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Liu J, Yin Y, Ni J, Zhang P, Li WM, Liu Z. Dual Specific Phosphatase 7 Exacerbates Dilated Cardiomyopathy, Heart Failure, and Cardiac Death by Inactivating the ERK1/2 Signaling Pathway. J Cardiovasc Transl Res 2022; 15:1219-1238. [PMID: 35596107 DOI: 10.1007/s12265-022-10268-3] [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: 03/06/2022] [Accepted: 04/25/2022] [Indexed: 12/16/2022]
Abstract
Heart failure is one of the most common but complicated end-stage syndromes in clinical practice. Dilated cardiomyopathy is a myocardial structural abnormality that is associated with heart failure. Dual-specificity phosphatases (DUSPs) are a group of protein phosphatases that regulate signaling pathways in numerous diseases; however, their physiological and pathological impact on cardiovascular disease remains unknown. In the present study, we generated two transgenic mouse models, a DUSP7 knockout and a cardiac-specific DUSP7 overexpressor. Mice overexpressing DUSP7 showed an exacerbated disease phenotype, including severe dilated cardiomyopathy, heart failure, and cardiac death. We further demonstrated that high levels of DUSP7 inhibited ERK1/2 phosphorylation and influenced downstream c-MYC, c-FOS, and c-JUN gene expression but did not affect upstream activators. Taken together, our study reveals a novel molecular mechanism for DUSP7 and provides a new therapeutic target and clinical path to alleviate dilated cardiomyopathy and improve cardiac function.
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Affiliation(s)
- Jing Liu
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yihen Yin
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
- Heart, Lung, and Blood Center, Pan-Vascular Research Institute, Tongji University School of Medicine, Shanghai, China
| | - Jing Ni
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Peiyu Zhang
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Wei-Ming Li
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
- Heart, Lung, and Blood Center, Pan-Vascular Research Institute, Tongji University School of Medicine, Shanghai, China.
| | - Zheng Liu
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
- Heart, Lung, and Blood Center, Pan-Vascular Research Institute, Tongji University School of Medicine, Shanghai, China.
- Cryo-electron Microscopy Center, Southern University of Science and Technology, Guangdong Province, Shenzhen, China.
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2
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Thompson EM, Stoker AW. A Review of DUSP26: Structure, Regulation and Relevance in Human Disease. Int J Mol Sci 2021; 22:ijms22020776. [PMID: 33466673 PMCID: PMC7828806 DOI: 10.3390/ijms22020776] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/05/2021] [Accepted: 01/08/2021] [Indexed: 01/10/2023] Open
Abstract
Dual specificity phosphatases (DUSPs) play a crucial role in the regulation of intracellular signalling pathways, which in turn influence a broad range of physiological processes. DUSP malfunction is increasingly observed in a broad range of human diseases due to deregulation of key pathways, most notably the MAP kinase (MAPK) cascades. Dual specificity phosphatase 26 (DUSP26) is an atypical DUSP with a range of physiological substrates including the MAPKs. The residues that govern DUSP26 substrate specificity are yet to be determined; however, recent evidence suggests that interactions with a binding partner may be required for DUSP26 catalytic activity. DUSP26 is heavily implicated in cancer where, akin to other DUSPs, it displays both tumour-suppressive and -promoting properties, depending on the context. Here we review DUSP26 by evaluating its transcriptional patterns, protein crystallographic structure and substrate binding, as well as its physiological role(s) and binding partners, its role in human disease and the development of DUSP26 inhibitors.
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Phosphorylation Dynamics of JNK Signaling: Effects of Dual-Specificity Phosphatases (DUSPs) on the JNK Pathway. Int J Mol Sci 2019; 20:ijms20246157. [PMID: 31817617 PMCID: PMC6941053 DOI: 10.3390/ijms20246157] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/30/2019] [Accepted: 12/04/2019] [Indexed: 02/06/2023] Open
Abstract
Protein phosphorylation affects conformational change, interaction, catalytic activity, and subcellular localization of proteins. Because the post-modification of proteins regulates diverse cellular signaling pathways, the precise control of phosphorylation states is essential for maintaining cellular homeostasis. Kinases function as phosphorylating enzymes, and phosphatases dephosphorylate their target substrates, typically in a much shorter time. The c-Jun N-terminal kinase (JNK) signaling pathway, a mitogen-activated protein kinase pathway, is regulated by a cascade of kinases and in turn regulates other physiological processes, such as cell differentiation, apoptosis, neuronal functions, and embryonic development. However, the activation of the JNK pathway is also implicated in human pathologies such as cancer, neurodegenerative diseases, and inflammatory diseases. Therefore, the proper balance between activation and inactivation of the JNK pathway needs to be tightly regulated. Dual specificity phosphatases (DUSPs) regulate the magnitude and duration of signal transduction of the JNK pathway by dephosphorylating their substrates. In this review, we will discuss the dynamics of phosphorylation/dephosphorylation, the mechanism of JNK pathway regulation by DUSPs, and the new possibilities of targeting DUSPs in JNK-related diseases elucidated in recent studies.
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Nunes-Xavier CE, Zaldumbide L, Aurtenetxe O, López-Almaraz R, López JI, Pulido R. Dual-Specificity Phosphatases in Neuroblastoma Cell Growth and Differentiation. Int J Mol Sci 2019; 20:ijms20051170. [PMID: 30866462 PMCID: PMC6429076 DOI: 10.3390/ijms20051170] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 03/01/2019] [Accepted: 03/01/2019] [Indexed: 12/19/2022] Open
Abstract
Dual-specificity phosphatases (DUSPs) are important regulators of neuronal cell growth and differentiation by targeting proteins essential to neuronal survival in signaling pathways, among which the MAP kinases (MAPKs) stand out. DUSPs include the MAPK phosphatases (MKPs), a family of enzymes that directly dephosphorylate MAPKs, as well as the small-size atypical DUSPs, a group of low molecular-weight enzymes which display more heterogeneous substrate specificity. Neuroblastoma (NB) is a malignancy intimately associated with the course of neuronal and neuroendocrine cell differentiation, and constitutes the source of more common extracranial solid pediatric tumors. Here, we review the current knowledge on the involvement of MKPs and small-size atypical DUSPs in NB cell growth and differentiation, and discuss the potential of DUSPs as predictive biomarkers and therapeutic targets in human NB.
