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Sha F, Kurosawa K, Glasser E, Ketavarapu G, Albazzaz S, Koide A, Koide S. Monobody Inhibitor Selective to the Phosphatase Domain of SHP2 and its Use as a Probe for Quantifying SHP2 Allosteric Regulation. J Mol Biol 2023; 435:168010. [PMID: 36806475 PMCID: PMC10079645 DOI: 10.1016/j.jmb.2023.168010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 02/04/2023] [Accepted: 02/07/2023] [Indexed: 02/17/2023]
Abstract
SHP2 is a phosphatase/adaptor protein that plays an important role in various signaling pathways. Its mutations are associated with cancers and developmental diseases. SHP2 contains a protein tyrosine phosphatase (PTP) and two SH2 domains. Selective inhibition of these domains has been challenging due to the multitude of homologous proteins in the proteome. Here, we developed a monobody, synthetic binding protein, that bound to and inhibited the SHP2 PTP domain. It was selective to SHP2 PTP over close homologs. A crystal structure of the monobody-PTP complex revealed that the monobody bound both highly conserved residues in the active site and less conserved residues in the periphery, rationalizing its high selectivity. Its epitope overlapped with the interface between the PTP and N-terminal SH2 domains that is formed in auto-inhibited SHP2. By using the monobody as a probe for the accessibility of the PTP active site, we developed a simple, nonenzymatic assay for the allosteric regulation of SHP2. The assay showed that, in the absence of an activating phospho-Tyr ligand, wild-type SHP2 and the "PTP-dead" C459E mutant were predominantly in the closed state in which the PTP active site is inaccessible, whereas the E76K and C459S mutants were in the open, active state. It also revealed that previously developed monobodies to the SH2 domains, ligands lacking a phospho-Tyr, weakly favored the open state. These results provide corroboration for a conformational equilibrium underlying allosteric regulation of SHP2, provide powerful tools for characterizing and controlling SHP2 functions, and inform drug discovery against SHP2.
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Affiliation(s)
- Fern Sha
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, United States
| | - Kohei Kurosawa
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, United States; Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, United States
| | - Eliezra Glasser
- Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, United States
| | - Gayatri Ketavarapu
- Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, United States
| | - Samara Albazzaz
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, United States
| | - Akiko Koide
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, United States; Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, United States; Department of Medicine, New York University Grossman School of Medicine, New York, NY 10016, United States
| | - Shohei Koide
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL 60637, United States; Perlmutter Cancer Center, New York University Langone Health, New York, NY 10016, United States; Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, United States.
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2
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Bobone S, Pannone L, Biondi B, Solman M, Flex E, Canale VC, Calligari P, De Faveri C, Gandini T, Quercioli A, Torini G, Venditti M, Lauri A, Fasano G, Hoeksma J, Santucci V, Cattani G, Bocedi A, Carpentieri G, Tirelli V, Sanchez M, Peggion C, Formaggio F, den Hertog J, Martinelli S, Bocchinfuso G, Tartaglia M, Stella L. Targeting Oncogenic Src Homology 2 Domain-Containing Phosphatase 2 (SHP2) by Inhibiting Its Protein-Protein Interactions. J Med Chem 2021; 64:15973-15990. [PMID: 34714648 PMCID: PMC8591604 DOI: 10.1021/acs.jmedchem.1c01371] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
We developed a new class of inhibitors of protein-protein interactions of the SHP2 phosphatase, which is pivotal in cell signaling and represents a central target in the therapy of cancer and rare diseases. Currently available SHP2 inhibitors target the catalytic site or an allosteric pocket but lack specificity or are ineffective for disease-associated SHP2 mutants. Considering that pathogenic lesions cause signaling hyperactivation due to increased levels of SHP2 association with cognate proteins, we developed peptide-based molecules with nanomolar affinity for the N-terminal Src homology domain of SHP2, good selectivity, stability to degradation, and an affinity for pathogenic variants of SHP2 that is 2-20 times higher than for the wild-type protein. The best peptide reverted the effects of a pathogenic variant (D61G) in zebrafish embryos. Our results provide a novel route for SHP2-targeted therapies and a tool for investigating the role of protein-protein interactions in the function of SHP2.
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Affiliation(s)
- Sara Bobone
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome 00133, Italy
| | - Luca Pannone
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome 00146, Italy.,Dipartimento di Oncologia e Medicina Molecolare, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Barbara Biondi
- Institute of Biomolecular Chemistry, Padova Unit, CNR, Padova 35131, Italy
| | - Maja Solman
- Hubrecht institute-KNAW and University Medical Center Utrecht, Utrecht 3584 CT, The Netherlands
| | - Elisabetta Flex
- Dipartimento di Oncologia e Medicina Molecolare, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Viviana Claudia Canale
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome 00133, Italy
| | - Paolo Calligari
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome 00133, Italy
| | - Chiara De Faveri
- Department of Chemical Sciences, University of Padova, Padova 35131, Italy
| | - Tommaso Gandini
- Department of Chemical Sciences, University of Padova, Padova 35131, Italy
| | - Andrea Quercioli
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome 00133, Italy
| | - Giuseppe Torini
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome 00133, Italy
| | - Martina Venditti
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome 00146, Italy
| | - Antonella Lauri
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome 00146, Italy
| | - Giulia Fasano
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome 00146, Italy
| | - Jelmer Hoeksma
- Hubrecht institute-KNAW and University Medical Center Utrecht, Utrecht 3584 CT, The Netherlands
| | - Valerio Santucci
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome 00133, Italy
| | - Giada Cattani
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome 00133, Italy
| | - Alessio Bocedi
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome 00133, Italy
| | - Giovanna Carpentieri
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome 00146, Italy.,Dipartimento di Oncologia e Medicina Molecolare, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Valentina Tirelli
- Centre of Core Facilities, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Massimo Sanchez
- Centre of Core Facilities, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Cristina Peggion
- Department of Chemical Sciences, University of Padova, Padova 35131, Italy
| | - Fernando Formaggio
- Institute of Biomolecular Chemistry, Padova Unit, CNR, Padova 35131, Italy.,Department of Chemical Sciences, University of Padova, Padova 35131, Italy
| | - Jeroen den Hertog
- Institute of Biomolecular Chemistry, Padova Unit, CNR, Padova 35131, Italy.,Institute of Biology Leiden, Leiden University, Leiden 2333 BE, The Netherlands
| | - Simone Martinelli
- Dipartimento di Oncologia e Medicina Molecolare, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Gianfranco Bocchinfuso
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome 00133, Italy
| | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome 00146, Italy
| | - Lorenzo Stella
- Department of Chemical Science and Technologies, University of Rome Tor Vergata, Rome 00133, Italy
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3
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Ye Y, Gu J, Liu P, Wang H, Jiang L, Lei T, Yu S, Han G, Wang Z. Long Non-Coding RNA SPRY4-IT1 Reverses Cisplatin Resistance by Downregulating MPZL-1 via Suppressing EMT in NSCLC. Onco Targets Ther 2020; 13:2783-2793. [PMID: 32308413 PMCID: PMC7135170 DOI: 10.2147/ott.s232769] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 03/08/2020] [Indexed: 01/18/2023] Open
Abstract
Purpose Long non-coding RNA (lncRNA) SPRY4 intronic transcript 1 (SPRY4-IT1) is reported to play important roles in the occurrence and development of many tumors. However, the possible role of SPRY4-IT1 in cisplatin (DDP) resistance of non-small-cell lung cancer (NSCLC) remains unclear. The aim of this study is to investigate the functions and molecular mechanisms underlying SPRY4-IT1 of cisplatin resistance in NSCLC. Methods Expression of SPRY4-IT1 was analyzed in A549 and cisplatin-resistant A549/DDP cell lines by quantitative real-time polymerase chain reaction (RT-qPCR). Overexpression techniques were applied to investigate the biological functions of SPRY4-IT1 in cisplatin-resistant A549/DDP cells. The effects of SPRY4-IT1 on proliferation and apoptosis were evaluated using cell counting kit-8 (CCK8) assays, colony formation assay and flow-cytometric analysis. The expressions of epithelial–mesenchymal transition (EMT)-associated proteins, including E-cadherin and Vimentin, were detected by Western blot. Microarray analysis was performed to identify the putative targets of SPRY4-IT1, which were further verified by Western blotting and RT-qPCR. A549/DDP cells transfected with pCDNA-SPRY4-IT1 were injected into nude mice in order to verify the effect of SPRY4-IT1 on cisplatin resistance in vivo. Results The present study demonstrated that SPRY4-IT1 expression was decreased in A549/DDP cells compared with parental A549 cells. Upregulation of SPRY4-IT1 suppressed cell proliferation and caused apoptosis of A549/DDP cells both in vitro and in vivo. MPZL-1 was negatively regulated by SPRY4-IT1. Furthermore, upregulation of SPRY4-IT1 and downregulation of MPZL-1 could suppress epithelial–mesenchymal transition (EMT), which was characterized by increased E-cadherin expression and decreased Vimentin expression. Conclusion Upregulation of SPRY4-IT1 reversed the cisplatin-resistant phenotype of NSCLC partially by downregulating MPZL-1 via inhibiting EMT process.
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Affiliation(s)
- Yunyao Ye
- Department of Oncology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China.,Department of Oncology, Taizhou People's Hospital, Taizhou, Jiangsu, People's Republic of China
| | - Jingyao Gu
- Department of Oncology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Pei Liu
- Department of Oncology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China.,Department of Digestive Oncology, The Fourth Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - He Wang
- Department of Oncology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China.,Department of Oncology, Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Lihua Jiang
- Department of Oncology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Tianyao Lei
- Department of Oncology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
| | - Shanxun Yu
- Department of Oncology, Taizhou People's Hospital, Taizhou, Jiangsu, People's Republic of China
| | - Gaohua Han
- Department of Oncology, Taizhou People's Hospital, Taizhou, Jiangsu, People's Republic of China
| | - Zhaoxia Wang
- Department of Oncology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China
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4
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Luo X, Liao R, Hanley KL, Zhu HH, Malo KN, Hernandez C, Wei X, Varki NM, Alderson N, Chu C, Li S, Fan J, Loomba R, Qiu SJ, Feng GS. Dual Shp2 and Pten Deficiencies Promote Non-alcoholic Steatohepatitis and Genesis of Liver Tumor-Initiating Cells. Cell Rep 2017; 17:2979-2993. [PMID: 27974211 DOI: 10.1016/j.celrep.2016.11.048] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 10/20/2016] [Accepted: 11/15/2016] [Indexed: 01/14/2023] Open
Abstract
The complexity of liver tumorigenesis is underscored by the recently observed anti-oncogenic effects of oncoproteins, although the mechanisms are unclear. Shp2/Ptpn11 is a proto-oncogene in hematopoietic cells and antagonizes the effect of tumor suppressor Pten in leukemogenesis. In contrast, we show here cooperative functions of Shp2 and Pten in suppressing hepatocarcinogenesis. Ablating both Shp2 and Pten in hepatocytes induced early-onset non-alcoholic steatohepatitis (NASH) and promoted genesis of liver tumor-initiating cells likely due to augmented cJun expression/activation and elevated ROS and inflammation in the hepatic microenvironment. Inhibiting cJun partially suppressed NASH-driven liver tumorigenesis without improving NASH. SHP2 and PTEN deficiencies were detected in liver cancer patients with poor prognosis. These data depict a mechanism of hepato-oncogenesis and suggest a potential therapeutic strategy.
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Affiliation(s)
- Xiaolin Luo
- Department of Pathology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Rui Liao
- Department of Pathology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai 200032, China; Department of Hepatobiliary Surgery, The First Affiliated Hospital, Chongqing Medical University, Chongqing 40016, China
| | - Kaisa L Hanley
- Molecular Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Helen He Zhu
- Department of Pathology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kirsten N Malo
- Molecular Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Carolyn Hernandez
- Department of Medicine, NAFLD Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Xufu Wei
- Department of Pathology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Department of Hepatobiliary Surgery, The First Affiliated Hospital, Chongqing Medical University, Chongqing 40016, China
| | - Nissi M Varki
- Department of Pathology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nazilla Alderson
- Department of Pathology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Catherine Chu
- Molecular Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Shuangwei Li
- Department of Pathology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jia Fan
- Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Rohit Loomba
- Department of Medicine, NAFLD Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Shuang-Jian Qiu
- Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Gen-Sheng Feng
- Department of Pathology, School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Molecular Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093, USA.
