1
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Martin-Vega A, Cobb MH. Navigating the ERK1/2 MAPK Cascade. Biomolecules 2023; 13:1555. [PMID: 37892237 PMCID: PMC10605237 DOI: 10.3390/biom13101555] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 10/29/2023] Open
Abstract
The RAS-ERK pathway is a fundamental signaling cascade crucial for many biological processes including proliferation, cell cycle control, growth, and survival; common across all cell types. Notably, ERK1/2 are implicated in specific processes in a context-dependent manner as in stem cells and pancreatic β-cells. Alterations in the different components of this cascade result in dysregulation of the effector kinases ERK1/2 which communicate with hundreds of substrates. Aberrant activation of the pathway contributes to a range of disorders, including cancer. This review provides an overview of the structure, activation, regulation, and mutational frequency of the different tiers of the cascade; with a particular focus on ERK1/2. We highlight the importance of scaffold proteins that contribute to kinase localization and coordinate interaction dynamics of the kinases with substrates, activators, and inhibitors. Additionally, we explore innovative therapeutic approaches emphasizing promising avenues in this field.
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Affiliation(s)
- Ana Martin-Vega
- Department of Pharmacology, UT Southwestern Medical Center, 6001 Forest Park Rd., Dallas, TX 75390, USA;
| | - Melanie H. Cobb
- Department of Pharmacology, UT Southwestern Medical Center, 6001 Forest Park Rd., Dallas, TX 75390, USA;
- Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, 6001 Forest Park Rd., Dallas, TX 75390, USA
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2
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Soudah N, Baskin A, Smorodinsky-Atias K, Beenstock J, Ganon Y, Hayouka R, Aboraya M, Livnah O, Ilouz R, Engelberg D. A conserved arginine within the αC-helix of Erk1/2 is a latch of autoactivation and of oncogenic capabilities. J Biol Chem 2023; 299:105072. [PMID: 37474104 PMCID: PMC10458722 DOI: 10.1016/j.jbc.2023.105072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 06/30/2023] [Accepted: 07/14/2023] [Indexed: 07/22/2023] Open
Abstract
Eukaryotic protein kinases (EPKs) adopt an active conformation following phosphorylation of a particular activation loop residue. Most EPKs spontaneously autophosphorylate this residue. While structure-function relationships of the active conformation are essentially understood, those of the "prone-to-autophosphorylate" conformation are unclear. Here, we propose that a site within the αC-helix of EPKs, occupied by Arg in the mitogen-activated protein kinase (MAPK) Erk1/2 (Arg84/65), impacts spontaneous autophosphorylation. MAPKs lack spontaneous autoactivation, but we found that converting Arg84/65 of Erk1/2 to various residues enables spontaneous autophosphorylation. Furthermore, Erk1 molecules mutated in Arg84 are oncogenic. Arg84/65 thus obstructs the adoption of the "prone-to-autophosphorylate" conformation. All MAPKs harbor an Arg that is equivalent to Arg84/65 of Erks, whereas Arg is rarely found at the equivalent position in other EPKs. We observed that Arg84/65 of Erk1/2 interacts with the DFG motif, suggesting that autophosphorylation may be inhibited by the Arg84/65-DFG interactions. Erk1/2s mutated in Arg84/65 autophosphorylate not only the TEY motif, known as critical for catalysis, but also on Thr207/188. Our MS/MS analysis revealed that a large proportion of the Erk2R65H population is phosphorylated on Thr188 or on Tyr185 + Thr188, and a small fraction is phosphorylated on the TEY motif. No molecules phosphorylated on Thr183 + Thr188 were detected. Thus, phosphorylation of Thr183 and Thr188 is mutually exclusive suggesting that not only TEY-phosphorylated molecules are active but perhaps also those phosphorylated on Tyr185 + Thr188. The effect of mutating Arg84/65 may mimic a physiological scenario in which allosteric effectors cause Erk1/2 activation by autophosphorylation.
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Affiliation(s)
- Nadine Soudah
- Department of Biological Chemistry, The Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Alexey Baskin
- Department of Biological Chemistry, The Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Karin Smorodinsky-Atias
- School of Neurobiology, Biochemistry and Biophysics, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Jonah Beenstock
- Department of Biological Chemistry, The Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yifat Ganon
- Department of Biological Chemistry, The Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ruchama Hayouka
- The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Mohammed Aboraya
- The Azrieli Faculty of Medicine, Bar Ilan University, Safed, Israel
| | - Oded Livnah
- Department of Biological Chemistry, The Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem, Israel; The Wolfson Centre for Applied Structural Biology, Jerusalem, Israel
| | - Ronit Ilouz
- The Azrieli Faculty of Medicine, Bar Ilan University, Safed, Israel
| | - David Engelberg
- Department of Biological Chemistry, The Institute of Life Science, The Hebrew University of Jerusalem, Jerusalem, Israel; Singapore-HUJ Alliance for Research and Enterprise, Mechanisms of Liver Inflammatory Diseases Program, National University of Singapore, Singapore; Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
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3
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Harabuchi S, Khan O, Bassiri H, Yoshida T, Okada Y, Takizawa M, Ikeda O, Katada A, Kambayashi T. Manipulation of diacylglycerol and ERK-mediated signaling differentially controls CD8 + T cell responses during chronic viral infection. Front Immunol 2022; 13:1032113. [PMID: 36846018 PMCID: PMC9951774 DOI: 10.3389/fimmu.2022.1032113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 11/07/2022] [Indexed: 11/25/2022] Open
Abstract
Introduction Activation of T cell receptor (TCR) signaling is critical for clonal expansion of CD8+ T cells. However, the effects of augmenting TCR signaling during chronic antigen exposure is less understood. Here, we investigated the role of diacylglycerol (DAG)-mediated signaling downstream of the TCR during chronic lymphocytic choriomeningitis virus clone 13 (LCMV CL13) infection by blocking DAG kinase zeta (DGKζ), a negative regulator of DAG. Methods We examined the activation, survival, expansion, and phenotype of virus-specific T cell in the acute and chronic phases of LCMV CL13-infected in mice after DGKζ blockade or selective activation of ERK. Results Upon LCMV CL13 infection, DGKζ deficiency promoted early short-lived effector cell (SLEC) differentiation of LCMV-specific CD8+ T cells, but this was followed by abrupt cell death. Short-term inhibition of DGKζ with ASP1570, a DGKζ-selective pharmacological inhibitor, augmented CD8+ T cell activation without causing cell death, which reduced virus titers both in the acute and chronic phases of LCMV CL13 infection. Unexpectedly, the selective enhancement of ERK, one key signaling pathway downstream of DAG, lowered viral titers and promoted expansion, survival, and a memory phenotype of LCMV-specific CD8+ T cells in the acute phase with fewer exhausted T cells in the chronic phase. The difference seen between DGKζ deficiency and selective ERK enhancement could be potentially explained by the activation of the AKT/mTOR pathway by DGKζ deficiency, since the mTOR inhibitor rapamycin rescued the abrupt cell death seen in virus-specific DGKζ KO CD8+ T cells. Discussion Thus, while ERK is downstream of DAG signaling, the two pathways lead to distinct outcomes in the context of chronic CD8+ T cell activation, whereby DAG promotes SLEC differentiation and ERK promotes a memory phenotype.
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Affiliation(s)
- Shohei Harabuchi
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States
- Department of Otolaryngology-Head and Neck surgery, Asahikawa Medical University, Asahikawa, Japan
| | - Omar Khan
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Hamid Bassiri
- Division of Infectious Diseases, Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States
| | - Taku Yoshida
- Immuno-Oncology, Astellas Pharma Inc., Tsukuba, Japan
| | - Yohei Okada
- Immuno-Oncology, Astellas Pharma Inc., Tsukuba, Japan
| | - Masaomi Takizawa
- Research Program Management-Applied Research Management, Astellas Pharma Inc., Tokyo, Japan
| | - Osamu Ikeda
- Immuno-Oncology, Astellas Pharma Inc., Tsukuba, Japan
| | - Akihiro Katada
- Department of Otolaryngology-Head and Neck surgery, Asahikawa Medical University, Asahikawa, Japan
| | - Taku Kambayashi
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States
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4
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Alexa A, Ember O, Szabó I, Mo'ath Y, Póti ÁL, Reményi A, Bánóczi Z. Peptide Based Inhibitors of Protein Binding to the Mitogen-Activated Protein Kinase Docking Groove. Front Mol Biosci 2021; 8:690429. [PMID: 34277705 PMCID: PMC8281026 DOI: 10.3389/fmolb.2021.690429] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 06/18/2021] [Indexed: 11/21/2022] Open
Abstract
Mitogen-activated protein kinases (MAPK) are important regulatory units in cells and they take part in the regulation of many cellular functions such as cell division, differentiation or apoptosis. All MAPKs have a shallow docking groove that interacts with linear binding motifs of their substrate proteins and their regulatory proteins such as kinases, phosphatases, scaffolds. Inhibition of these protein–protein interactions may reduce or abolish the activity of the targeted kinase. Based on the wide range of their biological activity, this kind of inhibition can be useful in the treatment of many disorders like tumors, inflammation or undesired cell apoptosis. In this study a linear binding motif from the RHDF1 protein—a 15 amino acids long peptide—was selected for optimization to increase its cellular uptake but retaining its low micromolar binding affinity. First, we synthesized an octaarginine conjugate that showed efficient cellular uptake. Next, we set out to reduce the size of this construct. We were able to decrease the length of the original peptide, and to increase its cellular uptake with specific chemical modifications. These new constructs bound better to ERK2 and p38 kinases than the original peptide and they showed markedly increased cellular uptake. The new octaarginine conjugate and one of the minimized bicyclic derivatives could inhibit the phosphorylation of intracellular ERK or p38. However, the modulation of MAPK phosphorylation levels by these cell-penetrating peptides were complex, despite that in biochemical assays they all inhibited MAPK-substrate binding as well as phosphorylation. The optimized peptides depending on the applied concentration caused an expected decrease, but also some unexpected increase in MAPK phosphorylation patterns in the cell. This possibly reflects the complexity of MAPK docking groove mediated protein–protein interactions including bone fide MAPK clients such activator kinases, deactivating phosphatases or regulatory scaffolds. Thus, our findings with optimized cell-penetrating “inhibitory” peptides highlight the opportunities but also the pitfalls of docking peptide based MAPK activity regulation and call for a better quantitative understanding of MAPK mediated protein–protein interactions in cells.
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Affiliation(s)
- Anita Alexa
- Biomolecular Interactions Laboratory, Institute of Organic Chemistry, Research Centre for Natural Sciences, Budapest, Hungary
| | - Orsolya Ember
- Biomolecular Interactions Laboratory, Institute of Organic Chemistry, Research Centre for Natural Sciences, Budapest, Hungary.,Department of Organic Chemistry, Institute of Chemistry, Eötvös Loránd University, Budapest, Hungary
| | - Ildikó Szabó
- MTA-ELTE Research Group of Peptide Chemistry, Eötvös Loránd Research Network (ELKH), Eötvös L. University, Budapest, Hungary
| | - Yousef Mo'ath
- Department of Organic Chemistry, Institute of Chemistry, Eötvös Loránd University, Budapest, Hungary
| | - Ádám L Póti
- Biomolecular Interactions Laboratory, Institute of Organic Chemistry, Research Centre for Natural Sciences, Budapest, Hungary
| | - Attila Reményi
- Biomolecular Interactions Laboratory, Institute of Organic Chemistry, Research Centre for Natural Sciences, Budapest, Hungary
| | - Zoltán Bánóczi
- Department of Organic Chemistry, Institute of Chemistry, Eötvös Loránd University, Budapest, Hungary
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5
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Paul S, Yang L, Mattingly H, Goyal Y, Shvartsman SY, Veraksa A. Activation-induced substrate engagement in ERK signaling. Mol Biol Cell 2020; 31:235-243. [PMID: 31913744 PMCID: PMC7183763 DOI: 10.1091/mbc.e19-07-0355] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The extracellular signal-regulated kinase (ERK) pathway is an essential component of developmental signaling in metazoans. Previous models of pathway activation suggested that dissociation of activated dually phosphorylated ERK (dpERK) from MAPK/ERK kinase (MEK), a kinase that phosphorylates ERK, and other cytoplasmic anchors, is sufficient for allowing ERK interactions with its substrates. Here, we provide evidence for an additional step controlling ERK’s access to substrates. Specifically, we demonstrate that interaction of ERK with its substrate Capicua (Cic) is controlled at the level of ERK phosphorylation, whereby Cic binds to dpERK much stronger than to unphosphorylated ERK, both in vitro and in vivo. Mathematical modeling suggests that the differential affinity of Cic for dpERK versus ERK is required for both down-regulation of Cic and stabilizing phosphorylated ERK. Preferential association of Cic with dpERK serves two functions: it prevents unproductive competition of Cic with unphosphorylated ERK and contributes to efficient signal propagation. We propose that high-affinity substrate binding increases the specificity and efficiency of signal transduction through the ERK pathway.