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Affiliation(s)
- Caroline E Nunes-Xavier
- Biomarkers in Cancer Unit, Biocruces-Bizkaia Health Research Institute, Barakaldo, Bizkaia 48903, Spain.
- Department of Tumor Biology, Institute for Cancer Research, Oslo University Hospital HF Radiumhospitalet, Oslo 0424, Norway.
| | - Laura Zaldumbide
- Department of Pathology, Cruces University Hospital, University of the Basque Country (UPV/EHU), Barakaldo, Bizkaia 48903, Spain.
| | - Olaia Aurtenetxe
- Biomarkers in Cancer Unit, Biocruces-Bizkaia Health Research Institute, Barakaldo, Bizkaia 48903, Spain.
| | - Ricardo López-Almaraz
- Pediatric Oncology and Hematology, Cruces University Hospital, Barakaldo, Bizkaia 48903, Spain.
| | - José I López
- Biomarkers in Cancer Unit, Biocruces-Bizkaia Health Research Institute, Barakaldo, Bizkaia 48903, Spain.
- Department of Pathology, Cruces University Hospital, University of the Basque Country (UPV/EHU), Barakaldo, Bizkaia 48903, Spain.
| | - Rafael Pulido
- Biomarkers in Cancer Unit, Biocruces-Bizkaia Health Research Institute, Barakaldo, Bizkaia 48903, Spain.
- IKERBASQUE, Basque Foundation for Science, Bilbao 48011, Spain.
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5
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Buiga P, Elson A, Tabernero L, Schwartz JM. Regulation of dual specificity phosphatases in breast cancer during initial treatment with Herceptin: a Boolean model analysis. BMC SYSTEMS BIOLOGY 2018; 12:11. [PMID: 29671404 PMCID: PMC5907139 DOI: 10.1186/s12918-018-0534-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Background 25% of breast cancer patients suffer from aggressive HER2-positive tumours that are characterised by overexpression of the HER2 protein or by its increased tyrosine kinase activity. Herceptin is a major drug used to treat HER2 positive breast cancer. Understanding the molecular events that occur when breast cancer cells are exposed to Herceptin is therefore of significant importance. Dual specificity phosphatases (DUSPs) are central regulators of cell signalling that function downstream of HER2, but their role in the cellular response to Herceptin is mostly unknown. This study aims to model the initial effects of Herceptin exposure on DUSPs in HER2-positive breast cancer cells using Boolean modelling. Results We experimentally measured expression time courses of 21 different DUSPs between 0 and 24 h following Herceptin treatment of human MDA-MB-453 HER2-positive breast cancer cells. We clustered these time courses into patterns of similar dynamics over time. In parallel, we built a series of Boolean models representing the known regulatory mechanisms of DUSPs and then demonstrated that the dynamics predicted by the models is in agreement with the experimental data. Furthermore, we used the models to predict regulatory mechanisms of DUSPs, where these mechanisms were partially known. Conclusions Boolean modelling is a powerful technique to investigate and understand signalling pathways. We obtained an understanding of different regulatory pathways in breast cancer and new insights on how these signalling pathways are activated. This method can be generalized to other drugs and longer time courses to better understand how resistance to drugs develops in cancer cells over time. Electronic supplementary material The online version of this article (10.1186/s12918-018-0534-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Petronela Buiga
- Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, Israel.,School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Ari Elson
- Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot, Israel
| | - Lydia Tabernero
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Jean-Marc Schwartz
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
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Ku B, Hong W, Keum CW, Kim M, Ryu H, Jeon D, Shin HC, Kim JH, Kim SJ, Ryu SE. Structural and biochemical analysis of atypically low dephosphorylating activity of human dual-specificity phosphatase 28. PLoS One 2017; 12:e0187701. [PMID: 29121083 PMCID: PMC5679558 DOI: 10.1371/journal.pone.0187701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 10/24/2017] [Indexed: 12/20/2022] Open
Abstract
Dual-specificity phosphatases (DUSPs) constitute a subfamily of protein tyrosine phosphatases, and are intimately involved in the regulation of diverse parameters of cellular signaling and essential biological processes. DUSP28 is one of the DUSP subfamily members that is known to be implicated in the progression of hepatocellular and pancreatic cancers, and its biological functions and enzymatic characteristics are mostly unknown. Herein, we present the crystal structure of human DUSP28 determined to 2.1 Å resolution. DUSP28 adopts a typical DUSP fold, which is composed of a central β-sheet covered by α-helices on both sides and contains a well-ordered activation loop, as do other enzymatically active DUSP proteins. The catalytic pocket of DUSP28, however, appears hardly accessible to a substrate because of the presence of nonconserved bulky residues in the protein tyrosine phosphatase signature motif. Accordingly, DUSP28 showed an atypically low phosphatase activity in the biochemical assay, which was remarkably improved by mutations of two nonconserved residues in the activation loop. Overall, this work reports the structural and biochemical basis for understanding a putative oncological therapeutic target, DUSP28, and also provides a unique mechanism for the regulation of enzymatic activity in the DUSP subfamily proteins.