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5
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Corallino S, Iwai LK, Payne LS, Huang PH, Sacco F, Cesareni G, Castagnoli L. Alterations in the phosphoproteomic profile of cells expressing a non-functional form of the SHP2 phosphatase. N Biotechnol 2015; 33:524-36. [PMID: 26316256 DOI: 10.1016/j.nbt.2015.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Revised: 08/09/2015] [Accepted: 08/14/2015] [Indexed: 12/13/2022]
Abstract
The phosphatase SHP-2 plays an essential role in growth factor signaling and mutations in its locus is the cause of congenital and acquired pathologies. Mutations of SHP-2 are known to affect the activation of the RAS pathway. Gain-of-function mutations cause the Noonan syndrome, the most common non-chromosomal congenital disorder. In order to obtain a holistic picture of the intricate regulatory mechanisms underlying SHP-2 physiology and pathology, we set out to characterize perturbations of the cell phosphorylation profile caused by an altered localization of SHP-2. To describe the proteins whose activity may be directly or indirectly modulated by SHP-2 activity, we identified tyrosine peptides that are differentially phosphorylated in wild type SHP-2 cells and isogenic cells expressing a non-functional SHP-2 variant that cannot dephosphorylate the physiological substrates due to a defect in cellular localization upon growth factor stimulation. By an iTRAQ based strategy coupled to mass spectrometry, we have identified 63 phosphorylated tyrosine residues in 53 different proteins whose phosphorylation is affected by SHP-2 activity. Some of these confirm already established regulatory mechanisms while many others suggest new possible signaling routes that may contribute to the modulation of the ERK and p38 pathways by SHP-2. Interestingly many new proteins that we found to be regulated by SHP-2 activity are implicated in the formation and regulation of focal adhesions.
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Affiliation(s)
- Salvatore Corallino
- Department of Biology, University of Rome Tor Vergata, Via della ricerca scientifica, 00133 Rome, Italy.
| | - Leo K Iwai
- Protein Networks Team, Division of Cancer Biology, Institute of Cancer Research, London SW3 6JB, United Kingdom
| | - Leo S Payne
- Protein Networks Team, Division of Cancer Biology, Institute of Cancer Research, London SW3 6JB, United Kingdom
| | - Paul H Huang
- Protein Networks Team, Division of Cancer Biology, Institute of Cancer Research, London SW3 6JB, United Kingdom
| | - Francesca Sacco
- Department of Biology, University of Rome Tor Vergata, Via della ricerca scientifica, 00133 Rome, Italy
| | - Gianni Cesareni
- Department of Biology, University of Rome Tor Vergata, Via della ricerca scientifica, 00133 Rome, Italy; IRCCS Fondazione Santa Lucia, 00143 Rome, Italy.
| | - Luisa Castagnoli
- Department of Biology, University of Rome Tor Vergata, Via della ricerca scientifica, 00133 Rome, Italy.
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6
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Li S, Hsu DDF, Li B, Luo X, Alderson N, Qiao L, Ma L, Zhu HH, He Z, Suino-Powell K, Ji K, Li J, Shao J, Xu HE, Li T, Feng GS. Cytoplasmic tyrosine phosphatase Shp2 coordinates hepatic regulation of bile acid and FGF15/19 signaling to repress bile acid synthesis. Cell Metab 2014; 20:320-32. [PMID: 24981838 PMCID: PMC4365973 DOI: 10.1016/j.cmet.2014.05.020] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 04/18/2014] [Accepted: 05/16/2014] [Indexed: 02/06/2023]
Abstract
Bile acid (BA) biosynthesis is tightly controlled by intrahepatic negative feedback signaling elicited by BA binding to farnesoid X receptor (FXR) and also by enterohepatic communication involving ileal BA reabsorption and FGF15/19 secretion. However, how these pathways are coordinated is poorly understood. We show here that nonreceptor tyrosine phosphatase Shp2 is a critical player that couples and regulates the intrahepatic and enterohepatic signals for repression of BA synthesis. Ablating Shp2 in hepatocytes suppressed signal relay from FGFR4, receptor for FGF15/19, and attenuated BA activation of FXR signaling, resulting in elevation of systemic BA levels and chronic hepatobiliary disorders in mice. Acting immediately downstream of FGFR4, Shp2 associates with FRS2α and promotes the receptor activation and signal relay to several pathways. These results elucidate a molecular mechanism for the control of BA homeostasis by Shp2 through the orchestration of multiple signals in hepatocytes.
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Affiliation(s)
- Shuangwei Li
- Department of Pathology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0864, USA
| | - Diane D F Hsu
- Department of Pathology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0864, USA
| | - Bing Li
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Xiaolin Luo
- Department of Pathology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0864, USA
| | - Nazilla Alderson
- Department of Pathology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0864, USA
| | - Liping Qiao
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0983, USA
| | - Lina Ma
- Molecular Neuroscience Laboratory, The Salk Institute for Biological Sciences, La Jolla, CA 92186, USA
| | - Helen H Zhu
- Department of Pathology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0864, USA
| | - Zhao He
- Department of Pathology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0864, USA
| | - Kelly Suino-Powell
- Laboratory of Structural Sciences, Van Andel Research Institute, 333 Bostwick Avenue Northeast, Grand Rapids, MI 49503, USA
| | - Kaihong Ji
- Department of Pathology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0864, USA
| | - Jiefu Li
- Department of Pathology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0864, USA
| | - Jianhua Shao
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0983, USA
| | - H Eric Xu
- Laboratory of Structural Sciences, Van Andel Research Institute, 333 Bostwick Avenue Northeast, Grand Rapids, MI 49503, USA; VARI-SIMM Center, Center for Structure and Function of Drug Targets, CAS-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Tiangang Li
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Gen-Sheng Feng
- Department of Pathology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093-0864, USA.
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7
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Demoulin JB, Essaghir A. PDGF receptor signaling networks in normal and cancer cells. Cytokine Growth Factor Rev 2014; 25:273-83. [DOI: 10.1016/j.cytogfr.2014.03.003] [Citation(s) in RCA: 165] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 03/10/2014] [Indexed: 01/05/2023]
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8
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Abstract
Replication stress- and DNA damage-induced cell cycle checkpoints are critical for maintaining genome stability. To identify protein phosphatases involved in the activation and maintenance of the checkpoints, we have carried out RNA interference-based screens with a human phosphatome shRNA library. Several phosphatases, including SHP2 (also called PTPN11) were found to be required for cell survival upon hydroxyurea-induced replicative stress in HeLa cells. More detailed studies revealed that SHP2 was also important for the maintenance of the checkpoint after DNA damage induced by cisplatin or ionizing radiation in HeLa cells. Furthermore, SHP2 was activated after replicative stress and DNA damage. Although depletion of SHP2 resulted in a delay in cyclin E accumulation and an extension of G1 phase, these cell cycle impairments were not responsible for the increase in apoptosis after DNA damage. Depletion of SHP2 impaired CHK1 activation, checkpoint-mediated cell cycle arrest, and DNA repair. These effects could be rescued with a shRNA-resistant SHP2. These results underscore the importance of protein phosphatases in checkpoint control and revealed a novel link between SHP2 and cell cycle checkpoints.
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Affiliation(s)
- Yiu Huen Tsang
- Division of Life Science and Center for Cancer Research, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Xianxian Han
- Division of Life Science and Center for Cancer Research, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Wing Yu Man
- Division of Life Science and Center for Cancer Research, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Nelson Lee
- Division of Life Science and Center for Cancer Research, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
| | - Randy Y. C. Poon
- Division of Life Science and Center for Cancer Research, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong
- * E-mail:
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9
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Sacco F, Perfetto L, Castagnoli L, Cesareni G. The human phosphatase interactome: An intricate family portrait. FEBS Lett 2012; 586:2732-9. [PMID: 22626554 PMCID: PMC3437441 DOI: 10.1016/j.febslet.2012.05.008] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 05/08/2012] [Accepted: 05/08/2012] [Indexed: 11/17/2022]
Abstract
The concerted activities of kinases and phosphatases modulate the phosphorylation levels of proteins, lipids and carbohydrates in eukaryotic cells. Despite considerable effort, we are still missing a holistic picture representing, at a proteome level, the functional relationships between kinases, phosphatases and their substrates. Here we focus on phosphatases and we review and integrate the available information that helps to place the members of the protein phosphatase superfamilies into the human protein interaction network. In addition we show how protein interaction domains and motifs, either covalently linked to the phosphatase domain or in regulatory/adaptor subunits, play a prominent role in substrate selection.
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Affiliation(s)
- Francesca Sacco
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
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10
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Yun JH, Park SJ, Jo A, Kang JL, Jou I, Park JS, Choi YH. Caveolin-1 is involved in reactive oxygen species-induced SHP-2 activation in astrocytes. Exp Mol Med 2012; 43:660-8. [PMID: 21918362 DOI: 10.3858/emm.2011.43.12.075] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Recent evidence supports a neuroprotective role of Src homology 2-containing protein tyrosine phosphatase 2 (SHP-2) against ischemic brain injury. However, the molecular mechanisms of SHP-2 activation and those governing how SHP-2 exerts its function under oxidative stress conditions are not well understood. Recently we have reported that reactive oxygen species (ROS)-mediated oxidative stress promotes the phosphorylation of endogenous SHP-2 through lipid rafts, and that this phosphorylation strongly occurs in astrocytes, but not in microglia. To investigate the molecules involved in events leading to phosphorylation of SHP-2, raft proteins were analyzed using astrocytes and microglia. Interestingly, caveolin-1 and -2 were detected only in astrocytes but not in microglia, whereas flotillin-1 was expressed in both cell types. To examine whether the H2O2-dependent phosphorylation of SHP-2 is mediated by caveolin-1, we used specific small interfering RNA (siRNA) to downregulate caveolin- 1 expression. In the presence of caveolin-1 siRNA, the level of SHP-2 phosphorylation induced by H2O2 was significantly decreased, compared with in the presence of control siRNA. Overexpression of caveolin- 1 effectively increased H2O2-induced SHP-2 phosphorylation in microglia. Lastly, H2O2 induced extracellular signal-regulated kinase (ERK) activation in astrocytes through caveolin-1. Our results suggest that caveolin-1 is involved in astrocyte-specific intracellular responses linked to the SHP-2-mediated signaling cascade following ROS-induced oxidative stress.
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Affiliation(s)
- Ji Hee Yun
- Department of Physiology, Ewha Womans University School of Medicine Seoul 158-710, Korea
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11
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Nardozza AP, D'Orazio M, Trapannone R, Corallino S, Filomeni G, Tartaglia M, Battistoni A, Cesareni G, Castagnoli L. Reactive oxygen species and epidermal growth factor are antagonistic cues controlling SHP-2 dimerization. Mol Cell Biol 2012; 32:1998-2009. [PMID: 22411627 DOI: 10.1128/MCB.06674-11] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The SHP-2 tyrosine phosphatase plays key regulatory roles in the modulation of the cell response to growth factors and cytokines. Over the past decade, the integration of genetic, biochemical, and structural data has helped in interpreting the pathological consequences of altered SHP-2 function. Using complementary approaches, we provide evidence here that endogenous SHP-2 can dimerize through the formation of disulfide bonds that may also involve the catalytic cysteine. We show that the fraction of dimeric SHP-2 is modulated by growth factor stimulation and by the cell redox state. Comparison of the phosphatase activities of the monomeric self-inhibited and dimeric forms indicated that the latter is 3-fold less active, thus pointing to the dimerization process as an additional mechanism for controlling SHP-2 activity. Remarkably, dimers formed by different SHP-2 mutants displaying diverse biochemical properties were found to respond differently to epidermal growth factor (EGF) stimulation. Although this differential behavior cannot be rationalized mechanistically yet, these findings suggest a possible regulatory role of dimerization in SHP-2 function.
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12
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Futami M, Zhu QS, Whichard ZL, Xia L, Ke Y, Neel BG, Feng GS, Corey SJ. G-CSF receptor activation of the Src kinase Lyn is mediated by Gab2 recruitment of the Shp2 phosphatase. Blood 2011; 118:1077-86. [PMID: 21636860 DOI: 10.1182/blood-2009-12-261636] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Src activation involves the coordinated regulation of positive and negative tyrosine phosphorylation sites. The mechanism whereby receptor tyrosine kinases, cytokine receptors, and integrins activate Src is not known. Here, we demonstrate that granulocyte colony-stimulating factor (G-CSF) activates Lyn, the predominant Src kinase in myeloid cells, through Gab2-mediated recruitment of Shp2. After G-CSF stimulation, Lyn dynamically associates with Gab2 in a spatiotemporal manner. The dephosphorylation of phospho-Lyn Tyr507 was abrogated in Shp2-deficient cells transfected with the G-CSF receptor but intact in cells expressing phosphatase-defective Shp2. Auto-phosphorylation of Lyn Tyr396 was impaired in cells treated with Gab2 siRNA. The constitutively activated Shp2E76A directed the dephosphorylation of phospho-Lyn Tyr507 in vitro. Tyr507 did not undergo dephosphorylation in G-CSF-stimulated cells expressing a mutant Gab2 unable to bind Shp2. We propose that Gab2 forms a complex with Lyn and after G-CSF stimulation, Gab2 recruits Shp2, which dephosphorylates phospho-Lyn Tyr507, leading to Lyn activation.
