1
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Ke M, Xu J, Ouyang Y, Chen J, Yuan D, Guo T. SUGT1 regulates the progression of ovarian cancer through the AKT/PI3K/mTOR signaling pathway. Transl Oncol 2024; 49:102088. [PMID: 39167956 PMCID: PMC11379980 DOI: 10.1016/j.tranon.2024.102088] [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: 06/06/2024] [Revised: 08/01/2024] [Accepted: 08/11/2024] [Indexed: 08/23/2024] Open
Abstract
This study investigates the expression and functional roles of SUGT1 in ovarian cancer, utilizing data from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) projects. Our analyses reveal that SUGT1 is significantly upregulated in ovarian cancer tissues compared to normal controls. We further explore the prognostic value of SUGT1, where elevated expression correlates with poorer patient outcomes, particularly in ovarian cancer. The functional implications of SUGT1 in cancer biology were assessed through in vitro and in vivo experiments. Gene Set Enrichment Analysis (GSEA) indicates a significant association between high SUGT1 expression and the activation of glycolytic pathways, suggesting a potential role in metabolic reprogramming. Inhibition of SUGT1 via siRNA in ovarian cancer cell lines results in decreased proliferation and increased apoptosis, along with reduced migration and invasion capabilities. Additionally, our study identifies the transcription factor ELF1 as a significant regulator of SUGT1 expression. Through promoter analysis and chromatin immunoprecipitation, we demonstrate that ELF1 directly binds to the SUGT1 promoter, enhancing its transcription. This regulatory mechanism underscores the importance of transcriptional control in cancer metabolism, providing insights into potential therapeutic targets. Our findings establish SUGT1 as a crucial player in the oncogenic processes of ovarian cancer, influencing both metabolic pathways and transcriptional regulation. This highlights its potential as a biomarker and therapeutic target in managing ovarian cancer.
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Affiliation(s)
- Miao Ke
- Department of Gynecology and Obstetrics, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong, China
| | - Jie Xu
- Institute of Clinical Medicine, The Affiliated Taizhou People's Hospital of Nanjing Medical University, Taizhou School of Clinical Medicine, Nanjing Medical University, Taizhou, China
| | - Ye Ouyang
- Graduate Management Department, The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong Province, China
| | - Junyu Chen
- School of Nursing, Nanjing University of Chinese Medicine, Nanjing, China
| | - Donglan Yuan
- Department of Gynecology and Obstetrics, The Affiliated Taizhou People's Hospital of Nanjing Medical University, Taizhou School of Clinical Medicine, Nanjing Medical University, Taizhou, China.
| | - Ting Guo
- Institute of Clinical Medicine, The Affiliated Taizhou People's Hospital of Nanjing Medical University, Taizhou School of Clinical Medicine, Nanjing Medical University, Taizhou, China.
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2
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Zhang D, Yang X, Wen Z, Li Z, Zhang X, Zhong C, She J, Zhang Q, Zhang H, Li W, Zhao X, Xu M, Su Z, Li D, Dinesh-Kumar SP, Zhang Y. Proxitome profiling reveals a conserved SGT1-NSL1 signaling module that activates NLR-mediated immunity. MOLECULAR PLANT 2024; 17:1369-1391. [PMID: 39066482 DOI: 10.1016/j.molp.2024.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 06/13/2024] [Accepted: 07/22/2024] [Indexed: 07/28/2024]
Abstract
Suppressor of G2 allele of skp1 (SGT1) is a highly conserved eukaryotic protein that plays a vital role in growth, development, and immunity in both animals and plants. Although some SGT1 interactors have been identified, the molecular regulatory network of SGT1 remains unclear. SGT1 serves as a co-chaperone to stabilize protein complexes such as the nucleotide-binding leucine-rich repeat (NLR) class of immune receptors, thereby positively regulating plant immunity. SGT1 has also been found to be associated with the SKP1-Cullin-F-box (SCF) E3 ubiquitin ligase complex. However, whether SGT1 targets immune repressors to coordinate plant immune activation remains elusive. In this study, we constructed a toolbox for TurboID- and split-TurboID-based proximity labeling (PL) assays in Nicotiana benthamiana and used the PL toolbox to explore the SGT1 interactome during pre- and post-immune activation. The comprehensive SGT1 interactome network we identified highlights a dynamic shift from proteins associated with plant development to those linked with plant immune responses. We found that SGT1 interacts with Necrotic Spotted Lesion 1 (NSL1), which negatively regulates salicylic acid-mediated defense by interfering with the nucleocytoplasmic trafficking of non-expressor of pathogenesis-related genes 1 (NPR1) during N NLR-mediated response to tobacco mosaic virus. SGT1 promotes the SCF-dependent degradation of NSL1 to facilitate immune activation, while salicylate-induced protein kinase-mediated phosphorylation of SGT1 further potentiates this process. Besides N NLR, NSL1 also functions in several other NLR-mediated immunity. Collectively, our study unveils the regulatory landscape of SGT1 and reveals a novel SGT1-NSL1 signaling module that orchestrates plant innate immunity.