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Affiliation(s)
- Bonsu Ku
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
- Department of Bioscience, University of Science and Technology KRIBB School, Daejeon, Republic of Korea
| | - Won Hong
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Republic of Korea
| | - Chae Won Keum
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
- Department of Bioscience, University of Science and Technology KRIBB School, Daejeon, Republic of Korea
| | - Myeongbin Kim
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Republic of Korea
| | - Hyunyeol Ryu
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Republic of Korea
| | - Donghwan Jeon
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Republic of Korea
| | - Ho-Chul Shin
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
| | - Jae Hoon Kim
- Department of Biotechnology, College of Applied Life Science, SARI, Jeju National University, Jeju-do, Republic of Korea
| | - Seung Jun Kim
- Disease Target Structure Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea
- Department of Bioscience, University of Science and Technology KRIBB School, Daejeon, Republic of Korea
- * E-mail: (SJK); (SER)
| | - Seong Eon Ryu
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Republic of Korea
- * E-mail: (SJK); (SER)
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Moon J, Ha J, Park SH. Identification of PTPN1 as a novel negative regulator of the JNK MAPK pathway using a synthetic screening for pathway-specific phosphatases. Sci Rep 2017; 7:12974. [PMID: 29021559 PMCID: PMC5636874 DOI: 10.1038/s41598-017-13494-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 09/25/2017] [Indexed: 12/19/2022] Open
Abstract
The mitogen activated protein kinase (MAPK) signaling cascades transmit extracellular stimulations to generate various cellular responses via the sequential and reversible phosphorylation of kinases. Since the strength and duration of kinase phosphorylation within the pathway determine the cellular response, both kinases and phosphatases play an essential role in the precise control of MAPK pathway activation and attenuation. Thus, the identification of pathway-specific phosphatases is critical for understanding the functional mechanisms by which the MAPK pathway is regulated. To identify phosphatases specific to the c-Jun N-terminal kinase (JNK) MAPK pathway, a synthetic screening approach was utilized in which phosphatases were individually tethered to the JNK pathway specific-JIP1 scaffold protein. Of 77 mammalian phosphatases tested, PTPN1 led to the inhibition of JNK pathway activation. Further analyses revealed that of three pathway member kinases, PTPN1 directly dephosphorylates JNK, the terminal kinase of the pathway, and negatively regulates the JNK MAPK pathway. Specifically, PTPN1 appears to regulate the overall signaling magnitude, rather than the adaptation timing, suggesting that PTPN1 might be involved in the control and maintenance of signaling noise. Finally, the negative regulation of the JNK MAPK pathway by PTPN1 was found to reduce the tumor necrosis factor α (TNFα)-dependent cell death response.
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Affiliation(s)
- Jiyoung Moon
- Department of Biological Sciences, Seoul National University, Seoul, 08826, Korea
| | - Jain Ha
- Department of Biological Sciences, Seoul National University, Seoul, 08826, Korea
| | - Sang-Hyun Park
- Department of Biological Sciences, Seoul National University, Seoul, 08826, Korea.
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Ren JX, Cheng Z, Huang YX, Zhao JF, Guo P, Zou ZM, Xie Y. Identification of novel dual-specificity phosphatase 26 inhibitors by a hybrid virtual screening approach based on pharmacophore and molecular docking. Biomed Pharmacother 2017; 89:376-385. [PMID: 28249240 DOI: 10.1016/j.biopha.2017.02.064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 01/31/2017] [Indexed: 10/20/2022] Open
Abstract
Dual-specificity phosphatase 26 (DUSP26) has recently emerged as a target for treatment of human cancers. However, only two small-molecule inhibitors of DUSP26 are known so far, namely NSC-87877 and ethyl-3, 4-dephostatin. DUSP26 contains an N-terminal region (residues 1-60) and a conserved C-terminal catalytic domain (residues 61-211, DUSP26-C). The crystal structure of DUSP26-C, showing a catalytically inactive conformation of the active site, was reported in a previous study. However, the detailed catalytic mechanism of DUSP26 cannot be described based on that structure. In this study, the 3D structure of DUSP26 (residues 42-211) adopting catalytically active conformation, was built by homology modeling, and the established 3D structure was validated using enzyme kinetic assays. Pharmacophore modeling based on the validated 3D structure of human DUSP26 was carried out. The established pharmacophore model was considered as a 3D query for retrieving novel DUSP26 inhibitors from the chemical databases "Diversity Libraries" (129,087 compounds). Next, a docking study was performed to refine the obtained hit compounds. Then a total of 100 compounds were selected based on the ranking order and visual examination, which were then evaluated by an enzyme-based assay. Eight compounds were found to have inhibitory activities against DUSP26, and the most potent compound was assigned No. F1063-0967 with an IC50 value of 11.62μM. The inhibitory activity of F1063-0967 against DUSP26 is higher than that of NCS87877 (IC50 value: 16.67±2.89μM), but lower than that of ethyl-3, 4-dephostatin (IC50 value: 6.8±0.41μM). MTT assay results revealed that F1063-0967 can induce apoptosis in IMR-32 cell line with an IC50 value of 4.13μM. These results suggest that F1063-0967 should be investigated further for other pharmacological properties.
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Affiliation(s)
- Ji-Xia Ren
- Institute of Medicinal Plant Development, Chinese Academy of Medical Science & Peking Union Medical College, 151 Malianwa North Road, Haidian District, Beijing 100193, China,; College of Life Science, Liaocheng University, Liaocheng 252059, Shandong, China
| | - Zhong Cheng
- Department of Biochemistry and Molecular Biology, Ministry of Education Key Laboratory of Cellular Physiology, Shanxi University, Taiyuan 030001, Shanxi, China
| | - Yu-Xin Huang
- Institute of Medicinal Plant Development, Chinese Academy of Medical Science & Peking Union Medical College, 151 Malianwa North Road, Haidian District, Beijing 100193, China
| | - Jing-Feng Zhao
- Institute of Medicinal Plant Development, Chinese Academy of Medical Science & Peking Union Medical College, 151 Malianwa North Road, Haidian District, Beijing 100193, China
| | - Peng Guo
- Institute of Medicinal Plant Development, Chinese Academy of Medical Science & Peking Union Medical College, 151 Malianwa North Road, Haidian District, Beijing 100193, China
| | - Zhong-Mei Zou
- Institute of Medicinal Plant Development, Chinese Academy of Medical Science & Peking Union Medical College, 151 Malianwa North Road, Haidian District, Beijing 100193, China
| | - Yong Xie
- Institute of Medicinal Plant Development, Chinese Academy of Medical Science & Peking Union Medical College, 151 Malianwa North Road, Haidian District, Beijing 100193, China,.
