differentially expressed. Further analysis of the correlation between differentially expressed IRGs and lymph node metastasis revealed 18 lymph node metastasis-associated IRGs. In addition, we analyzed the mutations status, function and pathway enrichment of these IRGs, and regulatory networks established through TF genes. We then identified eight IRGs (IKBKB, LTBR, MIF, PPARD, PPIA, PSME3, S100A6, SEMA4B) as the best predictors by LASSO Logistic analysis and used these IRGs to construct a model to predict lymph node metastasis in patients with LUAD (AUC 0.75; 95% CI: 0.7064-0.7978), and survival analysis showed that the risk score independently affected patient survival. We validated the predictive effect of risk scores on lymph node metastasis and survival using the GEO database as a validation cohort and the results showed good agreement. In addition, the risk score was highly correlated with infiltration of immune cells (mast cells activated, macrophages M2, macrophages M0 and B cells naïve), immune and stromal scores, and immune checkpoint genes (LTBR, CD40LG, EDA2R, and TNFRSF19). We identified key IRGs associated with lymph node metastasis in LUAD and constructed a reliable risk score model, which may provide valuable biomarkers for LUAD patients and further reveal the mechanism of its occurrence.
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Affiliation(s)
- Ran Jia
- Department of Esophageal Cancer, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin, Tianjin's Clinical Research Center for Cancer, National Clinical Research Center of Cancer, Tianjin, China.,Department of Thoracic Surgery, National Cancer Center, National Clinical Research Center for Cancer, Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and PeKing Union Medical College, Shenzhen, China
| | - Zhilin Sui
- Department of Esophageal Cancer, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin, Tianjin's Clinical Research Center for Cancer, National Clinical Research Center of Cancer, Tianjin, China
| | - Hongdian Zhang
- Department of Esophageal Cancer, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin, Tianjin's Clinical Research Center for Cancer, National Clinical Research Center of Cancer, Tianjin, China
| | - Zhentao Yu
- Department of Esophageal Cancer, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin, Tianjin's Clinical Research Center for Cancer, National Clinical Research Center of Cancer, Tianjin, China.,Department of Thoracic Surgery, National Cancer Center, National Clinical Research Center for Cancer, Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and PeKing Union Medical College, Shenzhen, China
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28
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The proteasome and its role in the nervous system. Cell Chem Biol 2021; 28:903-917. [PMID: 33905676 DOI: 10.1016/j.chembiol.2021.04.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/04/2021] [Accepted: 04/05/2021] [Indexed: 12/14/2022]
Abstract
Proteasomes are multisubunit complexes that catalyze the majority of protein degradation in mammalian cells to maintain protein homeostasis and influence the regulation of most cellular processes. The proteasome, a multicatalytic protease complex, is a ring-like structure with a narrow pore that exhibits regulated gating, enabling the selective degradation of target proteins into peptide fragments. This process of removing proteins is essential for eliminating proteins that are no longer wanted, such as unfolded or aggregated proteins. This is important for preserving cellular function relevant to brain health and disease. Recently, in the nervous system, specialized proteasomes have been shown to generate peptides with important cellular functions. These discoveries challenge the prevailing notion that proteasomes primarily operate to eliminate proteins and identify signaling-competent proteasomes. This review focuses on the structure, function, and regulation of proteasomes and sheds light on emerging areas of investigation regarding the role of proteasomes in the nervous system.
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29
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REGγ regulates hair cycle by activating Lgr5 positive hair follicle stem cells. J Dermatol Sci 2021; 102:101-108. [PMID: 33933312 DOI: 10.1016/j.jdermsci.2021.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 03/27/2021] [Accepted: 04/12/2021] [Indexed: 01/14/2023]
Abstract
BACKGROUND REGγ acts as a proteasome activating factor mediating proteasome degradation of substrate proteins in an ATP and ubiquitination independent manner and also as an important regulator of cell cycle, proliferation and apoptosis. Hair cycle involves dynamic, continuous morphological changes of three stages (anagen, catagen and telogen). OBJECTIVE The function of REGγ in hair cycling is still unclear. METHODS Here, we used REGγ knockout 293 T cells, inducible 293WT and 293N151Y cell, REGγ knockout mice to identify the novel molecular mechanism of REGγ in regulating hair follicle stem cells. RESULTS In the present study, we found that REGγ deletion markedly delayed the transition of hair follicles from telogen to anagen and hair regeneration in mice. We also observed significant decrease of hair follicle stem cell number, stem-like property and proliferation ability. Interestingly, the results from real-time PCR, FACS, Western Blot and immunofluorescent analysis showed that REGγ deletion could greatly downregulate Lgr5 expression in the hair follicles. Meanwhile, REGγ was demonstrated to directly interact with LHX2 and promotes its degradation. Importantly, REGγ specific deletion in Lgr5+ stem cells induced the marked delay of hair regeneration after depilation. CONCLUSION These data together indicate that REGγ was a new mediator of Lgr5 expression in hair follicle at least partly by promoting the degradation of its suppressive transcription factor LHX2. It seemed that REGγ regulated hair anagen entry and hair regrowth by activating Lgr5 positive hair follicle stem cells.
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30
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Wen X, Ge X, Zhou L, Zhang Y, Guo X, Yang H. PRRSV Promotes MARC-145 Cells Entry Into S Phase of the Cell Cycle to Facilitate Viral Replication via Degradation of p21 by nsp11. Front Vet Sci 2021; 8:642095. [PMID: 33869322 PMCID: PMC8044838 DOI: 10.3389/fvets.2021.642095] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/03/2021] [Indexed: 12/21/2022] Open
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) remains one of the most economically significant pathogens that seriously affect the global swine industry. Despite sustained efforts, the factors that affect PRRSV replication in host cells are far from being fully elucidated and thus warrants further investigation. In this study, we first demonstrated that PRRSV infection can cause downregulation of endogenous p21 protein in MARC-145 cells in a virus dose-dependent manner. Next, we analyzed the effect of p21 knockdown by RNA interference on cell cycle progression using flow cytometric analysis, and found that knockdown of p21 promotes MARC-145 cells entry into S phase of the cell cycle. Interestingly, we further discovered PRRSV infection is also able to promote MARC-145 cells entry into the S phase. Subsequently, we synchronized MARC-145 cells into G0/G1, S and G2/M phases, respectively, and then determined PRRSV replication in these cells. Results here show that the MARC-145 cells synchronized into the S phase exhibited the highest viral titer among the cells synchronized to different phases. Additionally, to reliably analyze the potential role of endogenous p21 protein in PRRSV replication, we constructed a p21 gene-knockout MARC-145 cell line (p21-/-) using CRISPR/Cas9 technology and evaluated its capability to support PRRSV replication. Our results indicate that knockout of p21 is conducive to PRRSV replication in MARC-145 cells. Furthermore, through construction of a series of eukaryotic plasmids expressing each of individual PRRSV proteins combined with cell transfection, we demonstrated that the nonstructural protein 11 (nsp11) of PRRSV mediates p21 degradation, which was further confirmed by generating a stable MARC-145 cell line constitutively expressing nsp11 using a lentivirus system. Notably, we further demonstrated that the endoribonuclease activity rather than the deubiquitinating activity of nsp11 is essential for p21 degradation via mutagenic analysis. Finally, we demonstrated that nsp11 mediates p21 degradation via a ubiquitin-independent proteasomal degradation manner. Altogether, our study not only uncovers a new pathogenesis of PRRSV, but also provides new insights into development of novel antiviral strategies.