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Affiliation(s)
- Dingliang Zhang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China; State Key Laboratory of Plant Environmental Resilience, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Xinxin Yang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Zhiyan Wen
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Zhen Li
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xinyu Zhang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Chenchen Zhong
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Jiajie She
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Qianshen Zhang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - He Zhang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Wenli Li
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xiaoyun Zhao
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Mingliang Xu
- State Key Laboratory of Plant Environmental Resilience, College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Zhen Su
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Dawei Li
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Savithramma P Dinesh-Kumar
- Department of Plant Biology and The Genome Center, College of Biological Sciences, University of California, Davis, Davis, CA 95616, USA.
| | - Yongliang Zhang
- State Key Laboratory of Plant Environmental Resilience, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
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3
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Mohammed Abdul KS, Han K, Guerrero AB, Wilson CN, Kulkarni A, Purcell NH. Increased PHLPP1 expression through ERK-4E-BP1 signaling axis drives nicotine induced oxidative stress related damage of cardiomyocytes. J Mol Cell Cardiol 2024; 193:100-112. [PMID: 38851627 DOI: 10.1016/j.yjmcc.2024.05.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 05/30/2024] [Accepted: 05/31/2024] [Indexed: 06/10/2024]
Abstract
Nicotine, a key constituent of tobacco/electronic cigarettes causes cardiovascular injury and mortality. Nicotine is known to induce oxidative stress and mitochondrial dysfunction in cardiomyocytes leading to cell death. However, the underlying mechanisms remain unclear. Pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP) is a member of metal-dependent protein phosphatase (PPM) family and is known to dephosphorylate several AGC family kinases and thereby regulate a diverse set of cellular functions including cell growth, survival, and death. Our lab has previously demonstrated that PHLPP1 removal reduced cardiomyocyte death and cardiac dysfunction following injury. Here, we present a novel finding that nicotine exposure significantly increased PHLPP1 protein expression in the adolescent rodent heart. Building upon our in vivo finding, we determined the mechanism of PHLPP1 expression in cardiomyocytes. Nicotine significantly increased PHLPP1 protein expression without altering PHLPP2 in cardiomyocytes. In cardiomyocytes, nicotine significantly increased NADPH oxidase 4 (NOX4), which coincided with increased reactive oxygen species (ROS) and increased cardiomyocyte apoptosis which were dependent on PHLPP1 expression. PHLPP1 expression was both necessary and sufficient for nicotine induced mitochondrial dysfunction. Mechanistically, nicotine activated extracellular signal-regulated protein kinases (ERK1/2) and subsequent eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) to increase PHLPP1 protein expression. Inhibition of protein synthesis with cycloheximide (CHX) and 4EGI-1 abolished nicotine induced PHLPP1 protein expression. Moreover, inhibition of ERK1/2 activity by U0126 significantly blocked nicotine induced PHLPP1 expression. Overall, this study reveals a novel mechanism by which nicotine regulates PHLPP1 expression through ERK-4E-BP1 signaling axis to drive cardiomyocyte injury.
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Affiliation(s)
| | - Kimin Han
- Cardiovascular Signaling Division, Huntington Medical Research Institutes, Pasadena, California, USA
| | - Alyssa B Guerrero
- Cardiovascular Signaling Division, Huntington Medical Research Institutes, Pasadena, California, USA
| | - Cekia N Wilson
- Cardiovascular Signaling Division, Huntington Medical Research Institutes, Pasadena, California, USA
| | - Amogh Kulkarni
- Cardiovascular Signaling Division, Huntington Medical Research Institutes, Pasadena, California, USA
| | - Nicole H Purcell
- Cardiovascular Signaling Division, Huntington Medical Research Institutes, Pasadena, California, USA; Cardiovascular Division, Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, USA.
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4
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Ye Z, Meng Q, Zhang W, He J, Zhao H, Yu C, Liang W, Li X, Wang H. Exploration of the Shared Gene and Molecular Mechanisms Between Endometriosis and Recurrent Pregnancy Loss. Front Vet Sci 2022; 9:867405. [PMID: 35601407 PMCID: PMC9120926 DOI: 10.3389/fvets.2022.867405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 03/14/2022] [Indexed: 12/14/2022] Open
Abstract
Endometriosis (EMs) is a common benign gynecological disease in women of childbearing age, which usually causes pelvic pain, secondary dysmenorrhea, and infertility. EMs has been linked to recurrent pregnancy loss (RPL) in epidemiological data. The relationship of both, however, remains unknown. The purpose of this study is to explore the underlying pathological mechanisms between EMs and RPL. We searched Gene Expression Omnibus (GEO) database to obtain omics data of EMs and RPL. Co-expression modules for EMs and RPL were investigated by using weighted gene co-expression network analysis (WGCNA). The intersections of gene modules with the strong correlation to EMs or RPL obtained by WGCNA analysis were considered as shared genes. MicroRNAs (miRNAs) and their corresponding target genes linked to EMs and RPL were found though the Human MicroRNA Disease Database (HMDD) and the miRTarbase database. Finally, we constructed miRNAs-mRNAs regulatory networks associated with the two disorders by using the intersection of previously obtained target genes and shared genes. We discovered as significant modules for EMs and RPL, respectively, by WGCNA. The energy metabolism might be the common pathogenic mechanism of EMs and RPL, according to the findings of a Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. We discovered several target genes that might be linked to these two disorders, as well as the potential mechanisms. RAB8B, GNAQ, H2AFZ, SUGT1, and LEO1 could be therapeutic candidates for RPL and EMs. The PI3K-Akt signaling pathway and platelet activation were potentially involved in the mechanisms of EM-induced RPL. Our findings for the first time revealed the underlying pathological mechanisms of EM-induced RPL and identified several useful biomarkers and potential therapeutic targets.