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Balada E, Felip L, Ordi-Ros J, Vilardell-Tarrés M. DUSP23 is over-expressed and linked to the expression of DNMTs in CD4 + T cells from systemic lupus erythematosus patients. Clin Exp Immunol 2016; 187:242-250. [PMID: 27737517 DOI: 10.1111/cei.12883] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/07/2016] [Indexed: 12/17/2022] Open
Abstract
We evaluated the transcriptional expression of dual-specificity protein phosphatase 23 (DUSP23) in CD4+ T cells from 30 systemic lupus erythematosus (SLE) patients and 30 healthy controls. DUSP23 mRNA levels were considerably higher in the patient group: 1490 ± 1713 versus 294·1 ± 204·2. No association was found between DUSP23 mRNA expression and the presence of typical serological and clinical parameters associated with SLE. Meaningful statistical values were obtained in the patient group between the levels of DUSP23 and integrin subunit alpha L (ITGAL), perforin 1 (PRF1) and CD40L. Similarly, transcript levels of different DNA methylation-related enzymes [DNA methylation-related enzymes (DNMT1, DNMT3A, DNMT3B, MBD2, and MBD4)] were also correlated positively with the expression of DUSP23. In an attempt to counteract the hypomethylation status of the promoters of certain genes known to be over-expressed in SLE, it is possible that DUSP23 acts as a negative regulatory mechanism which ultimately silences the transcription of these epigenetically regulated genes by triggering an increase in the expression of different DNMTs.
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Affiliation(s)
- E Balada
- Research Unit in Systemic Autoimmune Diseases, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - L Felip
- Research Unit in Systemic Autoimmune Diseases, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - J Ordi-Ros
- Research Unit in Systemic Autoimmune Diseases, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - M Vilardell-Tarrés
- Research Unit in Systemic Autoimmune Diseases, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
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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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11
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Kim SY, Oh M, Lee KS, Kim WK, Oh KJ, Lee SC, Bae KH, Han BS. Profiling analysis of protein tyrosine phosphatases during neuronal differentiation. Neurosci Lett 2015; 612:219-224. [PMID: 26704437 DOI: 10.1016/j.neulet.2015.12.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 12/07/2015] [Accepted: 12/11/2015] [Indexed: 10/22/2022]
Abstract
During neuronal differentiation, it is generally accepted that many kinases and phosphatases fulfill different roles. In this study, phospho-tyrosine phosphatases were focused on and their expression profiling was evaluated during neuronal differentiation of mouse J1 embryonic stem cells. Among 83 phospho-tyrosine phosphatases, expressions of 21 PTPs were increased but mRNA expressions of 10 PTPs decreased depending on the differentiation. We checked the protein expression patterns for the cases where PTPs mRNA expressions changed. Some of them showed consistent results with the mRNA expressions. In particular, it was found that dual-specific phosphatase23 (DUSP23) affected neuronal differentiation. The knock-down of DUSP23 decreased neuronal differentiation in terms of neuronal outgrowth and the expression of neuronal marker proteins and mRNAs. Taken together, the obtained results show that many PTPs play specific roles during neuronal differentiation and manipulating their activities by activators or inhibitors could adjust neuronal differentiation.
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Affiliation(s)
- Sun Young Kim
- Functional Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea
| | - Mihee Oh
- Functional Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea
| | - Kyu-Suk Lee
- Functional Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea
| | - Won-Kon Kim
- Functional Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea; Department of Functional Genomics, University of Science and Technology (UST) of Korea, Daejeon, Republic of Korea
| | - Kyoung-Jin Oh
- Functional Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea
| | - Sang Chul Lee
- Functional Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea; Department of Functional Genomics, University of Science and Technology (UST) of Korea, Daejeon, Republic of Korea
| | - Kwang-Hee Bae
- Functional Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea; Department of Functional Genomics, University of Science and Technology (UST) of Korea, Daejeon, Republic of Korea
| | - Baek-Soo Han
- Functional Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea; Department of Functional Genomics, University of Science and Technology (UST) of Korea, Daejeon, Republic of Korea.
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12
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Oppong E, Flink N, Cato ACB. Molecular mechanisms of glucocorticoid action in mast cells. Mol Cell Endocrinol 2013; 380:119-26. [PMID: 23707629 DOI: 10.1016/j.mce.2013.05.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 05/13/2013] [Indexed: 01/07/2023]
Abstract
Glucocorticoids are compounds that have successfully been used over the years in the treatment of inflammatory disorders. They are known to exhibit their effects through the glucocorticoid receptor (GR) that acts to downregulate the action of proinflammatory transcription factors such as AP-1 and NF-κB. The GR also exerts anti-inflammatory effects through activation of distinct genes. In addition to their anti-inflammatory actions, glucocorticoids are also potent antiallergic compounds that are widely used in conditions such as asthma and anaphylaxis. Nevertheless the mechanism of action of this hormone in these disorders is not known. In this article, we have reviewed reports on the effects of glucocorticoids in mast cells, one of the important immune cells in allergy. Building on the knowledge of the molecular action of glucocorticoids and the GR in the treatment of inflammation in other cell types, we have made suggestions as to the likely mechanisms of action of glucocorticoids in mast cells. We have further identified some important questions and research directions that need to be addressed in future studies to improve the treatment of allergic disorders.
