1
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Beauchamp E, Gamma JM, Cromwell CR, Moussa EW, Pain R, Kostiuk MA, Acevedo-Morantes C, Iyer A, Yap M, Vincent KM, Postovit LM, Julien O, Hubbard BP, Mackey JR, Berthiaume LG. Multiomics analysis identifies oxidative phosphorylation as a cancer vulnerability arising from myristoylation inhibition. J Transl Med 2024; 22:431. [PMID: 38715059 PMCID: PMC11075276 DOI: 10.1186/s12967-024-05150-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 03/31/2024] [Indexed: 05/12/2024] Open
Abstract
BACKGROUND In humans, two ubiquitously expressed N-myristoyltransferases, NMT1 and NMT2, catalyze myristate transfer to proteins to facilitate membrane targeting and signaling. We investigated the expression of NMTs in numerous cancers and found that NMT2 levels are dysregulated by epigenetic suppression, particularly so in hematologic malignancies. This suggests that pharmacological inhibition of the remaining NMT1 could allow for the selective killing of these cells, sparing normal cells with both NMTs. METHODS AND RESULTS Transcriptomic analysis of 1200 NMT inhibitor (NMTI)-treated cancer cell lines revealed that NMTI sensitivity relates not only to NMT2 loss or NMT1 dependency, but also correlates with a myristoylation inhibition sensitivity signature comprising 54 genes (MISS-54) enriched in hematologic cancers as well as testis, brain, lung, ovary, and colon cancers. Because non-myristoylated proteins are degraded by a glycine-specific N-degron, differential proteomics revealed the major impact of abrogating NMT1 genetically using CRISPR/Cas9 in cancer cells was surprisingly to reduce mitochondrial respiratory complex I proteins rather than cell signaling proteins, some of which were also reduced, albeit to a lesser extent. Cancer cell treatments with the first-in-class NMTI PCLX-001 (zelenirstat), which is undergoing human phase 1/2a trials in advanced lymphoma and solid tumors, recapitulated these effects. The most downregulated myristoylated mitochondrial protein was NDUFAF4, a complex I assembly factor. Knockout of NDUFAF4 or in vitro cell treatment with zelenirstat resulted in loss of complex I, oxidative phosphorylation and respiration, which impacted metabolomes. CONCLUSIONS Targeting of both, oxidative phosphorylation and cell signaling partly explains the lethal effects of zelenirstat in select cancer types. While the prognostic value of the sensitivity score MISS-54 remains to be validated in patients, our findings continue to warrant the clinical development of zelenirstat as cancer treatment.
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Affiliation(s)
| | - Jay M Gamma
- Department of Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Christopher R Cromwell
- Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Eman W Moussa
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Rony Pain
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Morris A Kostiuk
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Claudia Acevedo-Morantes
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Aishwarya Iyer
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Megan Yap
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Krista M Vincent
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Lynne M Postovit
- Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Olivier Julien
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Basil P Hubbard
- Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | | | - Luc G Berthiaume
- Pacylex Pharmaceuticals Inc., Edmonton, AB, Canada.
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.
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2
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Chen L, Su H, Tao Z, Liang C, Liu Z, Dong Y, Zheng P, Liu Y. DUSP22 Ameliorates Endothelial-to-Mesenchymal Transition in HUVECs through Smad2/3 and MAPK Signaling Pathways. Cardiovasc Ther 2024; 2024:5583961. [PMID: 38495810 PMCID: PMC10942825 DOI: 10.1155/2024/5583961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/27/2024] [Accepted: 02/01/2024] [Indexed: 03/19/2024] Open
Abstract
Endothelial-to-mesenchymal transition (EndMT) is the process by which endothelial cells lose their endothelial properties and acquire mesenchymal characteristics. Dual-specific protein phosphatase 22 (DUSP22) inactivates various protein kinases and transcription factors by dephosphorylating serine/threonine residues: hence, it plays a key role in many diseases. The aim of this study was to explore the functional role of DUSP22 in EndMT. In the transforming growth factor-β-induced EndMT model in human umbilical vein endothelial cells (HUVECs), we observed a downregulation of DUSP22 expression. This DUSP22 deficiency could aggravate EndMT. Conversely, the overexpression of DUSP22 could ameliorate EndMT. We used signaling pathway inhibitors to verify our results and found that DUSP22 could regulate EndMT through the smad2/3 and the mitogen-activated protein kinase (MAPK) signaling pathways. In summary, DUSP22 ameliorates EndMT in HUVECs in vitro through the smad2/3 and MAPK signaling pathways.