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Affiliation(s)
- Zhuang Ye
- Department of Rheumatology, The First Hospital of Jilin University, Changchun, China
| | - Qingxue Meng
- Department of Pediatrics, Shenzhen University General Hospital, Shenzhen, China
| | - Weiwen Zhang
- Department of Obstetrics and Gynecology, Shenzhen University General Hospital, Shenzhen, China
| | - Junli He
- Department of Pediatrics, Shenzhen University General Hospital, Shenzhen, China
| | - Huanyi Zhao
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Chengwei Yu
- School of Future Technology, University of Chinese Academy of Sciences, Beijing, China
- *Correspondence: Chengwei Yu
| | - Weizheng Liang
- Department of Pediatrics, Shenzhen University General Hospital, Shenzhen, China
- Weizheng Liang
| | - Xiushen Li
- Department of Obstetrics and Gynecology, Shenzhen University General Hospital, Shenzhen, China
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen, China
- Shenzhen Key Laboratory, Shenzhen University General Hospital, Shenzhen, China
- Xiushen Li
| | - Hao Wang
- Department of Obstetrics and Gynecology, Shenzhen University General Hospital, Shenzhen, China
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen, China
- Shenzhen Key Laboratory, Shenzhen University General Hospital, Shenzhen, China
- Hao Wang
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5
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Abstract
Over the last decades, research has focused on the role of pleckstrin homology (PH) domain leucine-rich repeat protein phosphatases (PHLPPs) in regulating cellular signaling via PI3K/Akt inhibition. The PKB/Akt signaling imbalances are associated with a variety of illnesses, including various types of cancer, inflammatory response, insulin resistance, and diabetes, demonstrating the relevance of PHLPPs in the prevention of diseases. Furthermore, identification of novel substrates of PHLPPs unveils their role as a critical mediator in various cellular processes. Recently, researchers have explored the increasing complexity of signaling networks involving PHLPPs whereby relevant information of PHLPPs in metabolic diseases was obtained. In this review, we discuss the current knowledge of PHLPPs on the well-known substrates and metabolic regulation, especially in liver, pancreatic beta cell, adipose tissue, and skeletal muscle in relation with the stated diseases. Understanding the context-dependent functions of PHLPPs can lead to a promising treatment strategy for several kinds of metabolic diseases.
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Affiliation(s)
- Jong-Ho Cha
- Department of Biomedical Sciences, College of Medicine, Inha University, Incheon 22212, Korea
- Program in Biomedical Science & Engineering, Inha University, Incheon 22212, Korea
| | - Yelin Jeong
- Department of Biomedical Sciences, College of Medicine, Inha University, Incheon 22212, Korea
- Program in Biomedical Science & Engineering, Inha University, Incheon 22212, Korea
- Research Center for Controlling Intercellular Communication (RCIC), College of Medicine, Inha University, Incheon 22212, Korea
| | - Ah-Reum Oh
- Department of Biomedical Sciences, College of Medicine, Inha University, Incheon 22212, Korea
- Program in Biomedical Science & Engineering, Inha University, Incheon 22212, Korea
- Research Center for Controlling Intercellular Communication (RCIC), College of Medicine, Inha University, Incheon 22212, Korea
| | - Sang Bae Lee
- Division of Life Sciences, Jeonbuk National University; Sarcopenia Total Solution Center, Jeonju 54896, Korea
| | - Soon-Sun Hong
- Department of Biomedical Sciences, College of Medicine, Inha University, Incheon 22212, Korea
- Program in Biomedical Science & Engineering, Inha University, Incheon 22212, Korea
- Research Center for Controlling Intercellular Communication (RCIC), College of Medicine, Inha University, Incheon 22212, Korea
| | - KyeongJin Kim
- Department of Biomedical Sciences, College of Medicine, Inha University, Incheon 22212, Korea
- Program in Biomedical Science & Engineering, Inha University, Incheon 22212, Korea
- Research Center for Controlling Intercellular Communication (RCIC), College of Medicine, Inha University, Incheon 22212, Korea
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6
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The PHLPP1 N-Terminal Extension Is a Mitotic Cdk1 Substrate and Controls an Interactome Switch. Mol Cell Biol 2021; 41:e0033320. [PMID: 33397691 PMCID: PMC8088274 DOI: 10.1128/mcb.00333-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
PH domain leucine-rich repeat protein phosphatase 1 (PHLPP1) is a tumor suppressor that directly dephosphorylates a wide array of substrates, most notably the prosurvival kinase Akt. However, little is known about the molecular mechanisms governing PHLPP1 itself. Here, we report that PHLPP1 is dynamically regulated in a cell cycle-dependent manner and deletion of PHLPP1 results in mitotic delays and increased rates of chromosomal segregation errors. We show that PHLPP1 is hyperphosphorylated during mitosis by Cdk1 in a functionally uncharacterized region known as the PHLPP1 N-terminal extension (NTE). A proximity-dependent biotin identification (BioID) interaction screen revealed that during mitosis, PHLPP1 dissociates from plasma membrane scaffolds, such as Scribble, by a mechanism that depends on its NTE and gains proximity to kinetochore and mitotic spindle proteins such as KNL1 and TPX2. Our data are consistent with a model in which phosphorylation of PHLPP1 during mitosis regulates binding to its mitotic partners and allows accurate progression through mitosis. The finding that PHLPP1 binds mitotic proteins in a cell cycle- and phosphorylation-dependent manner may have relevance to its tumor-suppressive function.