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13
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Abstract
Deregulation of signaling pathways, through mutation or other molecular changes, can ultimately result in disease. The tyrosine phosphatase Shp2 has emerged as a major regulator of receptor tyrosine kinase (RTK) and cytokine receptor signaling. In the last decade, germline mutations in the human PTPN11 gene, encoding Shp2, were linked to Noonan (NS) and LEOPARD syndromes, two multisymptomatic developmental disorders that are characterized by short stature, craniofacial defects, cardiac defects, and mental retardation. Somatic Shp2 mutations are also associated with several types of human malignancies, such as the most common juvenile leukemia, juvenile myelomonocytic leukemia (JMML). Whereas NS and JMML are caused by gain-of-function (GOF) mutations of Shp2, loss-of-function (LOF) mutations are thought to be associated with LEOPARD syndrome. Animal models that carry conditional LOF and GOF mutations have allowed a better understanding of the mechanism of Shp2 function in disease, and shed light on the role of Shp2 in signaling pathways that control decisive events during embryonic development or during cellular transformation/tumorigenesis.
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14
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Schwertassek U, Buckley DA, Xu CF, Lindsay AJ, McCaffrey MW, Neubert TA, Tonks NK. Myristoylation of the dual-specificity phosphatase c-JUN N-terminal kinase (JNK) stimulatory phosphatase 1 is necessary for its activation of JNK signaling and apoptosis. FEBS J 2010; 277:2463-73. [PMID: 20553486 DOI: 10.1111/j.1742-4658.2010.07661.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Activation of the c-JUN N-terminal kinase (JNK) pathway is implicated in a number of important physiological processes, from embryonic morphogenesis to cell survival and apoptosis. JNK stimulatory phosphatase 1 (JSP1) is a member of the dual-specificity phosphatase subfamily of protein tyrosine phosphatases. In contrast to other dual-specificity phosphatases that catalyze the inactivation of mitogen-activated protein kinases, expression of JSP1 activates JNK-mediated signaling. JSP1 and its relative DUSP15 are unique among members of the protein tyrosine phosphatase family in that they contain a potential myristoylation site at the N-terminus (MGNGMXK). In this study, we investigated whether JSP1 was myristoylated and examined the functional consequences of myristoylation. Using mass spectrometry, we showed that wild-type JSP1, but not a JSP1 mutant in which Gly2 was mutated to Ala (JSP1-G2A), was myristoylated in cells. Although JSP1 maintained intrinsic phosphatase activity in the absence of myristoylation, the subcellular localization of the enzyme was altered. Compared with the wild type, the ability of nonmyristoylated JSP1 to induce JNK activation and phosphorylation of the transcription factor c-JUN was attenuated. Upon expression of wild-type JSP1, a subpopulation of cells, with the highest levels of the phosphatase, was induced to float off the dish and undergo apoptosis. In contrast, cells expressing similar levels of JSP1-G2A remained attached, further highlighting that the myristoylation mutant was functionally compromised.
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Affiliation(s)
- Ulla Schwertassek
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724-2208, USA
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15
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Kundu S, Fan K, Cao M, Lindner DJ, Zhao ZJ, Borden E, Yi T. Novel SHP-1 inhibitors tyrosine phosphatase inhibitor-1 and analogs with preclinical anti-tumor activities as tolerated oral agents. J Immunol 2010; 184:6529-36. [PMID: 20421638 DOI: 10.4049/jimmunol.0903562] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Src homology region 2 domain-containing phosphatase 1 (SHP-1) has been implicated as a potential cancer therapeutic target by its negative regulation of immune cell activation and the activity of the SHP-1 inhibitor sodium stibogluconate that induced IFN-gamma(+) cells for anti-tumor action. To develop more potent SHP-1-targeted anti-cancer agents, inhibitory leads were identified from a library of 34,000 drug-like compounds. Among the leads and active at low nM for recombinant SHP-1, tyrosine phosphatase inhibitor-1 (TPI-1) selectively increased SHP-1 phospho-substrates (pLck-pY394, pZap70, and pSlp76) in Jurkat T cells but had little effects on pERK1/2 or pLck-pY505 regulated by phosphatases SHP-2 or CD45, respectively. TPI-1 induced mouse splenic-IFN-gamma(+) cells in vitro, approximately 58-fold more effective than sodium stibogluconate, and increased mouse splenic-pLck-pY394 and -IFN-gamma(+) cells in vivo. TPI-1 also induced IFN-gamma(+) cells in human peripheral blood in vitro. Significantly, TPI-1 inhibited ( approximately 83%, p < 0.002) the growth of B16 melanoma tumors in mice at a tolerated oral dose in a T cell-dependent manner but had little effects on B16 cell growth in culture. TPI-1 also inhibited B16 tumor growth and prolonged tumor mice survival as a tolerated s.c. agent. TPI-1 analogs were identified with improved activities in IFN-gamma(+) cell induction and in anti-tumor actions. In particular, analog TPI-1a4 as a tolerated oral agent completely inhibited the growth of K1735 melanoma tumors and was more effective than the parental lead against MC-26 colon cancer tumors in mice. These results designate TPI-1 and the analogs as novel SHP-1 inhibitors with anti-tumor activity likely via an immune mechanism, supporting SHP-1 as a novel target for cancer treatment.
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Affiliation(s)
- Suman Kundu
- Department of Cancer Biology, Lerner Research Institute, The Cleveland Clinic, Cleveland, OH 44195, USA
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16
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Yamaji S, Saegusa J, Ieguchi K, Fujita M, Mori S, Takada YK, Takada Y. A novel fibroblast growth factor-1 (FGF1) mutant that acts as an FGF antagonist. PLoS One 2010; 5:e10273. [PMID: 20422052 PMCID: PMC2858075 DOI: 10.1371/journal.pone.0010273] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Accepted: 03/30/2010] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Crosstalk between integrins and FGF receptors has been implicated in FGF signaling, but the specifics of the crosstalk are unclear. We recently discovered that 1) FGF1 directly binds to integrin alphavbeta3, 2) the integrin-binding site and FGF receptor (FGFR) binding site are distinct, and 3) the integrin-binding-defective FGF1 mutant (R50E) is defective in inducing FGF signaling although R50E still binds to FGFR and heparin and induces transient ERK1/2 activation. PRINCIPAL FINDINGS We tested if excess R50E affect DNA synthesis and cell survival induced by WT FGF1 in BaF3 mouse pro-B cells expressing human FGFR1. R50E suppressed DNA synthesis and cell proliferation induced by WT FGF1. We tested if WT FGF1 and R50E generate integrin-FGF1-FGFR ternary complex. WT FGF1 induced ternary complex formation (integrin-FGF-FGFR1) and recruitment of SHP-2 to the complex in NIH 3T3 cells and human umbilical endothelial cells, but R50E was defective in these functions. It has been reported that sustained ERK1/2 activation is integrin-dependent and crucial to cell cycle entry upon FGF stimulation. We thus determined the time-course of ERK1/2 activation induced by WT FGF1 and R50E. We found that WT FGF1 induced sustained activation of ERK1/2, but R50E was defective in this function. CONCLUSIONS/SIGNIFICANCE Our results suggest that 1) R50E is a dominant-negative mutant, 2) Ternary complex formation is involved in FGF signaling, 3) The defect of R50E to bind to integrin may be directly related to the antagonistic action of R50E. Taken together, these results suggest that R50E has potential as a therapeutic in cancer.
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Affiliation(s)
- Satoshi Yamaji
- Department of Dermatology, University of California Davis School of Medicine, Sacramento, California, United States of America
| | - Jun Saegusa
- Department of Dermatology, University of California Davis School of Medicine, Sacramento, California, United States of America
| | - Katsuaki Ieguchi
- Department of Dermatology, University of California Davis School of Medicine, Sacramento, California, United States of America
| | - Masaaki Fujita
- Department of Dermatology, University of California Davis School of Medicine, Sacramento, California, United States of America
| | - Seiji Mori
- Department of Dermatology, University of California Davis School of Medicine, Sacramento, California, United States of America
| | - Yoko K. Takada
- Department of Dermatology, University of California Davis School of Medicine, Sacramento, California, United States of America
| | - Yoshikazu Takada
- Department of Dermatology, University of California Davis School of Medicine, Sacramento, California, United States of America
- * E-mail:
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Forbes K, West G, Garside R, Aplin JD, Westwood M. The protein-tyrosine phosphatase, SRC homology-2 domain containing protein tyrosine phosphatase-2, is a crucial mediator of exogenous insulin-like growth factor signaling to human trophoblast. Endocrinology 2009; 150:4744-54. [PMID: 19589868 DOI: 10.1210/en.2009-0166] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Adequate fetal growth depends on placental transfer of nutrients and gases from the mother; thus, as pregnancy progresses, the placenta must grow to meet the increasing demands of the developing fetus. IGFs control proliferation, differentiation, and survival of trophoblast in first-trimester placenta via intracellular tyrosine kinase signaling cascades, the activation of which is also regulated by tyrosine phosphatases. The protein-tyrosine phosphatase, Src homology-2 domain containing protein tyrosine phosphatase (SHP)-2, is crucial for mouse placental development and is known to mediate IGF actions in other systems. In this study we examined the role of SHP-2 in regulating IGF-mediated proliferation in human trophoblast. Immunohistochemical analysis demonstrated that SHP-2 is expressed strongly in cytotrophoblast and only weakly in syncytium. After small interfering RNA-mediated knockdown of SHP-2 in BeWo choriocarcinoma cells and human first-trimester placental explants, IGF-induced trophoblast proliferation, examined using immunohistochemical analysis of Ki67 and 5-bromo-2'-deoxyuridine incorporation, was significantly reduced (P < 0.05). Kinase activation assays suggested that SHP-2 interacts with the MAPK pathway to mediate these effects. Markers of trophoblast differentiation were elevated after SHP-2 knockdown. This study demonstrates a role for tyrosine phosphatases in human trophoblast and establishes SHP-2 as a component of the IGF signaling pathway that is required for normal placental growth.
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Affiliation(s)
- Karen Forbes
- Maternal and Fetal Health Research Group, University of Manchester, Manchester M13 0JH, United Kingdom
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18
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Zhan Y, Counelis GJ, O'Rourke DM. The protein tyrosine phosphatase SHP-2 is required for EGFRvIII oncogenic transformation in human glioblastoma cells. Exp Cell Res 2009; 315:2343-57. [PMID: 19427850 DOI: 10.1016/j.yexcr.2009.05.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 05/04/2009] [Accepted: 05/05/2009] [Indexed: 02/03/2023]
Abstract
Oncogenic EGFRvIII is a naturally occurring oncoprotein and is expressed in about 40-50% of human glioblastomas, particularly those that arise de novo. To understand the molecular mechanisms by which this oncoprotein alters transforming phenotypes, and since our previous work indicated that SHP-2 protein tyrosine phosphatase activity modulated EGFRvIII activation and downstream signaling, we examined whether SHP-2 plays a role in EGFRvIII-induced oncogenesis by using both PTEN-deficient U87MG.EGFRvIII and PTEN-intact LN229.EGFRvIII cells. Inhibition of SHP-2 expression by Shp-2 siRNA inhibited cell growth, transformation and altered morphology of these EGFRvIII transformed GBM cells. Ectopic expression of a PTPase-inactive form of SHP-2, SHP-2 C459S, but not its wild-type SHP-2 or either of two SH2 domain mutants, abrogated transformation of EGFRvIII-expressing glioblastomas in soft agar and in nude mice. SHP-2 C459S cells grew slower and exhibited a more flattened morphology with more organized actin stress fibers under both full growth and low serum conditions. Furthermore, shp-2+/- and -/- mouse embryonic fibroblasts (MEFs) could not be transformed by EGFRvIII while shp-2+/+ MEFs displayed a fully transformed phenotype upon introduction of EGFRvIII, again indicating a requirement for functional SHP-2 in EGFRvIII transformation. Moreover, the SHP-2 PTPase activity inhibitor NSC-87877 inhibited endogenous SHP-2 activity, Erk phosphorylation and transformation in both GBM cell lines. EGFRvIII expression recruited SHP-2 to the receptor complex to transduce signals and also increased SHP-2 phosphorylation at Tyr542. Inhibition of EGFRvIII-induced cell growth and transformation by SHP-2 C459S or shp-2 siRNA was mediated by its ability to block cell cycle progression at different phases in these GBM cells. These data indicate that differential activation of SHP-2 phosphorylation at Tyr542 in these two GBM cell lines likely results in increased different PTPase activity and distinct mechanisms of cell cycle progression and SHP-2, in particular its PTPase activity, plays a critical role in EGFRvIII-mediated transformation.