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Affiliation(s)
- Emmanuel Oppong
- Karlsruhe Institute of Technology, Institute of Toxicology and Genetics, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
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13
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Kuznetsov VI, Hengge AC. New functional aspects of the atypical protein tyrosine phosphatase VHZ. Biochemistry 2013; 52:8012-25. [PMID: 24073992 DOI: 10.1021/bi400776z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
LDP3 (VHZ) is the smallest classical protein tyrosine phosphatase (PTP) known to date and was originally misclassified as an atypical dual-specificity phosphatase. Kinetic isotope effects with steady-state and pre-steady-state kinetics of VHZ and mutants with p-nitrophenol phosphate have revealed several unusual properties. VHZ is significantly more active than previously reported but remains one of the least active PTPs. Highly unusual for a PTP, VHZ possesses two acidic residues (E134 and D65) in the active site. D65 occupies the position corresponding to the typical general acid in the PTP family. However, VHZ primarily utilizes E134 as the general acid, with D65 taking over this role when E134 is mutated. This unusual behavior is facilitated by two coexisting, but unequally populated, substrate binding modes. Unlike most classical PTPs, VHZ exhibits phosphotransferase activity. Despite the presence of the Q-loop that normally prevents alcoholysis of the phosphoenzyme intermediate in other classical PTPs, VHZ readily phosphorylates ethylene glycol. Although mutations of Q-loop residues affect this phosphotransferase activity, mutations on the IPD loop that contains the general acid exert more control over this process. A single P68V substitution on this loop completely abolishes phosphotransferase activity. The ability of native VHZ to catalyze transphosphorylation may lead to an imbalance of intracellular phosphorylation, which could explain the correlation of its overexpression with several types of cancer.
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Affiliation(s)
- Vyacheslav I Kuznetsov
- Department of Chemistry and Biochemistry, Utah State University , Logan, Utah 84322-0300, United States
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Kuznetsov VI, Hengge AC, Johnson SJ. New aspects of the phosphatase VHZ revealed by a high-resolution structure with vanadate and substrate screening. Biochemistry 2012; 51:9869-79. [PMID: 23145819 DOI: 10.1021/bi300908y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The recently discovered 150-residue human VHZ (VH1-related protein, Z member) is one of the smallest protein tyrosine phosphatases (PTPs) known and contains only the minimal structural elements common to all PTPs. We report a substrate screening analysis and a crystal structure of the VHZ complex with vanadate at 1.1 Å resolution, with a detailed structural comparison with other members of the protein tyrosine phosphatase family, including classical tyrosine-specific protein tyrosine phosphatases (PTPs) and dual-specificity phosphatases (DSPs). A screen with 360 phosphorylated peptides shows VHZ efficiently catalyzes the hydrolysis of phosphotyrosine (pY)-containing peptides but exhibits no activity toward phosphoserine (pS) or phosphothreonine (pT) peptides. The new structure reveals a deep and narrow active site more typical of the classical tyrosine-specific PTPs. Despite the high degrees of structural and sequence similarity between VHZ and classical PTPs, its general acid IPD-loop is most likely conformationally rigid, in contrast to the flexible WPD counterpart of classical PTPs. VHZ also lacks substrate recognition domains and other domains typically found on classical PTPs. It is therefore proposed that VHZ is more properly classified as an atypical PTP rather than an atypical DSP, as has been suggested.
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Affiliation(s)
- Vyacheslav I Kuznetsov
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322-0300, USA
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15
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Park H, Park SY, Oh JJ, Ryu SE. Identification of Potent VHZ Phosphatase Inhibitors with Structure-Based Virtual Screening. ACTA ACUST UNITED AC 2012; 18:226-31. [DOI: 10.1177/1087057112463067] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
VH1-like phosphatase Z (VHZ) has proved to be a promising target for the development of therapeutics for the treatment of human cancers. Here, we report the first example for a successful application of structure-based virtual screening to identify the novel small-molecule inhibitors of VHZ. These inhibitors revealed high potencies with the associated IC50 values ranging from 3 to 20 µM and were also screened for having desirable physicochemical properties as a drug candidate. Therefore, they deserve consideration for further development by structure-activity relationship studies to optimize inhibitory and anticancer activities. Structural features relevant to the stabilization of the newly identified inhibitors in the active site of VHZ are discussed in detail.
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Affiliation(s)
| | | | - Jung Jin Oh
- The Johns Hopkins University, Baltimore, MD, USA
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16
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Wallgard E, Nitzsche A, Larsson J, Guo X, Dieterich LC, Dimberg A, Olofsson T, Pontén FC, Mäkinen T, Kalén M, Hellström M. Paladin (X99384) is expressed in the vasculature and shifts from endothelial to vascular smooth muscle cells during mouse development. Dev Dyn 2012; 241:770-86. [PMID: 22354871 DOI: 10.1002/dvdy.23753] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/25/2012] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Angiogenesis is implicated in many pathological conditions. The role of the proteins involved remains largely unknown, and few vascular-specific drug targets have been discovered. Previously, in a screen for angiogenesis regulators, we identified Paladin (mouse: X99384, human: KIAA1274), a protein containing predicted S/T/Y phosphatase domains. RESULTS We present a mouse knockout allele for Paladin with a β-galactosidase reporter, which in combination with Paladin antibodies demonstrate that Paladin is expressed in the vasculature. During mouse embryogenesis, Paladin is primarily expressed in capillary and venous endothelial cells. In adult mice Paladin is predominantly expressed in arterial pericytes and vascular smooth muscle cells. Paladin also displays vascular-restricted expression in human brain, astrocytomas, and glioblastomas. CONCLUSIONS Paladin, a novel putative phosphatase, displays a dynamic expression pattern in the vasculature. During embryonic stages it is broadly expressed in endothelial cells, while in the adult it is selectively expressed in arterial smooth muscle cells.
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Affiliation(s)
- Elisabet Wallgard
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
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Ip AKC, Tso PH, Lee MMK, Wong YH. Elevated expression of RGS19 impairs the responsiveness of stress-activated protein kinases to serum. Mol Cell Biochem 2011; 362:159-68. [PMID: 22045062 DOI: 10.1007/s11010-011-1138-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 10/22/2011] [Indexed: 12/17/2022]
Abstract
Regulators of G protein signaling (RGS proteins) serve as GTPase activating proteins for the signal transducing Gα subunits. RGS19, also known as Gα-interacting protein (GAIP), has been shown to subserve other functions such as the regulation of macroautophagy and growth factor signaling. We have recently demonstrated that the expression of RGS19 in human embryonic kidney (HEK) 293 cells resulted in the disruption of serum-induced mitogenic response along the classical Ras/Raf/MEK/ERK pathway. Here, we further examined the effect of RGS19 expression on the stress-activated protein kinases (SAPKs). Both c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) became non-responsive to serum in 293/RGS19 cells, yet the two SAPKs responded to UV irradiation or osmotic stress induced by sorbitol. Kinases upstream of JNK and p38 MAPK, including MKK3/6, MKK4, and MLK3, also failed to respond to serum stimulation in 293/RGS19 cells. Serum-induced activation of the small GTPases Rac1 and Cdc42 was similarly suppressed in these cells. Our results indicate that elevated expression of RGS19 can severely disrupt the regulation of MAPKs by small GTPases.