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Affiliation(s)
- Lu Chen
- Department of Cardiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Hongyu Su
- Department of Cardiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Zekai Tao
- Department of Cardiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Cui Liang
- Department of Cardiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Zhongzhao Liu
- Department of Cardiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Yiming Dong
- Department of Cardiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Peipei Zheng
- Department of Cardiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Yuan Liu
- Department of Cardiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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3
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Wu H, Yang L, Luo R, Li L, Zheng T, Huang K, Qin Y, Yang X, Zhang X, Wang Y. A drug-free cardiovascular stent functionalized with tailored collagen supports in-situ healing of vascular tissues. Nat Commun 2024; 15:735. [PMID: 38272886 PMCID: PMC10810808 DOI: 10.1038/s41467-024-44902-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 01/10/2024] [Indexed: 01/27/2024] Open
Abstract
Drug-eluting stent implantation suppresses the excessive proliferation of smooth muscle cells to reduce in-stent restenosis. However, the efficacy of drug-eluting stents remains limited due to delayed reendothelialization, impaired intimal remodeling, and potentially increased late restenosis. Here, we show that a drug-free coating formulation functionalized with tailored recombinant humanized type III collagen exerts one-produces-multi effects in response to injured tissue following stent implantation. We demonstrate that the one-produces-multi coating possesses anticoagulation, anti-inflammatory, and intimal hyperplasia suppression properties. We perform transcriptome analysis to indicate that the drug-free coating favors the endothelialization process and induces the conversion of smooth muscle cells to a contractile phenotype. We find that compared to drug-eluting stents, our drug-free stent reduces in-stent restenosis in rabbit and porcine models and improves vascular neointimal healing in a rabbit model. Collectively, the one-produces-multi drug-free system represents a promising strategy for the next-generation of stents.
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Affiliation(s)
- Haoshuang Wu
- National Engineering Research Center for Biomaterials and College of Biomedical Engineering, Sichuan University, Chengdu, 610065, China
| | - Li Yang
- National Engineering Research Center for Biomaterials and College of Biomedical Engineering, Sichuan University, Chengdu, 610065, China
| | - Rifang Luo
- National Engineering Research Center for Biomaterials and College of Biomedical Engineering, Sichuan University, Chengdu, 610065, China
| | - Li Li
- Institute of Clinical Pathology, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Tiantian Zheng
- National Engineering Research Center for Biomaterials and College of Biomedical Engineering, Sichuan University, Chengdu, 610065, China
| | - Kaiyang Huang
- National Engineering Research Center for Biomaterials and College of Biomedical Engineering, Sichuan University, Chengdu, 610065, China
| | - Yumei Qin
- National Engineering Research Center for Biomaterials and College of Biomedical Engineering, Sichuan University, Chengdu, 610065, China
| | - Xia Yang
- Shanxi Key Laboratory of Functional Proteins, Shanxi Jinbo Bio-Pharmaceutical Co., Ltd., Taiyuan, 030032, Shanxi, China
| | - Xingdong Zhang
- National Engineering Research Center for Biomaterials and College of Biomedical Engineering, Sichuan University, Chengdu, 610065, China
| | - Yunbing Wang
- National Engineering Research Center for Biomaterials and College of Biomedical Engineering, Sichuan University, Chengdu, 610065, China.
- Tianfu Jincheng Laboratory (Frontier Medical Center), Chengdu, 610213, China.
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4
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Rahman MM, Ishikawa H, Yamauchi M, Takashima S, Kamatari YO, Shimizu K, Okada A, Inoshima Y. Characterization of mRNA Signature in Milk Small Extracellular Vesicles from Cattle Infected with Bovine Leukemia Virus. Pathogens 2023; 12:1239. [PMID: 37887755 PMCID: PMC10610248 DOI: 10.3390/pathogens12101239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 10/06/2023] [Accepted: 10/11/2023] [Indexed: 10/28/2023] Open
Abstract
This study aimed to characterize the mRNA signature of milk small extracellular vesicles (sEVs) from BLV-infected cattle. A total of 23 mRNAs, which showed greater abundance in milk sEVs from BLV-infected cattle compared to those from BLV-uninfected (control) cattle, were identified through microarray analyses conducted in our previous study. To assess the significance of these differences in mRNA abundance, milk was collected from six control cattle and twenty-six cattle infected with BLV. The infected cattle were categorized into two distinct groups based on their proviral loads: a group of eight cattle with low proviral loads (LPVL), characterized by <10,000 copies per 105 white blood cells (WBC), and a group of eighteen cattle with high proviral loads (HPVL), marked by ≥10,000 copies per 105 WBC. The qPCR analysis quantified 7 out of 23 mRNAs, including BoLA, CALB1, IL33, ITGB2, MYOF, TGFBR1, and TMEM156, in the milk sEVs from control cattle, LPVL cattle, and HPVL cattle. Significantly, the average relative expression of CALB1 mRNA in milk sEVs was higher in LPVL cattle compared to HPVL cattle and control cattle (p < 0.05), while it was relatively lower in HPVL cattle compared to LPVL cattle and control cattle (p > 0.05). Likewise, the average relative expression of TMEM156 mRNA in milk sEVs was significantly higher in LPVL cattle compared to HPVL cattle (p < 0.05), and relatively lower in HPVL cattle compared to LPVL cattle and control cattle (p > 0.05). The results indicate distinct patterns of CALB1 and TMEM156 mRNA levels in milk sEVs, with higher levels observed in LPVL cattle and lower levels in HPVL cattle. The current study could provide essential information to comprehend the complexities during the progression of BLV infection and direct the exploration of mRNA biomarkers for monitoring the clinical stage of BLV infection.