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Affiliation(s)
- Xuexia Wen
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, China.,Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China
| | - Xinna Ge
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Lei Zhou
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yongning Zhang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xin Guo
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Hanchun Yang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, China
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31
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Cha S, Jang KL. Hepatitis B virus X protein stimulates cell growth by downregulating p16 levels via PA28γ-mediated proteasomal degradation. J Gen Virol 2021; 101:963-971. [PMID: 32568029 DOI: 10.1099/jgv.0.001461] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Proteasomal activator 28 gamma (PA28γ), an essential constituent of the 20S proteasome responsible for ubiquitin-independent degradation of target proteins, is frequently overexpressed in hepatocellular carcinoma. Recently, we have reported that hepatitis B virus (HBV) X protein (HBx) activates PA28γ expression in human hepatocytes via upregulation of p53 levels; however, its role in HBV tumorigenesis remains unknown. Here, we found that HBx-activated PA28γ downregulates p16 levels via ubiquitin-independent proteasomal degradation. As a result, HBx activated the Rb-E2F pathway and stimulated G1/S cell cycle progression, resulting in an increase in cell proliferation. The potential of HBx to induce these effects was reproduced in a 1.2-mer HBV replicon and in in vitro HBV infection systems and was almost completely abolished by either PA28γ knockdown or p16 overexpression, demonstrating the critical role of the PA28γ-mediated p16 degradation in HBV tumorigenesis.
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Affiliation(s)
- Sungkyung Cha
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea
| | - Kyung Lib Jang
- Department of Microbiology, College of Natural Sciences, Pusan National University, Busan 46241, Republic of Korea
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32
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Burris A, Waite KA, Reuter Z, Ockerhausen S, Roelofs J. Proteasome activator Blm10 levels and autophagic degradation directly impact the proteasome landscape. J Biol Chem 2021; 296:100468. [PMID: 33639167 PMCID: PMC8039559 DOI: 10.1016/j.jbc.2021.100468] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 02/12/2021] [Accepted: 02/23/2021] [Indexed: 12/09/2022] Open
Abstract
The proteasome selectively degrades proteins. It consists of a core particle (CP), which contains proteolytic active sites that can associate with different regulators to form various complexes. How these different complexes are regulated and affected by changing physiological conditions, however, remains poorly understood. In this study, we focused on the activator Blm10 and the regulatory particle (RP). In yeast, increased expression of Blm10 outcompeted RP for CP binding, which suggests that controlling the cellular levels of Blm10 can affect the relative amounts of RP-bound CP. While strong overexpression of BLM10 almost eliminated the presence of RP-CP complexes, the phenotypes this should induce were not observed. Our results show this was due to the induction of Blm10-CP autophagy under prolonged growth in YPD. Similarly, under conditions of endogenous BLM10 expression, Blm10 was degraded through autophagy as well. This suggests that reducing the levels of Blm10 allows for more CP-binding surfaces and the formation of RP-CP complexes under nutrient stress. This work provides important insights into maintaining the proteasome landscape and how protein expression levels affect proteasome function.
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Affiliation(s)
- Alicia Burris
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, USA; Molecular, Cellular, and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Kenrick A Waite
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Zachary Reuter
- Molecular, Cellular, and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Samuel Ockerhausen
- Molecular, Cellular, and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, Kansas, USA
| | - Jeroen Roelofs
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas, USA; Molecular, Cellular, and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, Kansas, USA.
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Abstract
The 26S proteasome is the most complex ATP-dependent protease machinery, of ~2.5 MDa mass, ubiquitously found in all eukaryotes. It selectively degrades ubiquitin-conjugated proteins and plays fundamentally indispensable roles in regulating almost all major aspects of cellular activities. To serve as the sole terminal "processor" for myriad ubiquitylation pathways, the proteasome evolved exceptional adaptability in dynamically organizing a large network of proteins, including ubiquitin receptors, shuttle factors, deubiquitinases, AAA-ATPase unfoldases, and ubiquitin ligases, to enable substrate selectivity and processing efficiency and to achieve regulation precision of a vast diversity of substrates. The inner working of the 26S proteasome is among the most sophisticated, enigmatic mechanisms of enzyme machinery in eukaryotic cells. Recent breakthroughs in three-dimensional atomic-level visualization of the 26S proteasome dynamics during polyubiquitylated substrate degradation elucidated an extensively detailed picture of its functional mechanisms, owing to progressive methodological advances associated with cryogenic electron microscopy (cryo-EM). Multiple sites of ubiquitin binding in the proteasome revealed a canonical mode of ubiquitin-dependent substrate engagement. The proteasome conformation in the act of substrate deubiquitylation provided insights into how the deubiquitylating activity of RPN11 is enhanced in the holoenzyme and is coupled to substrate translocation. Intriguingly, three principal modes of coordinated ATP hydrolysis in the heterohexameric AAA-ATPase motor were discovered to regulate intermediate functional steps of the proteasome, including ubiquitin-substrate engagement, deubiquitylation, initiation of substrate translocation and processive substrate degradation. The atomic dissection of the innermost working of the 26S proteasome opens up a new era in our understanding of the ubiquitin-proteasome system and has far-reaching implications in health and disease.
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Affiliation(s)
- Youdong Mao
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, 02215, Massachusetts, USA. .,School of Physics, Center for Quantitative Biology, Peking University, Beijing, 100871, China.
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34
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Cascio P. PA28γ: New Insights on an Ancient Proteasome Activator. Biomolecules 2021; 11:228. [PMID: 33562807 PMCID: PMC7915322 DOI: 10.3390/biom11020228] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 02/06/2023] Open
Abstract
PA28 (also known as 11S, REG or PSME) is a family of proteasome regulators whose members are widely present in many of the eukaryotic supergroups. In jawed vertebrates they are represented by three paralogs, PA28α, PA28β, and PA28γ, which assemble as heptameric hetero (PA28αβ) or homo (PA28γ) rings on one or both extremities of the 20S proteasome cylindrical structure. While they share high sequence and structural similarities, the three isoforms significantly differ in terms of their biochemical and biological properties. In fact, PA28α and PA28β seem to have appeared more recently and to have evolved very rapidly to perform new functions that are specifically aimed at optimizing the process of MHC class I antigen presentation. In line with this, PA28αβ favors release of peptide products by proteasomes and is particularly suited to support adaptive immune responses without, however, affecting hydrolysis rates of protein substrates. On the contrary, PA28γ seems to be a slow-evolving gene that is most similar to the common ancestor of the PA28 activators family, and very likely retains its original functions. Notably, PA28γ has a prevalent nuclear localization and is involved in the regulation of several essential cellular processes including cell growth and proliferation, apoptosis, chromatin structure and organization, and response to DNA damage. In striking contrast with the activity of PA28αβ, most of these diverse biological functions of PA28γ seem to depend on its ability to markedly enhance degradation rates of regulatory protein by 20S proteasome. The present review will focus on the molecular mechanisms and biochemical properties of PA28γ, which are likely to account for its various and complex biological functions and highlight the common features with the PA28αβ paralog.