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7
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Baffi TR, Cohen-Katsenelson K, Newton AC. PHLPPing the Script: Emerging Roles of PHLPP Phosphatases in Cell Signaling. Annu Rev Pharmacol Toxicol 2021; 61:723-743. [PMID: 32997603 PMCID: PMC11003498 DOI: 10.1146/annurev-pharmtox-031820-122108] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Whereas protein kinases have been successfully targeted for a variety of diseases, protein phosphatases remain an underutilized therapeutic target, in part because of incomplete characterization of their effects on signaling networks. The pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP) is a relatively new player in the cell signaling field, and new roles in controlling the balance among cell survival, proliferation, and apoptosis are being increasingly identified. Originally characterized for its tumor-suppressive function in deactivating the prosurvival kinase Akt, PHLPP may have an opposing role in promoting survival, as recent evidence suggests. Additionally, identification of the transcription factor STAT1 as a substrate unveils a role for PHLPP as a critical mediator of transcriptional programs in cancer and the inflammatory response. This review summarizes the current knowledge of PHLPP as both a tumor suppressor and an oncogene and highlights emerging functions in regulating gene expression and the immune system. Understanding the context-dependent functions of PHLPP is essential for appropriate therapeutic intervention.
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Affiliation(s)
- Timothy R Baffi
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093-0721, USA;
| | - Ksenya Cohen-Katsenelson
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093-0721, USA;
| | - Alexandra C Newton
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093-0721, USA;
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8
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Meng F, Liang Z, Zhao K, Luo C. Drug design targeting active posttranslational modification protein isoforms. Med Res Rev 2020; 41:1701-1750. [PMID: 33355944 DOI: 10.1002/med.21774] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/29/2020] [Accepted: 12/03/2020] [Indexed: 12/11/2022]
Abstract
Modern drug design aims to discover novel lead compounds with attractable chemical profiles to enable further exploration of the intersection of chemical space and biological space. Identification of small molecules with good ligand efficiency, high activity, and selectivity is crucial toward developing effective and safe drugs. However, the intersection is one of the most challenging tasks in the pharmaceutical industry, as chemical space is almost infinity and continuous, whereas the biological space is very limited and discrete. This bottleneck potentially limits the discovery of molecules with desirable properties for lead optimization. Herein, we present a new direction leveraging posttranslational modification (PTM) protein isoforms target space to inspire drug design termed as "Post-translational Modification Inspired Drug Design (PTMI-DD)." PTMI-DD aims to extend the intersections of chemical space and biological space. We further rationalized and highlighted the importance of PTM protein isoforms and their roles in various diseases and biological functions. We then laid out a few directions to elaborate the PTMI-DD in drug design including discovering covalent binding inhibitors mimicking PTMs, targeting PTM protein isoforms with distinctive binding sites from that of wild-type counterpart, targeting protein-protein interactions involving PTMs, and hijacking protein degeneration by ubiquitination for PTM protein isoforms. These directions will lead to a significant expansion of the biological space and/or increase the tractability of compounds, primarily due to precisely targeting PTM protein isoforms or complexes which are highly relevant to biological functions. Importantly, this new avenue will further enrich the personalized treatment opportunity through precision medicine targeting PTM isoforms.
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Affiliation(s)
- Fanwang Meng
- Drug Discovery and Design Center, the Center for Chemical Biology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, Canada
| | - Zhongjie Liang
- Center for Systems Biology, Department of Bioinformatics, School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
| | - Kehao Zhao
- School of Pharmacy, Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education, Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai, China
| | - Cheng Luo
- Drug Discovery and Design Center, the Center for Chemical Biology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
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9
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Cao S, Huang S, Guo Y, Zhou L, Lu Y, Lai S. Proteomic-based identification of oocyte maturation-related proteins in mouse germinal vesicle oocytes. Reprod Domest Anim 2020; 55:1607-1618. [PMID: 32920902 DOI: 10.1111/rda.13819] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 09/02/2020] [Indexed: 12/25/2022]
Abstract
Oocyte proteins play an important role in oocyte maturation, fertilization and embryonic development. However, the protein composition of mouse germinal vesicle (GV) oocytes is still unclear. Using one-dimensional Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (1D SDS-PAGE) and Reverse-phase liquid chromatography tandem mass spectrometry (RP-LC-MS/MS), we constructed a protein profile of mouse GV oocytes. First, our proteomics profile identified 1,405 different proteins from 11,000 mouse GV oocytes lacking zona pellucida. Second, with detailed bioinformatics analysis, a group of proteins that play an essential role in oocyte maturation was screened. In addition, the expression and localization of suppressor of G2 allele of skp1(SUGT1, also called SGT1), heterogeneous nuclear ribonucleoprotein K (Hnrpk), Seruin, Cullin1(Clu1) and nuclear distribution protein C (Nudc) in mouse ovaries and early embryos were also captured and investigated in this study. Moreover, the protein profile was submitted to the Proteomics Identifications Database (PRIDE) and is available via ProteomeXchange with the identifier PXD014314. Our research provides valuable resources for the study of oocyte proteins and oocyte maturation and helps to clarify the mechanisms of oocyte maturation.