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Affiliation(s)
- Angel K C Ip
- Division of Life Science and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
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18
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DUSP13B/TMDP inhibits stress-activated MAPKs and suppresses AP-1-dependent gene expression. Mol Cell Biochem 2011; 352:155-62. [PMID: 21360282 DOI: 10.1007/s11010-011-0749-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Accepted: 02/17/2011] [Indexed: 10/18/2022]
Abstract
The dual-specificity phosphatase (DUSP) 13 gene encodes two atypical DUSPs, DUSP13B/TMDP and DUSP13A/MDSP using alternative exons. DUSP13B protein is most highly expressed in testis, particularly in spermatocytes and round spermatids of the seminiferous tubules, while that of DUSP13A is restricted to skeletal muscle. Here, we show that DUSP13B inactivated MAPK activation in the order of selectivity, JNK = p38>ERK in cells, while DUSP13A did not show MAPK phosphatase activity. Reporter gene analysis showed that DUSP13B had significant inhibitory effect on AP-1-dependent gene expression, but DUSP13A did not. To our knowledge, DUSP13B is the first identified testis-specific phosphatase that inhibits stress-activated MAPKs. These data suggest an important role for DUSP13B in protection from external stress during spermatogenesis.
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Lin FY, Chang CW, Cheong ML, Chen HC, Lee DY, Chang GD, Chen H. Dual-specificity phosphatase 23 mediates GCM1 dephosphorylation and activation. Nucleic Acids Res 2010; 39:848-61. [PMID: 20855292 PMCID: PMC3035457 DOI: 10.1093/nar/gkq838] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Glial cells missing homolog 1 (GCM1) is a transcription factor essential for placental development. GCM1 promotes syncytiotrophoblast formation and placental vasculogenesis by activating fusogenic and proangiogenic gene expression in placenta. GCM1 activity is regulated by multiple post-translational modifications. The cAMP/PKA-signaling pathway promotes CBP-mediated GCM1 acetylation and stabilizes GCM1, whereas hypoxia-induced GSK-3β-mediated phosphorylation of Ser322 causes GCM1 ubiquitination and degradation. How and whether complex modifications of GCM1 are coordinated is not known. Here we show that the interaction of GCM1 and dual-specificity phosphatase 23 (DUSP23) is enhanced by PKA-dependent phosphorylation of GCM1 on Ser269 and Ser275. The recruitment of DUSP23 reverses GSK-3β-mediated Ser322 phosphorylation, which in turn promotes GCM1 acetylation, stabilization and activation. Supporting a central role in coordinating GCM1 modifications, knockdown of DUSP23 suppressed GCM1 target gene expression and placental cell fusion. Our study identifies DUSP23 as a novel factor that promotes placental cell fusion and reveals a complex regulation of GCM1 activity by coordinated phosphorylation, dephosphorylation and acetylation.
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Affiliation(s)
- Fang-Yu Lin
- Graduate Institute of Biochemical Sciences, National Taiwan University, Nankang, Taipei 115, Taiwan
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20
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Park JE, Park BC, Kim HA, Song M, Park SG, Lee DH, Kim HJ, Choi HK, Kim JT, Cho S. Positive regulation of apoptosis signal-regulating kinase 1 by dual-specificity phosphatase 13A. Cell Mol Life Sci 2010; 67:2619-29. [PMID: 20358250 PMCID: PMC11115920 DOI: 10.1007/s00018-010-0353-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Revised: 03/07/2010] [Accepted: 03/11/2010] [Indexed: 10/19/2022]
Abstract
Apoptosis signal-regulating kinase 1 (ASK1), a member of the MAP kinase kinase kinase, is activated by several death stimuli and is tightly regulated by several mechanisms such as interactions with regulatory proteins and post-translational modifications. Here, we report that dual-specificity phosphatase 13A (DUSP13A) functions as a novel regulator of ASK1. DUSP13A interacts with the N-terminal domain of ASK1 and induces ASK1-mediated apoptosis through the activation of caspase-3. DUSP13A enhances ASK1 kinase activity and thus its downstream factors. Small interfering RNA (siRNA) analyses show that knock-down of DUSP13A in human neuroblastoma SK-N-SH cells reduces ASK1 kinase activity. The phosphatase activity of DUSP13A is not required for the regulation of ASK1. This regulatory action of DSUP13 on ASK1 activity involves competition with Akt1, a negative regulator of ASK1, for binding to ASK1. Taken together, this study provides novel insights into the role of DUSP13A in the precise regulation of ASK1.