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Affiliation(s)
- Paolo Cascio
- Department of Veterinary Sciences, University of Turin, Largo P. Braccini 2, 10095 Grugliasco, Italy
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35
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Fesquet D, Llères D, Grimaud C, Viganò C, Méchali F, Boulon S, Coux O, Bonne-Andrea C, Baldin V. The 20S proteasome activator PA28γ controls the compaction of chromatin. J Cell Sci 2021; 134:134/3/jcs257717. [PMID: 33526472 DOI: 10.1242/jcs.257717] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 12/03/2020] [Indexed: 12/16/2022] Open
Abstract
PA28γ (also known as PSME3), a nuclear activator of the 20S proteasome, is involved in the degradation of several proteins regulating cell growth and proliferation and in the dynamics of various nuclear bodies, but its precise cellular functions remain unclear. Here, using a quantitative FLIM-FRET based microscopy assay monitoring close proximity between nucleosomes in living human cells, we show that PA28γ controls chromatin compaction. We find that its depletion induces a decompaction of pericentromeric heterochromatin, which is similar to what is observed upon the knockdown of HP1β (also known as CBX1), a key factor of the heterochromatin structure. We show that PA28γ is present at HP1β-containing repetitive DNA sequences abundant in heterochromatin and, importantly, that HP1β on its own is unable to drive chromatin compaction without the presence of PA28γ. At the molecular level, we show that this novel function of PA28γ is independent of its stable interaction with the 20S proteasome, and most likely depends on its ability to maintain appropriate levels of H3K9me3 and H4K20me3, histone modifications that are involved in heterochromatin formation. Overall, our results implicate PA28γ as a key factor involved in the regulation of the higher order structure of chromatin.
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Affiliation(s)
- Didier Fesquet
- Centre de Recherche de Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34293 Montpellier, France
| | - David Llères
- Institut de Génétique Moléculaire de Montpellier (IGMM), Université de Montpellier, CNRS, 34293 Montpellier, France
| | - Charlotte Grimaud
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, Institut Régional du Cancer (ICM), Université de Montpellier, CNRS Route de Mende, 34293 Montpellier, France
| | - Cristina Viganò
- Centre de Recherche de Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34293 Montpellier, France
| | - Francisca Méchali
- Centre de Recherche de Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34293 Montpellier, France
| | - Séverine Boulon
- Centre de Recherche de Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34293 Montpellier, France
| | - Olivier Coux
- Centre de Recherche de Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34293 Montpellier, France
| | - Catherine Bonne-Andrea
- Centre de Recherche de Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34293 Montpellier, France
| | - Véronique Baldin
- Centre de Recherche de Biologie cellulaire de Montpellier (CRBM), Université de Montpellier, CNRS, 34293 Montpellier, France
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36
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Jia R, Sui Z, Zhang H, Yu Z. Identification and Validation of Immune-Related Gene Signature for Predicting Lymph Node Metastasis and Prognosis in Lung Adenocarcinoma. Front Mol Biosci 2021. [PMID: 34109216 DOI: 10.3389/fmolb.2020.585245/full] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/21/2023] Open
Abstract
Lung cancer is a serious malignancy, and lung adenocarcinoma (LUAD) is the most common pathological subtype. Immune-related factors play an important role in lymph node metastasis. In this study, we obtained gene expression profile data for LUAD and normal tissues from the TCGA database and analyzed their immune-related genes (IRGs), and observed that 459 IRGs were differentially expressed. Further analysis of the correlation between differentially expressed IRGs and lymph node metastasis revealed 18 lymph node metastasis-associated IRGs. In addition, we analyzed the mutations status, function and pathway enrichment of these IRGs, and regulatory networks established through TF genes. We then identified eight IRGs (IKBKB, LTBR, MIF, PPARD, PPIA, PSME3, S100A6, SEMA4B) as the best predictors by LASSO Logistic analysis and used these IRGs to construct a model to predict lymph node metastasis in patients with LUAD (AUC 0.75; 95% CI: 0.7064-0.7978), and survival analysis showed that the risk score independently affected patient survival. We validated the predictive effect of risk scores on lymph node metastasis and survival using the GEO database as a validation cohort and the results showed good agreement. In addition, the risk score was highly correlated with infiltration of immune cells (mast cells activated, macrophages M2, macrophages M0 and B cells naïve), immune and stromal scores, and immune checkpoint genes (LTBR, CD40LG, EDA2R, and TNFRSF19). We identified key IRGs associated with lymph node metastasis in LUAD and constructed a reliable risk score model, which may provide valuable biomarkers for LUAD patients and further reveal the mechanism of its occurrence.
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Affiliation(s)
- Ran Jia
- Department of Esophageal Cancer, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin, Tianjin's Clinical Research Center for Cancer, National Clinical Research Center of Cancer, Tianjin, China
- Department of Thoracic Surgery, National Cancer Center, National Clinical Research Center for Cancer, Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and PeKing Union Medical College, Shenzhen, China
| | - Zhilin Sui
- Department of Esophageal Cancer, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin, Tianjin's Clinical Research Center for Cancer, National Clinical Research Center of Cancer, Tianjin, China
| | - Hongdian Zhang
- Department of Esophageal Cancer, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin, Tianjin's Clinical Research Center for Cancer, National Clinical Research Center of Cancer, Tianjin, China
| | - Zhentao Yu
- Department of Esophageal Cancer, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy of Tianjin, Tianjin's Clinical Research Center for Cancer, National Clinical Research Center of Cancer, Tianjin, China
- Department of Thoracic Surgery, National Cancer Center, National Clinical Research Center for Cancer, Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and PeKing Union Medical College, Shenzhen, China
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37
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Gu Y, Barwick BG, Shanmugam M, Hofmeister CC, Kaufman J, Nooka A, Gupta V, Dhodapkar M, Boise LH, Lonial S. Downregulation of PA28α induces proteasome remodeling and results in resistance to proteasome inhibitors in multiple myeloma. Blood Cancer J 2020; 10:125. [PMID: 33318477 PMCID: PMC7736847 DOI: 10.1038/s41408-020-00393-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 10/14/2020] [Accepted: 10/28/2020] [Indexed: 01/05/2023] Open
Abstract
Protein homeostasis is critical for maintaining eukaryotic cell function as well as responses to intrinsic and extrinsic stress. The proteasome is a major portion of the proteolytic machinery in mammalian cells and plays an important role in protein homeostasis. Multiple myeloma (MM) is a plasma cell malignancy with high production of immunoglobulins and is especially sensitive to treatments that impact protein catabolism. Therapeutic agents such as proteasome inhibitors have demonstrated significant benefit for myeloma patients in all treatment phases. Here, we demonstrate that the 11S proteasome activator PA28α is upregulated in MM cells and is key for myeloma cell growth and proliferation. PA28α also regulates MM cell sensitivity to proteasome inhibitors. Downregulation of PA28α inhibits both proteasomal load and activity, resulting in a change in protein homeostasis less dependent on the proteasome and leads to cell resistance to proteasome inhibitors. Thus, our findings suggest an important role of PA28α in MM biology, and also provides a new approach for targeting the ubiquitin-proteasome system and ultimately sensitivity to proteasome inhibitors.