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Affiliation(s)
- Sayantanee Paul
- Department of Biology, University of Massachusetts, Boston, Boston, MA 02125
| | - Liu Yang
- Department of Biology, University of Massachusetts, Boston, Boston, MA 02125.,Lewis-Sigler Institute for Integrative Genomics
| | - Henry Mattingly
- Lewis-Sigler Institute for Integrative Genomics.,Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544
| | - Yogesh Goyal
- Lewis-Sigler Institute for Integrative Genomics.,Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544
| | - Stanislav Y Shvartsman
- Lewis-Sigler Institute for Integrative Genomics.,Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544.,Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Alexey Veraksa
- Department of Biology, University of Massachusetts, Boston, Boston, MA 02125
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6
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Mutations That Confer Drug-Resistance, Oncogenicity and Intrinsic Activity on the ERK MAP Kinases-Current State of the Art. Cells 2020; 9:cells9010129. [PMID: 31935908 PMCID: PMC7016714 DOI: 10.3390/cells9010129] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 12/31/2019] [Accepted: 01/02/2020] [Indexed: 12/11/2022] Open
Abstract
Unique characteristics distinguish extracellular signal-regulated kinases (Erks) from other eukaryotic protein kinases (ePKs). Unlike most ePKs, Erks do not autoactivate and they manifest no basal activity; they become catalysts only when dually phosphorylated on neighboring Thr and Tyr residues and they possess unique structural motifs. Erks function as the sole targets of the receptor tyrosine kinases (RTKs)-Ras-Raf-MEK signaling cascade, which controls numerous physiological processes and is mutated in most cancers. Erks are therefore the executers of the pathway’s biology and pathology. As oncogenic mutations have not been identified in Erks themselves, combined with the tight regulation of their activity, Erks have been considered immune against mutations that would render them intrinsically active. Nevertheless, several such mutations have been generated on the basis of structure-function analysis, understanding of ePK evolution and, mostly, via genetic screens in lower eukaryotes. One of the mutations conferred oncogenic properties on Erk1. The number of interesting mutations in Erks has dramatically increased following the development of Erk-specific pharmacological inhibitors and identification of mutations that cause resistance to these compounds. Several mutations have been recently identified in cancer patients. Here we summarize the mutations identified in Erks so far, describe their properties and discuss their possible mechanism of action.
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7
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Kushnir T, Bar-Cohen S, Mooshayef N, Lange R, Bar-Sinai A, Rozen H, Salzberg A, Engelberg D, Paroush Z. An Activating Mutation in ERK Causes Hyperplastic Tumors in a scribble Mutant Tissue in Drosophila. Genetics 2020; 214:109-120. [PMID: 31740452 PMCID: PMC6944410 DOI: 10.1534/genetics.119.302794] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 10/23/2019] [Indexed: 12/19/2022] Open
Abstract
Receptor tyrosine kinase signaling plays prominent roles in tumorigenesis, and activating oncogenic point mutations in the core pathway components Ras, Raf, or MEK are prevalent in many types of cancer. Intriguingly, however, analogous oncogenic mutations in the downstream effector kinase ERK have not been described or validated in vivo To determine if a point mutation could render ERK intrinsically active and oncogenic, we have assayed in Drosophila the effects of a mutation that confers constitutive activity upon a yeast ERK ortholog and has also been identified in a few human tumors. Our analyses indicate that a fly ERK ortholog harboring this mutation alone (RolledR80S), and more so in conjunction with the known sevenmaker mutation (RolledR80S+D334N), suppresses multiple phenotypes caused by loss of Ras-Raf-MEK pathway activity, consistent with an intrinsic activity that is independent of upstream signaling. Moreover, expression of RolledR80S and RolledR80S+D334N induces tissue overgrowth in an established Drosophila cancer model. Our findings thus demonstrate that activating mutations can bestow ERK with pro-proliferative, tumorigenic capabilities and suggest that Drosophila represents an effective experimental system for determining the oncogenicity of ERK mutants and their response to therapy.
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Affiliation(s)
- Tatyana Kushnir
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Shaked Bar-Cohen
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Navit Mooshayef
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
- Department of Biological Chemistry, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
- Singapore-Hebrew University of Jerusalem Alliance for Research and Enterprise, Molecular Mechanisms of Inflammatory Diseases Interdisciplinary Research Group, Campus for Research Excellence and Technological Enterprise, 138602, Singapore
| | - Rotem Lange
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Allan Bar-Sinai
- Department of Biological Chemistry, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Helit Rozen
- Faculty of Medicine in the Galilee, Bar-Ilan University, Safed 1311502, Israel
| | - Adi Salzberg
- Department of Genetics and Developmental Biology, The Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa 3109601, Israel
| | - David Engelberg
- Department of Biological Chemistry, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
- Singapore-Hebrew University of Jerusalem Alliance for Research and Enterprise, Molecular Mechanisms of Inflammatory Diseases Interdisciplinary Research Group, Campus for Research Excellence and Technological Enterprise, 138602, Singapore
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117456, Singapore
| | - Ze'ev Paroush
- Department of Developmental Biology and Cancer Research, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
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8
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Taylor CA, Cormier KW, Keenan SE, Earnest S, Stippec S, Wichaidit C, Juang YC, Wang J, Shvartsman SY, Goldsmith EJ, Cobb MH. Functional divergence caused by mutations in an energetic hotspot in ERK2. Proc Natl Acad Sci U S A 2019; 116:15514-15523. [PMID: 31296562 PMCID: PMC6681740 DOI: 10.1073/pnas.1905015116] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The most frequent extracellular signal-regulated kinase 2 (ERK2) mutation occurring in cancers is E322K (E-K). ERK2 E-K reverses a buried charge in the ERK2 common docking (CD) site, a region that binds activators, inhibitors, and substrates. Little is known about the cellular consequences associated with this mutation, other than apparent increases in tumor resistance to pathway inhibitors. ERK2 E-K, like the mutation of the preceding aspartate (ERK2 D321N [D-N]) known as the sevenmaker mutation, causes increased activity in cells and evades inactivation by dual-specificity phosphatases. As opposed to findings in cancer cells, in developmental assays in Drosophila, only ERK2 D-N displays a significant gain of function, revealing mutation-specific phenotypes. The crystal structure of ERK2 D-N is indistinguishable from that of wild-type protein, yet this mutant displays increased thermal stability. In contrast, the crystal structure of ERK2 E-K reveals profound structural changes, including disorder in the CD site and exposure of the activation loop phosphorylation sites, which likely account for the decreased thermal stability of the protein. These contiguous mutations in the CD site of ERK2 are both required for docking interactions but lead to unpredictably different functional outcomes. Our results suggest that the CD site is in an energetically strained configuration, and this helps drive conformational changes at distal sites on ERK2 during docking interactions.
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Affiliation(s)
- Clinton A Taylor
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390
| | - Kevin W Cormier
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390
| | - Shannon E Keenan
- Department of Chemical and Biological Engineering, Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544
| | - Svetlana Earnest
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390
| | - Steve Stippec
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390
| | - Chonlarat Wichaidit
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390
| | - Yu-Chi Juang
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390
| | - Junmei Wang
- Department of Biophysics, UT Southwestern Medical Center, Dallas, TX 75390
| | - Stanislav Y Shvartsman
- Department of Chemical and Biological Engineering, Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544
| | | | - Melanie H Cobb
- Department of Pharmacology, UT Southwestern Medical Center, Dallas, TX 75390;
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9
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Sammons RM, Perry NA, Li Y, Cho EJ, Piserchio A, Zamora-Olivares DP, Ghose R, Kaoud TS, Debevec G, Bartholomeusz C, Gurevich VV, Iverson TM, Giulianotti M, Houghten RA, Dalby KN. A Novel Class of Common Docking Domain Inhibitors That Prevent ERK2 Activation and Substrate Phosphorylation. ACS Chem Biol 2019; 14:1183-1194. [PMID: 31058487 DOI: 10.1021/acschembio.9b00093] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Extracellular signal-regulated kinases (ERK1/2) are mitogen-activated protein kinases (MAPKs) that play a pro-tumorigenic role in numerous cancers. ERK1/2 possess two protein-docking sites that are distinct from the active site: the D-recruitment site (DRS) and the F-recruitment site. These docking sites facilitate substrate recognition, intracellular localization, signaling specificity, and protein complex assembly. Targeting these sites on ERK in a therapeutic context may overcome many problems associated with traditional ATP-competitive inhibitors. Here, we identified a new class of inhibitors that target the ERK DRS by screening a synthetic combinatorial library of more than 30 million compounds. The screen detects the competitive displacement of a fluorescent peptide from the DRS of ERK2. The top molecular scaffold from the screen was optimized for structure-activity relationship by positional scanning of different functional groups. This resulted in 10 compounds with similar binding affinities and a shared core structure consisting of a tertiary amine hub with three functionalized cyclic guanidino branches. Compound 2507-1 inhibited ERK2 from phosphorylating a DRS-targeting substrate and prevented the phosphorylation of ERK2 by a constitutively active MEK1 (MAPK/ERK kinase 1) mutant. Interaction between an analogue, 2507-8, and the ERK2 DRS was confirmed by nuclear magnetic resonance and X-ray crystallography. 2507-8 forms critical interactions at the common docking domain residue Asp319 via an arginine-like moiety that is shared by all 10 hits, suggesting a common binding mode. The structural and biochemical insights reported here provide the basis for developing new ERK inhibitors that are not ATP-competitive but instead function by disrupting critical protein-protein interactions.
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Affiliation(s)
| | | | - Yangmei Li
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida 34987, United States
- Department of Drug Discovery & Biomedical Sciences, University of South Carolina, Columbia, South Carolina 29208, United States
| | | | - Andrea Piserchio
- Department of Chemistry and Biochemistry, The City College of New York, New York, New York 10031, United States
| | | | - Ranajeet Ghose
- Department of Chemistry and Biochemistry, The City College of New York, New York, New York 10031, United States
| | - Tamer S. Kaoud
- Department of Medicinal Chemistry, Faculty of Pharmacy, Minia University, 61519 Minia, Egypt
| | - Ginamarie Debevec
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida 34987, United States
| | | | | | | | - Marc Giulianotti
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida 34987, United States
| | - Richard A. Houghten
- Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida 34987, United States
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10
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Sammons RM, Ghose R, Tsai KY, Dalby KN. Targeting ERK beyond the boundaries of the kinase active site in melanoma. Mol Carcinog 2019; 58:1551-1570. [PMID: 31190430 DOI: 10.1002/mc.23047] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/30/2019] [Accepted: 05/10/2019] [Indexed: 12/14/2022]
Abstract
Extracellular signal-regulated kinase 1/2 (ERK1/2) constitute a point of convergence for complex signaling events that regulate essential cellular processes, including proliferation and survival. As such, dysregulation of the ERK signaling pathway is prevalent in many cancers. In the case of BRAF-V600E mutant melanoma, ERK inhibition has emerged as a viable clinical approach to abrogate signaling through the ERK pathway, even in cases where MEK and Raf inhibitor treatments fail to induce tumor regression due to resistance mechanisms. Several ERK inhibitors that target the active site of ERK have reached clinical trials, however, many critical ERK interactions occur at other potentially druggable sites on the protein. Here we discuss the role of ERK signaling in cell fate, in driving melanoma, and in resistance mechanisms to current BRAF-V600E melanoma treatments. We explore targeting ERK via a distinct site of protein-protein interaction, known as the D-recruitment site (DRS), as an alternative or supplementary mode of ERK pathway inhibition in BRAF-V600E melanoma. Targeting the DRS with inhibitors in melanoma has the potential to not only disrupt the catalytic apparatus of ERK but also its noncatalytic functions, which have significant impacts on spatiotemporal signaling dynamics and cell fate.