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Affiliation(s)
- Yi Zhan
- Department of Neurosurgery, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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19
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Abstract
Diverse cellular processes are regulated by tyrosyl phosphorylation, which is controlled by protein-tyrosine kinases (PTKs) and protein-tyrosine phosphatases (PTPs). De-regulated tyrosyl phosphorylation, evoked by gain-of-function mutations and/or over-expression of PTKs, contributes to the pathogenesis of many cancers and other human diseases. PTPs, because they oppose the action of PTKs, had been considered to be prime suspects for potential tumor suppressor genes. Surprisingly, few, if any, tumor suppressor PTPs have been identified. However, the Src homology-2 domain-containing phosphatase Shp2 (encoded by PTPN11) is a bona fide proto-oncogene. Germline mutations in PTPN11 cause Noonan and LEOPARD syndromes, whereas somatic PTPN11 mutations occur in several types of hematologic malignancies, most notably juvenile myelomonocytic leukemia and, more rarely, in solid tumors. Shp2 also is an essential component in several other oncogene signaling pathways. Elucidation of the events underlying Shp2-evoked transformation may provide new insights into oncogenic mechanisms and novel targets for anti-cancer therapy.
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Koyama T, Nakaoka Y, Fujio Y, Hirota H, Nishida K, Sugiyama S, Okamoto K, Yamauchi-Takihara K, Yoshimura M, Mochizuki S, Hori M, Hirano T, Mochizuki N. Interaction of scaffolding adaptor protein Gab1 with tyrosine phosphatase SHP2 negatively regulates IGF-I-dependent myogenic differentiation via the ERK1/2 signaling pathway. J Biol Chem 2008; 283:24234-44. [PMID: 18577518 DOI: 10.1074/jbc.m803907200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Grb2-associated binder 1 (Gab1) coordinates various receptor tyrosine kinase signaling pathways. Although skeletal muscle differentiation is regulated by some growth factors, it remains elusive whether Gab1 coordinates myogenic signals. Here, we examined the molecular mechanism of insulin-like growth factor-I (IGF-I)-mediated myogenic differentiation, focusing on Gab1 and its downstream signaling. Gab1 underwent tyrosine phosphorylation and subsequent complex formation with protein-tyrosine phosphatase SHP2 upon IGF-I stimulation in C2C12 myoblasts. On the other hand, Gab1 constitutively associated with phosphatidylinositol 3-kinase regulatory subunit p85. To delineate the role of Gab1 in IGF-I-dependent signaling, we examined the effect of adenovirus-mediated forced expression of wild-type Gab1 (Gab1(WT)), mutated Gab1 that is unable to bind SHP2 (Gab1(DeltaSHP2)), or mutated Gab1 that is unable to bind p85 (Gab1(Deltap85)), on the differentiation of C2C12 myoblasts. IGF-I-induced myogenic differentiation was enhanced in myoblasts overexpressing Gab1(DeltaSHP2), but inhibited in those overexpressing either Gab1(WT) or Gab1(Deltap85). Conversely, IGF-I-induced extracellular signal-regulated kinase 1/2 (ERK1/2) activation was significantly repressed in myoblasts overexpressing Gab1(DeltaSHP2) but enhanced in those overexpressing either Gab1(WT) or Gab1(Deltap85). Furthermore, small interference RNA-mediated Gab1 knockdown enhanced myogenic differentiation. Overexpression of catalytic-inactive SHP2 modulated IGF-I-induced myogenic differentiation and ERK1/2 activation similarly to that of Gab1(DeltaSHP2), suggesting that Gab1-SHP2 complex inhibits IGF-I-dependent myogenesis through ERK1/2. Consistently, the blockade of ERK1/2 pathway reversed the inhibitory effect of Gab1(WT) overexpression on myogenic differentiation, and constitutive activation of the ERK1/2 pathway suppressed the enhanced myogenic differentiation by overexpression of Gab1(DeltaSHP2). Collectively, these data suggest that the Gab1-SHP2-ERK1/2 signaling pathway comprises an inhibitory axis for IGF-I-dependent myogenic differentiation.
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Affiliation(s)
- Tatsuya Koyama
- Department of Structural Analysis, National Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka, Japan
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Fourmentraux-Neves E, Jalil A, Da Rocha S, Pichon C, Chouaib S, Bismuth G, Caignard A. Two opposite signaling outputs are driven by the KIR2DL1 receptor in human CD4+ T cells. Blood 2008; 112:2381-9. [PMID: 18574028 DOI: 10.1182/blood-2007-12-127779] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Inhibitory killer Ig-like receptors (KIR), expressed by human natural killer cells and effector memory CD8(+) T-cell subsets, bind HLA-C molecules and suppress cell activation through recruitment of the Src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP-1). To further analyze the still largely unclear role of inhibitory KIR receptors on CD4(+) T cells, KIR2DL1 transfectants were obtained from a CD4(+) T-cell line and primary cells. Transfection of CD4(+) T cells with KIR2DL1 dramatically increased the T-cell receptor (TCR)-induced production of interleukin-2 independently of ligand binding but inhibited TCR-induced activation after ligation. KIR-mediated costimulation of TCR activation involves intact KIR2DL1-ITIM phosphorylation, SHP-2 recruitment, and PKC- phosphorylation. Synapses leading to activation were characterized by an increase in the recruitment of p-Tyr, SHP-2, and p-PKC-, but not of SHP-1. Interaction of KIR2DL1 with its ligand led to a strong synaptic accumulation of KIR2DL1 and the recruitment of SHP-1/2, inhibiting TCR-induced interleukin-2 production. KIR2DL1 may induce 2 opposite signaling outputs in CD4(+) T cells, depending on whether the KIR receptor is bound to its ligand. These data highlight unexpected aspects of the regulation of T cells by KIR2DL1 receptors, the therapeutic manipulation of which is currently being evaluated.
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Abstract
Protein tyrosine phosphatases (PTPases) are attractive targets for developing novel cancer therapeutics. Activated via gain-of-function point mutations or overexpression, several PTPases have been identified as critical oncogenic molecules in human malignancies that may be targeted with small chemical inhibitors as a therapeutic strategy. Tumor suppressor PTPases have also been discovered as contributing factors in cancer development that may be targeted via intervention of downstream signaling events for therapeutic purposes. In addition, PTPases have been identified as key negative regulators of cytokines or immune cells. Targeting these negative PTPases may improve the efficacy of cytokine therapy and immunotherapy, which currently have modest response rates and limited survival benefit. Inhibitors of selective PTPases have demonstrated significant preclinical antitumor activity, leading to early-phase clinical trials. Further research and development could lead to PTPase-targeted cancer therapeutics in the near future.
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Kontaridis MI, Yang W, Bence KK, Cullen D, Wang B, Bodyak N, Ke Q, Hinek A, Kang PM, Liao R, Neel BG. Deletion of Ptpn11 (Shp2) in cardiomyocytes causes dilated cardiomyopathy via effects on the extracellular signal-regulated kinase/mitogen-activated protein kinase and RhoA signaling pathways. Circulation 2008; 117:1423-35. [PMID: 18316486 DOI: 10.1161/circulationaha.107.728865] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Heart failure is the leading cause of death in the United States. By delineating the pathways that regulate cardiomyocyte function, we can better understand the pathogenesis of cardiac disease. Many cardiomyocyte signaling pathways activate protein tyrosine kinases. However, the role of specific protein tyrosine phosphatases (PTPs) in these pathways is unknown. METHODS AND RESULTS Here, we show that mice with muscle-specific deletion of Ptpn11, the gene encoding the SH2 domain-containing PTP Shp2, rapidly develop a compensated dilated cardiomyopathy without an intervening hypertrophic phase, with signs of cardiac dysfunction appearing by the second postnatal month. Shp2-deficient primary cardiomyocytes are defective in extracellular signal-regulated kinase/mitogen-activated protein kinase (Erk/MAPK) activation in response to a variety of soluble agonists and pressure overload but show hyperactivation of the RhoA signaling pathway. Treatment of primary cardiomyocytes with Erk1/2- and RhoA pathway-specific inhibitors suggests that both abnormal Erk/MAPK and RhoA activities contribute to the dilated phenotype of Shp2-deficient hearts. CONCLUSIONS Our results identify Shp2 as the first PTP with a critical role in adult cardiac function, indicate that in the absence of Shp2 cardiac hypertrophy does not occur in response to pressure overload, and demonstrate that the cardioprotective role of Shp2 is mediated via control of both the Erk/MAPK and RhoA signaling pathways.
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Affiliation(s)
- Maria I Kontaridis
- Cancer Biology Program, Department of Medicine, Beth Israel Deaconess Medical Center, NRB, Room 1036, 77 Ave Louis Pasteur, Boston, MA 02115, USA.
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Ha CH, Bennett AM, Jin ZG. A novel role of vascular endothelial cadherin in modulating c-Src activation and downstream signaling of vascular endothelial growth factor. J Biol Chem 2008; 283:7261-70. [PMID: 18180305 DOI: 10.1074/jbc.m702881200] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Vascular endothelial growth factor (VEGF) is a potent mediator of angiogenesis and vascular permeability, in which c-Src tyrosine kinase plays an essential role. However, the mechanisms by which VEGF stimulates c-Src activation have remained unclear. Here, we demonstrate that vascular endothelial cadherin (VE-cadherin) plays a critical role in regulating c-Src activation in response to VEGF. In vascular endothelial cells, VE-cadherin was basally associated with c-Src and Csk (C-terminal Src kinase), a negative regulator of Src activation. VEGF stimulated Csk release from VE-cadherin by recruiting the protein tyrosine phosphatase SHP2 to VE-cadherin signaling complex, leading to an increase in c-Src activation. Silencing VE-cadherin with small interference RNA significantly reduced VEGF-stimulated c-Src activation. Disrupting the association of VE-cadherin and Csk through the reconstitution of Csk binding-defective mutant of VE-cadherin also diminished Src activation. Moreover, inhibiting SHP2 by small interference RNA and adenovirus-mediated expression of a catalytically inactive mutant of SHP2 attenuated c-Src activation by blocking the disassociation of Csk from VE-cadherin. Furthermore, VE-cadherin and SHP2 differentially regulates VEGF downstream signaling. The inhibition of c-Src, VE-cadherin, and SHP2 diminished VEGF-mediated activation of Akt and endothelial nitric-oxide synthase. In contrast, inhibiting VE-cadherin and SHP2 enhanced ERK1/2 activation in response to VEGF. These findings reveal a novel role for VE-cadherin in modulating c-Src activation in VEGF signaling, thus providing new insights into the importance of VE-cadherin in VEGF signaling and vascular function.
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Affiliation(s)
- Chang Hoon Ha
- Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, Rochester, New York 14586, USA
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Ruhul Amin ARM, Uddin Biswas MH, Senga T, Feng GS, Kannagi R, Agarwal ML, Hamaguchi M. A role for SHPS-1/SIRPalpha in Concanavalin A-dependent production of MMP-9. Genes Cells 2007; 12:1023-33. [PMID: 17825046 DOI: 10.1111/j.1365-2443.2007.01115.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
SHPS-1/SIRPalpha1 is a transmembrane glycoprotein that belongs to the immunoglobulin (Ig) super family. In the present study, we show that SHPS-1 strongly associates with Concanavalin A (Con A), a plant lectin obtained from jack beans. Further studies with SHPS-1 mutants reveal that the extracellular domain of SHPS-1 containing the Ig sequence is responsible for its association with Con A. Con A treatment induces cross-linking and multimerization of the SHPS-1 protein in the plasma membrane, accompanied by its tyrosine phosphorylation and recruitment of SHP-2. In contrast, Ricinus communis agglutinin (RCA), another lectin obtained from castor bean, does not bind or activate tyrosine phosphorylation of SHPS-1. Moreover, Con A activates Akt in a SHP-2-dependent manner. Treatment of mouse embryonic fibroblasts (MEFs) with Con A induces secretion of matrix metalloproteinase (MMP)-9, a phenomenon that is inhibited in cells expressing YF mutant of SHPS-1, a dominant negative form of Akt or in cells pre-treated with an Akt inhibitor, LY294002 or extracellular-signal regulated kinase (Erk) inhibitor, U0126. In addition, expression of the YF mutant of SHPS-1 inhibits Con A-dependent activation of Akt and Erk kinases. Taken together, our results suggest that SHPS-1 is a receptor for Con A that mediates Con A-dependent MMP-9 secretion through SHP-2-promoted activation of both Akt and Erk pathways.