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Affiliation(s)
- Yanyan Gu
- Department of Hematology and Medical Oncology, Emory University School of Medicine, 1365 Clifton Road, Atlanta, GA, 30322, USA.,Winship Cancer Institute, Emory University, 1365 Clifton Road, Atlanta, GA, 30322, USA
| | - Benjamin G Barwick
- Department of Hematology and Medical Oncology, Emory University School of Medicine, 1365 Clifton Road, Atlanta, GA, 30322, USA.,Winship Cancer Institute, Emory University, 1365 Clifton Road, Atlanta, GA, 30322, USA
| | - Mala Shanmugam
- Department of Hematology and Medical Oncology, Emory University School of Medicine, 1365 Clifton Road, Atlanta, GA, 30322, USA.,Winship Cancer Institute, Emory University, 1365 Clifton Road, Atlanta, GA, 30322, USA
| | - Craig C Hofmeister
- Department of Hematology and Medical Oncology, Emory University School of Medicine, 1365 Clifton Road, Atlanta, GA, 30322, USA.,Winship Cancer Institute, Emory University, 1365 Clifton Road, Atlanta, GA, 30322, USA
| | - Jonathan Kaufman
- Department of Hematology and Medical Oncology, Emory University School of Medicine, 1365 Clifton Road, Atlanta, GA, 30322, USA.,Winship Cancer Institute, Emory University, 1365 Clifton Road, Atlanta, GA, 30322, USA
| | - Ajay Nooka
- Department of Hematology and Medical Oncology, Emory University School of Medicine, 1365 Clifton Road, Atlanta, GA, 30322, USA.,Winship Cancer Institute, Emory University, 1365 Clifton Road, Atlanta, GA, 30322, USA
| | - Vikas Gupta
- Department of Hematology and Medical Oncology, Emory University School of Medicine, 1365 Clifton Road, Atlanta, GA, 30322, USA.,Winship Cancer Institute, Emory University, 1365 Clifton Road, Atlanta, GA, 30322, USA
| | - Madhav Dhodapkar
- Department of Hematology and Medical Oncology, Emory University School of Medicine, 1365 Clifton Road, Atlanta, GA, 30322, USA.,Winship Cancer Institute, Emory University, 1365 Clifton Road, Atlanta, GA, 30322, USA
| | - Lawrence H Boise
- Department of Hematology and Medical Oncology, Emory University School of Medicine, 1365 Clifton Road, Atlanta, GA, 30322, USA.,Winship Cancer Institute, Emory University, 1365 Clifton Road, Atlanta, GA, 30322, USA
| | - Sagar Lonial
- Department of Hematology and Medical Oncology, Emory University School of Medicine, 1365 Clifton Road, Atlanta, GA, 30322, USA. .,Winship Cancer Institute, Emory University, 1365 Clifton Road, Atlanta, GA, 30322, USA.
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38
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Ubiquitin conjugating enzymes in the regulation of the autophagy-dependent degradation pathway. Matrix Biol 2020; 100-101:23-29. [PMID: 33276077 DOI: 10.1016/j.matbio.2020.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 11/27/2020] [Accepted: 11/27/2020] [Indexed: 12/15/2022]
Abstract
The ubiquitin-proteasomal system and the autophagy-lysosome system are two major degradation systems in mammalian cells. Ubiquitin not only regulates proteasomal degradation of substrates but also regulates the autophagy pathway. In one type of macroautophagy, called selective autophagy, cargos are recruited to phagophore in a ubiquitin-dependent manner. Ubiquitin can target autophagy regulators for proteasomal degradation, control protein conformation or change interacting partners of these regulators. To understand the regulatory mechanisms of these degradation pathways, it is critical to dissect how the ubiquitin system contributes to them. Since enzymes are key regulators of ubiquitination, in this review, such enzymes in autophagy regulation are discussed, with specific focus on ubiquitin conjugating enzyme E2s, of which roles in autophagy are emerging.
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39
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Reciprocal REGγ-mTORC1 regulation promotes glycolytic metabolism in hepatocellular carcinoma. Oncogene 2020; 40:677-692. [PMID: 33230243 DOI: 10.1038/s41388-020-01558-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 11/04/2020] [Indexed: 02/07/2023]
Abstract
Despite significant progression in the study of hepatocellular carcinoma (HCC), the role of the proteasome in regulating cross talk between mTOR signaling and glycolysis in liver cancer progression is not fully understood. Here, we demonstrate that deficiency of REGγ, a proteasome activator, in mice significantly attenuates DEN-induced liver tumor formation. Ablation of REGγ increases the stability of PP2Ac (protein phosphatase 2 catalytic subunit) in vitro and in vivo, which dephosphorylates PRAS40 (AKT1 substrate 1) and stabilizes the interaction between PRAS40 and Raptor to inactive mTORC1-mediated hyper-glycolytic metabolism. In the DEN-induced animal model and clinical hepato-carcinoma samples, high levels of REGγ in HCC tumor regions contribute to reduced expression of PP2Ac, leading to accumulation of phosphorylated PRAS40 and mTORC1-mediated activation of HIF1α. Interestingly, mTORC1 enhances REGγ activity in HCC, forming a positive feedback regulatory loop. In conclusion, our study identifies REGγ-PP2Ac-PRAS40 axis as a new layer in regulating mTORC1 activity and downstream glycolytic alterations during HCC development, highlighting the REGγ-proteasome as a potential target for personalized HCC therapy.
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40
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Lei K, Bai H, Sun S, Xin C, Li J, Chen Q. PA28γ, an Accomplice to Malignant Cancer. Front Oncol 2020; 10:584778. [PMID: 33194729 PMCID: PMC7662426 DOI: 10.3389/fonc.2020.584778] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 10/12/2020] [Indexed: 02/05/2023] Open
Abstract
PA28γ is a nuclear activator of the 20S proteasome, which is involved in the regulation of several essential cellular processes and angiogenesis. Over the past 20 years, many amino acid sites and motifs have been proven to play important roles in the characteristic functions of PA28γ. The number of binding partners and validated cellular functions of PA28γ have increased, which has facilitated the clarification of its involvement in different biological events. PA28γ is involved in the progression of various diseases, and its aberrant overexpression in cancer is remarkable. Patients with low levels of PA28γ expression have a higher survival rate than those with high levels of PA28γ expression, as has been shown for a wide variety of tumors. The functions of PA28γ in cancer can be divided into five main categories: cell proliferation, cell apoptosis, metastasis and invasion, cell nuclear dynamics that have relevance to angiogenesis, and viral infection. In this review, we focus on the role of PA28γ in cancer, summarizing its aberrant expression, prooncogenic effects and underlying mechanisms in various cancers, and we highlight the possible cancer-related applications of PA28γ, such as its potential use in the diagnosis, targeted treatment and prognostic assessment of cancer.