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Affiliation(s)
- Md. Matiur Rahman
- Laboratory of Food and Environmental Hygiene, Cooperative Department of Veterinary Medicine, Gifu University, Gifu 501-1112, Japan
- Department of Medicine, Faculty of Veterinary, Animal and Biomedical Sciences, Sylhet Agricultural University, Sylhet 3100, Bangladesh
| | - Hinata Ishikawa
- Laboratory of Food and Environmental Hygiene, Cooperative Department of Veterinary Medicine, Gifu University, Gifu 501-1112, Japan
| | - Marika Yamauchi
- Laboratory of Food and Environmental Hygiene, Cooperative Department of Veterinary Medicine, Gifu University, Gifu 501-1112, Japan
| | - Shigeo Takashima
- Division of Genomics Research, Life Science Research Center, Gifu University, Gifu 501-1112, Japan
- Institute for Glyco-Core Research (iGCORE), Gifu University, Gifu 501-1112, Japan
- The United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1112, Japan
| | - Yuji O. Kamatari
- Institute for Glyco-Core Research (iGCORE), Gifu University, Gifu 501-1112, Japan
- The United Graduate School of Drug Discovery and Medical Information Sciences, Gifu University, Gifu 501-1112, Japan
- Division of Instrumental Analysis, Life Science Research Center, Gifu University, Gifu 501-1112, Japan
| | - Kaori Shimizu
- Laboratory of Food and Environmental Hygiene, Cooperative Department of Veterinary Medicine, Gifu University, Gifu 501-1112, Japan
| | - Ayaka Okada
- Laboratory of Food and Environmental Hygiene, Cooperative Department of Veterinary Medicine, Gifu University, Gifu 501-1112, Japan
- Education and Research Center for Food Animal Health, Gifu University (GeFAH), Gifu 501-1112, Japan
| | - Yasuo Inoshima
- Laboratory of Food and Environmental Hygiene, Cooperative Department of Veterinary Medicine, Gifu University, Gifu 501-1112, Japan
- Education and Research Center for Food Animal Health, Gifu University (GeFAH), Gifu 501-1112, Japan
- Joint Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1112, Japan
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5
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Protein N-myristoylation: functions and mechanisms in control of innate immunity. Cell Mol Immunol 2021; 18:878-888. [PMID: 33731917 PMCID: PMC7966921 DOI: 10.1038/s41423-021-00663-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 02/18/2021] [Indexed: 02/08/2023] Open
Abstract
Protein N-myristoylation is an important fatty acylation catalyzed by N-myristoyltransferases (NMTs), which are ubiquitous enzymes in eukaryotes. Specifically, attachment of a myristoyl group is vital for proteins participating in various biological functions, including signal transduction, cellular localization, and oncogenesis. Recent studies have revealed unexpected mechanisms indicating that protein N-myristoylation is involved in host defense against microbial and viral infections. In this review, we describe the current understanding of protein N-myristoylation (mainly focusing on myristoyl switches) and summarize its crucial roles in regulating innate immune responses, including TLR4-dependent inflammatory responses and demyristoylation-induced innate immunosuppression during Shigella flexneri infection. Furthermore, we examine the role of myristoylation in viral assembly, intracellular host interactions, and viral spread during human immunodeficiency virus-1 (HIV-1) infection. Deeper insight into the relationship between protein N-myristoylation and innate immunity might enable us to clarify the pathogenesis of certain infectious diseases and better harness protein N-myristoylation for new therapeutics.
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6
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Castro-Sanchez P, Teagle AR, Prade S, Zamoyska R. Modulation of TCR Signaling by Tyrosine Phosphatases: From Autoimmunity to Immunotherapy. Front Cell Dev Biol 2020; 8:608747. [PMID: 33425916 PMCID: PMC7793860 DOI: 10.3389/fcell.2020.608747] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 11/18/2020] [Indexed: 02/06/2023] Open
Abstract
Early TCR signaling is dependent on rapid phosphorylation and dephosphorylation of multiple signaling and adaptor proteins, leading to T cell activation. This process is tightly regulated by an intricate web of interactions between kinases and phosphatases. A number of tyrosine phosphatases have been shown to modulate T cell responses and thus alter T cell fate by negatively regulating early TCR signaling. Mutations in some of these enzymes are associated with enhanced predisposition to autoimmunity in humans, and mouse models deficient in orthologous genes often show T cell hyper-activation. Therefore, phosphatases are emerging as potential targets in situations where it is desirable to enhance T cell responses, such as immune responses to tumors. In this review, we summarize the current knowledge about tyrosine phosphatases that regulate early TCR signaling and discuss their involvement in autoimmunity and their potential as targets for tumor immunotherapy.
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Affiliation(s)
- Patricia Castro-Sanchez
- Ashworth Laboratories, Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Alexandra R Teagle
- Ashworth Laboratories, Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Sonja Prade
- Ashworth Laboratories, Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
| | - Rose Zamoyska
- Ashworth Laboratories, Institute of Immunology and Infection Research, University of Edinburgh, Edinburgh, United Kingdom
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7
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Structural Insights into the Active Site Formation of DUSP22 in N-loop-containing Protein Tyrosine Phosphatases. Int J Mol Sci 2020; 21:ijms21207515. [PMID: 33053837 PMCID: PMC7589817 DOI: 10.3390/ijms21207515] [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: 08/28/2020] [Revised: 10/07/2020] [Accepted: 10/09/2020] [Indexed: 02/07/2023] Open
Abstract
Cysteine-based protein tyrosine phosphatases (Cys-based PTPs) perform dephosphorylation to regulate signaling pathways in cellular responses. The hydrogen bonding network in their active site plays an important conformational role and supports the phosphatase activity. Nearly half of dual-specificity phosphatases (DUSPs) use three conserved residues, including aspartate in the D-loop, serine in the P-loop, and asparagine in the N-loop, to form the hydrogen bonding network, the D-, P-, N-triloop interaction (DPN-triloop interaction). In this study, DUSP22 is used to investigate the importance of the DPN-triloop interaction in active site formation. Alanine mutations and somatic mutations of the conserved residues, D57, S93, and N128 substantially decrease catalytic efficiency (kcat/KM) by more than 102-fold. Structural studies by NMR and crystallography reveal that each residue can perturb the three loops and induce conformational changes, indicating that the hydrogen bonding network aligns the residues in the correct positions for substrate interaction and catalysis. Studying the DPN-triloop interaction reveals the mechanism maintaining phosphatase activity in N-loop-containing PTPs and provides a foundation for further investigation of active site formation in different members of this protein class.