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Affiliation(s)
- A R M Ruhul Amin
- Division of Cancer Biology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan
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Nakamura T, Colbert M, Krenz M, Molkentin JD, Hahn HS, Dorn GW, Robbins J. Mediating ERK 1/2 signaling rescues congenital heart defects in a mouse model of Noonan syndrome. J Clin Invest 2007; 117:2123-32. [PMID: 17641779 PMCID: PMC1913487 DOI: 10.1172/jci30756] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Accepted: 05/08/2007] [Indexed: 01/20/2023] Open
Abstract
Noonan syndrome (NS) is an autosomal dominant disorder characterized by a wide spectrum of defects, which most frequently include proportionate short stature, craniofacial anomalies, and congenital heart disease (CHD). NS is the most common nonchromosomal cause of CHD, and 80%-90% of NS patients have cardiac involvement. Mutations within the protein tyrosine phosphatase Src homology region 2, phosphatase 2 (SHP2) are responsible for approximately 50% of the cases of NS with cardiac involvement. To understand the developmental stage- and cell type-specific consequences of the NS SHP2 gain-of-function mutation, Q79R, we generated transgenic mice in which the mutated protein was expressed during gestation or following birth in cardiomyocytes. Q79R SHP2 embryonic hearts showed altered cardiomyocyte cell cycling, ventricular noncompaction, and ventricular septal defects, while, in the postnatal cardiomyocyte, Q79R SHP2 expression was completely benign. Fetal expression of Q79R led to the specific activation of the ERK1/2 pathway, and breeding of the Q79R transgenics into ERK1/2-null backgrounds confirmed the pathway's necessity and sufficiency in mediating mutant SHP2's effects. Our data establish the developmental stage-specific effects of Q79R cardiac expression in NS; show that ablation of subsequent ERK1/2 activation prevents the development of cardiac abnormalities; and suggest that ERK1/2 modulation could have important implications for developing therapeutic strategies in CHD.
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MESH Headings
- Amino Acid Substitution
- Animals
- Chromosome Disorders/embryology
- Chromosome Disorders/enzymology
- Chromosome Disorders/genetics
- Chromosome Disorders/pathology
- Chromosome Disorders/therapy
- Disease Models, Animal
- Gene Expression Regulation, Developmental/genetics
- Gene Expression Regulation, Enzymologic/genetics
- Heart Septal Defects, Ventricular/embryology
- Heart Septal Defects, Ventricular/enzymology
- Heart Septal Defects, Ventricular/genetics
- Heart Septal Defects, Ventricular/pathology
- Heart Septal Defects, Ventricular/prevention & control
- Heart Ventricles/embryology
- Heart Ventricles/enzymology
- Heart Ventricles/pathology
- Humans
- Intracellular Signaling Peptides and Proteins/genetics
- MAP Kinase Signaling System/genetics
- Mice
- Mice, Transgenic
- Mitogen-Activated Protein Kinase 1/genetics
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3/genetics
- Mitogen-Activated Protein Kinase 3/metabolism
- Mutation, Missense
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/pathology
- Noonan Syndrome/embryology
- Noonan Syndrome/enzymology
- Noonan Syndrome/genetics
- Noonan Syndrome/pathology
- Noonan Syndrome/therapy
- Protein Phosphatase 2
- Protein Tyrosine Phosphatase, Non-Receptor Type 11
- Protein Tyrosine Phosphatases/biosynthesis
- Protein Tyrosine Phosphatases/genetics
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Affiliation(s)
- Tomoki Nakamura
- Cincinnati Children’s Hospital Medical Center, The Children’s Hospital Research Foundation, Division of Molecular Cardiovascular Biology, Cincinnati, Ohio, USA.
Department of Internal Medicine and Department of Cardiology, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
| | - Melissa Colbert
- Cincinnati Children’s Hospital Medical Center, The Children’s Hospital Research Foundation, Division of Molecular Cardiovascular Biology, Cincinnati, Ohio, USA.
Department of Internal Medicine and Department of Cardiology, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
| | - Maike Krenz
- Cincinnati Children’s Hospital Medical Center, The Children’s Hospital Research Foundation, Division of Molecular Cardiovascular Biology, Cincinnati, Ohio, USA.
Department of Internal Medicine and Department of Cardiology, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
| | - Jeffery D. Molkentin
- Cincinnati Children’s Hospital Medical Center, The Children’s Hospital Research Foundation, Division of Molecular Cardiovascular Biology, Cincinnati, Ohio, USA.
Department of Internal Medicine and Department of Cardiology, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
| | - Harvey S. Hahn
- Cincinnati Children’s Hospital Medical Center, The Children’s Hospital Research Foundation, Division of Molecular Cardiovascular Biology, Cincinnati, Ohio, USA.
Department of Internal Medicine and Department of Cardiology, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
| | - Gerald W. Dorn
- Cincinnati Children’s Hospital Medical Center, The Children’s Hospital Research Foundation, Division of Molecular Cardiovascular Biology, Cincinnati, Ohio, USA.
Department of Internal Medicine and Department of Cardiology, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
| | - Jeffrey Robbins
- Cincinnati Children’s Hospital Medical Center, The Children’s Hospital Research Foundation, Division of Molecular Cardiovascular Biology, Cincinnati, Ohio, USA.
Department of Internal Medicine and Department of Cardiology, University of Cincinnati Medical Center, Cincinnati, Ohio, USA
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27
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Chong ZZ, Maiese K. The Src homology 2 domain tyrosine phosphatases SHP-1 and SHP-2: diversified control of cell growth, inflammation, and injury. Histol Histopathol 2007; 22:1251-67. [PMID: 17647198 PMCID: PMC2515712 DOI: 10.14670/hh-22.1251] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Interest in the diverse biology of protein tyrosine phosphatases that are encoded by more than 100 genes in the human genome continues to grow at an accelerated pace. In particular, two cytoplasmic protein tyrosine phosphatases composed of two Src homology 2 (SH2) NH2-terminal domains and a C-terminal protein-tyrosine phosphatase domain referred to as SHP-1 and SHP-2 are known to govern a host of cellular functions. SHP-1 and SHP-2 modulate progenitor cell development, cellular growth, tissue inflammation, and cellular chemotaxis, but more recently the role of SHP-1 and SHP-2 to directly control cell survival involving oxidative stress pathways has come to light. SHP-1 and SHP-2 are fundamental for the function of several growth factor and metabolic pathways yielding far reaching implications for disease pathways and disorders such as diabetes, neurodegeneration, and cancer. Although SHP-1 and SHP-2 can employ similar or parallel cellular pathways, these proteins also clearly exert opposing effects upon downstream cellular cascades that affect early and late apoptotic programs. SHP-1 and SHP-2 modulate cellular signals that involve phosphatidylinositol 3-kinase, Akt, Janus kinase 2, signal transducer and activator of transcription proteins, mitogen-activating protein kinases, extracellular signal-related kinases, c-Jun-amino terminal kinases, and nuclear factor-kappaB. Our progressive understanding of the impact of SHP-1 and SHP-2 upon multiple cellular environments and organ systems should continue to facilitate the targeted development of treatments for a variety of disease entities.
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Affiliation(s)
- Z Z Chong
- Division of Cellular and Molecular Cerebral Ischemia, Institute of Environmental Health Sciences, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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28
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Guo HB, Randolph M, Pierce M. Inhibition of a specific N-glycosylation activity results in attenuation of breast carcinoma cell invasiveness-related phenotypes: inhibition of epidermal growth factor-induced dephosphorylation of focal adhesion kinase. J Biol Chem 2007; 282:22150-62. [PMID: 17537730 DOI: 10.1074/jbc.m611518200] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Changes in the expression of glycosyltransferases that branch N-linked glycans can alter the function of several types of cell surface receptors and a glucose transporter. To study in detail the mechanisms by which aberrant N-glycosylation caused by altered N-acetylglucosaminyltransferase V(GnT-V, GnT-Va, and Mgat5a) expression can regulate the invasiveness-related phenotypes found in some carcinomas, we utilized specific small interfering RNA (siRNA) to selectively knock down GnT-V expression in the highly metastatic and invasive human breast carcinoma cell line, MDA-MB231. Knockdown of GnT-V by siRNA expression had no effect on epidermal growth factor receptor expression levels but lowered expression of N-linked beta(1,6)-branching on epidermal growth factor receptor, as expected. Compared with control cells, knockdown of GnT-V caused significant inhibition of the morphological changes and cell detachment from matrix that is normally seen after stimulation with epidermal growth factor (EGF). Decreased expression of GnT-V caused a marked inhibition of EGF-induced dephosphorylation of focal adhesion kinase (FAK), consistent with the lack of cell morphology changes in the cells expressing GnT-V siRNA. The attenuation of EGF-mediated phosphorylation and activation of the tyrosine phosphatase SHP-2 was dramatically observed in GnT-V knockdown cells, and these effects could be rescued by reintroduction of GnT-V into these cells, indicating that reduced EGF-mediated activation of SHP-2 was GnT-V related. Concomitantly, knockdown of GnT-V caused reduced EGF-mediated ERK signaling and tumor cell invasiveness-related phenotypes, including effects on actin rearrangement and cell motility. No changes in EGF binding were observed, however, after knockdown of GnT-V. Our results demonstrate that decreased GnT-V activity due to siRNA expression in human breast carcinoma cells resulted in an inhibition of EGF-stimulated SHP-2 activation and, consequently, caused attenuation of the dephosphorylation of FAK induced by EGF. These effects suppressed EGF-mediated downstream signaling and invasiveness-related phenotypes and suggest GnT-V as a potential therapeutic target.
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Affiliation(s)
- Hua-Bei Guo
- Department of Biochemistry and Molecular Biology, Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA
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29
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Amin ARMR, Thakur VS, Paul RK, Feng GS, Qu CK, Mukhtar H, Agarwal ML. SHP-2 tyrosine phosphatase inhibits p73-dependent apoptosis and expression of a subset of p53 target genes induced by EGCG. Proc Natl Acad Sci U S A 2007; 104:5419-24. [PMID: 17369354 PMCID: PMC1838507 DOI: 10.1073/pnas.0700642104] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Green tea polyphenol, epigallocatechin-3-gallate (EGCG) differentially regulates the cellular growth of cancer cells in a p53-dependent manner through apoptosis and/or cell cycle arrest. In an effort to further elucidate the mechanism of differential growth regulation by EGCG, we have investigated the role of the tyrosine phosphatase, SHP-2. Comparing the responses of mouse embryonic fibroblasts (MEFs), expressing either WT or functionally inactive/truncated SHP-2, we find that inactivation of SHP-2 remarkably sensitizes cells to EGCG-mediated killing. MEFs lacking functional SHP-2 undergo massive apoptosis upon treatment with EGCG. By comparing gene expression profiles, we have identified a set of transcriptional targets of p53 that are differentially modulated in cells undergoing apoptosis. Western blot and real-time PCR analyses of a select group of genes further confirm that the expression is SHP-2-dependent. Similar observations were made in MEFs lacking p53, confirming that the expression of these "p53 target genes" is p53-independent. In addition, EGCG treatment induced the expression of p73 mRNA and protein in both cell types, but not p63. Inactivation of p73 in cells expressing nonfunctional SHP-2 markedly inhibited apoptosis and p53 target gene expression. Although phosphorylation of JNK is differentially regulated by SHP2, it was found to be dispensable for EGCG-induced apoptosis and p53 target gene expression. Our results have identified SHP-2 as a negative regulator of EGCG-induced-apoptosis and have identified a subset of p53 target genes whose expression is paradoxically not mediated by p53 but by one of its family members, p73.
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Affiliation(s)
| | | | | | | | - Cheng-Kui Qu
- Hematology and Oncology, Case Western Reserve University, Cleveland, OH 44106
| | | | - Munna L. Agarwal
- Departments of *Genetics and
- To whom correspondence should be addressed. E-mail:
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30
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Abstract
A key issue to be addressed in stem cell biology is the molecular signaling mechanism controlling embryonic stem (ES) cell pluripotency. Stem cell properties are dictated by specific transcription factors and epigenetic processes such as DNA methylation and chromatin remodeling. Several cytokines/growth factors have been identified as critical ES cell regulators. However, there is a gap in our knowledge of the intracellular signaling pathways linking extracellular signals to transcriptional regulation in ES cells. This short review discusses the physiological role of Shp2, a cytoplasmic tyrosine phosphatase, in the molecular switch governing ES cell self-renewal versus differentiation. Shp2 promotes ES cell differentiation, mainly through bi-directional modulation of Erk and Stat3 pathways. Deletion of Shp2 in mouse ES cells results in more efficient self-renewal. This observation provides the impetus to develop Shp2 inhibitors for maintenance and amplification of ES cells in culture.