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Affiliation(s)
- Jae Eun Park
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-806 Korea
| | - Byoung Chul Park
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-806 Korea
| | - Hyun-A Kim
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-806 Korea
| | - Mina Song
- College of Pharmacy, Chung-Ang University, Seoul, 156-756 Korea
| | - Sung Goo Park
- Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-806 Korea
| | - Do Hee Lee
- Department of Biotechnology, College of Natural Sciences, Seoul Women’s University, Seoul, 139-774 Korea
| | - Hyeoung-Joon Kim
- Genome Research Center for Hematopoietic Diseases, Chonnam National University Hospital, Hwasun-gun, Jeonnam, 519-809 Korea
| | | | - Jong-Tae Kim
- Medical Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, 305-806 Korea
| | - Sayeon Cho
- College of Pharmacy, Chung-Ang University, Seoul, 156-756 Korea
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Tang JP, Tan CP, Li J, Siddique MM, Guo K, Chan SW, Park JE, Tay WN, Huang ZY, Li WC, Chen J, Zeng Q. VHZ is a novel centrosomal phosphatase associated with cell growth and human primary cancers. Mol Cancer 2010; 9:128. [PMID: 20509867 PMCID: PMC2893100 DOI: 10.1186/1476-4598-9-128] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Accepted: 05/28/2010] [Indexed: 11/14/2022] Open
Abstract
Background VHZ is a VH1-like (member Z) dual specific protein phosphatase encoded by DUSP23 gene. Some of the dual specific protein phosphatases (DSPs) play an important role in cell cycle control and have shown to be associated with carcinogenesis. Here, the expression of VHZ associated with cell growth and human cancers was investigated. Results We generated a mouse monoclonal antibody (mAb clone#209) and rabbit polyclonal antibodies (rAb) against VHZ. We performed cell proliferation assay to learn how VHZ is associated with cell cycle by retroviral transduction to express VHZ, VHZ(C95S), and control vector in MCF-7 cells. Overexpression of VHZ [but not VHZ(C95S)] in MCF-7 cells promoted cell proliferation compared to control cells. shRNA-mediated knockdown of VHZ in MCF-7 cells showed that reduction of VHZ resulted in increased G1 but decreased S phase cell populations. Using indirect immunofluorescence, we showed that both exogenous and endogenous VHZ protein was localized at the centrosome in addition to its cytoplasmic distribution. Furthermore, using immunohistochemistry, we revealed that VHZ protein was overexpressed either in enlarged centrosomes (VHZ-centrosomal-stain) of some invasive ductal carcinomas (IDC) Stage I (8/65 cases) or in entire cytoplasm (VHZ-cytosol-stain) of invasive epithelia of some IDC Stage II/III (11/47 cases) of breast cancers examined. More importantly, upregulation of VHZ protein is also associated with numerous types of human cancer, in particular breast cancer. VHZ mAb may be useful as a reagent in clinical diagnosis for assessing VHZ positive tumors. Conclusions We generated a VHZ-specific mAb to reveal that VHZ has a novel subcellular localization, namely the centrosome. VHZ is able to facilitate G1/S cell cycle transition in a PTP activity-dependent manner. The upregulation of its protein levels in primary human cancers supports the clinical relevance of the protein in cancers.
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Affiliation(s)
- Jing Ping Tang
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Proteos, Singapore
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Abstract
DUSPs (dual-specificity phosphatases) are a heterogeneous group of protein phosphatases that can dephosphorylate both phosphotyrosine and phosphoserine/phosphothreonine residues within the one substrate. DUSPs have been implicated as major modulators of critical signalling pathways that are dysregulated in various diseases. DUSPs can be divided into six subgroups on the basis of sequence similarity that include slingshots, PRLs (phosphatases of regenerating liver), Cdc14 phosphatases (Cdc is cell division cycle), PTENs (phosphatase and tensin homologues deleted on chromosome 10), myotubularins, MKPs (mitogen-activated protein kinase phosphatases) and atypical DUSPs. Of these subgroups, a great deal of research has focused on the characterization of the MKPs. As their name suggests, MKPs dephosphorylate MAPK (mitogen-activated protein kinase) proteins ERK (extracellular-signal-regulated kinase), JNK (c-Jun N-terminal kinase) and p38 with specificity distinct from that of individual MKP proteins. Atypical DUSPs are mostly of low-molecular-mass and lack the N-terminal CH2 (Cdc25 homology 2) domain common to MKPs. The discovery of most atypical DUSPs has occurred in the last 6 years, which has initiated a large amount of interest in their role and regulation. In the past, atypical DUSPs have generally been grouped together with the MKPs and characterized for their role in MAPK signalling cascades. Indeed, some have been shown to dephosphorylate MAPKs. The current literature hints at the potential of the atypical DUSPs as important signalling regulators, but is crowded with conflicting reports. The present review provides an overview of the DUSP family before focusing on atypical DUSPs, emerging as a group of proteins with vastly diverse substrate specificity and function.
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Boutros T, Chevet E, Metrakos P. Mitogen-activated protein (MAP) kinase/MAP kinase phosphatase regulation: roles in cell growth, death, and cancer. Pharmacol Rev 2009; 60:261-310. [PMID: 18922965 DOI: 10.1124/pr.107.00106] [Citation(s) in RCA: 438] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Mitogen-activated protein kinase dual-specificity phosphatase-1 (also called MKP-1, DUSP1, ERP, CL100, HVH1, PTPN10, and 3CH134) is a member of the threonine-tyrosine dual-specificity phosphatases, one of more than 100 protein tyrosine phosphatases. It was first identified approximately 20 years ago, and since that time extensive investigations into both mkp-1 mRNA and protein regulation and function in different cells, tissues, and organs have been conducted. However, no general review on the topic of MKP-1 exists. As the subject matter pertaining to MKP-1 encompasses many branches of the biomedical field, we focus on the role of this protein in cancer development and progression, highlighting the potential role of the mitogen-activated protein kinase (MAPK) family. Section II of this article elucidates the MAPK family cross-talk. Section III reviews the structure of the mkp-1 encoding gene, and the known mechanisms regulating the expression and activity of the protein. Section IV is an overview of the MAPK-specific dual-specificity phosphatases and their role in cancer. In sections V and VI, mkp-1 mRNA and protein are examined in relation to cancer biology, therapeutics, and clinical studies, including a discussion of the potential role of the MAPK family. We conclude by proposing an integrated scheme for MKP-1 and MAPK in cancer.
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Affiliation(s)
- Tarek Boutros
- Department of Surgery, Royal Victoria Hospital, McGill University, 687 Pine Ave. W., Montreal, QC H3A1A1, Canada.