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Affiliation(s)
- Rachel M Sammons
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas.,Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, Texas
| | - Ranajeet Ghose
- Department of Chemistry and Biochemistry, The City College of New York, New York, New York
| | - Kenneth Y Tsai
- Departments of Anatomic Pathology and Tumor Biology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida
| | - Kevin N Dalby
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, Texas.,Department of Oncology, Dell Medical School, The University of Texas at Austin, Austin, Texas
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11
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Biological Rationale for Targeting MEK/ERK Pathways in Anti-Cancer Therapy and to Potentiate Tumour Responses to Radiation. Int J Mol Sci 2019; 20:ijms20102530. [PMID: 31126017 PMCID: PMC6567863 DOI: 10.3390/ijms20102530] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 05/16/2019] [Accepted: 05/21/2019] [Indexed: 02/07/2023] Open
Abstract
ERK1 and ERK2 (ERKs), two extracellular regulated kinases (ERK1/2), are evolutionary-conserved and ubiquitous serine-threonine kinases involved in regulating cell signalling in normal and pathological tissues. The expression levels of these kinases are almost always different, with ERK2 being the more prominent. ERK1/2 activation is fundamental for the development and progression of cancer. Since their discovery, much research has been dedicated to their role in mitogen-activated protein kinases (MAPK) pathway signalling and in their activation by mitogens and mutated RAF or RAS in cancer cells. In order to gain a better understanding of the role of ERK1/2 in MAPK pathway signalling, many studies have been aimed at characterizing ERK1/2 splicing isoforms, mutants, substrates and partners. In this review, we highlight the differences between ERK1 and ERK2 without completely discarding the hypothesis that ERK1 and ERK2 exhibit functional redundancy. The main goal of this review is to shed light on the role of ERK1/2 in targeted therapy and radiotherapy and highlight the importance of identifying ERK inhibitors that may overcome acquired resistance. This is a highly relevant therapeutic issue that needs to be addressed to combat tumours that rely on constitutively active RAF and RAS mutants and the MAPK pathway.
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Misiura M, Kolomeisky AB. Kinetic network model to explain gain-of-function mutations in ERK2 enzyme. J Chem Phys 2019; 150:155101. [PMID: 31005085 DOI: 10.1063/1.5088647] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
ERK2 is a kinase protein that belongs to a Ras/Raf/MEK/ERK signaling pathway, which is activated in response to a range of extracellular signals. Malfunctioning of this cascade leads to a variety of serious diseases, including cancers. This is often caused by mutations in proteins belonging to the cascade, frequently leading to abnormally high activity of the cascade even in the absence of an external signal. One such "gain-of-function" mutation in the ERK2 protein, called a "sevenmaker" mutation (D319N), was discovered in 1994 in Drosophila. The mutation leads to disruption of interactions of other proteins with the D-site of ERK2 and results, contrary to expectations, in an increase of its activity in vivo. However, no molecular mechanism to explain this effect has been presented so far. The difficulty is that this mutation should equally negatively affect interactions of ERK2 with all substrates, activators, and deactivators. In this paper, we present a semiquantitative kinetic network model that gives a possible explanation of the increased activity of mutant ERK2 species. A simplified biochemical network for ERK2, viewed as a system of coupled Michaelis-Menten processes, is presented. Its dynamic properties are calculated explicitly using the method of first-passage processes. The effect of mutation is associated with changes in the strength of interaction energy between the enzyme and the substrates. It is found that the dependence of kinetic properties of the protein on the interaction energy is nonmonotonic, suggesting that some mutations might lead to more efficient catalytic properties, despite weakening intermolecular interactions. Our theoretical predictions agree with experimental observations for the sevenmaker mutation in ERK2. It is also argued that the effect of mutations might depend on the concentrations of substrates.
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Affiliation(s)
- Mikita Misiura
- Department of Chemistry, Rice University, Houston, Texas 77005-1892, USA
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13
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Paramee S, Sookkhee S, Sakonwasun C, Na Takuathung M, Mungkornasawakul P, Nimlamool W, Potikanond S. Anti-cancer effects of Kaempferia parviflora on ovarian cancer SKOV3 cells. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2018; 18:178. [PMID: 29891015 PMCID: PMC5996531 DOI: 10.1186/s12906-018-2241-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 05/25/2018] [Indexed: 11/16/2022]
Abstract
BACKGROUND Kaempferia parviflora (KP) is an herb found in the north of Thailand and used as a folk medicine for improving vitality. Current reports have shown the anti-cancer activities of KP. However, the anti-cancer effects of KP on highly aggressive ovarian cancer have not been investigated. Therefore, we determined the effects of KP on cell proliferation, migration, and cell death in SKOV3 cells. METHODS Ovarian cancer cell line, SKOV3 was used to investigate the anti-cancer effect of KP extract. Cell viability, cell proliferation, MMP activity, cell migration, and invasion were measured by MTT assay, cell counting, gelatin zymography, wound healing assay, and Transwell migration and invasion assays, respectively. Cell death was determined by trypan blue exclusion test, AnnexinV/PI with flow cytometry, and nuclear staining. The level of ERK and AKT phosphorylation, and caspase-3, caspase-7, caspase-9 was investigated by western blot analysis. RESULTS KP extract was cytotoxic to SKOV3 cells when the concentration was increased, and this effect could still be observed even though EGF was present. Besides, the cell doubling time was significantly prolonged in the cells treated with KP. Moreover, KP strongly suppressed cell proliferation, cell migration and invasion. These consequences may be associated with the ability of KP in inhibiting the activity of MMP-2 and MMP-9 assayed by gelatin zymography. Moreover, KP at high concentrations could induce SKOV3 cell apoptosis demonstrated by AnnexinV/PI staining and flow cytometry. Consistently, nuclear labelling of cells treated with KP extract showed DNA fragmentation and deformity. The induction of caspase-3, caspase-7, and caspase-9 indicates that KP induces cell death through the intrinsic apoptotic pathway. The antitumor activities of KP might be regulated through PI3K/AKT and MAPK pathways since the phosphorylation of AKT and ERK1/2 was reduced. CONCLUSIONS The inhibitory effects of KP in cell proliferation, cell migration and invasion together with apoptotic cell death induction in SKOV3 cells suggest that KP has a potential to be a new candidate for ovarian cancer chemotherapeutic agent.
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Affiliation(s)
- Suthasinee Paramee
- Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand
- Graduate School, Chiang Mai University, Chiang Mai, 50200 Thailand
| | - Siriwoot Sookkhee
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand
| | - Choompone Sakonwasun
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand
| | - Mingkwan Na Takuathung
- Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand
| | - Pitchaya Mungkornasawakul
- Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai, 50200 Thailand
- Environmental Science Program, Faculty of Science, Chiang Mai University, Chiang Mai, 50200 Thailand
| | - Wutigri Nimlamool
- Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand
| | - Saranyapin Potikanond
- Department of Pharmacology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200 Thailand
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Activating MAPK1 (ERK2) mutation in an aggressive case of disseminated juvenile xanthogranuloma. Oncotarget 2018; 8:46065-46070. [PMID: 28512266 PMCID: PMC5542249 DOI: 10.18632/oncotarget.17521] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 03/13/2017] [Indexed: 11/25/2022] Open
Abstract
Juvenile xanthogranuloma (JXG) is a rare histiocytic disorder that is usually benign and self-limiting. We present a case of atypical, aggressive JXG harboring a novel mitogen-activated protein kinase (MAPK) pathway mutation in the MAPK1 gene, which encodes mitogen-activated protein kinase 1 or extracellular signal-regulated 2 (ERK2). Our analysis revealed that the mutation results in constitutive ERK activation that is resistant to BRAF or MEK inhibitors but susceptible to an ERK inhibitor. These data highlight the importance of identifying specific MAPK pathway alterations as part of the diagnostic workup for patients with histiocytic disorders rather than initiating empiric treatment with MEK inhibitors.
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15
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Molnar C, Estrada B, de Celis JF. Tay bridge and extracellular-regulated kinase activity are required for motoneuron function in the Drosophila neural system. GENES BRAIN AND BEHAVIOR 2018. [PMID: 29524312 DOI: 10.1111/gbb.12470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Extracellular regulated kinase (Erk) activity is required during neural development for the specification of cell fates in neuroblasts and neuronal lineages, and also regulates several aspects of the activity and survival of mature neurons. The activation of Erk is regulated at multiple levels by kinases and phosphatases that alter its phosphorylation state and by other proteins that regulate its subcellular localization. Here, we find that tay bridge (tay), a negative regulator of Erk in Drosophila imaginal discs, is required in the motoneurons to regulate the number and size of neuromuscular synapses in these cells. The expression of Tay is maximal in motoneurons with low levels of activated ERK, suggesting that Tay modulates the activity of Erk in these cells. We also found that loss of tay expression and increased Erk activity specifically in the motoneurons cause a reversible decrease in walking speed. Impaired motoneurons activity may be caused by alterations in the functionality and number of synaptic boutons developing at the neuromuscular junction in tay mutants.
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Affiliation(s)
- C Molnar
- Centro de Biología Molecular "Severo Ochoa", CSIC and Universidad Autónoma de Madrid, Madrid, Spain.,Institute for Research in Biomedicine-Barcelona, Barcelona, Spain
| | - B Estrada
- Centro Andaluz de Biología del Desarrollo, CSIC and UPO, Sevilla, Spain
| | - J F de Celis
- Centro de Biología Molecular "Severo Ochoa", CSIC and Universidad Autónoma de Madrid, Madrid, Spain
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Keenan SE, Shvartsman SY. Mechanisms and causality in molecular diseases. HISTORY AND PHILOSOPHY OF THE LIFE SCIENCES 2017; 39:35. [PMID: 29038918 PMCID: PMC6445273 DOI: 10.1007/s40656-017-0162-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
How is a disease contracted, and how does it progress through the body? Answers to these questions are fundamental to understanding both basic biology and medicine. Advances in the biomedical sciences continue to provide more tools to address these fundamental questions and to uncover questions that have not been thought of before. Despite these major advances, we are still facing conceptual and technical challenges when learning about the etiology of disease, especially for genetic diseases. In this review, we illustrate this point by discussing the causal links between molecular mechanisms and systems-level phenotypes in molecular diseases. We begin with an examination of sickle cell anemia, and how mechanisms of the disease have been comprehended over the last century. While sickle cell anemia involves a mutation in a single protein in a single cell type, other diseases involve mutations in networks with many protein interactions and in diverse cell types. We introduce the challenges that result from these differences and illustrate the current obstacles by discussing the RASopathies, a recently discovered class of developmental syndromes that result from mutations in signaling networks. Methods to study mutant genotypes that lead to mutant phenotypes are discussed, particularly the use of model organisms and mutant proteins to study protein interactions that may be important for development of disease. These studies will point toward the future of diagnosing and treating genetic disease.
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Affiliation(s)
- Shannon E Keenan
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA.
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, 08544, USA.
| | - Stanislav Y Shvartsman
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA
- Department of Molecular Biology, Princeton University, Princeton, NJ, 08544, USA
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, 08544, USA
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17
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Brenan L, Andreev A, Cohen O, Pantel S, Kamburov A, Cacchiarelli D, Persky NS, Zhu C, Bagul M, Goetz EM, Burgin AB, Garraway LA, Getz G, Mikkelsen TS, Piccioni F, Root DE, Johannessen CM. Phenotypic Characterization of a Comprehensive Set of MAPK1/ERK2 Missense Mutants. Cell Rep 2016; 17:1171-1183. [PMID: 27760319 PMCID: PMC5120861 DOI: 10.1016/j.celrep.2016.09.061] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 09/01/2016] [Accepted: 09/19/2016] [Indexed: 10/20/2022] Open
Abstract
Tumor-specific genomic information has the potential to guide therapeutic strategies and revolutionize patient treatment. Currently, this approach is limited by an abundance of disease-associated mutants whose biological functions and impacts on therapeutic response are uncharacterized. To begin to address this limitation, we functionally characterized nearly all (99.84%) missense mutants of MAPK1/ERK2, an essential effector of oncogenic RAS and RAF. Using this approach, we discovered rare gain- and loss-of-function ERK2 mutants found in human tumors, revealing that, in the context of this assay, mutational frequency alone cannot identify all functionally impactful mutants. Gain-of-function ERK2 mutants induced variable responses to RAF-, MEK-, and ERK-directed therapies, providing a reference for future treatment decisions. Tumor-associated mutations spatially clustered in two ERK2 effector-recruitment domains yet produced mutants with opposite phenotypes. This approach articulates an allele-characterization framework that can be scaled to meet the goals of genome-guided oncology.