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8
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Yuan M, Song ZH, Ying MD, Zhu H, He QJ, Yang B, Cao J. N-myristoylation: from cell biology to translational medicine. Acta Pharmacol Sin 2020; 41:1005-1015. [PMID: 32203082 PMCID: PMC7468318 DOI: 10.1038/s41401-020-0388-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Accepted: 02/20/2020] [Indexed: 02/07/2023] Open
Abstract
Various lipids and lipid metabolites are bound to and modify the proteins in eukaryotic cells, which are known as ‘protein lipidation’. There are four major types of the protein lipidation, i.e. myristoylation, palmitoylation, prenylation, and glycosylphosphatidylinositol anchor. N-myristoylation refers to the attachment of 14-carbon fatty acid myristates to the N-terminal glycine of proteins by N-myristoyltransferases (NMT) and affects their physiology such as plasma targeting, subcellular tracking and localization, thereby influencing the function of proteins. With more novel pathogenic N-myristoylated proteins are identified, the N-myristoylation will attract great attentions in various human diseases including infectious diseases, parasitic diseases, and cancers. In this review, we summarize the current understanding of N-myristoylation in physiological processes and discuss the hitherto implication of crosstalk between N-myristoylation and other protein modification. Furthermore, we mention several well-studied NMT inhibitors mainly in infectious diseases and cancers and generalize the relation of NMT and cancer progression by browsing the clinic database. This review also aims to highlight the further investigation into the dynamic crosstalk of N-myristoylation in physiological processes as well as the potential application of protein N-myristoylation in translational medicine.
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9
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Hawiger J, Zienkiewicz J. Decoding inflammation, its causes, genomic responses, and emerging countermeasures. Scand J Immunol 2019; 90:e12812. [PMID: 31378956 PMCID: PMC6883124 DOI: 10.1111/sji.12812] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 07/03/2019] [Accepted: 07/29/2019] [Indexed: 12/11/2022]
Abstract
Inflammation is the mechanism of diseases caused by microbial, autoimmune, allergic, metabolic and physical insults that produce distinct types of inflammatory responses. This aetiologic view of inflammation informs its classification based on a cause‐dependent mechanism as well as a cause‐directed therapy and prevention. The genomic era ushered in a new understanding of inflammation by highlighting the cell's nucleus as the centre of the inflammatory response. Exogenous or endogenous inflammatory insults evoke genomic responses in immune and non‐immune cells. These genomic responses depend on transcription factors, which switch on and off a myriad of inflammatory genes through their regulatory networks. We discuss the transcriptional paradigm of inflammation based on denying transcription factors’ access to the nucleus. We present two approaches that control proinflammatory signalling to the nucleus. The first approach constitutes a novel intracellular protein therapy with bioengineered physiologic suppressors of cytokine signalling. The second approach entails control of proinflammatory transcriptional cascades by targeting nuclear transport with a cell‐penetrating peptide that inhibits the expression of 23 out of the 26 mediators of inflammation along with the nine genes required for metabolic responses. We compare these emerging anti‐inflammatory countermeasures to current therapies. The transcriptional paradigm of inflammation offers nucleocentric strategies for microbial, autoimmune, metabolic, physical and other types of inflammation afflicting millions of people worldwide.