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Agarwal R, Burley SK, Swaminathan S. Structure of Human Dual Specificity Protein Phosphatase 23, VHZ, Enzyme-Substrate/Product Complex. J Biol Chem 2008; 283:8946-53. [DOI: 10.1074/jbc.m708945200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Romá-Mateo C, Ríos P, Tabernero L, Attwood TK, Pulido R. A novel phosphatase family, structurally related to dual-specificity phosphatases, that displays unique amino acid sequence and substrate specificity. J Mol Biol 2007; 374:899-909. [PMID: 17976645 DOI: 10.1016/j.jmb.2007.10.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2007] [Revised: 09/28/2007] [Accepted: 10/02/2007] [Indexed: 01/30/2023]
Abstract
Members of the superfamily of protein tyrosine phosphatases (PTPs) share the presence of an evolutionarily conserved PTP catalytic domain. Among them, the dual-specificity phosphatases (DSPs) constitute a diverse group of enzymes in terms of substrate specificity, including nonprotein substrates. In recent years, an increasing number of novel DSPs, whose functions and biological substrates are not well defined, have been discovered in a variety of organisms. In this study, we define the structural and functional properties of evolutionarily related atypical DSPs from different phyla. Sets of conserved motifs were defined that (i) uniquely segregated mammalian atypical DSPs from closely related enzymes and (ii) exclusively characterised a novel family of atypical DSPs present in plants, fungi, and kinetoplastids [plant and fungi atypical (PFA)-DSPs]; despite having different sequence "fingerprints," the PTP tertiary structure of PFA-DSPs is conserved. Analysis of the catalytic properties of PFA-DSPs suggests the existence of a unique substrate specificity for these enzymes. Our findings predict characteristic functional motifs for the diverse members of the DSP families of PTPs and provide insights into the functional properties of DSPs of unknown function.
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Affiliation(s)
- Carlos Romá-Mateo
- Centro de Investigación Príncipe Felipe, Avenida Autopista del Saler, 16-3, 46013 Valencia, Spain
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Yuan C, Jin Q, Tang X, Hu W, Cao R, Yang S, Xiong J, Xie C, Xie J, Liang S. Proteomic and peptidomic characterization of the venom from the Chinese bird spider, Ornithoctonus huwena Wang. J Proteome Res 2007; 6:2792-801. [PMID: 17567163 DOI: 10.1021/pr0700192] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The bird spider Ornithoctonus huwena Wang is a very venomous spider in China. Several compounds with different types of biological activities have been identified previously from the venom of this spider. In this study, we have performed a proteomic and peptidomic analysis of the venom. The venom was preseparated into two parts: the venom proteins with molecular weight (MW) higher than 10,000 and the venom peptides with MW lower than 10 000. Using one-dimensional gel electrophoresis (1-DE), two-dimensional gel electrophoresis (2-DE), and mass spectrometry, 90 proteins were identified, including some important enzymes, binding proteins, and some proteins with significant biological functions. For venom peptides, a combination of cation-exchange and reversed-phase chromatography was employed. More than 100 components were detected by mass spectrometry, and 47 peptides were sequenced by Edman degradation. The peptides display structural and pharmacological diversity and share little sequence similarity with peptides from other animal venoms, which indicates the venom of O. huwena Wang is unique. The venom peptides can be classified into several superfamilies. Also it is revealed that gene duplication and focal hypermutation have taken place during the evolution of the spider toxins.
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Affiliation(s)
- Chunhua Yuan
- Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, Life Science College, Hunan Normal University, Changsha 410081, People's Republic of China
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Takagaki K, Shima H, Tanuma N, Nomura M, Satoh T, Watanabe M, Kikuchi K. Characterization of a novel low-molecular-mass dual specificity phosphatase-4 (LDP-4) expressed in brain. Mol Cell Biochem 2006; 296:177-84. [PMID: 17001450 DOI: 10.1007/s11010-006-9313-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Accepted: 08/25/2006] [Indexed: 10/24/2022]
Abstract
Dual-specificity phosphatases (DSPs), which dephosphorylate proteins at Ser/Thr as well as Tyr residues, are thought to be involved in critical signaling events such as control of MAP kinases (MAPKs). We have isolated the cDNA for a novel DSP and termed it low molecular mass DSP-4 (LDP-4). LDP-4 is composed of 211 amino acids with a predicted molecular mass of 23.9-kDa. Northern blot analysis using various mouse tissues showed that the LDP-4 transcript was expressed exclusively in brain. In situ hybridization showed that brain expression of LDP-4 was ubiquitous except for the hippocampus. When expressed in COS-7 cells, FLAG-tagged LDP-4 protein was present within the nucleus and Golgi apparatus. LDP-4 expression did not reduce phosphorylation levels of MAPKs, but rather evoked activation of JNK and p38.
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Affiliation(s)
- Kentaro Takagaki
- Division of Biochemical Oncology and Immunology, Institute for Genetic Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo, Japan
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Fukukawa C, Tanuma N, Okada T, Kikuchi K, Shima H. pp32/ I-1(PP2A) negatively regulates the Raf-1/MEK/ERK pathway. Cancer Lett 2004; 226:155-60. [PMID: 16039954 DOI: 10.1016/j.canlet.2004.11.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2004] [Revised: 11/11/2004] [Accepted: 11/11/2004] [Indexed: 11/29/2022]
Abstract
In this study, we focus on the potential interaction of pp32/I-1(PP2A) (pp32) with the Raf-MEK-ERK signaling pathway. We show that overexpressed pp32 suppresses Raf-1 activation, thereby downregulating the level of ERK activation. This suppression of Raf-1 requires the C-terminal half of pp32. Conversely, knock-down of PP32 by siRNA enhances ERK and MEK activations. Taken together, we propose that tumor-suppression by pp32 is, at least in part, mediated by downregulation of the Raf-MEK-ERK signaling pathway.
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Affiliation(s)
- Chikako Fukukawa
- Division of Biochemical Oncology and Immunology, Institute for Genetic Medicine, Hokkaido University, Kita-15, Nishi-7, Kita-ku, Sapporo 060-0815, Japan
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