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Affiliation(s)
- Lisa Brenan
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Ofir Cohen
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Sasha Pantel
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Atanas Kamburov
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Pathology and Cancer Center, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Davide Cacchiarelli
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Nicole S Persky
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Cong Zhu
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Mukta Bagul
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Eva M Goetz
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Alex B Burgin
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Levi A Garraway
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Gad Getz
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Department of Pathology and Cancer Center, Massachusetts General Hospital, Boston, MA 02114, USA
| | | | | | - David E Root
- The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
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18
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Goshen-Lago T, Goldberg-Carp A, Melamed D, Darlyuk-Saadon I, Bai C, Ahn NG, Admon A, Engelberg D. Variants of the yeast MAPK Mpk1 are fully functional independently of activation loop phosphorylation. Mol Biol Cell 2016; 27:2771-83. [PMID: 27413009 PMCID: PMC5007096 DOI: 10.1091/mbc.e16-03-0167] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 07/06/2016] [Indexed: 12/13/2022] Open
Abstract
MAPKs are catalytically and biologically active only when dually phosphorylated on a TEY motif. Mutations in the yeast MAPK Mpk1 are described that render it fully functional when mutated in its TEY motif and even when it carries a kinase-dead mutation. MAP kinases of the ERK family are conserved from yeast to humans. Their catalytic activity is dependent on dual phosphorylation of their activation loop’s TEY motif, catalyzed by MAPK kinases (MEKs). Here we studied variants of Mpk1, a yeast orthologue of Erk, which is essential for cell wall integrity. Cells lacking MPK1, or the genes encoding the relevant MEKs, MKK1 and MKK2, do not proliferate under cell wall stress, imposed, for example, by caffeine. Mutants of Mpk1, Mpk1(Y268C) and Mpk1(Y268A), function independently of Mkk1 and Mkk2. We show that these variants are phosphorylated at their activation loop in mkk1∆mkk2∆ and mkk1∆mkk2∆pbs2∆ste7∆ cells, suggesting that they autophosphorylate. However, strikingly, when Y268C/A mutations were combined with the kinase-dead mutation, K54R, or mutations at the TEY motif, T190A+Y192F, the resulting proteins still allowed mkk1∆mkk2∆ cells to proliferate under caffeine stress. Mutating the equivalent residue, Tyr-280/Tyr-261, in Erk1/Erk2 significantly impaired Erk1/2’s catalytic activity. This study describes the first case in which a MAPK, Erk/Mpk1, imposes a phenotype via a mechanism that is independent of TEY phosphorylation and an unusual case in which an equivalent mutation in a highly conserved domain of yeast and mammalian Erks causes an opposite effect.
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Affiliation(s)
- Tal Goshen-Lago
- Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Anat Goldberg-Carp
- Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Dganit Melamed
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Ilona Darlyuk-Saadon
- CREATE-NUS-HUJ, Cellular and Molecular Mechanisms of Inflammation Program, National University of Singapore, Singapore 138602 Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456
| | - Chen Bai
- CREATE-NUS-HUJ, Cellular and Molecular Mechanisms of Inflammation Program, National University of Singapore, Singapore 138602 Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456
| | - Natalie G Ahn
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309
| | - Arie Admon
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - David Engelberg
- Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel CREATE-NUS-HUJ, Cellular and Molecular Mechanisms of Inflammation Program, National University of Singapore, Singapore 138602 Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456
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Rubinstein BY, Mattingly HH, Berezhkovskii AM, Shvartsman SY. Long-term dynamics of multisite phosphorylation. Mol Biol Cell 2016; 27:2331-40. [PMID: 27226482 PMCID: PMC4945148 DOI: 10.1091/mbc.e16-03-0137] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 05/16/2016] [Indexed: 01/14/2023] Open
Abstract
A systematic framework for exploring the long-term dynamics of a reaction network is applied to a minimal model of ERK regulation that distinguishes both monophosphorylated forms and allows for nonzero enzyme processivity. Bistability and oscillations can be observed at high levels of processivity. Multisite phosphorylation cycles are ubiquitous in cell regulation systems and are studied at multiple levels of complexity, from molecules to organisms, with the ultimate goal of establishing predictive understanding of the effects of genetic and pharmacological perturbations of protein phosphorylation in vivo. Achieving this goal is essentially impossible without mathematical models, which provide a systematic framework for exploring dynamic interactions of multiple network components. Most of the models studied to date do not discriminate between the distinct partially phosphorylated forms and focus on two limiting reaction regimes, distributive and processive, which differ in the number of enzyme–substrate binding events needed for complete phosphorylation or dephosphorylation. Here we use a minimal model of extracellular signal-related kinase regulation to explore the dynamics of a reaction network that includes all essential phosphorylation forms and arbitrary levels of reaction processivity. In addition to bistability, which has been studied extensively in distributive mechanisms, this network can generate periodic oscillations. Both bistability and oscillations can be realized at high levels of reaction processivity. Our work provides a general framework for systematic analysis of dynamics in multisite phosphorylation systems.
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Affiliation(s)
| | - Henry H Mattingly
- Lewis-Sigler Institute for Integrative Genomics and Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544
| | - Alexander M Berezhkovskii
- Mathematical and Statistical Computing Laboratory, Division of Computational Bioscience, Center for Information Technology, National Institutes of Health, Bethesda, MD 20892
| | - Stanislav Y Shvartsman
- Lewis-Sigler Institute for Integrative Genomics and Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ 08544
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20
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Smorodinsky-Atias K, Goshen-Lago T, Goldberg-Carp A, Melamed D, Shir A, Mooshayef N, Beenstock J, Karamansha Y, Darlyuk-Saadon I, Livnah O, Ahn NG, Admon A, Engelberg D. Intrinsically active variants of Erk oncogenically transform cells and disclose unexpected autophosphorylation capability that is independent of TEY phosphorylation. Mol Biol Cell 2015; 27:1026-39. [PMID: 26658610 PMCID: PMC4791124 DOI: 10.1091/mbc.e15-07-0521] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 12/03/2015] [Indexed: 01/03/2023] Open
Abstract
The receptor-tyrosine kinase (RTK)/Ras/Raf pathway is an essential cascade for mediating growth factor signaling. It is abnormally overactive in almost all human cancers. The downstream targets of the pathway are members of the extracellular regulated kinases (Erk1/2) family, suggesting that this family is a mediator of the oncogenic capability of the cascade. Although all oncogenic mutations in the pathway result in strong activation of Erks, activating mutations in Erks themselves were not reported in cancers. Here we used spontaneously active Erk variants to check whether Erk's activity per se is sufficient for oncogenic transformation. We show that Erk1(R84S) is an oncoprotein, as NIH3T3 cells that express it form foci in tissue culture plates, colonies in soft agar, and tumors in nude mice. We further show that Erk1(R84S) and Erk2(R65S) are intrinsically active due to an unusual autophosphorylation activity they acquire. They autophosphorylate the activatory TEY motif and also other residues, including the critical residue Thr-207 (in Erk1)/Thr-188 (in Erk2). Strikingly, Erk2(R65S) efficiently autophosphorylates its Thr-188 even when dually mutated in the TEY motif. Thus this study shows that Erk1 can be considered a proto-oncogene and that Erk molecules possess unusual autoregulatory properties, some of them independent of TEY phosphorylation.
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Affiliation(s)
- Karina Smorodinsky-Atias
- Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456
| | - Tal Goshen-Lago
- Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Anat Goldberg-Carp
- Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Dganit Melamed
- Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Alexei Shir
- Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Navit Mooshayef
- Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456
| | - Jonah Beenstock
- Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Yael Karamansha
- Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel Wolfson Centre for Applied Structural Biology, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Ilona Darlyuk-Saadon
- Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456 CREATE-NUS-HUJ, Cellular and Molecular Mechanisms of Inflammation Program, National University of Singapore, Singapore 138602
| | - Oded Livnah
- Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel Wolfson Centre for Applied Structural Biology, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Natalie G Ahn
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309
| | - Arie Admon
- Department of Biology, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - David Engelberg
- Department of Biological Chemistry, Institute of Life Science, Hebrew University of Jerusalem, Jerusalem 91904, Israel Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456 CREATE-NUS-HUJ, Cellular and Molecular Mechanisms of Inflammation Program, National University of Singapore, Singapore 138602 CREATE-NUS-HUJ, Cellular and Molecular Mechanisms of Inflammation Program, National University of Singapore, Singapore 138602
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21
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Wu PK, Hong SK, Yoon SH, Park JI. Active ERK2 is sufficient to mediate growth arrest and differentiation signaling. FEBS J 2015; 282:1017-30. [PMID: 25639353 DOI: 10.1111/febs.13197] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 01/07/2015] [Accepted: 01/13/2015] [Indexed: 12/01/2022]
Abstract
Although extracellular signal-regulated kinases (ERK1/2) have been shown to be required in Raf/MEK/ERK pathway signaling, its sufficiency for mediating the pathway signaling has not been firmly established. In an effort to address this, we evaluated previously described ERK2 mutants that exhibit enhanced autophosphorylation of TEY sites in the activation loop in terms of their ability to induce growth arrest and differentiation in LNCaP and PC12 cells. We demonstrate that expression of ERK2-L73P/S151D, containing Lys73Pro and Ser151Asp substitutions that synergistically promote ERK autophosphorylation, is sufficient to induce growth arrest and differentiation, whereas expression of ERK2-I84A and ERK2-R65S/D319N is not as effective. When compared to the constitutively active MEK1-ΔN3/S218E/S222D, expression of ERK2-L73P/S151D only mildly increased ERK kinase activity in cells, as assessed using the ERK substrates p90(RSK) and ETS domain-containing protein (ELK1). However, ERK2-L73P/S151D expression effectively induced down-regulation of androgen receptors, Retinoblastoma (Rb) protein and E2F1 transcription factor, and up-regulation of p16(INK4A) and p21(CIP1), accompanied by cell-cycle arrest and morphological differentiation in LNCaP cells and neurite-like processes in PC12 cells. These effects and the TEY site phosphorylation of ERK2-L73P/S151D were abrogated upon introduction of the active site-disabling Lys52Arg mutation, suggesting that its autoactivation drives this signaling. Moreover, introduction of mutations Asp316/319Ala or Asp319Asn, which impair the common docking site/D-domain-based physical interaction of ERK, did not significantly affect ERK2-L73P/S151D signaling, suggesting that ERK2 mediates growth arrest and differentiation independently of the conventional ERK-target interaction mechanism. Thus, our study presents convincing evidence of ERK sufficiency for Raf/MEK/ERK signaling.
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Affiliation(s)
- Pui-Kei Wu
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, USA
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22
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Goetz EM, Ghandi M, Treacy DJ, Wagle N, Garraway LA. ERK mutations confer resistance to mitogen-activated protein kinase pathway inhibitors. Cancer Res 2014; 74:7079-89. [PMID: 25320010 DOI: 10.1158/0008-5472.can-14-2073] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The use of targeted therapeutics directed against BRAF(V600)-mutant metastatic melanoma improves progression-free survival in many patients; however, acquired drug resistance remains a major medical challenge. By far, the most common clinical resistance mechanism involves reactivation of the MAPK (RAF/MEK/ERK) pathway by a variety of mechanisms. Thus, targeting ERK itself has emerged as an attractive therapeutic concept, and several ERK inhibitors have entered clinical trials. We sought to preemptively determine mutations in ERK1/2 that confer resistance to either ERK inhibitors or combined RAF/MEK inhibition in BRAF(V600)-mutant melanoma. Using a random mutagenesis screen, we identified multiple point mutations in ERK1 (MAPK3) and ERK2 (MAPK1) that could confer resistance to ERK or RAF/MEK inhibitors. ERK inhibitor-resistant alleles were sensitive to RAF/MEK inhibitors and vice versa, suggesting that the future development of alternating RAF/MEK and ERK inhibitor regimens might help circumvent resistance to these agents.
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Affiliation(s)
- Eva M Goetz
- Dana-Farber Cancer Institute, Boston, Massachusetts. Broad Institute, Cambridge, Massachusetts
| | | | | | - Nikhil Wagle
- Dana-Farber Cancer Institute, Boston, Massachusetts. Broad Institute, Cambridge, Massachusetts
| | - Levi A Garraway
- Dana-Farber Cancer Institute, Boston, Massachusetts. Broad Institute, Cambridge, Massachusetts.