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Affiliation(s)
- Kexin Lei
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Hetian Bai
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Silu Sun
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Chuan Xin
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jing Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Qianming Chen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Chinese Academy of Medical Sciences Research Unit of Oral Carcinogenesis and Management, West China Hospital of Stomatology, Sichuan University, Chengdu, China
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41
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Tundo GR, Sbardella D, Santoro AM, Coletta A, Oddone F, Grasso G, Milardi D, Lacal PM, Marini S, Purrello R, Graziani G, Coletta M. The proteasome as a druggable target with multiple therapeutic potentialities: Cutting and non-cutting edges. Pharmacol Ther 2020; 213:107579. [PMID: 32442437 PMCID: PMC7236745 DOI: 10.1016/j.pharmthera.2020.107579] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 05/05/2020] [Indexed: 01/10/2023]
Abstract
Ubiquitin Proteasome System (UPS) is an adaptable and finely tuned system that sustains proteostasis network under a large variety of physiopathological conditions. Its dysregulation is often associated with the onset and progression of human diseases; hence, UPS modulation has emerged as a promising new avenue for the development of treatments of several relevant pathologies, such as cancer and neurodegeneration. The clinical interest in proteasome inhibition has considerably increased after the FDA approval in 2003 of bortezomib for relapsed/refractory multiple myeloma, which is now used in the front-line setting. Thereafter, two other proteasome inhibitors (carfilzomib and ixazomib), designed to overcome resistance to bortezomib, have been approved for treatment-experienced patients, and a variety of novel inhibitors are currently under preclinical and clinical investigation not only for haematological malignancies but also for solid tumours. However, since UPS collapse leads to toxic misfolded proteins accumulation, proteasome is attracting even more interest as a target for the care of neurodegenerative diseases, which are sustained by UPS impairment. Thus, conceptually, proteasome activation represents an innovative and largely unexplored target for drug development. According to a multidisciplinary approach, spanning from chemistry, biochemistry, molecular biology to pharmacology, this review will summarize the most recent available literature regarding different aspects of proteasome biology, focusing on structure, function and regulation of proteasome in physiological and pathological processes, mostly cancer and neurodegenerative diseases, connecting biochemical features and clinical studies of proteasome targeting drugs.
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Affiliation(s)
- G R Tundo
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, Rome, Italy.
| | | | - A M Santoro
- CNR, Institute of Crystallography, Catania, Italy
| | - A Coletta
- Department of Chemistry, University of Aarhus, Aarhus, Denmark
| | - F Oddone
- IRCCS-Fondazione Bietti, Rome, Italy
| | - G Grasso
- Department of Chemical Sciences, University of Catania, Catania, Italy
| | - D Milardi
- CNR, Institute of Crystallography, Catania, Italy
| | - P M Lacal
- Laboratory of Molecular Oncology, IDI-IRCCS, Rome, Italy
| | - S Marini
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, Rome, Italy
| | - R Purrello
- Department of Chemical Sciences, University of Catania, Catania, Italy
| | - G Graziani
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.
| | - M Coletta
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, Rome, Italy.
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42
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Shen M, Wang Q, Xu S, Chen G, Xu H, Li X, Zhao S. Role of oncogenic REGγ in cancer. Biomed Pharmacother 2020; 130:110614. [PMID: 32935661 DOI: 10.1016/j.biopha.2020.110614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 08/01/2020] [Accepted: 08/02/2020] [Indexed: 12/24/2022] Open
Abstract
Cancer is a critical global health-care problem with limited therapeutic options. Since cancers are life-threatening illnesses, the identification of a promising oncotarget and its clinical correlates are relevant. Mounting evidence has emerged indicating that REG gamma (REGγ), a member of the 11S proteasome activators, plays a pivotal role in the development of multiple human cancers. However, an elaborate summary on the association between REGγ and cancer is still lacking. In this Review, we discuss how REGγ, through its ATP- and ubiquitin-independent manners, represents a promising cancer biomarker and therapeutic oncotarget for multiple human cancers. Aberrant REGγ expression closely associated with tumorigenesis attributes to its biological functions for controlling and regulating cell cycle, proliferation, migration, invasion, angiogenesis, and metastasis of the cancer cells by degrading proteins of cytosol and nucleus in the eukaryotic cells. REGγ serves as a molecular switch to activate multifarious oncogenic signaling pathways, such as MAPK/p38, TGF-β/Smad, and Wnt/β-catenin. The review describes that targeting REGγ may provide new diagnostic and therapeutic applications in cancer.
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Affiliation(s)
- Maolei Shen
- Department of Urology, Taizhou Central Hospital (Taizhou University Hospital), Taizhou, 318000, Zhejiang, China
| | - Qinzhang Wang
- Department of Urology, The First Affiliated Hospital of Shihezi University Medical School, Shihezi, China
| | - Shuaijun Xu
- Hebei North University, Zhangjiakou, 075000, Hebei, China
| | - Guang Chen
- Department of Pharmacology, School of Medicine, Taizhou University, Taizhou, 318000, Zhejiang, China
| | - Hao Xu
- Health Company, 69235, Army of PLA, China
| | - Xin Li
- Department of Urology, Taizhou Central Hospital (Taizhou University Hospital), Taizhou, 318000, Zhejiang, China
| | - Shankun Zhao
- Department of Urology, Taizhou Central Hospital (Taizhou University Hospital), Taizhou, 318000, Zhejiang, China.
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43
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Gao X, Wang Q, Wang Y, Liu J, Liu S, Liu J, Zhou X, Zhou L, Chen H, Pan L, Chen J, Wang D, Zhang Q, Shen S, Xiao Y, Wu Z, Cheng Y, Chen G, Kubra S, Qin J, Huang L, Zhang P, Wang C, Moses RE, Lonard DM, Malley BWO, Fares F, Zhang B, Li X, Li L, Xiao J. The REGγ inhibitor NIP30 increases sensitivity to chemotherapy in p53-deficient tumor cells. Nat Commun 2020; 11:3904. [PMID: 32764536 PMCID: PMC7413384 DOI: 10.1038/s41467-020-17667-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 07/08/2020] [Indexed: 11/09/2022] Open
Abstract
A major challenge in chemotherapy is chemotherapy resistance in cells lacking p53. Here we demonstrate that NIP30, an inhibitor of the oncogenic REGγ-proteasome, attenuates cancer cell growth and sensitizes p53-compromised cells to chemotherapeutic agents. NIP30 acts by binding to REGγ via an evolutionarily-conserved serine-rich domain with 4-serine phosphorylation. We find the cyclin-dependent phosphatase CDC25A is a key regulator for NIP30 phosphorylation and modulation of REGγ activity during the cell cycle or after DNA damage. We validate CDC25A-NIP30-REGγ mediated regulation of the REGγ target protein p21 in vivo using p53-/- and p53/REGγ double-deficient mice. Moreover, Phosphor-NIP30 mimetics significantly increase the growth inhibitory effect of chemotherapeutic agents in vitro and in vivo. Given that NIP30 is frequently mutated in the TCGA cancer database, our results provide insight into the regulatory pathway controlling the REGγ-proteasome in carcinogenesis and offer a novel approach to drug-resistant cancer therapy.