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Affiliation(s)
- Jacek Hawiger
- Immunotherapy Program at Vanderbilt University School of Medicine, Nashville, TN, USA.,Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA.,Department of Veterans Affairs, Tennessee Valley Health Care System, Nashville, TN, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Jozef Zienkiewicz
- Immunotherapy Program at Vanderbilt University School of Medicine, Nashville, TN, USA.,Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA.,Department of Veterans Affairs, Tennessee Valley Health Care System, Nashville, TN, USA
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10
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Recurrent MSC E116K mutations in ALK-negative anaplastic large cell lymphoma. Blood 2019; 133:2776-2789. [PMID: 31101622 DOI: 10.1182/blood.2019000626] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 04/24/2019] [Indexed: 02/06/2023] Open
Abstract
Anaplastic large cell lymphomas (ALCLs) represent a relatively common group of T-cell non-Hodgkin lymphomas (T-NHLs) that are unified by similar pathologic features but demonstrate marked genetic heterogeneity. ALCLs are broadly classified as being anaplastic lymphoma kinase (ALK)+ or ALK-, based on the presence or absence of ALK rearrangements. Exome sequencing of 62 T-NHLs identified a previously unreported recurrent mutation in the musculin gene, MSC E116K, exclusively in ALK- ALCLs. Additional sequencing for a total of 238 T-NHLs confirmed the specificity of MSC E116K for ALK- ALCL and further demonstrated that 14 of 15 mutated cases (93%) had coexisting DUSP22 rearrangements. Musculin is a basic helix-loop-helix (bHLH) transcription factor that heterodimerizes with other bHLH proteins to regulate lymphocyte development. The E116K mutation localized to the DNA binding domain of musculin and permitted formation of musculin-bHLH heterodimers but prevented their binding to authentic target sequence. Functional analysis showed MSCE116K acted in a dominant-negative fashion, reversing wild-type musculin-induced repression of MYC and cell cycle inhibition. Chromatin immunoprecipitation-sequencing and transcriptome analysis identified the cell cycle regulatory gene E2F2 as a direct transcriptional target of musculin. MSCE116K reversed E2F2-induced cell cycle arrest and promoted expression of the CD30-IRF4-MYC axis, whereas its expression was reciprocally induced by binding of IRF4 to the MSC promoter. Finally, ALCL cells expressing MSC E116K were preferentially targeted by the BET inhibitor JQ1. These findings identify a novel recurrent MSC mutation as a key driver of the CD30-IRF4-MYC axis and cell cycle progression in a unique subset of ALCLs.
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11
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Ray P, Torck A, Quigley L, Wangzhou A, Neiman M, Rao C, Lam T, Kim JY, Kim TH, Zhang MQ, Dussor G, Price TJ. Comparative transcriptome profiling of the human and mouse dorsal root ganglia: an RNA-seq-based resource for pain and sensory neuroscience research. Pain 2019; 159:1325-1345. [PMID: 29561359 DOI: 10.1097/j.pain.0000000000001217] [Citation(s) in RCA: 213] [Impact Index Per Article: 42.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Molecular neurobiological insight into human nervous tissues is needed to generate next-generation therapeutics for neurological disorders such as chronic pain. We obtained human dorsal root ganglia (hDRG) samples from organ donors and performed RNA-sequencing (RNA-seq) to study the hDRG transcriptional landscape, systematically comparing it with publicly available data from a variety of human and orthologous mouse tissues, including mouse DRG (mDRG). We characterized the hDRG transcriptional profile in terms of tissue-restricted gene coexpression patterns and putative transcriptional regulators, and formulated an information-theoretic framework to quantify DRG enrichment. Relevant gene families and pathways were also analyzed, including transcription factors, G-protein-coupled receptors, and ion channels. Our analyses reveal an hDRG-enriched protein-coding gene set (∼140), some of which have not been described in the context of DRG or pain signaling. Most of these show conserved enrichment in mDRG and were mined for known drug-gene product interactions. Conserved enrichment of the vast majority of transcription factors suggests that the mDRG is a faithful model system for studying hDRG, because of evolutionarily conserved regulatory programs. Comparison of hDRG and tibial nerve transcriptomes suggests trafficking of neuronal mRNA to axons in adult hDRG, and are consistent with studies of axonal transport in rodent sensory neurons. We present our work as an online, searchable repository (https://www.utdallas.edu/bbs/painneurosciencelab/sensoryomics/drgtxome), creating a valuable resource for the community. Our analyses provide insight into DRG biology for guiding development of novel therapeutics and a blueprint for cross-species transcriptomic analyses.
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Affiliation(s)
- Pradipta Ray
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA.,Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Andrew Torck
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Lilyana Quigley
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Andi Wangzhou
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Matthew Neiman
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Chandranshu Rao
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Tiffany Lam
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Ji-Young Kim
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Tae Hoon Kim
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Michael Q Zhang
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Gregory Dussor
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
| | - Theodore J Price
- School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, TX, USA
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12
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Monteiro LF, Ferruzo PYM, Russo LC, Farias JO, Forti FL. DUSP3/VHR: A Druggable Dual Phosphatase for Human Diseases. Rev Physiol Biochem Pharmacol 2018; 176:1-35. [PMID: 30069819 DOI: 10.1007/112_2018_12] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Protein tyrosine kinases (PTK), discovered in the 1970s, have been considered master regulators of biological processes with high clinical significance as targets for human diseases. Their actions are countered by protein tyrosine phosphatases (PTP), enzymes yet underrepresented as drug targets because of the high homology of their catalytic domains and high charge of their catalytic pocket. This scenario is still worse for some PTP subclasses, for example, for the atypical dual-specificity phosphatases (ADUSPs), whose biological functions are not even completely known. In this sense, the present work focuses on the dual-specificity phosphatase 3 (DUSP3), also known as VH1-related phosphatase (VHR), an uncommon regulator of mitogen-activated protein kinase (MAPK) phosphorylation. DUSP3 expression and activities are suggestive of a tumor suppressor or tumor-promoting enzyme in different types of human cancers. Furthermore, DUSP3 has other biological functions involving immune response mediation, thrombosis, hemostasis, angiogenesis, and genomic stability that occur through either MAPK-dependent or MAPK-independent mechanisms. This broad spectrum of actions is likely due to the large substrate diversity and molecular mechanisms that are still under scrutiny. The growing advances in characterizing new DUSP3 substrates will allow the development of pharmacological inhibitors relevant for possible future clinical trials. This review covers all aspects of DUSP3, since its gene cloning and crystallographic structure resolution, in addition to its classical and novel substrates and the biological processes involved, followed by an update of what is currently known about the DUSP3/VHR-inhibiting compounds that might be considered potential drugs to treat human diseases.