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Affiliation(s)
- Gen-Sheng Feng
- Programs in Signal Transduction and Stem Cells and Regeneration, Burnham Institute for Medical Research, 10901 N. Torrey Pines Rd, La Jolla, CA 92037, USA.
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31
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Abstract
We present here a computational, rule-based model to study the function of the SH2 domain-containing protein tyrosine phosphatase, Shp2, in intracellular signal transduction. The two SH2 domains of Shp2 differentially regulate the enzymatic activity by a well-characterized mechanism, but they also affect the targeting of Shp2 to signaling receptors in cells. Our kinetic model integrates these potentially competing effects by considering the intra- and intermolecular interactions of the Shp2 SH2 domains and catalytic site as well as the effect of Shp2 phosphorylation. Even for the isolated Shp2/receptor system, which may seem simple by certain standards, we find that the network of possible binding and phosphorylation states is composed of over 1000 members. To our knowledge, this is the first kinetic model to fully consider the modular, multifunctional structure of a signaling protein, and the computational approach should be generally applicable to other complex intermolecular interactions.
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Affiliation(s)
- Dipak Barua
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA
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32
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Duan HF, Qu CK, Zhang QW, Yu WM, Wang H, Wu CT, Wang LS. Shp-2 tyrosine phosphatase is required for hepatocyte growth factor-induced activation of sphingosine kinase and migration in embryonic fibroblasts. Cell Signal 2006; 18:2049-55. [PMID: 16765027 DOI: 10.1016/j.cellsig.2006.04.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Revised: 04/08/2006] [Accepted: 04/19/2006] [Indexed: 10/24/2022]
Abstract
Shp-2, a ubiquitously expressed protein tyrosine phosphatase containing two Src homology 2 domains, plays an important role in integrating signaling from the cell surface receptors to intracellular signaling mechanisms. Previous studies have demonstrated that the Shp-2 is involved in hepatocyte growth factor (HGF)-induced cell scattering. Here we report that Shp-2 is required for the HGF-induced activation of sphingosine kinase-1 (SPK1), a highly conserved lipid kinase that plays an important role in cell migration. Loss-of-function mutation of Shp-2 did not affect the expression of SPK1, but resulted in its inactivation and the blockage of HGF-induced migration in embryonic fibroblasts. Reintroduction of functional wild type (WT) Shp-2 into the mutant cells partially restored SPK1 activation, and overexpression of SPK1 in these mutant cells enhanced HGF-induced cell migration. Inhibition of expression or activity of SPK1 in WT cells markedly decreased intracellular S1P levels and HGF-induced cell migration. Furthermore, we found that Shp-2 co-immunoprecipitated with SPK1 and c-Met in embryonic fibroblasts. These studies suggest that Shp-2 is an SPK1-interacting protein and that it plays an indispensable role in HGF-induced SPK1 activation.
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Affiliation(s)
- Hai-Feng Duan
- Department of Experimental Hematology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Beijing 100850, P.R. China
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Chan RJ, Li Y, Hass MN, Walter A, Voorhorst CS, Shelley WC, Yang Z, Orschell CM, Yoder MC. Shp-2 heterozygous hematopoietic stem cells have deficient repopulating ability due to diminished self-renewal. Exp Hematol 2006; 34:1230-9. [PMID: 16939816 DOI: 10.1016/j.exphem.2006.04.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Revised: 04/14/2006] [Accepted: 04/17/2006] [Indexed: 10/24/2022]
Abstract
OBJECTIVE Improved understanding of hematopoietic stem cell (HSC) differentiation, proliferation, and self-renewal is sought to develop improved stem cell-based therapies as well as to define novel therapies for stem cell-based diseases such as leukemia. Shp-2 is a widely expressed nonreceptor protein tyrosine phosphatase that participates early in hematopoietic development. The following study was performed to examine the role of Shp-2 in HSC function. METHODS Bone marrow low-density mononuclear cells were isolated from WT and Shp-2(+/-) littermate controls and utilized in competitive repopulation studies, homing analysis, cell-cycle analysis, and serial transplantation studies. RESULTS Haploinsufficiency of Shp-2 causes a threefold reduction in HSC repopulating units following transplantation into lethally irradiated recipients. Homing of Shp-2(+/-) and WT cells to the bone marrow and spleen compartments was equal. Cell-cycle analysis studies revealed that the Shp-2(+/-) lin(-)Sca-1(+)c-kit(+) cells are less quiescent than WT cells, providing a potential etiology for the observed reduced engraftment of the Shp-2(+/-) cells. Consistently, in serial transplantation studies, we observed a significant reduction of Shp-2(+/-) self-renewal compared to that of WT cells. CONCLUSION These data demonstrate that Shp-2 is required for the physiologic homeostasis of the HSC compartment and potentially provide insight into how oncogenic Shp-2 may contribute to the pathogenesis of myeloproliferative disorders and leukemias.
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Affiliation(s)
- Rebecca J Chan
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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34
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Abstract
Elucidation of the molecular mechanisms underlying carcinogenesis has benefited tremendously from the identification and characterization of oncogenes and tumor suppressor genes. One new advance in this field is the identification of PTPN11 as the first proto-oncogene that encodes a cytoplasmic tyrosine phosphatase with 2 Src-homology 2 (SH2) domains (Shp2). This tyrosine phosphatase was previously shown to play an essential role in normal hematopoiesis. More recently, somatic missense PTPN11 gain-of-function mutations have been detected in leukemias and rarely in solid tumors, and have been found to induce aberrant hyperactivation of the Ras-Erk pathway. This progress represents another milestone in the leukemia/cancer research field and provides a fresh view on the molecular mechanisms underlying cell transformation.
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Affiliation(s)
- Rebecca J Chan
- Department of Pediatrics, the Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, USA
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35
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Fu Z, Huang D, Cai J, Chen Q, Han L, Li B, Wang F, Gao J. Expression changes of ERK1/2, STAT3 and SHP-2 in bone marrow cells from gamma-ray induced leukemia mice. J Radiat Res 2006; 47:121-30. [PMID: 16819138 DOI: 10.1269/jrr.47.121] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The aim is to clarify expression changes of ERK1/2, STAT3 and SHP-2 in bone marrow cells from gamma-ray induced leukemia mice. A mouse model of gamma-ray induced leukemia was produced, and by means of quantitative real-time PCR, immunoprecipitation, Western blotting and electrophoretic mobility shift assays (EMSA), the expression of mRNA and protein, phosphorylation level, and protein activity of ERK1/2, STAT3 and SHP-2 in bone marrow cells were investigated in these mice. The results indicated that mRNA and protein expressions of ERK1/2 were upregulated, with significant increase of phosphorylation level and protein activity, but with insignificant differences in mRNA and protein expressions, phosphorylation level and protein activity of STAT3 and SHP-2 in bone marrow cells from gamma-ray induced leukemia mice compared to the radiation/tumor-free or control mice. It is concluded that in the pathogenesis of gamma-ray induced leukemia in Balb/C mice, activated ERK1/2 pathway may play a role, without involving STAT3 pathway; meanwhile, SHP-2 exerts no regulative effect on pathways of Ras-ERK1/2 and JAK-STAT.
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Affiliation(s)
- Zhichao Fu
- Department of Radiotherapy, General Hospital of Fuzhou Military Command, China
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36
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Tan EY, Richard CL, Zhang H, Hoskin DW, Blay J. Adenosine downregulates DPPIV on HT-29 colon cancer cells by stimulating protein tyrosine phosphatase(s) and reducing ERK1/2 activity via a novel pathway. Am J Physiol Cell Physiol 2006; 291:C433-44. [PMID: 16611738 DOI: 10.1152/ajpcell.00238.2005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The multifunctional cell-surface protein dipeptidyl peptidase IV (DPPIV/CD26) is aberrantly expressed in many cancers and plays a key role in tumorigenesis and metastasis. Its diverse cellular roles include modulation of chemokine activity by cleaving dipeptides from the chemokine NH(2)-terminus, perturbation of extracellular nucleoside metabolism by binding the ecto-enzyme adenosine deaminase, and interaction with the extracellular matrix by binding proteins such as collagen and fibronectin. We have recently shown that DPPIV can be downregulated from the cell surface of HT-29 colorectal carcinoma cells by adenosine, which is a metabolite that becomes concentrated in the extracellular fluid of hypoxic solid tumors. Most of the known responses to adenosine are mediated through four different subtypes of G protein-coupled adenosine receptors: A(1), A(2A), A(2B), and A(3). We report here that adenosine downregulation of DPPIV from the surface of HT-29 cells occurs independently of these classic receptor subtypes, and is mediated by a novel cell-surface mechanism that induces an increase in protein tyrosine phosphatase activity. The increase in protein tyrosine phosphatase activity leads to a decrease in the tyrosine phosphorylation of ERK1/2 MAP kinase that in turn links to the decline in DPPIV mRNA and protein. The downregulation of DPPIV occurs independently of changes in the activities of protein kinases A or C, phosphatidylinositol 3-kinase, other serine/threonine phosphatases, or the p38 or JNK MAP kinases. This novel action of adenosine has implications for our ability to manipulate adenosine-dependent events within the solid tumor microenvironment.
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Affiliation(s)
- Ernest Y Tan
- Department of Pharmacology, Faculty of Medicine, Sir Charles Tupper Medical Bldg., Dalhousie University, 1459 Oxford St., Halifax, Nova Scotia, Canada B3H 1X5
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37
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Easton JB, Royer AR, Middlemas DS. The protein tyrosine phosphatase, Shp2, is required for the complete activation of the RAS/MAPK pathway by brain-derived neurotrophic factor. J Neurochem 2006; 97:834-45. [PMID: 16573649 DOI: 10.1111/j.1471-4159.2006.03789.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) and other neurotrophins induce a unique prolonged activation of mitogen-activated protein kinase (MAPK) compared with growth factors. Characterization and kinetic and spatial modeling of the signaling pathways underlying this prolonged MAPK activation by BDNF will be important in understanding the physiological role of BDNF in many complex systems in the nervous system. In addition to Shc, fibroblast growth factor receptor substrate 2 (FRS2) is required for the BDNF-induced activation of MAPK. BDNF induces phosphorylation of FRS2. However, BDNF does not induce phosphorylation of FRS2 in cells expressing a deletion mutant of TrkB (TrkBDeltaPTB) missing the juxtamembrane NPXY motif. This motif is the binding site for SHC. NPXY is the consensus sequence for phosphotyrosine binding (PTB) domains, and notably, FRS2 and SHC contain PTB domains. This NPXY motif, which contains tyrosine 484 of TrkB, is therefore the binding site for both FRS2 and SHC. Moreover, the proline containing region (VIENP) of the NPXY motif is also required for FRS2 and SHC phosphorylation, which indicates this region is an important component of FRS2 and SHC recognition by TrkB. Previously, we had found that the phosphorylation of FRS2 induces association of FRS2 and growth factor receptor binding protein 2 (Grb2). Now, we have intriguing data that indicates BDNF induces association of the SH2 domain containing protein tyrosine phosphatase, Shp2, with FRS2. Moreover, the PTB association motif of TrkB containing tyrosine 484 is required for the BDNF-induced association of Shp2 with FRS2 and the phosphorylation of Shp2. These results imply that FRS2 and Shp2 are in a BDNF signaling pathway. Shp2 is required for complete MAPK activation by BDNF, as expression of a dominant negative Shp2 in cells attenuates BDNF-induced activation of MAPK. Moreover, expression of a dominant negative Shp2 attenuates Ras activation showing that the protein tyrosine phosphatase is required for complete activation of MAPKs by BDNF. In conclusion, Shp2 regulates BDNF signaling through the MAPK pathway by regulating either Ras directly or alternatively, by signaling components upstream of Ras. Characterization of MAPK signaling controlled by BDNF is likely to be required to understand the complex physiological role of BDNF in neuronal systems ranging from the regulation of neuronal growth and survival to the regulation of synapses.
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Affiliation(s)
- John B Easton
- Department of Molecular Pharmacology, St Jude Children's Research Hospital, North Lauderdale, Memphis, Tennessee, USA
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38
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Salmond RJ, Alexander DR. SHP2 forecast for the immune system: fog gradually clearing. Trends Immunol 2006; 27:154-60. [PMID: 16458607 DOI: 10.1016/j.it.2006.01.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2005] [Revised: 12/21/2005] [Accepted: 01/19/2006] [Indexed: 01/22/2023]
Abstract
The src homology 2 (SH2) domain containing tyrosine phosphatase SHP2 (also referred to as SHP-2) is ubiquitously expressed in mammalian tissues and has been shown to be essential for embryonic development, haematopoiesis and signalling downstream of a variety of growth factors. Dysregulation of SHP2 function or expression has recently been implicated in the pathogenesis of human diseases involving haematopoietic cell lineages. New findings also demonstrate the involvement of SHP2 in the regulation of immune responses through its effects on cytokine and inhibitory receptor signalling pathways, and novel transgenic models are providing valuable insights into the role of SHP2 in T cells.