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23
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Lu H, Jin W, Sun J, Feng L, Lan H, Shen Q, Ma Y, Li J, Yue Y, Jin H, Wang X. New tumor suppressor CXXC finger protein 4 inactivates mitogen activated protein kinase signaling. FEBS Lett 2014; 588:3322-6. [PMID: 25064842 DOI: 10.1016/j.febslet.2014.07.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 07/11/2014] [Accepted: 07/14/2014] [Indexed: 01/28/2023]
Abstract
As a well-characterized master player in epigenetic regulatory network, EZH2 is widely implicated in the development of many malignancies. We previously found that EZH2 promoted Wnt/β-catenin activation through downregulation of CXXC4 expression. In this report, we demonstrated that CXXC4 inhibited MAPK signaling through binding to ERK-1/2 and abrogating the interaction of ERK 1/2 with MEK1/2. L183, the critical residue in CXXC4 ERK D domain, was found to be essential for CXXC4-ERK 1/2 interaction and the growth inhibitory effect of CXXC4 in human cancer cells. In summary, CXXC4 directly disrupted MEK1/2-ERK 1/2 interaction to inactivate MAPK signaling. L183 site is indispensable for the binding of CXXC4 to ERK1/2 and growth inhibitory effect of CXXC4. Therefore, EZH2 can activate MAPK signaling by inhibiting CXXC4 expression.
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Affiliation(s)
- Haiqi Lu
- Department of Medical Oncology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Wei Jin
- Department of Medical Oncology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jie Sun
- Laboratory of Cancer Biology, Institute of Clinical Science, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Lifeng Feng
- Laboratory of Cancer Biology, Institute of Clinical Science, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Huiyin Lan
- Laboratory of Cancer Biology, Institute of Clinical Science, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Qi Shen
- Department of Medical Oncology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yanning Ma
- Laboratory of Cancer Biology, Institute of Clinical Science, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jiaqiu Li
- Department of Medical Oncology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yongfang Yue
- Laboratory of Cancer Biology, Institute of Clinical Science, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Hongchuan Jin
- Laboratory of Cancer Biology, Institute of Clinical Science, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xian Wang
- Department of Medical Oncology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
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24
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Molnar C, de Celis JF. Tay bridge is a negative regulator of EGFR signalling and interacts with Erk and Mkp3 in the Drosophila melanogaster wing. PLoS Genet 2013; 9:e1003982. [PMID: 24348264 PMCID: PMC3861119 DOI: 10.1371/journal.pgen.1003982] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2013] [Accepted: 10/14/2013] [Indexed: 11/18/2022] Open
Abstract
The regulation of Extracellular regulated kinase (Erk) activity is a key aspect of signalling by pathways activated by extracellular ligands acting through tyrosine kinase transmembrane receptors. In this process, participate proteins with kinase activity that phosphorylate and activate Erk, as well as different phosphatases that inactivate Erk by de-phosphorylation. The state of Erk phosphorylation affects not only its activity, but also its subcellular localization, defining the repertoire of Erk target proteins, and consequently, the cellular response to Erk. In this work, we characterise Tay bridge as a novel component of the EGFR/Erk signalling pathway. Tay bridge is a large nuclear protein with a domain of homology with human AUTS2, and was previously identified due to the neuronal phenotypes displayed by loss-of-function mutations. We show that Tay bridge antagonizes EGFR signalling in the Drosophila melanogaster wing disc and other tissues, and that the protein interacts with both Erk and Mkp3. We suggest that Tay bridge constitutes a novel element involved in the regulation of Erk activity, acting as a nuclear docking for Erk that retains this protein in an inactive form in the nucleus. Extracellular regulated kinases (Erk) mediate signalling by pathways activated by tyrosine kinase transmembrane receptors. The level of activated Erk depends on a highly regulated balance between cytoplasmic kinases and nuclear/cytoplasmic phosphatases, which determine the state of Erk phosphorylation. This affects Erk activity and its subcellular localization, defining the repertoire of Erk targets, and consequently, the cellular response to Erk. In this work, we use a genetic approach to characterise the gene tay bridge as a novel component of the EGFR/Erk signalling pathway. Tay bridge has a domain of homology with human AUTS2, and was previously identified due to the neuronal phenotypes displayed by loss-of-function mutations. We show that Tay bridge antagonizes EGFR signalling in the Drosophila melanogaster wing disc and other tissues, and that the protein interacts with both Erk and Mkp3. We suggest that Tay bridge constitutes a novel element involved in the regulation of Erk activity, acting as a nuclear docking for Erk that retains this protein in an inactive form in the nucleus. These results could provide important insights into the clinical consequences of AUTS2 mutations in humans, which are related to behavioural perturbations including autism, mental retardation, Attention Deficit Hyperactivity Disorder and alcohol drinking behaviour.
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Affiliation(s)
- Cristina Molnar
- Centro de Biología Molecular “Severo Ochoa,” CSIC and Universidad Autónoma de Madrid, Madrid, Spain
| | - Jose F. de Celis
- Centro de Biología Molecular “Severo Ochoa,” CSIC and Universidad Autónoma de Madrid, Madrid, Spain
- * E-mail:
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25
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Shim JH, Greenblatt MB, Zou W, Huang Z, Wein MN, Brady N, Hu D, Charron J, Brodkin HR, Petsko GA, Zaller D, Zhai B, Gygi S, Glimcher LH, Jones DC. Schnurri-3 regulates ERK downstream of WNT signaling in osteoblasts. J Clin Invest 2013; 123:4010-22. [PMID: 23945236 DOI: 10.1172/jci69443] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 06/21/2013] [Indexed: 11/17/2022] Open
Abstract
Mice deficient in Schnurri-3 (SHN3; also known as HIVEP3) display increased bone formation, but harnessing this observation for therapeutic benefit requires an improved understanding of how SHN3 functions in osteoblasts. Here we identified SHN3 as a dampener of ERK activity that functions in part downstream of WNT signaling in osteoblasts. A D-domain motif within SHN3 mediated the interaction with and inhibition of ERK activity and osteoblast differentiation, and knockin of a mutation in Shn3 that abolishes this interaction resulted in aberrant ERK activation and consequent osteoblast hyperactivity in vivo. Additionally, in vivo genetic interaction studies demonstrated that crossing to Lrp5(-/-) mice partially rescued the osteosclerotic phenotype of Shn3(-/-) mice; mechanistically, this corresponded to the ability of SHN3 to inhibit ERK-mediated suppression of GSK3β. Inducible knockdown of Shn3 in adult mice resulted in a high-bone mass phenotype, providing evidence that transient blockade of these pathways in adults holds promise as a therapy for osteoporosis.
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Affiliation(s)
- Jae-Hyuck Shim
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, New York 10065, USA.
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26
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Tzarum N, Komornik N, Ben Chetrit D, Engelberg D, Livnah O. DEF pocket in p38α facilitates substrate selectivity and mediates autophosphorylation. J Biol Chem 2013; 288:19537-47. [PMID: 23671282 DOI: 10.1074/jbc.m113.464511] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Signaling processes are primarily promoted by molecular recognition and corresponding protein-protein interactions. One of the key eukaryotic signaling pathways is the MAP kinase cascade involved in vital cellular processes such as cell proliferation, differentiation, apoptosis, and stress response. The principle recognition site of MAP kinases, the common docking (CD) region, forms selective interactions with substrates, upstream activators, and phosphatases. A second docking site, defined as the DEF site interaction pocket (DEF pocket), is formed subsequent to ERK2 and p38α activation. Both crystal structures of p38α in its dually phosphorylated form and of intrinsically active mutants showed the DEF pocket, giving motivation for studying its role in substrate activation and selectivity. Mutating selected DEF pocket residues significantly decreased the phosphorylation levels of three p38α substrates (ATFII, Elk-1, and MBP) with no apparent effect on the phosphorylation of MK2 kinase. Conversely, mutating the CD region gave the opposite effect, suggesting p38α substrates can be classified into DEF-dependent and DEF-independent substrates. In addition, mutating DEF pocket residues decreased the autophosphorylation capability of intrinsically active p38α mutants, suggesting DEF-mediated trans-autophosphorylation in p38α. These results could contribute to understanding substrate selectivity of p38α and serve as a platform for designing p38α-selective DEF site blockers, which partially inhibit p38α binding DEF-dependent substrates, whereas maintaining its other functions intact. In this context, preliminary results using synthetic peptides reveal significant inhibition of substrate phosphorylation by activated p38α.
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Affiliation(s)
- Netanel Tzarum
- Department of Biological Chemistry, The Alexander Silverman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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27
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Abstract
Dual-specificity MAP kinase phosphatases (MKPs) provide a complex negative regulatory network that acts to shape the duration, magnitude and spatiotemporal profile of MAP kinase activities in response to both physiological and pathological stimuli. Individual MKPs may exhibit either exquisite specificity towards a single mitogen-activated protein kinase (MAPK) isoform or be able to regulate multiple MAPK pathways in a single cell or tissue. They can act as negative feedback regulators of MAPK activity, but can also provide mechanisms of crosstalk between distinct MAPK pathways and between MAPK signalling and other intracellular signalling modules. In this review, we explore the current state of knowledge with respect to the regulation of MKP expression levels and activities, the mechanisms by which individual MKPs recognize and interact with different MAPK isoforms and their role in the spatiotemporal regulation of MAPK signalling.
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28
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Armstrong SP, Caunt CJ, McArdle CA. Gonadotropin-releasing hormone and protein kinase C signaling to ERK: spatiotemporal regulation of ERK by docking domains and dual-specificity phosphatases. Mol Endocrinol 2009; 23:510-9. [PMID: 19179479 DOI: 10.1210/me.2008-0333] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Activated ERK translocates to the nucleus to regulate transcription. Spatiotemporal aspects of this response dictate biological consequences and are influenced by dual-specificity phosphatases (DUSPs) that can scaffold and dephosphorylate ERK. In HeLa cells, GnRH causes transient and protein kinase C (PKC)-dependent ERK activation, but termination mechanisms are unknown. We now explore DUSP roles using short inhibitory RNA to knock down endogenous ERK, adenoviruses to express GnRH receptors and add-back ERK2-GFP, and automated microscopy to monitor ERK location and activation. GnRH caused rapid and transient increases in dual phosphorylated ERK2 (ppERK2) and nuclear to cytoplasmic ERK2-green fluorescent protein (GFP) ratio, whereas responses to a PKC-activating phorbol ester were more sustained. In cells expressing D319N ERK2-GFP (D319N mutation impairs docking-domain-dependent binding to DUSPs), GnRH caused more sustained increases in ppERK2 and nuclear to cytoplasmic ERK2-GFP ratio and also had more pronounced effects on Egr-1 luciferase (a transcriptional reporter for ERK activation). Cycloheximide caused more sustained effects of GnRH and phorbol ester on ppERK, suggesting termination by nuclear-inducible DUSPs. GnRH also increased expression of nuclear-inducible DUSP1 and -4, but their knockdown did not alter GnRH-mediated ERK signaling. Screening a short inhibitory RNA library targeting 16 DUSPs (nuclear-inducible DUSPs, cytoplasmic ERK MAPK phosphatases, c-Jun N-terminal kinase/p38 MAPK phosphatases, and atypical DUSPs) revealed GnRH effects to be influenced by DUSPs 5, 9, 10, 16, and 3 (i.e. by each DUSP class). Thus, GnRH-mediated ERK responses (like PKC-mediated ERK responses) are dependent on protein neosynthesis and docking-domain-dependent binding, but for GnRH activation (unlike PKC activation), this does not reflect dependence on nuclear-inducible DUSPs. Termination of these GnRH effects is apparently dependent upon a preexisting rapid turnover protein.
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Affiliation(s)
- Stephen Paul Armstrong
- Department of Clinical Sciences at South Bristol, University of Bristol, Bristol BS1 3NY, UK
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29
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Levin-Salomon V, Kogan K, Ahn NG, Livnah O, Engelberg D. Isolation of intrinsically active (MEK-independent) variants of the ERK family of mitogen-activated protein (MAP) kinases. J Biol Chem 2008; 283:34500-10. [PMID: 18829462 PMCID: PMC3259889 DOI: 10.1074/jbc.m806443200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Revised: 09/29/2008] [Indexed: 11/06/2022] Open
Abstract
MAPKs are key components of cell signaling pathways with a unique activation mechanism: i.e. dual phosphorylation of neighboring threonine and tyrosine residues. The ERK enzymes form a subfamily of MAPKs involved in proliferation, differentiation, development, learning, and memory. The exact role of each Erk molecule in these processes is not clear. An efficient strategy for addressing this question is to activate individually each molecule, for example, by expressing intrinsically active variants of them. However, such molecules were not produced so far. Here, we report on the isolation, via a specifically designed genetic screen, of six variants (each carries a point mutation) of the yeast MAPK Mpk1/Erk that are active, independent of upstream phosphorylation. One of the activating mutations, R68S, occurred in a residue conserved in the mammalian Erk1 (Arg-84) and Erk2 (Arg-65) and in the Drosophila ERK Rolled (Arg-80). Replacing this conserved Arg with Ser rendered these MAPKs intrinsically active to very high levels when tested in vitro as recombinant proteins. Combination of the Arg to Ser mutation with the sevenmaker mutation (producing Erk2(R65S+D319N) and Rolled(R80S+D334N)) resulted in even higher activity (45 and 70%, respectively, in reference to fully active dually phosphorylated Erk2 or Rolled). Erk2(R65S) and Erk2(R65S+D319N) were found to be spontaneously active also when expressed in human HEK293 cells. We further revealed the mechanism of action of the mutants and show that it involves acquisition of autophosphorylation activity. Thus, a first generation of Erk molecules that are spontaneously active in vitro and in vivo has been obtained.