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Affiliation(s)
- Lucas Falcão Monteiro
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, Brazil
| | | | - Lilian Cristina Russo
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, Brazil
| | - Jessica Oliveira Farias
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, Brazil
| | - Fábio Luís Forti
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, Brazil.
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Hamada N, Mizuno M, Tomita H, Iwamoto I, Hara A, Nagata KI. Expression analyses of Dusp22 (Dual-specificity phosphatase 22) in mouse tissues. Med Mol Morphol 2017; 51:111-117. [PMID: 29282540 DOI: 10.1007/s00795-017-0178-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 12/21/2017] [Indexed: 12/25/2022]
Abstract
Dusp22 (dual-specificity phosphatase 22) is considered to regulate various cellular processes through the regulation of protein dephosphorylation. In this study, we prepared a specific antibody against Dusp22, anti-Dusp22, and carried out expression analyses with mouse tissues and cultured cell lines. Western blotting analyses demonstrated a tissue-dependent expression profile of Dusp22 in the adult mouse, and strongly suggested the presence of isoforms with larger molecular masses. In fibroblast NIH3T3 cells, while both endogenous and Myc-tagged Dusp22 was diffusely distributed in the cytoplasm, Myc-Dusp22 was partially colocalized with actin cytoskeleton. From the obtained results, anti-Dusp22 was found to be a useful tool for biochemical and cell biological analyses of Dusp22.
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Affiliation(s)
- Nanako Hamada
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center, 713-8 Kamiya, Kasugai, 480-0392, Japan
| | - Makoto Mizuno
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center, 713-8 Kamiya, Kasugai, 480-0392, Japan
| | - Hiroyuki Tomita
- Department of Tumor Pathology, Gifu University Graduate School of Medicine, Gifu, 501-1194, Japan
| | - Ikuko Iwamoto
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center, 713-8 Kamiya, Kasugai, 480-0392, Japan
| | - Akira Hara
- Department of Tumor Pathology, Gifu University Graduate School of Medicine, Gifu, 501-1194, Japan
| | - Koh-Ichi Nagata
- Department of Molecular Neurobiology, Institute for Developmental Research, Aichi Human Service Center, 713-8 Kamiya, Kasugai, 480-0392, Japan.
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Meeusen B, Janssens V. Tumor suppressive protein phosphatases in human cancer: Emerging targets for therapeutic intervention and tumor stratification. Int J Biochem Cell Biol 2017; 96:98-134. [PMID: 29031806 DOI: 10.1016/j.biocel.2017.10.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 10/04/2017] [Accepted: 10/05/2017] [Indexed: 02/06/2023]
Abstract
Aberrant protein phosphorylation is one of the hallmarks of cancer cells, and in many cases a prerequisite to sustain tumor development and progression. Like protein kinases, protein phosphatases are key regulators of cell signaling. However, their contribution to aberrant signaling in cancer cells is overall less well appreciated, and therefore, their clinical potential remains largely unexploited. In this review, we provide an overview of tumor suppressive protein phosphatases in human cancer. Along their mechanisms of inactivation in defined cancer contexts, we give an overview of their functional roles in diverse signaling pathways that contribute to their tumor suppressive abilities. Finally, we discuss their emerging roles as predictive or prognostic markers, their potential as synthetic lethality targets, and the current feasibility of their reactivation with pharmacologic compounds as promising new cancer therapies. We conclude that their inclusion in clinical practice has obvious potential to significantly improve therapeutic outcome in various ways, and should now definitely be pushed forward.
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Affiliation(s)
- Bob Meeusen
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, Faculty of Medicine, KU Leuven & Leuven Cancer Institute (LKI), KU Leuven, Belgium
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation & Proteomics, Dept. of Cellular & Molecular Medicine, Faculty of Medicine, KU Leuven & Leuven Cancer Institute (LKI), KU Leuven, Belgium.
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Shah M, Smolko CM, Kinicki S, Chapman ZD, Brautigan DL, Janes KA. Profiling Subcellular Protein Phosphatase Responses to Coxsackievirus B3 Infection of Cardiomyocytes. Mol Cell Proteomics 2017; 16:S244-S262. [PMID: 28174228 DOI: 10.1074/mcp.o116.063487] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 01/31/2017] [Indexed: 01/23/2023] Open
Abstract
Cellular responses to stimuli involve dynamic and localized changes in protein kinases and phosphatases. Here, we report a generalized functional assay for high-throughput profiling of multiple protein phosphatases with subcellular resolution and apply it to analyze coxsackievirus B3 (CVB3) infection counteracted by interferon signaling. Using on-plate cell fractionation optimized for adherent cells, we isolate protein extracts containing active endogenous phosphatases from cell membranes, the cytoplasm, and the nucleus. The extracts contain all major classes of protein phosphatases and catalyze dephosphorylation of plate-bound phosphosubstrates in a microtiter format, with cellular activity quantified at the end point by phosphospecific ELISA. The platform is optimized for six phosphosubstrates (ERK2, JNK1, p38α, MK2, CREB, and STAT1) and measures specific activities from extracts of fewer than 50,000 cells. The assay was exploited to examine viral and antiviral signaling in AC16 cardiomyocytes, which we show can be engineered to serve as susceptible and permissive hosts for CVB3. Phosphatase responses were profiled in these cells by completing a full-factorial experiment for CVB3 infection and type I/II interferon signaling. Over 850 functional measurements revealed several independent, subcellular changes in specific phosphatase activities. During CVB3 infection, we found that type I interferon signaling increases subcellular JNK1 phosphatase activity, inhibiting nuclear JNK1 activity that otherwise promotes viral protein synthesis in the infected host cell. Our assay provides a high-throughput way to capture perturbations in important negative regulators of intracellular signal-transduction networks.