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Affiliation(s)
- Senyang Cao
- Center of Reproductive Medicine, Huai'an Maternity and Child Health Care Center, Huai'an, China.,State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
| | - Shaoping Huang
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China.,Department of Histology and Embryology, Medical School, Southeast University, Nanjing, China
| | - Ying Guo
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
| | - Lin Zhou
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
| | - Ying Lu
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, China
| | - Shanshan Lai
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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10
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Wang M, Dai W, Ke Z, Li Y. Functional roles of E3 ubiquitin ligases in gastric cancer. Oncol Lett 2020; 20:22. [PMID: 32774495 PMCID: PMC7405480 DOI: 10.3892/ol.2020.11883] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 04/29/2020] [Indexed: 12/15/2022] Open
Abstract
To date, >650 E3 ubiquitin ligases have been described in humans, including >600 really interesting new genes (RINGs), 28 homologous to E6-associated protein C-terminus (HECTs) and several RING-in-between-RINGs. They are considered key regulators and therapeutic targets of many types of human cancers, including gastric cancer (GC). Among them, some RING and HECT E3 ligases are closely related to the proliferation, infiltration and prognosis of GC. During the past few years, abnormal expressions and functions of many E3 ligases have been identified in GC. However, the functional roles of E3 ligases in GC have not been fully elucidated. The present article focuses on the functional roles of E3 ligases related to the proteasome in GC. In this comprehensive review, the latest research progress on E3 ligases involved in GC and elaborate their structure, classification, functional roles and therapeutic value in GC was summarized. Finally, 30 E3 ligases that serve essential roles in regulating the development of GC were described. Some of these ligases may serve as oncogenes or tumor suppressors in GC, whereas the pathological mechanism of others needs further study; for example, constitutive photomorphogenic 1. In conclusion, the present review demonstrated that E3 ligases are crucial tumor regulatory factors and potential therapeutic targets in GC. Therefore, more studies should focus on the therapeutic targeting of E3 ligases in GC.
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Affiliation(s)
- Mingliang Wang
- Department of General Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230032, P.R. China
| | - Wei Dai
- Department of General Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230032, P.R. China
| | - Zhangyan Ke
- Department of Geriatric Medicine, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230032, P.R. China
| | - Yongxiang Li
- Department of General Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230032, P.R. China
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11
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Long noncoding RNA SAM promotes myoblast proliferation through stabilizing Sugt1 and facilitating kinetochore assembly. Nat Commun 2020; 11:2725. [PMID: 32483152 PMCID: PMC7264179 DOI: 10.1038/s41467-020-16553-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 04/30/2020] [Indexed: 01/01/2023] Open
Abstract
The functional study of lncRNAs in skeletal muscle satellite cells (SCs) remains at the infancy stage. Here we identify SAM (Sugt1 asssociated muscle) lncRNA that is enriched in the proliferating myoblasts. Global deletion of SAM has no overt effect on mice but impairs adult muscle regeneration following acute damage; it also exacerbates the chronic injury-induced dystrophic phenotype in mdx mice. Consistently, inducible deletion of SAM in SCs leads to deficiency in muscle regeneration. Further examination reveals that SAM loss results in a cell-autonomous defect in the proliferative expansion of myoblasts. Mechanistically, we find SAM interacts and stabilizes Sugt1, a co-chaperon protein key to kinetochore assembly during cell division. Loss of SAM or Sugt1 both disrupts kinetochore assembly in mitotic cells due to the mislocalization of two components: Dsn1 and Hec1. Altogether, our findings identify SAM as a regulator of SC proliferation through facilitating Sugt1 mediated kinetochore assembly during cell division. Long noncoding RNA SAM (Sugt1 associated muscle) is upregulated in the proliferating myoblast cells. Here the authors investigate SAM knockout mice and suggest that SAM binds and stabilizes Sugt1, a co-chaperone protein that regulates kinetochore assembly.
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12
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Pini T, Parks J, Russ J, Dzieciatkowska M, Hansen KC, Schoolcraft WB, Katz-Jaffe M. Obesity significantly alters the human sperm proteome, with potential implications for fertility. J Assist Reprod Genet 2020; 37:777-787. [PMID: 32026202 PMCID: PMC7183029 DOI: 10.1007/s10815-020-01707-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 01/30/2020] [Indexed: 11/25/2022] Open
Abstract
PURPOSE In men, obesity may lead to poor semen parameters and reduced fertility. However, the causative links between obesity and male infertility are not totally clear, particularly on a molecular level. As such, we investigated how obesity modifies the human sperm proteome, to elucidate any important implications for fertility. METHODS Sperm protein lysates from 5 men per treatment, classified as a healthy weight (body mass index (BMI) ≤ 25 kg/m2) or obese (BMI ≥ 30 kg/m2), were FASP digested, submitted to liquid chromatography tandem mass spectrometry, and compared by label-free quantification. Findings were confirmed for several proteins by qualitative immunofluorescence and a quantitative protein immunoassay. RESULTS A total of 2034 proteins were confidently identified, with 24 proteins being significantly (p < 0.05) less abundant (fold change < 0.05) in the spermatozoa of obese men and 3 being more abundant (fold change > 1.5) compared with healthy weight controls. Proteins with altered abundance were involved in a variety of biological processes, including oxidative stress (GSS, NDUFS2, JAGN1, USP14, ADH5), inflammation (SUGT1, LTA4H), translation (EIF3F, EIF4A2, CSNK1G1), DNA damage repair (UBEA4), and sperm function (NAPA, RNPEP, BANF2). CONCLUSION These results suggest that oxidative stress and inflammation are closely tied to reproductive dysfunction in obese men. These processes likely impact protein translation and folding during spermatogenesis, leading to poor sperm function and subfertility. The observation of these changes in obese men with no overt andrological diagnosis further suggests that traditional clinical semen assessments fail to detect important biochemical changes in spermatozoa which may compromise fertility.