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Affiliation(s)
- Xiao Gao
- East China Normal University and Shanghai Changzheng Hospital Joint Research Center for Orthopedic Oncology, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China
- Department of Orthopedic Oncology, Changzheng Hospital, The Second Military Medical University, 415 Fengyang Road, 200003, Shanghai, China
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China
| | - Qingwei Wang
- Department of Surgery, Department of Physiology & Cell Biology, College of Medicine, Davis Heart and Lung Research Institute, Wexner Medical Center, The Ohio State University, Columbus, OH, 43210, USA
| | - Ying Wang
- The Institute of Aging Research, School of Medicine, Hangzhou Normal University, 310036, Hangzhou, Zhejiang, China
| | - Jiang Liu
- The Institute of Aging Research, School of Medicine, Hangzhou Normal University, 310036, Hangzhou, Zhejiang, China
| | - Shuang Liu
- Department of Hematology, Guangdong Second Provincial General Hospital, Guangzhou, Guangdong Province, P. R. China
| | - Jian Liu
- Reproductive & Developmental Biology Laboratory, National Institute of Environmental Health Sciences (NIEHS), Research Triangle Prk, NC, 27709, USA
| | - Xingli Zhou
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China
| | - Li Zhou
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China
| | - Hui Chen
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China
| | - Linian Pan
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China
| | - Jiwei Chen
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China
| | - Da Wang
- East China Normal University and Shanghai Changzheng Hospital Joint Research Center for Orthopedic Oncology, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China
- Department of Orthopedic Oncology, Changzheng Hospital, The Second Military Medical University, 415 Fengyang Road, 200003, Shanghai, China
| | - Qing Zhang
- Department of Hematology, Guangdong Second Provincial General Hospital, Guangzhou, Guangdong Province, P. R. China
| | - Shihui Shen
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China
| | - Yu Xiao
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China
| | - Zhipeng Wu
- East China Normal University and Shanghai Changzheng Hospital Joint Research Center for Orthopedic Oncology, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China
- Department of Orthopedic Oncology, Changzheng Hospital, The Second Military Medical University, 415 Fengyang Road, 200003, Shanghai, China
| | - Yiyun Cheng
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China
| | - Geng Chen
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China
| | - Syeda Kubra
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China
| | - Jun Qin
- The Joint Laboratory of Translational Medicine, National Center for Protein Sciences (Beijing) and Peking University Cancer Hospital, State Key Laboratory of Proteomics, Institute of Lifeomics, 102206, Beijing, China
| | - Lan Huang
- Department of Physiology and Biophysics, University of California, Irvine, CA, 92697, USA
| | - Pei Zhang
- Department of Pathology, The Second Chengdu Municipal Hospital, 610017, Chengdu, China
| | - Chuangui Wang
- Institute of Translational Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Robb E Moses
- Department of Molecular and Cellular Biology, Dan L. Duncan Cancer Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - David M Lonard
- Department of Molecular and Cellular Biology, Dan L. Duncan Cancer Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Bert W O' Malley
- Department of Molecular and Cellular Biology, Dan L. Duncan Cancer Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Fuad Fares
- Department of Human Biology. Faculty of Natural Sciences, University of Haifa, Haifa, 3498838, Israel
| | - Bianhong Zhang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China.
| | - Xiaotao Li
- East China Normal University and Shanghai Changzheng Hospital Joint Research Center for Orthopedic Oncology, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China.
- Department of Molecular and Cellular Biology, Dan L. Duncan Cancer Center, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA.
| | - Lei Li
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China.
| | - Jianru Xiao
- East China Normal University and Shanghai Changzheng Hospital Joint Research Center for Orthopedic Oncology, East China Normal University, 500 Dongchuan Road, 200241, Shanghai, China.
- Department of Orthopedic Oncology, Changzheng Hospital, The Second Military Medical University, 415 Fengyang Road, 200003, Shanghai, China.
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44
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Li Y, Sun D, Ma Z, Yamaguchi K, Wang L, Zhong S, Yan X, Shang B, Nagashima Y, Koiwa H, Han J, Xie Q, Zhou M, Wang Z, Zhang X. Degradation of SERRATE via ubiquitin-independent 20S proteasome to survey RNA metabolism. NATURE PLANTS 2020; 6:970-982. [PMID: 32690892 PMCID: PMC7426255 DOI: 10.1038/s41477-020-0721-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 04/16/2020] [Indexed: 05/18/2023]
Abstract
SERRATE (SE) is a key factor in RNA metabolism. Here, we report that SE binds 20S core proteasome α subunit G1 (PAG1) among other components and is accumulated in their mutants. Purified PAG1-containing 20S proteasome degrades recombinant SE via an ATP- and ubiquitin-independent manner in vitro. Nevertheless, PAG1 is a positive regulator for SE in vivo, as pag1 shows comparable molecular and/or developmental defects relative to se. Furthermore, SE is poorly assembled into macromolecular complexes, exemplified by the microprocessor in pag1 compared with Col-0. SE overexpression triggered the destruction of both transgenic and endogenous protein, leading to similar phenotypes of se and SE overexpression lines. We therefore propose that PAG1 degrades the intrinsically disordered portion of SE to secure the functionality of folded SE that is assembled and protected in macromolecular complexes. This study provides insight into how the 20S proteasome regulates RNA metabolism through controlling its key factor in eukaryotes.
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Affiliation(s)
- Yanjun Li
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Di Sun
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA
| | - Zeyang Ma
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA
| | - Karissa Yamaguchi
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Lin Wang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Songxiao Zhong
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA
| | - Xingxing Yan
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA
| | - Baoshuan Shang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA
| | - Yukihiro Nagashima
- Department of Horticultural Sciences, Texas A&M University, College Station, TX, USA
| | - Hisashi Koiwa
- Department of Horticultural Sciences, Texas A&M University, College Station, TX, USA
| | - Jiajia Han
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- Yunnan Key Laboratory of Plant Reproductive Adaption and Evolutionary Ecology, Yunnan University, Kunming, China
| | - Qi Xie
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Mingguo Zhou
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Zhiye Wang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA.
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA.
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China.
| | - Xiuren Zhang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA.
- Institute for Plant Genomics and Biotechnology, Texas A&M University, College Station, TX, USA.