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Affiliation(s)
- Robert J Salmond
- Laboratory of Lymphocyte Signalling and Development, The Babraham Institute, Babraham, Cambridge, UK, CB2 4AT.
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Yuan L, Yu WM, Xu M, Qu CK. SHP-2 Phosphatase Regulates DNA Damage-induced Apoptosis and G2/M Arrest in Catalytically Dependent and Independent Manners, Respectively. J Biol Chem 2005; 280:42701-6. [PMID: 16260787 DOI: 10.1074/jbc.m506768200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
SHP-2, a tyrosine phosphatase implicated in diverse signaling pathways induced by growth factors and cytokines, is also involved in DNA damage-triggered signaling and cellular responses. We previously demonstrated that SHP-2 played an important role in DNA damage-induced apoptosis and G2/M cell cycle checkpoint. In the present studies, we have provided evidence that SHP-2 functions in DNA damage apoptosis and G2/M arrest in catalytically dependent and independent manners, respectively. Mutant embryonic fibroblasts with the Exon 3 deletion mutation in SHP-2 showed decreased apoptosis and diminished G2/M arrest in response to cisplatin treatment. Wild type (WT), but not catalytically inactive mutant SHP-2 (SHP-2 C459S), rescued the apoptotic response of the mutant cells. Interestingly, both WT and SHP-2 C459S efficiently restored the G2/M arrest response. Furthermore, inhibition of the catalytic activity of endogenous SHP-2 in WT cells by overexpression of SHP-2 C459S greatly decreased cell death but not G2/M arrest induced by cisplatin. Biochemical analyses revealed that activation of c-Abl kinase was decreased in SHP-2 C459S-overexpressing cells. However, DNA damage-induced translocation of Cdc25C from the nucleus to the cytoplasm was fully restored in both WT and SHP-2 C459S "rescued" cells. Additionally, we demonstrated that the role of SHP-2 in DNA damage-induced cellular responses was independent of the tumor suppressor p53. Embryonic stem cells with the SHP-2 deletion mutation showed markedly decreased sensitivity to cisplatin-induced apoptosis, attributed to impaired induction of p73 but not p53. In agreement with these results, DNA damage-induced apoptosis and G2/M arrest were also decreased in SHP-2/p53 double mutant embryonic fibroblasts. Collectively, these studies have further defined the mechanisms by which SHP-2 phosphatase regulates DNA damage responses.
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Affiliation(s)
- Liangping Yuan
- Department of Medicine, Division of Hematology/Oncology, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Krenz M, Yutzey KE, Robbins J. Noonan syndrome mutation Q79R in Shp2 increases proliferation of valve primordia mesenchymal cells via extracellular signal-regulated kinase 1/2 signaling. Circ Res 2005; 97:813-20. [PMID: 16166557 PMCID: PMC1388074 DOI: 10.1161/01.res.0000186194.06514.b0] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The molecular pathways regulating valve development are only partially understood. Recent studies indicate that dysregulation of mitogen-activated protein kinase (MAPK) signaling might play a major role in the pathogenesis of congenital valvular malformations, and, in this study, we explored the role of extracellular signal-regulated kinase (ERK) 1/2 activation in valve primordia expressing the Noonan syndrome mutation Q79R-Shp2. Noonan syndrome is an autosomal dominant disease characterized by dysmorphic features and cardiac abnormalities, with frequent pulmonic stenosis. The Q79R mutation of PTPN11 previously identified in Noonan syndrome families results in a gain-of-function of the encoded protein tyrosine phosphatase Shp2. We compared the effects of wild-type Shp2 and Q79R-Shp2 on endocardial cushion development. Atrioventricular and outflow tract endocardial cushions were excised from chick embryos, infected with wild-type Shp2 or Q79R-Shp2 adenovirus and embedded in a gel matrix. Q79R-Shp2, but not wild-type-Shp2, expression resulted in increased outgrowth of cells into the gel. The dependence of the Q79R-Shp2 effect on ERK1/2 and p38 MAPK signaling was then determined. The MAPK/ERK kinase (MEK)-1 inhibitor U0126, but not the p38-MAPK pathway inhibitor SB203580, abolished the effect of Q79R-Shp2 on cushion outgrowth. Coinfection with Q79R-Shp2 and dominant negative MEK-1 prevented enhanced endocardial cushion outgrowth, whereas expression of constitutively active MEK-1 mimicked the effect of Q79R-Shp2. Furthermore, dissociated cushion cells displayed increased 5-bromodeoxyuridine incorporation when infected with Q79R-Shp2 but not with wild-type Shp2. This promitotic effect was eliminated by U0126. Our results demonstrate that ERK1/2 activation is both necessary and sufficient to mediate the hyperproliferative effect of a gain-of-function mutation of Shp2 on mesenchymal cells in valve primordia.
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Affiliation(s)
| | | | - Jeffrey Robbins
- ¶Correspondence to: Jeffrey Robbins, Division of Molecular Cardiovascular Biology, 3333 Burnet Avenue, Cincinnati, OH 45229-3039. Tel.: 513-636-8098; Fax: 513-636-5958; E-mail:
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Sun H, Shen Y, Dokainish H, Holgado-Madruga M, Wong A, Ireton K. Host adaptor proteins Gab1 and CrkII promote InlB-dependent entry of Listeria monocytogenes. Cell Microbiol 2005; 7:443-57. [PMID: 15679846 DOI: 10.1111/j.1462-5822.2004.00475.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The bacterial surface protein InlB mediates internalization of Listeria monocytogenes into mammalian cells through interaction with the host receptor tyrosine kinase, Met. InlB/Met interaction results in activation of the host phosphoinositide (PI) 3-kinase p85-p110, an event required for bacterial entry. p85-p110 activation coincides with tyrosine phosphorylation of the host adaptor Gab1, and formation of complexes between Gab1 and the p85 regulatory subunit of PI 3-kinase. When phosphorylated in response to agonists, Gab1 is known to recruit several Src-homology 2 (SH2) domain-containing proteins including p85, the tyrosine phosphatase Shp2 and the adaptor CrkII. Here, we demonstrate that Gab1.p85 and Gab1.CrkII complexes promote entry of Listeria. Overexpression of wild-type Gab1 stimulated entry, whereas Gab1 alleles unable to recruit all SH2 proteins known to bind wild-type Gab1 inhibited internalization. Further analysis with Gab1 alleles defective in binding individual effectors suggested that recruitment of p85 and CrkII are critical for entry. Consistent with this data, overexpression of wild-type CrkII stimulated bacterial uptake. Experiments with mutant CrkII alleles indicated that both the first and second SH3 domains of this adaptor participate in entry, with the second domain playing the most critical role. Taken together, these findings demonstrate novel roles for Gab1 and CrkII in Listeria internalization.
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Affiliation(s)
- Hong Sun
- Department of Medical Genetics and Microbiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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42
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Abstract
Patients with Noonan syndrome, which is thought to have an incidence of 1 : 1,000 to 1 : 2,500 live births, have variable hypogonadism together with features such as pulmonary valvular stenosis, dysmorphism, deafness, visual problems, cryptorchidism, clotting disorders, and short stature. Noonan syndrome is now known to be associated with mutations in the PTPN11 gene encoding the protein tyrosine phosphatase SHP-2 on chromosome 12 (12q24.1). This discovery will facilitate both knowledge of the true incidence and phenotypic diversity. There are poor genotype-phenotype correlations in Noonan syndrome, and the currently defined gene abnormalities only account for a minority of those identified on a clinical basis. Puberty in patients with Noonan syndrome generally occurs spontaneously but is typically delayed. Mean adult height is 162.5cm (men) and 153cm (women), although standards are based on relatively small samples of largely cross-sectional data and are subject to ascertainment bias. Available evidence suggests that there may be disturbance of the growth hormone/insulin-like growth factor axis in Noonan syndrome and that somatropin (growth hormone therapy) dose-dependently improves vertical growth in the short to medium-term. Final height data from a number of European studies will be available later in 2003. Noonan syndrome patients with echocardiographic features of hypertrophic cardiomyopathy may be at particular risk from somatropin therapy because of its known effects on cardiac muscle mass; these patients have generally been excluded from trials of somatropin. Unbiased evidence for the efficacy and safety of somatropin therapy in Noonan syndrome will come from appropriately controlled studies of sufficiently large numbers of patients defined on such a basis and followed to final height. This is now possible but will require international cooperation. Nevertheless, the clinical relevance of somatropin therapy in Noonan syndrome and other short stature syndromes will be dependent on looking beyond improvement in final height (even if achievable) to psychological and quality of life outcomes.
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Affiliation(s)
- Chris J H Kelnar
- Department of Reproductive and Developmental Sciences, University of Edinburgh, Edinburgh, Scotland.
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43
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Brandt S, Kwok T, Hartig R, König W, Backert S. NF-kappaB activation and potentiation of proinflammatory responses by the Helicobacter pylori CagA protein. Proc Natl Acad Sci U S A 2005; 102:9300-5. [PMID: 15972330 PMCID: PMC1166591 DOI: 10.1073/pnas.0409873102] [Citation(s) in RCA: 396] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2004] [Indexed: 12/11/2022] Open
Abstract
The Helicobacter pylori immunodominant protein, CagA, is associated with severe gastritis and carcinoma. Injection of CagA into gastric epithelial cells by type IV secretion leads to actin-cytoskeletal rearrangements and cell scattering. CagA has been reported to have no role in the induction of transcription factor NF-kappaB and IL-8, which are crucial determinants for chronic inflammation. Here, we provide several lines of evidence showing that CagA is able to induce IL-8 in a time- and strain-dependent manner. We also show that by exchanging specific cagA genes, high IL-8-inducing H. pylori strains could be converted into low inducing strains and vice versa. Our results suggest that IL-8 release induced by CagA occurs via a Ras-->Raf-->Mek-->Erk-->NF-kappaB signaling pathway in a Shp-2- and c-Met-independent manner. Thus, CagA is a multifunctional protein capable of effecting both actin remodeling and potentiation of chemokine release.
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MESH Headings
- Actins/chemistry
- Active Transport, Cell Nucleus
- Antigens, Bacterial/chemistry
- Antigens, Bacterial/metabolism
- Bacterial Adhesion
- Bacterial Proteins/chemistry
- Bacterial Proteins/metabolism
- Cell Line, Tumor
- Cloning, Molecular
- Cytoskeleton/metabolism
- Enzyme Inhibitors/pharmacology
- Enzyme-Linked Immunosorbent Assay
- Epithelial Cells/microbiology
- Gastric Mucosa/metabolism
- Genetic Complementation Test
- Genomic Islands
- Green Fluorescent Proteins/metabolism
- Helicobacter pylori/metabolism
- Humans
- Immunoblotting
- Inflammation
- Interleukin-8/metabolism
- Intracellular Signaling Peptides and Proteins/metabolism
- Microscopy, Fluorescence
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- NF-kappa B/metabolism
- Protein Binding
- Protein Transport
- Protein Tyrosine Phosphatase, Non-Receptor Type 11
- Protein Tyrosine Phosphatases/metabolism
- Proto-Oncogene Proteins c-met/metabolism
- Sequence Analysis, DNA
- Stomach Neoplasms/microbiology
- Time Factors
- Transcription, Genetic
- Transfection
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Affiliation(s)
- Sabine Brandt
- Department of Medical Microbiology, Otto von Guericke University, Leipziger Strasse 44, D-39120 Magdeburg, Germany
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Allen RT, Krueger KD, Dhume A, Agrawal DK. Sustained Akt/PKB activation and transient attenuation of c-jun N-Terminal kinase in the inhibition of apoptosis by IGF-1 in vascular smooth muscle cells. Apoptosis 2005; 10:525-35. [PMID: 15909115 DOI: 10.1007/s10495-005-1882-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Characteristics of hVSMC apoptosis and its inhibition by insulin-like growth factor-1 (IGF-1) remain unclear. Also unclear is whether a balance in hVSMCs exists whereby c-Jun N-terminal stress kinases (JNK) promote apoptosis while extracellular signal-regulated (ERK1/2) MAP kinases inhibit cell death. In this study, we examined the involvement of Akt/PKB and its upstream kinase, PDK1 and whether JNK activation correlated with human and rat VSMC apoptosis induced by staurosporine and by c-myc, respectively. We observed a strong, sustained JNK activation (and c-Jun phosphorylation), which correlated with VSMC apoptosis. IGF-1 (13.3 nM), during apoptosis inhibition, transiently inhibited JNK activity at 1 h in a phosphatidylinositol 3-kinase (PI3-K)- and MEK-ERK-dependent manner, as wortmannin (100 nM) or PD98059 (30 muM) partially attenuated the IGF-1 effect. PKC down-regulation had no effect on JNK inhibition by IGF-1. While IGF-1 alone produced a strong phosphorylation of Akt/PKB in hVSMCs up to 6 h, it was notably stronger and more sustained during ratmyc and hVSMCs apoptosis inhibition. Further, whereas transient expression of phosphorylated Akt protected VSMCs from apoptosis by nearly 50%, expression of dominant interfering alleles of Akt or PDK1 strongly inhibited IGF-1-mediated VSMC survival. These results demonstrate for the first time that transient inhibition of a pro-apoptotic stimulus in VSMCs may be sufficient to inhibit a programmed cell death and that sustained anti-apoptotic signals (Akt) elicited by IGF-1 are augmented during a death stimulus. Furthermore, PI3-K and ERK-MAPK pathways may cooperate to protect VSMCs from cell death.