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Affiliation(s)
- Vered Levin-Salomon
- The Department of Biological Chemistry,
The Alexander Silberman Institute of Life Sciences, The Hebrew University of
Jerusalem, Jerusalem 91904, Israel, The Wolfson
Centre for Applied Structural Biology, The Hebrew University of Jerusalem,
Jerusalem 91904, Israel, and the Department of
Chemistry and Biochemistry, Howard Hughes Medical Institute, University of
Colorado, Boulder, Colorado 80309
| | - Konstantin Kogan
- The Department of Biological Chemistry,
The Alexander Silberman Institute of Life Sciences, The Hebrew University of
Jerusalem, Jerusalem 91904, Israel, The Wolfson
Centre for Applied Structural Biology, The Hebrew University of Jerusalem,
Jerusalem 91904, Israel, and the Department of
Chemistry and Biochemistry, Howard Hughes Medical Institute, University of
Colorado, Boulder, Colorado 80309
| | - Natalie G. Ahn
- The Department of Biological Chemistry,
The Alexander Silberman Institute of Life Sciences, The Hebrew University of
Jerusalem, Jerusalem 91904, Israel, The Wolfson
Centre for Applied Structural Biology, The Hebrew University of Jerusalem,
Jerusalem 91904, Israel, and the Department of
Chemistry and Biochemistry, Howard Hughes Medical Institute, University of
Colorado, Boulder, Colorado 80309
| | - Oded Livnah
- The Department of Biological Chemistry,
The Alexander Silberman Institute of Life Sciences, The Hebrew University of
Jerusalem, Jerusalem 91904, Israel, The Wolfson
Centre for Applied Structural Biology, The Hebrew University of Jerusalem,
Jerusalem 91904, Israel, and the Department of
Chemistry and Biochemistry, Howard Hughes Medical Institute, University of
Colorado, Boulder, Colorado 80309
| | - David Engelberg
- The Department of Biological Chemistry,
The Alexander Silberman Institute of Life Sciences, The Hebrew University of
Jerusalem, Jerusalem 91904, Israel, The Wolfson
Centre for Applied Structural Biology, The Hebrew University of Jerusalem,
Jerusalem 91904, Israel, and the Department of
Chemistry and Biochemistry, Howard Hughes Medical Institute, University of
Colorado, Boulder, Colorado 80309
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30
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Caunt CJ, Armstrong SP, Rivers CA, Norman MR, McArdle CA. Spatiotemporal regulation of ERK2 by dual specificity phosphatases. J Biol Chem 2008; 283:26612-23. [PMID: 18650424 PMCID: PMC2546534 DOI: 10.1074/jbc.m801500200] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Although many stimuli activate extracellular signal-regulated kinases 1 and
2 (ERK1/2), the kinetics and compartmentalization of ERK1/2 signals are
stimulus-dependent and dictate physiological consequences. ERKs can be
inactivated by dual specificity phosphatases (DUSPs), notably the MAPK
phosphatases (MKPs) and atypical DUSPs, that can both dephosphorylate and
scaffold ERK1/2. Using a cell imaging model (based on knockdown of endogenous
ERKs and add-back of wild-type or mutated ERK2-GFP reporters), we explored
possible effects of DUSPs on responses to transient or sustained ERK2
activators (epidermal growth factor and phorbol 12,13-dibutyrate,
respectively). For both stimuli, a D319N mutation (which impairs DUSP binding)
increased ERK2 activity and reduced nuclear accumulation. These stimuli also
increased mRNA levels for eight DUSPs. In a short inhibitory RNA screen, 12 of
16 DUSPs influenced ERK2 responses. These effects were evident among nuclear
inducible MKP, cytoplasmic ERK MKP, JNK/p38 MKP, and atypical DUSP subtypes
and, with the exception of the nuclear inducible MKPs, were paralleled by
corresponding changes in Egr-1 luciferase activation. Simultaneous removal of
all JNK/p38 MKPs or nuclear inducible MKPs revealed them as positive and
negative regulators of ERK2 signaling, respectively. The effects of JNK/p38
MKP short inhibitory RNAs were not dependent on protein neosynthesis but were
reversed in the presence of JNK and p38 kinase inhibitors, indicating
DUSP-mediated cross-talk between MAPK pathways. Overall, our data reveal that
a large number of DUSPs influence ERK2 signaling. Together with the known
tissue-specific expression of DUSPs and the importance of ERK1/2 in cell
regulation, our data support the potential value of DUSPs as targets for drug
therapy.
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Affiliation(s)
- Christopher J Caunt
- Laboratory for Integrated Neuroscience and Endocrinology, Department of Clinical Sciences at South Bristol, University of Bristol, Whitson Street, Bristol BS1 3NY, United Kingdom
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31
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Campbell PM, Singh A, Williams FJ, Frantz K, Ulkü AS, Kelley GG, Der CJ. Genetic and pharmacologic dissection of Ras effector utilization in oncogenesis. Methods Enzymol 2008; 407:195-217. [PMID: 16757325 DOI: 10.1016/s0076-6879(05)07017-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ras proteins function as signaling nodes that are activated by diverse extracellular stimuli. Equally complex for this family of molecular switches is the multitude of downstream effectors and the pathways that they traverse to translate extracellular signals into a spectrum of cellular consequences. To better understand the individual and collective roles of these effector signaling networks, both genetic and pharmacological tools have been developed. By either stimulating or ablating specific components in a cascade downstream of Ras activation, one can gain insight into the specific signaling underlying a particular Ras phenotype, for example, malignant transformation. In this chapter, we describe the use of activating and dominant-negative mutations, both artificial and naturally occurring, of Ras and its effectors, as well as pharmacological inhibitors used to probe the effector pathways (Raf kinase, phosphoinositol 3-kinase, Tiam1, phospholipase C epsilon, and RalGEF) implicated in Ras-mediated oncogenesis.
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Affiliation(s)
- Paul M Campbell
- Department of Pharmacology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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32
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Two adjacent docking sites in the yeast Hog1 mitogen-activated protein (MAP) kinase differentially interact with the Pbs2 MAP kinase kinase and the Ptp2 protein tyrosine phosphatase. Mol Cell Biol 2008; 28:2481-94. [PMID: 18212044 DOI: 10.1128/mcb.01817-07] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Functional interactions between a mitogen-activated protein kinase (MAPK) and its regulators require specific docking interactions. Here, we investigated the mechanism by which the yeast osmoregulatory Hog1 MAPK specifically interacts with its activator, the MAPK kinase Pbs2, and its major inactivator, the protein phosphatase Ptp2. We found, in the N-terminal noncatalytic region of Pbs2, a specific Hog1-binding domain, termed HBD-1. We also defined two adjacent Pbs2-binding sites in Hog1, namely, the common docking (CD) domain and Pbs2-binding domain 2 (PBD-2). The PBD-2 docking site appears to be sterically blocked in the intact Hog1 molecule, but its affinity to Pbs2 is apparent in shorter fragments of Hog1. Both the CD and the PBD-2 docking sites are required for the optimal activation of Hog1 by Pbs2, and in the absence of both sites, Hog1 cannot be activated by Pbs2. These data suggest that the initial interaction of Pbs2 with the CD site might induce a conformational change in Hog1 so that the PBD-2 site becomes accessible. The CD and PBD-2 docking sites are also involved in the specific interaction between Hog1 and Ptp2 and govern the dynamic dephosphorylation of activated Hog1. Thus, the CD and the PBD-2 docking sites play critical roles in both the activation and inactivation of Hog1.
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33
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Caunt CJ, Rivers CA, Conway-Campbell BL, Norman MR, McArdle CA. Epidermal growth factor receptor and protein kinase C signaling to ERK2: spatiotemporal regulation of ERK2 by dual specificity phosphatases. J Biol Chem 2008; 283:6241-52. [PMID: 18178562 DOI: 10.1074/jbc.m706624200] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Spatiotemporal aspects of ERK activation are stimulus-specific and dictate cellular consequences. They are dependent upon dual specificity phosphatases (DUSPs) that bind ERK via docking domains and can both inactivate and anchor ERK in cellular compartments. Using high throughput fluorescence microscopy in combination with a system where endogenous ERKs are removed and replaced with wild-type or mutated ERK2-green fluorescent protein (GFP), we show that ERK2 activation responses to epidermal growth factor (EGF) and protein kinase C (PKC) are transient and sustained, respectively. PKC-mediated ERK2 activation is associated with prolonged nuclear localization in the dephosphorylated form, whereas EGF-stimulated ERK2 activation mediates only transient nuclear accumulation. By using short inhibitory RNAs to nuclear inducible DUSP1, -2, or -4 (alone or in combination), we demonstrate that all three of these enzymes contribute to the dephosphorylation of PKC (but not EGF)-activated ERK2 in the nucleus but that they have opposing effects on localization. DUSP2 and -4 inactivate and anchor ERK2, whereas DUSP1 dephosphorylates ERK in the nucleus but allows its traffic back to the cytoplasm. Overexpression of DUSP1, -2, or -4 prevented ERK2 activation, but only DUSP2 and -4 caused ERK2-GFP nuclear accumulation or could be immunoprecipitated with ERK2. Furthermore, protein synthesis inhibition or replacement of wild-type ERK2-GFP with docking domain mutants selectively increased PKC effects on ERK activity and altered ERK2-GFP localization. These mutations also impaired the ability of ERK2-GFP to bind DUSP2 and -4. Together, our data reveal a novel, stimulus-specific, and phosphatase-specific mechanism of ERK2 regulation in the nucleus by DUSP1, -2, and -4.
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Affiliation(s)
- Christopher J Caunt
- Laboratories for Integrated Neuroscience and Endocrinology, Department of Clinical Sciences at South Bristol, University of Bristol, Whitson Street, Bristol, U.K
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34
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Slisz M, Rothenberger E, Hutter D. Attenuation of p38 MAPK activity upon contact inhibition in fibroblasts. Mol Cell Biochem 2007; 308:65-73. [PMID: 17906919 DOI: 10.1007/s11010-007-9613-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Accepted: 09/13/2007] [Indexed: 12/27/2022]
Abstract
The molecular events, which govern growth control upon contact inhibition have not yet been clearly defined. Previous work has indicated that there is an increase in the expression of mitogen-activated protein kinase phosphatases (MKPs) upon the attainment of contact inhibition in normal fibroblasts, concurrently with a decrease in ERK activity. To investigate the potential role of p38 and JNK in the transition to a contact-inhibited state, normal human fibroblasts (BJ) were grown to subconfluent and confluent densities. The total levels and phosphorylation states of p38 and JNK were assayed, and were compared to protein levels seen in HT-1080 fibrosarcoma cells, which lack contact-inhibited growth control. Activation of JNK was not apparent in these cells, though p38 was found to be active in proliferating cells, but attenuated in contact-inhibited cultures. Such fluctuations in p38 activity were not seen in cultures of fibrosarcoma cells of increasing density. This alteration in p38 activity was also reflected by attenuated activation of the downstream transcription factor ATF-2 upon contact inhibition. Overexpression of MKP-1 in fibrosarcoma cells and fibroblasts reduced proliferation, while expression of a phosphatase-resistant p38 protein (p38(N316)) enhanced proliferation of normal fibroblasts. Taken together, these results suggest the involvement of negative regulation of p38 in contact-inhibited growth control.