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Affiliation(s)
- T Pini
- Colorado Center for Reproductive Medicine, Lone Tree, CO, 80124, USA.
| | - J Parks
- Colorado Center for Reproductive Medicine, Lone Tree, CO, 80124, USA
| | - J Russ
- Colorado Center for Reproductive Medicine, Lone Tree, CO, 80124, USA
| | - M Dzieciatkowska
- School of Medicine Biological Mass Spectrometry Facility, University of Colorado, Aurora, CO, 80045, USA
| | - K C Hansen
- School of Medicine Biological Mass Spectrometry Facility, University of Colorado, Aurora, CO, 80045, USA
| | - W B Schoolcraft
- Colorado Center for Reproductive Medicine, Lone Tree, CO, 80124, USA
| | - M Katz-Jaffe
- Colorado Center for Reproductive Medicine, Lone Tree, CO, 80124, USA
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13
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Becerra CC, Mattson AM, Molstad DHH, Lorang IM, Westendorf JJ, Bradley EW. DNA methylation and FoxO3a regulate PHLPP1 expression in chondrocytes. J Cell Biochem 2018; 119:7470-7478. [PMID: 29775231 PMCID: PMC6150803 DOI: 10.1002/jcb.27056] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 04/23/2018] [Indexed: 12/17/2022]
Abstract
The protein phosphatase Phlpp1 is an essential enzyme for proper chondrocyte function. Altered Phlpp1 levels are associated with cancer and degenerative diseases such as osteoarthritis. While much is known about the post-transcriptional mechanisms controlling Phlpp1 levels, transcriptional regulation of the Phlpp1 gene locus is underexplored. We previously showed that CpG methylation of the PHLPP1 promoter is lower in osteoarthritic cartilage than in normal cartilage, and indirectly correlates with gene expression. Here we further defined the effects of DNA methylation on PHLPP1 promoter activity in chondrocytes. We cloned a 1791 bp fragment of the PHLPP1 promoter (-1589:+202) and found that the first 500 bp were required for maximal promoter activity. General methylation of CpG sites within this fragment significantly blunts transcriptional activity, whereas site-specific methyltransferases HhaI or HpaII decrease transcriptional activation by approximately 50%. We located putative FoxO consensus sites within the PHLPP1 promoter region. Inhibition of DNA methylation by incorporation of 5-azacytidine increases Phlpp1 mRNA levels, but FoxO inhibition abolishes this induction. To determine which FoxO transcription factor mediates Phlpp1 expression, we performed overexpression and siRNA-mediated knock down experiments. Overexpression of FoxO3a, but not FoxO1, increases Phlpp1 levels. Likewise, siRNAs targeting FoxO3a, but not FoxO1, diminished Phlpp1 levels. Last, FoxO inhibition increases glycosaminoglycan staining of cultured chondrocytes and leads to concomitant increases in FGF18 and HAS2 expression. Together, these data demonstrate that CpG methylation and FoxO3a regulate PHLPP1 expression.
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Affiliation(s)
| | - Anna M. Mattson
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN
| | | | - Ian M. Lorang
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN
| | - Jennifer J. Westendorf
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN
| | - Elizabeth W. Bradley
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN
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PHLPPing through history: a decade in the life of PHLPP phosphatases. Biochem Soc Trans 2017; 44:1675-1682. [PMID: 27913677 DOI: 10.1042/bst20160170] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 08/12/2016] [Accepted: 08/16/2016] [Indexed: 01/30/2023]
Abstract
In the decade since their discovery, the PH domain leucine-rich repeat protein phosphatases (PHLPP) have emerged as critical regulators of cellular homeostasis, and their dysregulation is associated with various pathophysiologies, ranging from cancer to degenerative diseases, such as diabetes and heart disease. The two PHLPP isozymes, PHLPP1 and PHLPP2, were identified in a search for phosphatases that dephosphorylate Akt, and thus suppress growth factor signaling. However, given that there are over 200 000 phosphorylated residues in a single cell, and fewer than 50 Ser/Thr protein phosphatases, it is not surprising that PHLPP has many other cellular functions yet to be discovered, including a recently identified role in regulating the epigenome. Both PHLPP1 and PHLPP2 are commonly deleted in human cancers, supporting a tumor suppressive role. Conversely, the levels of one isozyme, PHLPP1, are elevated in diabetes. Thus, mechanisms to correctly control PHLPP activity in cells are critical for normal cellular homeostasis. This review summarizes the known functions of PHLPP and its role in disease.