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Affiliation(s)
- R T Allen
- Departments of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, NE 68178, USA
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45
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Montagner A, Yart A, Dance M, Perret B, Salles JP, Raynal P. A Novel Role for Gab1 and SHP2 in Epidermal Growth Factor-induced Ras Activation. J Biol Chem 2005; 280:5350-60. [PMID: 15574420 DOI: 10.1074/jbc.m410012200] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
SHP2 was recently found to down-regulate PI3K activation by dephosphorylating Gab1 but the mechanisms explaining the positive role of the Gab1/SHP2 pathway in EGF-induced Ras activation remain ill defined. Substrate trapping experiments now suggest that SHP2 dephosphorylates other Gab1 phosphotyrosines located within a central region displaying four YXXP motifs. Because these sites are potential docking motifs for Ras-GAP, we tested whether SHP2 dephosphorylates them to facilitate Ras activation. We observed that a Gab1 construct preventing SHP2 recruitment promoted membrane relocation of RasGAP. Moreover, a RasGAP-inactive mutant restored the activation of Ras in cells transfected with SHP2-inactivating Gab1 mutant or in SHP2-deficient fibroblasts, supporting the hypothesis that RasGAP is a downstream target of SHP2. To determine whether Gab1 is a RasGAP-binding partner, a Gab1 mutant deleted of four YXXP motifs was produced. The deletion suppressed RasGAP redistribution and restored the defective Ras activation caused by SHP2-inactivating mutations. Moreover, Gab1 was found to interact with RasGAP SH2 domains, only under conditions where SHP2 is not activated. To identify Ras-GAP-binding sites, Tyr to Phe mutants of Gab1 YXXP motifs were produced. Gab1 constructs mutated on Tyr(317) were severely affected in RasGAP binding and were the most active in compensating for Ras-defective activation and blocking RasGAP redistribution induced by SHP2 inactivation. We have thus localized on Gab1 a Ras-negative regulatory tyrosine phosphorylation site involved in RasGAP binding and showed that an important SHP2 function is to down-regulate its phosphorylation to disengage RasGAP and sustain Ras activation.
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Affiliation(s)
- Alexandra Montagner
- Département Lipoprotéines et Médiateurs Lipidiques, INSERM U563, Hôpital Purpan, 31300 Toulouse, France
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46
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Ling Y, Maile LA, Badley-Clarke J, Clemmons DR. DOK1 Mediates SHP-2 Binding to the αVβ3 Integrin and Thereby Regulates Insulin-like Growth Factor I Signaling in Cultured Vascular Smooth Muscle Cells. J Biol Chem 2005; 280:3151-8. [PMID: 15546884 DOI: 10.1074/jbc.m411035200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Recruitment of the Src homology 2 domain tyrosine phosphatase (SHP-2) to the phosphorylated beta3 subunit of the alphaVbeta3 integrin is required for insulin-like growth factor I (IGF-I)-stimulated cell migration and proliferation in vascular smooth muscle cells. Because SHP-2 does not bind directly to beta3, we attempted to identify a linker protein that could mediate SHP-2/beta3 association. DOK1 is a member of insulin receptor substrate protein family that binds beta3 and contains YXXL/I motifs that are potential binding sites for SHP-2. Our results show that IGF-I induces DOK1 binding to beta3 and to SHP-2. Preincubation of cells with synthetic peptides that blocked either DOK1/beta3 or DOK1/SHP-2 association inhibited SHP-2 recruitment to beta3. Expression of a DOK1 mutant that does not bind to beta3 also disrupts SHP-2/beta3 association. As a result of SHP-2/beta3 disruption, IGF-I dependent phosphorylation of Akt and p44/p42 mitogen-activated protein kinase and its ability to stimulate cell migration and proliferation were significantly impaired. These results demonstrate that DOK1 mediates SHP-2/beta3 association in response to IGF-I thereby mediating the effect of integrin ligand occupancy on IGF-IR-linked signaling in smooth muscle cells.
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Affiliation(s)
- Yan Ling
- University of North Carolina, School of Medicine, Chapel Hill, North Carolina 27599, USA
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47
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Abstract
Gene33 is a cytoplasmic protein expressed in many cell types, including those of renal and hepatic origin. Its expression is regulated by a large number of mitogenic and stressful stimuli, both in cultured cells and in vivo. Gene33 protein possesses binding domains for ErbB receptors, 14-3-3 proteins, SH-3 domains, and GTP bound Cdc42, suggesting that it may play a role in signal transduction. Indeed, these regions of Gene33 have been reported to modulate signaling through the ERK, JNK, and NFkappaB pathways. In the present work, epitope-tagged full-length and truncation mutants, as well as wild-type Gene33, were overexpressed in 293 cells. The expression of these proteins was compared to the level of endogenous Gene33 by Western blot using a newly developed polyclonal antibody. As proxies for activity of the ERK and JNK pathways, Elk- and c-Jun-dependent transcription were measured by a luciferase reporter gene. Moderate expression levels of full-length Gene33 caused a twofold increase in Elk-dependent transcription, while at higher levels, c-Jun-dependent transcription was partially inhibited. The C-terminal half of Gene33 significantly increased both Elk- and c-Jun-dependent transcription when expressed at approximately threefold above control levels. This effect on Elk-dependent transcription was lost at higher levels of Gene33 expression. In contrast, higher levels of the C-terminal half of Gene33 caused a progressively greater effect on c-Jun-dependent transcription. These findings suggest that Gene33 may increase ERK activity, and that the C-terminal half of Gene33 may act less specifically in the absence of the N-terminal half, inducing JNK activity.
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Affiliation(s)
- Adam B Keeton
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, Alabama, 35294-0019
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Zhan Y, O'Rourke DM. SHP-2-Dependent Mitogen-Activated Protein Kinase Activation Regulates EGFRvIII but not Wild-Type Epidermal Growth Factor Receptor Phosphorylation and Glioblastoma Cell Survival. Cancer Res 2004; 64:8292-8. [PMID: 15548697 DOI: 10.1158/0008-5472.can-03-3143] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In human glioblastomas, the most common mutation of epidermal growth factor receptor (EGFR) is an in-frame deletion of an 801-bp sequence in the extracellular domain of EGFR termed EGFRvIII. The EGFRvIII does not bind ligand EGF but has constitutive tyrosine phosphorylation (pTyr) content and kinase activity that result in enhanced transformation, reduced apoptosis, and resistance to therapy. Here we report that the protein tyrosine phosphatase SHP-2 modulates a mitogen-activated protein kinase (MAPK) kinase (MEK)-mediated signaling pathway that regulates EGFRvIII pTyr and cell survival in U87MG.EGFRvIII cells. Overexpression of the phosphatase-inactive form of SHP-2 inhibited EGFRvIII pTyr by decreasing MAPK phosphorylation. Consistent with this, we observed that the MEK inhibitor PD98059, but not the phosphatidylinositol 3'-kinase inhibitor LY294002, inhibited EGFRvIII pTyr. Furthermore, constitutive EGFRvIII pTyr content observed in U87MG, LN229, and U373MG glioblastoma cells, but not in NR6.EGFRvIII fibroblasts, correlated with elevated MAPK levels in these cells. Interestingly, LY294002, but not PD98059, inhibited wild-type EGFR pTyr in response to EGF treatment in U87MG parental cells and in wild-type EGFR-overexpressing U87MG cells. Inhibition of EGFRvIII pTyr by PD98059 was not observed to be phosphorylation site specific. However, LY294002 more specifically inhibited wild-type EGFR pTyr at residues Tyr(992) and Tyr(1068) in the COOH terminus. Treatment of U87MG.EGFRvIII cells with PD98059, but not LY294002, also resulted in increased cell death in response to cisplatin. Collectively, a distinct MEK-mediated pathway in human glioblastoma cells appears to differentially modulate EGFRvIII and wild-type EGFR pTyr, and inhibition of the MAPK pathway sensitizes EGFRvIII-containing human glioblastoma cells to cisplatin-induced cell death.
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Affiliation(s)
- Yi Zhan
- Department of Neurosurgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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49
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Yan HX, Wang HY, Zhang R, Chen L, Li BA, Liu SQ, Cao HF, Qiu XH, Shan YF, Yan ZH, Wu HP, Tan YX, Wu MC. Negative regulation of hepatocellular carcinoma cell growth by signal regulatory protein alpha1. Hepatology 2004; 40:618-28. [PMID: 15349900 DOI: 10.1002/hep.20360] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Signal regulatory protein (SIRP) alpha1 is a member of the SIRP family that undergoes tyrosine phosphorylation and binds SHP-2 tyrosine phosphatase in response to various mitogens. The expression levels of SIRPalpha1 were decreased in HCC tissues, compared with the matched normal tissues. Exogenous expression of wild type SIRPalpha1, but not of a mutant SIRPalpha1 lacking the tyrosine phosphorylation sites, in SIRPalpha1-negative Huh7 human HCC cells resulted in suppression of tumor cell growth both in vitro and in vivo. Treatment of Huh7 transfectants with EGF or HGF induced tyrosine phosphorylation of SIRPalpha1 and its association with SHP-2, which were accompanied by reduced ERK1 activation. Expression of SIRPalpha1 significantly suppressed activation of NF-kappaB and also sensitized Huh7 cells to TNFalpha or cisplatin-induced cell death. In addition, SIRPalpha1-transfected Huh7 cells displayed reduced cell migration and cell spreading in a fashion that was dependent on SIRPalpha1/SHP-2 complex formation. In conclusion, a negative regulatory effect of SIRPalpha1 on hepatocarcinogenesis is exerted, at least in part, through inhibition of ERK and NF-kappaB pathways.
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Affiliation(s)
- He-Xin Yan
- International Cooperation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China
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50
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Kontaridis MI, Eminaga S, Fornaro M, Zito CI, Sordella R, Settleman J, Bennett AM. SHP-2 positively regulates myogenesis by coupling to the Rho GTPase signaling pathway. Mol Cell Biol 2004; 24:5340-52. [PMID: 15169898 PMCID: PMC419889 DOI: 10.1128/mcb.24.12.5340-5352.2004] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Myogenesis is an intricate process that coordinately engages multiple intracellular signaling cascades. The Rho family GTPase RhoA is known to promote myogenesis, however, the mechanisms controlling its regulation in myoblasts have yet to be fully elucidated. We show here that the SH2-containing protein tyrosine phosphatase, SHP-2, functions as an early modulator of myogenesis by regulating RhoA. When MyoD was expressed in fibroblasts lacking functional SHP-2, muscle-specific gene activity was impaired and abolition of SHP-2 expression by RNA interference inhibited muscle differentiation. By using SHP-2 substrate-trapping mutants, we identified p190-B RhoGAP as a SHP-2 substrate. When dephosphorylated, p190-B RhoGAP has been shown to stimulate the activation of RhoA. During myogenesis, p190-B RhoGAP was tyrosyl dephosphorylated concomitant with the stimulation of SHP-2's phosphatase activity. Moreover, overexpression of a catalytically inactive mutant of SHP-2 inhibited p190-B RhoGAP tyrosyl dephosphorylation, RhoA activity, and myogenesis. These observations strongly suggest that SHP-2 dephosphorylates p190-B RhoGAP, leading to the activation of RhoA. Collectively, these data provide a mechanistic basis for RhoA activation in myoblasts and demonstrate that myogenesis is critically regulated by the actions of SHP-2 on the p190-B Rho GAP/RhoA pathway.
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Affiliation(s)
- Maria I Kontaridis
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
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