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Affiliation(s)
- Michael Slisz
- Department of Biology, Monmouth University, 400 Cedar Avenue, West Long Branch, NJ 07764, USA
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35
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Owens DM, Keyse SM. Differential regulation of MAP kinase signalling by dual-specificity protein phosphatases. Oncogene 2007; 26:3203-13. [PMID: 17496916 DOI: 10.1038/sj.onc.1210412] [Citation(s) in RCA: 619] [Impact Index Per Article: 36.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The regulated dephosphorylation of mitogen-activated protein kinases (MAPKs) plays a key role in determining the magnitude and duration of kinase activation and hence the physiological outcome of signalling. In mammalian cells, an important component of this control is mediated by the differential expression and activities of a family of 10 dual-specificity (Thr/Tyr) MAPK phosphatases (MKPs). These enzymes share a common structure in which MAPK substrate recognition is determined by sequences within an amino-terminal non-catalytic domain whereas MAPK binding often leads to a conformational change within the C-terminal catalytic domain resulting in increased enzyme activity. MKPs can either recognize and inactivate a single class of MAP kinase, as in the specific inactivation of extracellular signal regulated kinase (ERK) by the cytoplasmic phosphatase DUSP6/MKP-3 or can regulate more than one MAPK pathway as illustrated by the ability of DUSP1/MKP-1 to dephosphorylate ERK, c-Jun amino-terminal kinase and p38 in the cell nucleus. These properties, coupled with transcriptional regulation of MKP expression in response to stimuli that activate MAPK signalling, suggest a complex negative regulatory network in which individual MAPK activities can be subject to negative feedback control, but also raise the possibility that signalling through multiple MAPK pathways may be integrated at the level of regulation by MKPs.
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Affiliation(s)
- D M Owens
- Cancer Research UK Stress Response Laboratory, Biomedical Research Centre, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, UK
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36
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Tresini M, Lorenzini A, Torres C, Cristofalo VJ. Modulation of replicative senescence of diploid human cells by nuclear ERK signaling. J Biol Chem 2006; 282:4136-51. [PMID: 17145763 DOI: 10.1074/jbc.m604955200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Normal somatic cells have a limited replicative lifespan, and serial subcultivation ultimately results in senescence. Senescent cells are irreversibly growth-arrested and show impaired responses to mitogens. Activation of the ERK signaling pathway, an absolute requirement for cell proliferation, results in nuclear relocalization of active ERKs, an event impaired in senescent fibroblasts. This impairment coincides with increased activity of the nuclear ERK phosphatase MKP2. Here we show that replicative lifespan can be altered by changes in nuclear ERK activity. Ectopic expression of MKP2 results in premature senescence. In contrast, knock-down of MKP2 expression, through transduction of MKP2 sequence-specific short hairpin RNA, or expression of the phosphatase resistant ERK2(D319N) mutant, abrogates the effects of increased endogenous MKP2 levels and senescence is postponed. Nuclear targeting of ERK2(D319N) significantly augments its effects and the transduced cultures show higher than 60% increase in replicative lifespan compared with cultures transduced with wt ERK2. Long-lived cultures senesce with altered molecular characteristics and retain the ability to express c-fos, and Rb is maintained in its inactive form. Our results support that MKP2-mediated inactivation of nuclear ERK2 represents a key event in the establishment of replicative senescence. Although it is evident that senescence can be imposed through multiple mechanisms, restoration of nuclear ERK activity can bypass a critical senescence checkpoint and, thus, extend replicative lifespan.
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Affiliation(s)
- Maria Tresini
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania 19096, USA.
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Abstract
Sequential activation of protein kinases within the mitogen-activated protein kinase (MAPK) cascades is a common mechanism of signal transduction in many cellular processes. Four such cascades have been elucidated thus far, and named according to their MAPK tier component as the ERK1/2, JNK, p38MAPK, and ERK5 cascades. These cascades cooperate in transmitting various extracellular signals, and thus control cellular processes such as proliferation, differentiation, development, stress response, and apoptosis. Here we describe the classic ERK1/2 cascade, and concentrate mainly on the properties of MEK1/2 and ERK1/2, including their mode of regulation and their role in various cellular processes and in oncogenesis. This cascade may serve as a prototype of the other MAPK cascades, and the study of this cascade is likely to contribute to the understanding of mitogenic and other processes in many cell lines and tissues.
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Affiliation(s)
- Hadara Rubinfeld
- Department of Biological Regulation, The Weizmann Institute of Science, Rehovot 76100, Israel
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38
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Askari N, Diskin R, Avitzour M, Yaakov G, Livnah O, Engelberg D. MAP-quest: could we produce constitutively active variants of MAP kinases? Mol Cell Endocrinol 2006; 252:231-40. [PMID: 16672172 DOI: 10.1016/j.mce.2006.03.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Constitutively active mutants that acquired intrinsic activity and escaped regulation, serve as powerful tools for revealing the biochemical, biological and pathological functions of proteins. Such mutants are not available for mitogen-activated protein kinases (MAPKs). It is not known how to mimic the unusual mode of MAPK activation and to enforce, by mutations, their active conformation. In this review we describe the strategies employed in attempts to overcome this obstacle. We focus on a recent breakthrough with the p38 family that suggests that active variants of all MAPKs will soon be available.
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Affiliation(s)
- Nadav Askari
- The Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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Chuderland D, Seger R. Protein-protein interactions in the regulation of the extracellular signal-regulated kinase. Mol Biotechnol 2006; 29:57-74. [PMID: 15668520 DOI: 10.1385/mb:29:1:57] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The extracellular signal-regulated kinase (ERK) cascade is a central intracellular signaling pathway that is activated by a variety of extracellular stimuli, and thereby regulates cellular processes such as proliferation, differentiation, and oncogenic transformation. To execute these functions, the signals of those stimuli are transmitted to the cytosolic and nuclear targets in a rapid and specific manner. In the last few years it has become clear that the specificity and the rapid function of the ERK cascade is largely determined by protein-protein interactions with various signaling components and substrates. This review describes interactions of ERK with its immediate regulators, scaffold proteins, substrates, and localizing proteins, and shows their involvement in the functioning of the ERK cascade. Understanding the full scope of ERK-interactions is important for the development of new drugs for the treatment of cancer and other diseases.
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Affiliation(s)
- Dana Chuderland
- Department of Biological Regulation, The Weizmann Institute of Science, Rehovot 76100, Israel
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40
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Murphy LO, Blenis J. MAPK signal specificity: the right place at the right time. Trends Biochem Sci 2006; 31:268-75. [PMID: 16603362 DOI: 10.1016/j.tibs.2006.03.009] [Citation(s) in RCA: 527] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Revised: 03/06/2006] [Accepted: 03/24/2006] [Indexed: 10/24/2022]
Abstract
Although the mechanisms that lead to activation of the Ras, extracellular-signal-regulated kinase mitogen-activated protein kinase (Ras/ERK-MAPK) signaling pathway have been studied intensively, the fundamental principles that determine how activation of ERK signaling can result in distinct biological outcomes have only recently received attention. Factors such as cell-surface receptor density, expression of scaffolding proteins, the surrounding extracellular matrix, and the interplay between kinases and phosphatases modulate the strength and duration of ERK signaling. Furthermore, the spatial distribution and temporal qualities of ERK can markedly alter the qualitative and quantitative features of downstream signaling to immediate early genes (IEG) and the expression of IEG-encoded protein products. As a result, IEG products provide a molecular interpretation of ERK dynamics, enabling the cell to program an appropriate biological response.
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Affiliation(s)
- Leon O Murphy
- Developmental and Molecular Pathways, Novartis Institutes for BioMedical Research, 250 Massachusetts Avenue, Cambridge, MA 02139, USA
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41
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Liu S, Sun JP, Zhou B, Zhang ZY. Structural basis of docking interactions between ERK2 and MAP kinase phosphatase 3. Proc Natl Acad Sci U S A 2006; 103:5326-31. [PMID: 16567630 PMCID: PMC1459354 DOI: 10.1073/pnas.0510506103] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mitogen-activated protein (MAP) kinases are central components of signal transduction pathways for cell proliferation, stress responses, and differentiation. Signaling efficiency and specificity are modulated in large part by docking interactions between individual MAP kinase and the kinase interaction motif (KIM), (R/K)(2-3)-X(1-6)-Phi(A)-X-Phi(B), in its cognate kinases, phosphatases, scaffolding proteins, and substrates. We have determined the crystal structure of extracellular signal-regulated protein kinase 2 bound to the KIM peptide from MAP kinase phosphatase 3, an extracellular signal-regulated protein kinase 2-specific phosphatase. The structure reveals that the KIM docking site, situated in a noncatalytic region opposite of the kinase catalytic pocket, is comprised of a highly acidic patch and a hydrophobic groove, which engage the basic and Phi(A)-X-Phi(B) residues, respectively, in the KIM sequence. The specific docking interactions observed in the structure consolidate all known biochemical data. In addition, structural comparison indicates that the KIM docking site is conserved in all MAP kinases. The results establish a structural model for understanding how MAP kinases interact with their regulators and substrates and provide new insights into how MAP kinase docking specificity can be achieved.
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Affiliation(s)
- Sijiu Liu
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202
| | - Jin-Peng Sun
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202
| | - Bo Zhou
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202
| | - Zhong-Yin Zhang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202
- *To whom correspondence should be addressed. E-mail:
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42
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Tárrega C, Ríos P, Cejudo-Marín R, Blanco-Aparicio C, van den Berk L, Schepens J, Hendriks W, Tabernero L, Pulido R. ERK2 shows a restrictive and locally selective mechanism of recognition by its tyrosine phosphatase inactivators not shared by its activator MEK1. J Biol Chem 2005; 280:37885-94. [PMID: 16148006 DOI: 10.1074/jbc.m504366200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The two regulatory residues that control the enzymatic activity of the mitogen-activated protein (MAP) kinase ERK2 are phosphorylated by the unique MAP kinase kinases MEK1/2 and dephosphorylated by several tyrosine-specific and dual specificity protein phosphatases. Selective docking interactions facilitate these phosphorylation and dephosphorylation events, controlling the specificity and duration of the MAP kinase activation-inactivation cycles. We have analyzed the contribution of specific residues of ERK2 in the physical and functional interaction with the ERK2 phosphatase inactivators PTP-SL and MKP-3 and with its activator MEK1. Single mutations in ERK2 that abrogated the dephosphorylation by endogenous tyrosine phosphatases from HEK293 cells still allowed efficient phosphorylation by endogenous MEK1/2. Discrete ERK2 mutations at the ERK2 docking groove differentially affected binding and inactivation by PTP-SL and MKP-3. Remarkably, the cytosolic retention of ERK2 by its activator MEK1 was not affected by any of the analyzed ERK2 single amino acid substitutions. A chimeric MEK1 protein, containing the kinase interaction motif of PTP-SL, bound tightly to ERK2 through its docking groove and behaved as a gain-of-function MAP kinase kinase that hyperactivated ERK2. Our results provide evidence that the ERK2 docking groove is more restrictive and selective for its tyrosine phosphatase inactivators than for MEK1/2 and indicate that distinct ERK2 residues modulate the docking interactions with activating and inactivating effectors.
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Affiliation(s)
- Céline Tárrega
- Centro de Investigación Príncipe Felipe, Valencia, Spain
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43
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Farooq A, Zhou MM. Structure and regulation of MAPK phosphatases. Cell Signal 2004; 16:769-79. [PMID: 15115656 DOI: 10.1016/j.cellsig.2003.12.008] [Citation(s) in RCA: 346] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2003] [Accepted: 12/16/2003] [Indexed: 11/25/2022]
Abstract
MAP kinases (MAPKs), which control mitogenic signal transduction in all eukaryotic organisms, are inactivated by dual specificity MAPK phosphatases (DS-MKPs). Recent studies reveal that substrate specificity and enzymatic activity of MKPs are tightly controlled not only by the conserved C-terminal phosphatase domain but also by an N-terminal (NT) kinase-binding domain. Notably, MKPs that consist of a kinase-binding domain and a phosphatase domain exhibit little phosphatase activity in the absence of their physiological substrates. MKP binding to a specific MAPK results in enzymatic activation of the phosphatase in a substrate-induced activation mechanism. This direct coupling of inactivation of an MAPK to activation of an MKP provides a tightly controlled regulation that enables these two key enzymes to keep each other in check, thus guaranteeing the fidelity of signal transduction. This review discusses the recent understanding of structure and regulation of the large family of dual specificity MKPs, which can be divided into four subgroups according to their functional domains and mechanism of substrate recognition and enzymatic regulation. Moreover, detailed comparison of the structural basis between this unique substrate-induced activation mechanism and the common auto-inhibition mechanism is provided.
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Affiliation(s)
- Amjad Farooq
- Structural Biology Program, Department of Physiology and Biophysics, Mount Sinai School of Medicine, One Gustave L Levy Place, Box 1677, New York, NY 10029, USA.