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15
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Gangula NR, Maddika S. Interplay between the phosphatase PHLPP1 and E3 ligase RNF41 stimulates proper kinetochore assembly via the outer-kinetochore protein SGT1. J Biol Chem 2017; 292:13947-13958. [PMID: 28696259 PMCID: PMC5572923 DOI: 10.1074/jbc.m117.782896] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 07/07/2017] [Indexed: 12/25/2022] Open
Abstract
Kinetochores link chromosomes to spindle microtubules and are essential for accurate chromosome segregation during cell division. Kinetochores assemble at the centromeric region of chromosomes as a multiprotein complex. However, the molecular mechanisms of kinetochore assembly have not yet been fully elucidated. In this study, we identified pleckstrin homology domain and leucine-rich repeat protein phosphatase 1 (PHLPP1) as a regulatory phosphatase that facilitates proper kinetochore assembly. We found that PHLPP1 interacted with the essential outer-kinetochore protein SGT1 and stabilized its protein levels. Loss of PHLPP1 from cells led to SGT1 degradation and thereby caused defective kinetochore assembly. We also found that the ring finger protein 41 (RNF41) as an E3 ligase ubiquitinated and degraded SGT1 in a phosphorylation-dependent manner. PHLPP1 dephosphorylated SGT1 at four conserved residues (Ser-17, Ser-249, Ser-289, and Thr-233) and thereby prevented SGT1 from associating with RNF41, in turn, countering SGT1 degradation. Importantly, depletion of RNF41 or expression of a non-phosphorylatable SGT1 mutant rescued the kinetochore defects caused by the loss of PHLPP1. Taken together, our results suggest that PHLPP1 plays an important role in the assembly of kinetochores by counteracting RNF41-mediated SGT1 degradation.
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Affiliation(s)
- Narmadha Reddy Gangula
- From the Laboratory of Cell Death and Cell Survival, Centre for DNA Fingerprinting and Diagnostics, Nampally, Hyderabad 500001, India
| | - Subbareddy Maddika
- From the Laboratory of Cell Death and Cell Survival, Centre for DNA Fingerprinting and Diagnostics, Nampally, Hyderabad 500001, India.
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16
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Willhoft O, Kerr R, Patel D, Zhang W, Al-Jassar C, Daviter T, Millson SH, Thalassinos K, Vaughan CK. The crystal structure of the Sgt1-Skp1 complex: the link between Hsp90 and both SCF E3 ubiquitin ligases and kinetochores. Sci Rep 2017; 7:41626. [PMID: 28139700 PMCID: PMC5282575 DOI: 10.1038/srep41626] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 12/21/2016] [Indexed: 12/05/2022] Open
Abstract
The essential cochaperone Sgt1 recruits Hsp90 chaperone activity to a range of cellular factors including SCF E3 ubiquitin ligases and the kinetochore in eukaryotes. In these pathways Sgt1 interacts with Skp1, a small protein that heterodimerizes with proteins containing the F-box motif. We have determined the crystal structure of the interacting domains of Saccharomyces cerevisiae Sgt1 and Skp1 at 2.8 Å resolution and validated the interface in the context of the full-length proteins in solution. The BTB/POZ domain of Skp1 associates with Sgt1 via the concave surface of its TPR domain using residues that are conserved in humans. Dimerization of yeast Sgt1 occurs via an insertion that is absent from monomeric human Sgt1. We identify point mutations that disrupt dimerization and Skp1 binding in vitro and find that the interaction with Skp1 is an essential function of Sgt1 in yeast. Our data provide a structural rationale for understanding the phenotypes of temperature-sensitive Sgt1 mutants and for linking Skp1-associated proteins to Hsp90-dependent pathways.
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Affiliation(s)
- Oliver Willhoft
- Institute of Structural and Molecular Biology, University College London and Birkbeck, Biological Sciences, Malet Street, London, WC1E 7HX, UK
| | - Richard Kerr
- Institute of Structural and Molecular Biology, University College London and Birkbeck, Division of Biosciences, Darwin Building, Gower Street, London, WC1E 6BT, UK
| | - Dipali Patel
- Institute of Structural and Molecular Biology, University College London and Birkbeck, Biological Sciences, Malet Street, London, WC1E 7HX, UK
| | - Wenjuan Zhang
- Institute of Structural and Molecular Biology, University College London and Birkbeck, Biological Sciences, Malet Street, London, WC1E 7HX, UK
| | - Caezar Al-Jassar
- Institute of Structural and Molecular Biology, University College London and Birkbeck, Biological Sciences, Malet Street, London, WC1E 7HX, UK
| | - Tina Daviter
- Institute of Structural and Molecular Biology, University College London and Birkbeck, Biological Sciences, Malet Street, London, WC1E 7HX, UK
| | - Stefan H Millson
- School of Life Sciences, Joseph Banks Laboratory, University of Lincoln, Lincoln, LN6 7TS, UK
| | - Konstantinos Thalassinos
- Institute of Structural and Molecular Biology, University College London and Birkbeck, Division of Biosciences, Darwin Building, Gower Street, London, WC1E 6BT, UK
| | - Cara K Vaughan
- Institute of Structural and Molecular Biology, University College London and Birkbeck, Biological Sciences, Malet Street, London, WC1E 7HX, UK
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17
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The oncogenic role of the cochaperone Sgt1. Oncogenesis 2015; 4:e149. [PMID: 25985210 PMCID: PMC4450263 DOI: 10.1038/oncsis.2015.12] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 03/24/2015] [Accepted: 03/30/2015] [Indexed: 12/14/2022] Open
Abstract
Sgt1/Sugt1, a cochaperone of Hsp90, is involved in several cellular activities including Cullin E3 ubiqutin ligase activity. The high level of Sgt1 expression in colorectal and gastric tumors suggests that Sgt1 is involved in tumorigenesis. Here, we report that Sgt1 is overexpressed in colon, breast and lung tumor tissues and in Ewing sarcoma and rhabdomyosarcoma xenografts. We also found that Sgt1 heterozygous knockout resulted in suppressed Hras-mediated transformation in vitro and tumor formation in p53−/− mouse embryonic fibroblast cells and significantly increased survival of p53−/− mice. Moreover, depletion of Sgt1 inhibited the growth of Ewing sarcoma and rhabdomyosarcoma cells and destabilized EWS-FLI1 and PAX3-FOXO1 oncogenic fusion proteins, respectively, which are required for cellular growth. Our results suggest that Sgt1 contributes to cancer development by stabilizing oncoproteins and that Sgt1 is a potential therapeutic target.