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Affiliation(s)
- Millie Shah
- From the ‡Department of Biomedical Engineering
| | | | | | | | - David L Brautigan
- the ‖Center for Cell Signaling and Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, Charlottesville, Virginia 22908
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Ju A, Cho YC, Kim BR, Park SG, Kim JH, Kim K, Lee J, Park BC, Cho S. Scaffold Role of DUSP22 in ASK1-MKK7-JNK Signaling Pathway. PLoS One 2016; 11:e0164259. [PMID: 27711255 PMCID: PMC5053508 DOI: 10.1371/journal.pone.0164259] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Accepted: 09/22/2016] [Indexed: 02/08/2023] Open
Abstract
Mitogen-activated protein kinases (MAPKs) are involved in a variety of intracellular events such as gene expression, cell proliferation, and programmed cell death. MAPKs are activated by dual phosphorylation on threonine and tyrosine residues through sequential activation of protein kinases. Recent studies have shown that the protein kinases involved in MAPK signal transductions might be organized into signaling complexes by scaffold proteins. These scaffold proteins are essential regulators that function by assembling the relevant molecular components in mammalian cells. In this study, we report that dual-specificity phosphatase 22 (DUSP22), a member of the protein tyrosine phosphatase family, acts as a distinct scaffold protein in c-Jun N-terminal kinase (JNK) signaling. DUSP22 increased the phosphorylation in the activation loop of JNK regardless of its phosphatase activity but had no effect on phosphorylation levels of ERK and p38 in mammalian cells. Furthermore, DUSP22 selectively associated with apoptosis signal-regulating kinase 1 (ASK1), MAPK kinase 7 (MKK7), and JNK1/2. Both JNK phosphorylation and JNK-mediated apoptosis increased in a concentration-dependent manner regardless of DUSP22 phosphatase activity at low DUSP22 concentrations, but then decreased at higher DUSP22 concentrations, which is the prominent feature of a scaffold protein. Thus, our data suggest that DUSP22 regulates cell death by acting as a scaffold protein for the ASK1-MKK7-JNK signal transduction pathway independently of its phosphatase activity.
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Affiliation(s)
- Anna Ju
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Young-Chang Cho
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Ba Reum Kim
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Sung Goo Park
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
| | - Jeong-Hoon Kim
- Personalized Genomic Medicine Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
| | - Kwonseop Kim
- College of Pharmacy and Research Institute for Drug Development, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Jaehwi Lee
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Byoung Chul Park
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 34141, Republic of Korea
- * E-mail: (SC); (BP)
| | - Sayeon Cho
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Republic of Korea
- * E-mail: (SC); (BP)
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Do very small adipocytes in subcutaneous adipose tissue (a proposed risk factor for insulin insensitivity) have a fetal origin? CLINICAL NUTRITION EXPERIMENTAL 2016. [DOI: 10.1016/j.yclnex.2016.05.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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RPM-1 uses both ubiquitin ligase and phosphatase-based mechanisms to regulate DLK-1 during neuronal development. PLoS Genet 2014; 10:e1004297. [PMID: 24810406 PMCID: PMC4014440 DOI: 10.1371/journal.pgen.1004297] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 02/21/2014] [Indexed: 01/06/2023] Open
Abstract
The Pam/Highwire/RPM-1 (PHR) proteins are key regulators of neuronal development that function in axon extension and guidance, termination of axon outgrowth, and synapse formation. Outside of development, the PHR proteins also regulate axon regeneration and Wallerian degeneration. The PHR proteins function in part by acting as ubiquitin ligases that degrade the Dual Leucine zipper-bearing Kinase (DLK). Here, we show that the Caenorhabditis elegans PHR protein, Regulator of Presynaptic Morphology 1 (RPM-1), also utilizes a phosphatase-based mechanism to regulate DLK-1. Using mass spectrometry, we identified Protein Phosphatase Magnesium/Manganese dependent 2 (PPM-2) as a novel RPM-1 binding protein. Genetic, transgenic, and biochemical studies indicated that PPM-2 functions coordinately with the ubiquitin ligase activity of RPM-1 and the F-box protein FSN-1 to negatively regulate DLK-1. PPM-2 acts on S874 of DLK-1, a residue implicated in regulation of DLK-1 binding to a short, inhibitory isoform of DLK-1 (DLK-1S). Our study demonstrates that PHR proteins function through both phosphatase and ubiquitin ligase mechanisms to inhibit DLK. Thus, PHR proteins are potentially more accurate and sensitive regulators of DLK than originally thought. Our results also highlight an important and expanding role for the PP2C phosphatase family in neuronal development. The molecular mechanisms that govern formation of functional synaptic connections are central to brain development and function. We have used the nematode C. elegans to explore the mechanism of how the intracellular signaling protein RPM-1 regulates neuronal development. Using a combination of proteomic, genetic, transgenic, and biochemical approaches we have shown that RPM-1 functions through a PP2C phosphatase, PPM-2, to regulate the activity of a MAP3 kinase, DLK-1. Our results indicate that a combination of PPM-2 phosphatase activity and RPM-1 ubiquitin ligase activity inhibit DLK-1.