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44
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Aebersold DM, Shaul YD, Yung Y, Yarom N, Yao Z, Hanoch T, Seger R. Extracellular signal-regulated kinase 1c (ERK1c), a novel 42-kilodalton ERK, demonstrates unique modes of regulation, localization, and function. Mol Cell Biol 2004; 24:10000-15. [PMID: 15509801 PMCID: PMC525466 DOI: 10.1128/mcb.24.22.10000-10015.2004] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Extracellular signal-regulated kinases (ERKs) are signaling molecules that regulate many cellular processes. We have previously identified an alternatively spliced 46-kDa form of ERK1 that is expressed in rats and mice and named ERK1b. Here we report that the same splicing event in humans and monkeys causes, due to sequence differences in the inserted introns, the production of an ERK isoform that migrates together with the 42-kDa ERK2. Because of the differences of this isoform from ERK1b, we named it ERK1c. We found that its expression levels are about 10% of ERK1. ERK1c seems to be expressed in a wide variety of tissues and cells. Its activation by MEKs and inactivation by phosphatases are slower than those of ERK1, which is probably the reason for its differential regulation in response to extracellular stimuli. Unlike ERK1, ERK1c undergoes monoubiquitination, which is increased with elevated cell density concomitantly with accumulation of ERK1c in the Golgi apparatus. Elevated cell density also causes enhanced Golgi fragmentation, which is facilitated by overexpression of native ERK1c and is prevented by dominant-negative ERK1c, indicating that ERK1c mediates cell density-induced Golgi fragmentation. The differential regulation of ERK1c extends the signaling specificity of MEKs after stimulation by various extracellular stimuli.
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Affiliation(s)
- Daniel M Aebersold
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100, Israel
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45
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Kusari AB, Molina DM, Sabbagh W, Lau CS, Bardwell L. A conserved protein interaction network involving the yeast MAP kinases Fus3 and Kss1. ACTA ACUST UNITED AC 2004; 164:267-77. [PMID: 14734536 PMCID: PMC2172336 DOI: 10.1083/jcb.200310021] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Saccharomyces cerevisiae mitogen-activated protein kinases (MAPKs) Fus3 and Kss1 bind to multiple regulators and substrates. We show that mutations in a conserved docking site in these MAPKs (the CD/7m region) disrupt binding to an important subset of their binding partners, including the Ste7 MAPK kinase, the Ste5 adaptor/scaffold protein, and the Dig1 and Dig2 transcriptional repressors. Supporting the possibility that Ste5 and Ste7 bind to the same region of the MAPKs, they partially competed for Fus3 binding. In vivo, some of the MAPK mutants displayed reduced Ste7-dependent phosphorylation, and all of them exhibited multiple defects in mating and pheromone response. The Kss1 mutants were also defective in Kss1-imposed repression of Ste12. We conclude that MAPKs contain a structurally and functionally conserved docking site that mediates an overall positively acting network of interactions with cognate docking sites on their regulators and substrates. Key features of this interaction network appear to have been conserved from yeast to humans.
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Affiliation(s)
- Anasua B Kusari
- Dept. of Developmental and Cell Biology, 5205 McGaugh Hall, University of California, Irvine, Irvine, CA 92697-2300, USA
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46
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Diskin R, Askari N, Capone R, Engelberg D, Livnah O. Active mutants of the human p38alpha mitogen-activated protein kinase. J Biol Chem 2004; 279:47040-9. [PMID: 15284239 DOI: 10.1074/jbc.m404595200] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mitogen-activated protein (MAP) kinases compose a family of serine/threonine kinases that function in many signal transduction pathways and affect various cellular phenotypes. Despite the abundance of available data, the exact role of each MAP kinase is not completely defined, in part because of the inability to activate MAP kinase molecules individually and specifically. Based on activating mutations found in the yeast MAP kinase p38/Hog1 (Bell, M., Capone, R., Pashtan, I., Levitzki, A., and Engelberg, D. (2001) J. Biol. Chem. 276, 25351-25358), we designed and constructed single and multiple mutants of human MAP kinase p38alpha. Single (p38D176A, p38F327L, and p38F327S) and subsequent double (p38D176A/F327L and p38D176A/F327S) mutants acquired high intrinsic activity independent of any upstream regulation and reached levels of 10 and 25%, respectively, in reference to the dually phosphorylated wild type p38alpha. The active p38 mutants have retained high specificity toward p38 substrates and were inhibited by the specific p38 inhibitors SB-203580 and PD-169316. We also show that similar mutations can render p38gamma active as well. Based on the available structures of p38 and ERK2, we have analyzed the p38 mutants and identified a hydrophobic core stabilized by three aromatic residues, Tyr-69, Phe-327, and Trp-337, in the vicinity of the L16 loop region. Upon activation, a segment of the L16 loop, including Phe-327, becomes disordered. Structural analysis suggests that the active p38 mutants emulate the conformational changes imposed naturally by dual phosphorylation, namely, destabilization of the hydrophobic core. Essentially, the hydrophobic core is an inherent stabilizer that maintains low basal activity level in unphosphorylated p38.
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Affiliation(s)
- Ron Diskin
- Department of Biological Chemistry, The Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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47
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Roux PP, Blenis J. ERK and p38 MAPK-activated protein kinases: a family of protein kinases with diverse biological functions. Microbiol Mol Biol Rev 2004; 68:320-44. [PMID: 15187187 PMCID: PMC419926 DOI: 10.1128/mmbr.68.2.320-344.2004] [Citation(s) in RCA: 1810] [Impact Index Per Article: 90.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Conserved signaling pathways that activate the mitogen-activated protein kinases (MAPKs) are involved in relaying extracellular stimulations to intracellular responses. The MAPKs coordinately regulate cell proliferation, differentiation, motility, and survival, which are functions also known to be mediated by members of a growing family of MAPK-activated protein kinases (MKs; formerly known as MAPKAP kinases). The MKs are related serine/threonine kinases that respond to mitogenic and stress stimuli through proline-directed phosphorylation and activation of the kinase domain by extracellular signal-regulated kinases 1 and 2 and p38 MAPKs. There are currently 11 vertebrate MKs in five subfamilies based on primary sequence homology: the ribosomal S6 kinases, the mitogen- and stress-activated kinases, the MAPK-interacting kinases, MAPK-activated protein kinases 2 and 3, and MK5. In the last 5 years, several MK substrates have been identified, which has helped tremendously to identify the biological role of the members of this family. Together with data from the study of MK-knockout mice, the identities of the MK substrates indicate that they play important roles in diverse biological processes, including mRNA translation, cell proliferation and survival, and the nuclear genomic response to mitogens and cellular stresses. In this article, we review the existing data on the MKs and discuss their physiological functions based on recent discoveries.
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Affiliation(s)
- Philippe P Roux
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave., Boston, MA 02115, USA.
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48
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Steinmetz R, Wagoner HA, Zeng P, Hammond JR, Hannon TS, Meyers JL, Pescovitz OH. Mechanisms regulating the constitutive activation of the extracellular signal-regulated kinase (ERK) signaling pathway in ovarian cancer and the effect of ribonucleic acid interference for ERK1/2 on cancer cell proliferation. Mol Endocrinol 2004; 18:2570-82. [PMID: 15243131 DOI: 10.1210/me.2004-0082] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The ERK1/2 MAPK pathway is a critical signaling system that mediates ligand-stimulated signals for the induction of cell proliferation, differentiation, and cell survival. Studies have shown that this pathway is constitutively active in several human malignancies and may be involved in the pathogenesis of these tumors. In the present study we examined the ERK1/2 pathway in cell lines derived from epithelial and granulosa cell tumors, two distinct forms of ovarian cancer. We show that ERK1 and ERK2 are constitutively active and that this activation results from both MAPK kinase-dependent and independent mechanisms and is correlated with elevated BRAF expression. MAPK phosphatase 1 (MKP-1) expression, which is involved in ERK1/2 deactivation, is down-regulated in the cancer cells, thus further contributing to ERK hyperactivity in these cells. Treatment of these cancer cell lines with the proteasome inhibitor ZLLF-CHO increased MKP-1 but not MKP-2 expression and decreased ERK1/2 phosphorylation. More importantly, silencing of ERK1/2 protein expression using RNA interference led to the complete suppression of tumor cell proliferation. These results provide evidence that the ERK pathway plays a major role in ovarian cancer pathogenesis and that down-regulation of this master signaling pathway is highly effective for the inhibition of ovarian tumor growth.
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Affiliation(s)
- Rosemary Steinmetz
- Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, James Whitcomb Riley Hospital for Children, Indianapolis, Indiana 46202, USA.
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49
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Kim M, Cha GH, Kim S, Lee JH, Park J, Koh H, Choi KY, Chung J. MKP-3 has essential roles as a negative regulator of the Ras/mitogen-activated protein kinase pathway during Drosophila development. Mol Cell Biol 2004; 24:573-83. [PMID: 14701731 PMCID: PMC343793 DOI: 10.1128/mcb.24.2.573-583.2004] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mitogen-activated protein kinase (MAPK) phosphatase 3 (MKP-3) is a well-known negative regulator in the Ras/extracellular signal-regulated kinase (ERK)-MAPK signaling pathway responsible for cell fate determination and proliferation during development. However, the physiological roles of MKP-3 and the mechanism by which MKP-3 regulates Ras/Drosophila ERK (DERK) signaling in vivo have not been determined. Here, we demonstrated that Drosophila MKP-3 (DMKP-3) is critically involved in cell differentiation, proliferation, and gene expression by suppressing the Ras/DERK pathway, specifically binding to DERK via the N-terminal ERK-binding domain of DMKP-3. Overexpression of DMKP-3 reduced the number of photoreceptor cells and inhibited wing vein differentiation. Conversely, DMKP-3 hypomorphic mutants exhibited extra photoreceptor cells and wing veins, and its null mutants showed striking phenotypes, such as embryonic lethality and severe defects in oogenesis. All of these phenotypes were highly similar to those of the gain-of-function mutants of DERK/rl. The functional interaction between DMKP-3 and the Ras/DERK pathway was further confirmed by genetic interactions between DMKP-3 loss-of-function mutants or overexpressing transgenic flies and various mutants of the Ras/DERK pathway. Collectively, these data provide the direct evidences that DMKP-3 is indispensable to the regulation of DERK signaling activity during Drosophila development.
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Affiliation(s)
- Myungjin Kim
- National Creative Research Initiatives Center for Cell Growth Regulation and Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 373-1 Kusong-Dong, Yusong, Taejon 305-701, Republic of Korea
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50
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Zhang J, Zhou B, Zheng CF, Zhang ZY. A bipartite mechanism for ERK2 recognition by its cognate regulators and substrates. J Biol Chem 2003; 278:29901-12. [PMID: 12754209 DOI: 10.1074/jbc.m303909200] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mitogen-activated protein (MAP) kinases control gene expression in response to extracellular stimuli and exhibit exquisite specificity for their cognate regulators and substrates. We performed a structure-based mutational analysis of ERK2 to identify surface areas that are important for recognition of its interacting proteins. We show that binding and activation of MKP3 by ERK2 involve two distinct protein-protein interaction sites in ERK2. Thus, the common docking (CD) site composed of Glu-79, Tyr-126, Arg-133, Asp-160, Tyr-314, Asp-316, and Asp-319 are important for high affinity MKP3 binding but not essential for ERK2-induced MKP3 activation. MKP3 activation requires residues Tyr-111, Thr-116, Leu-119, Lys-149, Arg-189, Trp-190, Glu-218, Arg-223, Lys-229, and His-230 in the ERK2 substrate-binding region, located distal to the common docking site. Interestingly, many of the residues important for MKP3 recognition are also used for Elk1 binding and phosphorylation. In addition to the shared residues, there are also residues that are unique to each target recognition. There is evidence indicating that the CD site and the substrate-binding region defined here are also utilized for MEK1 recognition, and indeed, we demonstrate that the binding of MKP3, Elk1, and MEK1 to ERK2 is mutually exclusive. Taken together, our data suggest that the efficiency and fidelity of ERK2 signaling is achieved by a bipartite recognition process. In this model, one part of the ERK2-binding proteins (e.g. the kinase interaction motif sequence) docks to the CD site located on the back side of the ERK2 catalytic pocket for high affinity association, whereas the interaction of the substrate-binding region with another structural element (e.g. the FXFP motif in MKP3 and Elk1) may not only stabilize binding but also provide contacts crucial for modulating the activity and/or specificity of ERK2 target molecules.
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Affiliation(s)
- Jialin Zhang
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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