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18
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Liang J, Wang WF, Xie S, Zhang XL, Qi WF, Zhou XP, Hu JX, Shi Q, Yu RT. Expression of β-transducin repeat-containing E3 ubiquitin protein ligase in human glioma and its correlation with prognosis. Oncol Lett 2015; 9:2651-2656. [PMID: 26137122 DOI: 10.3892/ol.2015.3113] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 03/09/2015] [Indexed: 11/05/2022] Open
Abstract
β-transducin repeat-containing E3 ubiquitin protein ligase (β-TrCP) targets a number of substrates essential for specific aspects of tumorigenesis. In addition, β-TrCP regulates various important signaling pathways. As β-TrCP is involved in regulating the ubiquitination and degradation of multiple oncogenes and tumor suppressors, the function of β-TrCP varies between cancer types. At present, the association between β-TrCP expression and clinicopathological factors in glioma is unknown. Therefore, the current study used western blotting and immunohistochemistry to investigate the expression of β-TrCP protein in glioma tissue specimens. It was identified that β-TrCP protein expression levels were significantly lower in glioma compared with non-tumorous human brain tissues. Furthermore, the higher the grade of glioma, the lower the level of β-TrCP expression. Kaplan-Meier analysis demonstrated that patients with low β-TrCP expression experienced significantly worse overall survival compared with patients with high β-TrCP expression. The results indicate that downregulation of β-TrCP may be associated with poor survival in patients with glioma. Together, the current data indicates that β-TrCP may be applied as a useful indicator of glioma prognosis and may serve as an anticancer therapeutic target for glioma, however further investigation is required.
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Affiliation(s)
- Jun Liang
- Department of Neurosurgery, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China ; Laboratory of Neurosurgery, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China
| | - Wei-Feng Wang
- Laboratory of Neurosurgery, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China ; Graduate School, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China
| | - Shao Xie
- Department of Neurosurgery, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China ; Laboratory of Neurosurgery, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China
| | - Xian-Li Zhang
- Laboratory of Neurosurgery, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China ; Graduate School, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China
| | - Wei-Feng Qi
- Laboratory of Neurosurgery, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China ; Graduate School, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China
| | - Xiu-Ping Zhou
- Department of Neurosurgery, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China ; Laboratory of Neurosurgery, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China
| | - Jin-Xia Hu
- Department of Neurosurgery, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China ; Laboratory of Neurosurgery, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China
| | - Qiong Shi
- Department of Neurosurgery, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China ; Laboratory of Neurosurgery, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China
| | - Ru-Tong Yu
- Department of Neurosurgery, Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China ; Laboratory of Neurosurgery, Xuzhou Medical College, Xuzhou, Jiangsu 221002, P.R. China
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Gangula NR, Maddika S. WD repeat protein WDR48 in complex with deubiquitinase USP12 suppresses Akt-dependent cell survival signaling by stabilizing PH domain leucine-rich repeat protein phosphatase 1 (PHLPP1). J Biol Chem 2013; 288:34545-54. [PMID: 24145035 PMCID: PMC3843068 DOI: 10.1074/jbc.m113.503383] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PHLPP1 (PH domain leucine-rich repeat protein phosphatase 1) is a protein-serine/threonine phosphatase and a negative regulator of the PI3-kinase/Akt pathway. Although its function as a suppressor of tumor cell growth has been established, the mechanism of its regulation is not completely understood. In this study, by utilizing the tandem affinity purification approach we have identified WDR48 and USP12 as novel PHLPP1-associated proteins. The WDR48·USP12 complex deubiquitinates PHLPP1 and thereby enhances its protein stability. Similar to PHLPP1 function, WDR48 and USP12 negatively regulate Akt activation and thus promote cellular apoptosis. Functionally, we show that WDR48 and USP12 suppress proliferation of tumor cells. Importantly, we found a WDR48 somatic mutation (L580F) that is defective in stabilizing PHLPP1 in colorectal cancers, supporting a WDR48 role in tumor suppression. Together, our results reveal WDR48 and USP12 as novel PHLPP1 regulators and potential suppressors of tumor cell survival.
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Affiliation(s)
- Narmadha Reddy Gangula
- From the Laboratory of Cell Death and Cell Survival, Centre for DNA Fingerprinting and Diagnostics (CDFD), Nampally, Hyderabad 500001, India
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