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Tonks NK. Protein tyrosine phosphatases--from housekeeping enzymes to master regulators of signal transduction. FEBS J 2013; 280:346-78. [PMID: 23176256 DOI: 10.1111/febs.12077] [Citation(s) in RCA: 338] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 11/13/2012] [Accepted: 11/15/2012] [Indexed: 12/12/2022]
Abstract
There are many misconceptions surrounding the roles of protein phosphatases in the regulation of signal transduction, perhaps the most damaging of which is the erroneous view that these enzymes exert their effects merely as constitutively active housekeeping enzymes. On the contrary, the phosphatases are critical, specific regulators of signalling in their own right and serve an essential function, in a coordinated manner with the kinases, to determine the response to a physiological stimulus. This review is a personal perspective on the development of our understanding of the protein tyrosine phosphatase family of enzymes. I have discussed various aspects of the structure, regulation and function of the protein tyrosine phosphatase family, which I hope will illustrate the fundamental importance of these enzymes in the control of signal transduction.
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Affiliation(s)
- Nicholas K Tonks
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724-2208, USA.
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Zhu J, Shen W, Gao L, Gu H, Shen S, Wang Y, Wu H, Guo J. PI3K/Akt-independent negative regulation of JNK signaling by MKP-7 after cerebral ischemia in rat hippocampus. BMC Neurosci 2013; 14:1. [PMID: 23280045 PMCID: PMC3583678 DOI: 10.1186/1471-2202-14-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 12/26/2012] [Indexed: 01/26/2023] Open
Abstract
Background The inactivation of c-Jun N-terminal kinase (JNK) is associated with anti-apoptotic and anti-inflammatory effects in cerebral ischemia, which can be induced by an imbalance between upstream phosphatases and kinases. Result Mitogen-activated protein kinase phosphatase 7 (MKP-7) was upregulated significantly at 4 h of reperfusion postischemia in rat hippocampi. By administration of cycloheximide or siRNA against mitogen-activated protein kinase phosphatase 7 (MKP-7) in a rat model of ischemia/reperfusion, an obvious enhancement of JNK activity was observed in 4 h of reperfusion following ischemia, suggesting MKP-7 was involved in JNK inactivation after ischemia. The subcellular localization of MKP-7 altered after ischemia, and the inhibition of MKP-7 nuclear export by Leptomycin B up-regulated JNK activity. Although PI3K/Akt inhibition could block downregulation of JNK activity through SEK1 and MKK-7 activation, PI3K/Akt activity was not associated with the regulation of JNK by MKP-7. Conclusions MKP-7, independently of PI3K/Akt pathway, played a key role in downregulation of JNK activity after ischemia in the rat hippocampus, and the export of MKP-7 from the nucleus was involved in downregulation of cytoplasmic JNK activity in response to ischemic stimuli.
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Affiliation(s)
- JianXi Zhu
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, Nanjing, 210029, People's Republic of China
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Ju AN, Cho SY. Inhibition of Dual-specificity Phosphatase 22 (DUSP22) by PRL-3 inhibitor I. B KOREAN CHEM SOC 2012. [DOI: 10.5012/bkcs.2012.33.9.3142] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Schmidt F, van den Eijnden M, Pescini Gobert R, Saborio GP, Carboni S, Alliod C, Pouly S, Staugaitis SM, Dutta R, Trapp B, Hooft van Huijsduijnen R. Identification of VHY/Dusp15 as a regulator of oligodendrocyte differentiation through a systematic genomics approach. PLoS One 2012; 7:e40457. [PMID: 22792334 PMCID: PMC3394735 DOI: 10.1371/journal.pone.0040457] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 06/07/2012] [Indexed: 12/20/2022] Open
Abstract
Multiple sclerosis (MS) is a neuroinflammatory disease characterized by a progressive loss of myelin and a failure of oligodendrocyte (OL)-mediated remyelination, particularly in the progressive phases of the disease. An improved understanding of the signaling mechanisms that control differentiation of OL precursors may lead to the identification of new therapeutic targets for remyelination in MS. About 100 mammalian Protein Tyrosine Phosphatases (PTPs) are known, many of which are involved in signaling both in health and disease. We have undertaken a systematic genomic approach to evaluate PTP gene activity in multiple sclerosis autopsies and in related in vivo and in vitro models of the disease. This effort led to the identification of Dusp15/VHY, a PTP previously believed to be expressed only in testis, as being transcriptionally regulated during OL differentiation and in MS lesions. Subsequent RNA interference studies revealed that Dusp15/VHY is a key regulator of OL differentiation. Finally, we identified PDGFR-beta and SNX6 as novel and specific Dusp15 substrates, providing an indication as to how this PTP might exert control over OL differentiation.
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