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45
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Boulpicante M, Darrigrand R, Pierson A, Salgues V, Rouillon M, Gaudineau B, Khaled M, Cattaneo A, Bachi A, Cascio P, Apcher S. Tumors escape immunosurveillance by overexpressing the proteasome activator PSME3. Oncoimmunology 2020; 9:1761205. [PMID: 32923122 PMCID: PMC7458623 DOI: 10.1080/2162402x.2020.1761205] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 04/03/2020] [Indexed: 11/09/2022] Open
Abstract
The success of CD8+ T cell-based cancer immunotherapy emphasizes the importance of understanding the mechanisms of generation of MHC-I peptide ligands and the possible pathways of tumor cell escape from immunosurveillance. Recently, we showed that peptides generated in the nucleus during a pioneer round of mRNA translation (pioneer translation products, or PTPs) are an important source of tumor specific peptides which correlates with the aberrant splicing and transcription events associated with oncogenesis. Here we show that up-regulation of PSME3 proteasome activator in cancer cells results in increased destruction of PTP-derived peptides in the nucleus thus enabling cancer cell to subvert immunosurveillance. These findings unveil a previously unexpected role for PSME3 in antigen processing and identify PSME3 as a druggable target to improve the efficacy of cancer immunotherapy.
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Affiliation(s)
- Mathilde Boulpicante
- Immunologie des Tumeurs et Immunothérapie, Université Paris-Saclay, Institut Gustave Roussy, Inserm, Villejuif, France
| | - Romain Darrigrand
- Immunologie des Tumeurs et Immunothérapie, Université Paris-Saclay, Institut Gustave Roussy, Inserm, Villejuif, France
| | - Alison Pierson
- Immunologie des Tumeurs et Immunothérapie, Université Paris-Saclay, Institut Gustave Roussy, Inserm, Villejuif, France
| | - Valérie Salgues
- Immunologie des Tumeurs et Immunothérapie, Université Paris-Saclay, Institut Gustave Roussy, Inserm, Villejuif, France
| | - Marine Rouillon
- Immunologie des Tumeurs et Immunothérapie, Université Paris-Saclay, Institut Gustave Roussy, Inserm, Villejuif, France
| | - Benoit Gaudineau
- Dynamique des Cellules Tumorales, Université Paris-Saclay, Institut Gustave Roussy, Inserm, Villejuif, France
| | - Mehdi Khaled
- Dynamique des Cellules Tumorales, Université Paris-Saclay, Institut Gustave Roussy, Inserm, Villejuif, France
| | - Angela Cattaneo
- IFOM, The FIRC Institute of Molecular Oncology, Milano, Italy
| | - Angela Bachi
- IFOM, The FIRC Institute of Molecular Oncology, Milano, Italy
| | - Paolo Cascio
- Department of Veterinary Sciences, University of Turin, 10095, Grugliasco, Turin, Italy
| | - Sébastien Apcher
- Immunologie des Tumeurs et Immunothérapie, Université Paris-Saclay, Institut Gustave Roussy, Inserm, Villejuif, France
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46
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Xie Y, Gao Y, Gao R, Yang W, Dong Z, Moses RE, Sun A, Li X, Ge J. The proteasome activator REGγ accelerates cardiac hypertrophy by declining PP2Acα-SOD2 pathway. Cell Death Differ 2020; 27:2952-2972. [PMID: 32424140 PMCID: PMC7494903 DOI: 10.1038/s41418-020-0554-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 04/27/2020] [Accepted: 04/28/2020] [Indexed: 12/05/2022] Open
Abstract
Pathological cardiac hypertrophy eventually leads to heart failure without adequate treatment. REGγ is emerging as 11S proteasome activator of 20S proteasome to promote the degradation of cellular proteins in a ubiquitin- and ATP-independent manner. Here, we found that REGγ was significantly upregulated in the transverse aortic constriction (TAC)-induced hypertrophic hearts and angiotensin II (Ang II)-treated cardiomyocytes. REGγ deficiency ameliorated pressure overload-induced cardiac hypertrophy were associated with inhibition of cardiac reactive oxygen species (ROS) accumulation and suppression of protein phosphatase 2A catalytic subunit α (PP2Acα) decay. Mechanistically, REGγ interacted with and targeted PP2Acα for degradation directly, thereby leading to increase of phosphorylation levels and nuclear export of Forkhead box protein O (FoxO) 3a and subsequent of SOD2 decline, ROS accumulation, and cardiac hypertrophy. Introducing exogenous PP2Acα or SOD2 to human cardiomyocytes significantly rescued the REGγ-mediated ROS accumulation of Ang II stimulation in vitro. Furthermore, treatment with superoxide dismutase mimetic, MnTBAP prevented cardiac ROS production and hypertrophy features that REGγ caused in vivo, thereby establishing a REGγ–PP2Acα–FoxO3a–SOD2 pathway in cardiac oxidative stress and hypertrophy, indicates modulating the REGγ-proteasome activity may be a potential therapeutic approach in cardiac hypertrophy-associated disorders.
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Affiliation(s)
- Yifan Xie
- Department of Cardiology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.,Institutes of Biomedical Science, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.,Shanghai Institute of Cardiovascular Diseases, 180 Fenglin Road, Shanghai, 200032, China
| | - Yang Gao
- Department of Cardiology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.,Shanghai Institute of Cardiovascular Diseases, 180 Fenglin Road, Shanghai, 200032, China
| | - Rifeng Gao
- Department of Cardiology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.,Shanghai Institute of Cardiovascular Diseases, 180 Fenglin Road, Shanghai, 200032, China
| | - Wenlong Yang
- Department of Cardiology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.,Shanghai Institute of Cardiovascular Diseases, 180 Fenglin Road, Shanghai, 200032, China
| | - Zheng Dong
- Department of Cardiology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.,Shanghai Institute of Cardiovascular Diseases, 180 Fenglin Road, Shanghai, 200032, China
| | - Robb E Moses
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA
| | - Aijun Sun
- Department of Cardiology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China. .,Institutes of Biomedical Science, Fudan University, 180 Fenglin Road, Shanghai, 200032, China. .,Shanghai Institute of Cardiovascular Diseases, 180 Fenglin Road, Shanghai, 200032, China.
| | - Xiaotao Li
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX, 77030, USA. .,Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, China.
| | - Junbo Ge
- Department of Cardiology, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China. .,Institutes of Biomedical Science, Fudan University, 180 Fenglin Road, Shanghai, 200032, China. .,Shanghai Institute of Cardiovascular Diseases, 180 Fenglin Road, Shanghai, 200032, China.
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47
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Yin Z, Jin H, Huang S, Qu G, Meng Q. REG γ knockdown suppresses proliferation by inducing apoptosis and cell cycle arrest in osteosarcoma. PeerJ 2020; 8:e8954. [PMID: 32328351 PMCID: PMC7166046 DOI: 10.7717/peerj.8954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 03/21/2020] [Indexed: 11/20/2022] Open
Abstract
Background Osteosarcoma (OS) is the most common malignant bone tumor with high mortality in children and adolescents. REG γ is overexpressed and plays oncogenic roles in various types of human cancers. However, the expression and potential roles of REG γ in osteosarcoma are elusive. This study aims at exploring possible biological functions of REG γ in the pathogenesis of osteosarcoma and its underlying mechanism. Methods Quantitativereverse transcription-polymerase chain reaction (qRT-PCR), western blotting andimmunohistochemistry (IHC)were performed to detect the expression levels of REG γ in OS tissues and cell lines. Then, the effects of REG γ expression on OS cell proliferation in vitro were analyzed by Cell Counting Kit-8 (CCK-8), ethylene deoxyuridine (EdU), colony formation, flow cytometry. The protein levels of apoptosis and cell-cycle related proteins were evaluated using western blotting. Results In present study, we found for the first time that REG γ is overexpressed in osteosarcoma tissues and cell lines and knockdown of REG γ significantly inhibits cell proliferation and induces apoptosis and cell cycle arrest in osteosarcoma cells. Furthermore, we observed that p21, caspase-3 and cleaved caspase-3 are increased while the expression of cycinD1 and bcl-2 are decreased after REG γ depletion in osteosarcoma cells. In conclusion, REG γ may be involved in the proliferation of osteosarcoma and serve as a novel therapeutic target in patients with osteosarcoma.
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Affiliation(s)
- Zhiqiang Yin
- Department of Orthopedics, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Hao Jin
- Department of Orthopedics, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Shibo Huang
- Department of General Surgery, Heilongjiang Agricultural Reclamation General Hospital, Harbin, China
| | - Guofan Qu
- The Affiliated Tumor Hospital of Harbin Medical University, Harbin Medical University, Harbin, Heilong, China
| | - Qinggang Meng
- Department of Medical Science Institute of Harbin, The Fourth Affiliated Hospital of Harbin Medical University, Harbin Medical University, Harbin, Heilong, China
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Olshina MA, Arkind G, Kumar Deshmukh F, Fainer I, Taranavsky M, Hayat D, Ben-Dor S, Ben-Nissan G, Sharon M. Regulation of the 20S Proteasome by a Novel Family of Inhibitory Proteins. Antioxid Redox Signal 2020; 32:636-655. [PMID: 31903784 DOI: 10.1089/ars.2019.7816] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Aims: The protein degradation machinery plays a critical role in the maintenance of cellular homeostasis, preventing the accumulation of damaged or misfolded proteins and controlling the levels of regulatory proteins. The 20S proteasome degradation machinery, which predominates during oxidative stress, is able to cleave any protein with a partially unfolded region, however, uncontrolled degradation of the myriad of potential substrates is improbable. This study aimed to identify and characterize the regulatory mechanism that controls 20S proteasome-mediated degradation. Results: Using a bioinformatic screen based on known 20S proteasome regulators, we have discovered a novel family of 20S proteasome regulators, named catalytic core regulators (CCRs). These regulators share structural and sequence similarities, and coordinate the function of the 20S proteasome by affecting the degradation of substrates. The CCRs are involved in the oxidative stress response via Nrf2, organizing into a feed-forward loop regulatory circuit, with some members stabilizing Nrf2, others being induced by Nrf2, and all of them inhibiting the 20S proteasome. Innovation and Conclusion: These data uncover a new family of regulatory proteins that utilize a fine-tuned mechanism to carefully modulate the activity of the 20S proteasome, in particular under conditions of oxidative stress, ensuring its proper functioning by controlling the degradative flux.
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Affiliation(s)
- Maya A Olshina
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Galina Arkind
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | | | - Irit Fainer
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Mark Taranavsky
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Daniel Hayat
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Shifra Ben-Dor
- Bioinformatics and Biological Computing Unit, Weizmann Institute of Science, Rehovot, Israel
| | - Gili Ben-Nissan
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Michal Sharon
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
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Wang X, Meul T, Meiners S. Exploring the proteasome system: A novel concept of proteasome inhibition and regulation. Pharmacol Ther 2020; 211:107526. [PMID: 32173559 DOI: 10.1016/j.pharmthera.2020.107526] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 03/08/2020] [Indexed: 12/13/2022]
Abstract
The proteasome is a well-identified therapeutic target for cancer treatment. It acts as the main protein degradation system in the cell and degrades key mediators of cell growth, survival and function. The term "proteasome" embraces a whole family of distinct complexes, which share a common proteolytic core, the 20S proteasome, but differ by their attached proteasome activators. Each of these proteasome complexes plays specific roles in the control of cellular function. In addition, distinct proteasome interacting proteins regulate proteasome activity in subcellular compartments and in response to cellular signals. Proteasome activators and regulators may thus serve as building blocks to fine-tune proteasome function in the cell according to cellular needs. Inhibitors of the proteasome, e.g. the FDA approved drugs Velcade™, Kyprolis™, Ninlaro™, inactivate the catalytic 20S core and effectively block protein degradation of all proteasome complexes in the cell resulting in inhibition of cell growth and induction of apoptosis. Efficacy of these inhibitors, however, is hampered by their pronounced cytotoxic side-effects as well as by the emerging development of resistance to catalytic proteasome inhibitors. Targeted inhibition of distinct buiding blocks of the proteasome system, i.e. proteasome activators or regulators, represents an alternative strategy to overcome these limitations. In this review, we stress the importance of the diversity of the proteasome complexes constituting an entire proteasome system. Our building block concept provides a rationale for the defined targeting of distinct proteasome super-complexes in disease. We thereby aim to stimulate the development of innovative therapeutic approaches beyond broad catalytic proteasome inhibition.
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Affiliation(s)
- Xinyuan Wang
- Comprehensive Pneumology Center (CPC), University Hospital of the Ludwig-Maximilians-University (LMU) and Helmholtz Zentrum München, German Center for Lung Research (DZL), 81377 Munich, Germany
| | - Thomas Meul
- Comprehensive Pneumology Center (CPC), University Hospital of the Ludwig-Maximilians-University (LMU) and Helmholtz Zentrum München, German Center for Lung Research (DZL), 81377 Munich, Germany
| | - Silke Meiners
- Comprehensive Pneumology Center (CPC), University Hospital of the Ludwig-Maximilians-University (LMU) and Helmholtz Zentrum München, German Center for Lung Research (DZL), 81377 Munich, Germany.
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50
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Proteasome Inhibitors: Harnessing Proteostasis to Combat Disease. Molecules 2020; 25:molecules25030671. [PMID: 32033280 PMCID: PMC7037493 DOI: 10.3390/molecules25030671] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 01/25/2020] [Accepted: 01/28/2020] [Indexed: 02/07/2023] Open
Abstract
The proteasome is the central component of the main cellular protein degradation pathway. During the past four decades, the critical function of the proteasome in numerous physiological processes has been revealed, and proteasome activity has been linked to various human diseases. The proteasome prevents the accumulation of misfolded proteins, controls the cell cycle, and regulates the immune response, to name a few important roles for this macromolecular "machine." As a therapeutic target, proteasome inhibitors have been approved for the treatment of multiple myeloma and mantle cell lymphoma. However, inability to sufficiently inhibit proteasome activity at tolerated doses has hampered efforts to expand the scope of proteasome inhibitor-based therapies. With emerging new modalities in myeloma, it might seem challenging to develop additional proteasome-based therapies. However, the constant development of new applications for proteasome inhibitors and deeper insights into the intricacies of protein homeostasis suggest that proteasome inhibitors might have novel therapeutic applications. Herein, we summarize the latest advances in proteasome inhibitor development and discuss the future of proteasome inhibitors and other proteasome-based therapies in combating human diseases.
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