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Buenaventura RGM, Merlino G, Yu Y. Ez-Metastasizing: The Crucial Roles of Ezrin in Metastasis. Cells 2023; 12:1620. [PMID: 37371090 DOI: 10.3390/cells12121620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/08/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023] Open
Abstract
Ezrin is the cytoskeletal organizer and functions in the modulation of membrane-cytoskeleton interaction, maintenance of cell shape and structure, and regulation of cell-cell adhesion and movement, as well as cell survival. Ezrin plays a critical role in regulating tumor metastasis through interaction with other binding proteins. Notably, Ezrin has been reported to interact with immune cells, allowing tumor cells to escape immune attack in metastasis. Here, we review the main functions of Ezrin, the mechanisms through which it acts, its role in tumor metastasis, and its potential as a therapeutic target.
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Affiliation(s)
- Rand Gabriel M Buenaventura
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Glenn Merlino
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yanlin Yu
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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2
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Sepers JJ, Ramalho JJ, Kroll JR, Schmidt R, Boxem M. ERM-1 Phosphorylation and NRFL-1 Redundantly Control Lumen Formation in the C. elegans Intestine. Front Cell Dev Biol 2022; 10:769862. [PMID: 35198555 PMCID: PMC8860247 DOI: 10.3389/fcell.2022.769862] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 01/04/2022] [Indexed: 11/13/2022] Open
Abstract
Reorganization of the plasma membrane and underlying actin cytoskeleton into specialized domains is essential for the functioning of most polarized cells in animals. Proteins of the ezrin-radixin-moesin (ERM) and Na+/H+ exchanger 3 regulating factor (NHERF) family are conserved regulators of cortical specialization. ERM proteins function as membrane-actin linkers and as molecular scaffolds that organize the distribution of proteins at the membrane. NHERF proteins are PDZ-domain containing adapters that can bind to ERM proteins and extend their scaffolding capability. Here, we investigate how ERM and NHERF proteins function in regulating intestinal lumen formation in the nematode Caenorhabditis elegans. C. elegans has single ERM and NHERF family proteins, termed ERM-1 and NRFL-1, and ERM-1 was previously shown to be critical for intestinal lumen formation. Using CRISPR/Cas9-generated nrfl-1 alleles we demonstrate that NRFL-1 localizes at the intestinal microvilli, and that this localization is depended on an interaction with ERM-1. However, nrfl-1 loss of function mutants are viable and do not show defects in intestinal development. Interestingly, combining nrfl-1 loss with erm-1 mutants that either block or mimic phosphorylation of a regulatory C-terminal threonine causes severe defects in intestinal lumen formation. These defects are not observed in the phosphorylation mutants alone, and resemble the effects of strong erm-1 loss of function. The loss of NRFL-1 did not affect the localization or activity of ERM-1. Together, these data indicate that ERM-1 and NRFL-1 function together in intestinal lumen formation in C. elegans. We postulate that the functioning of ERM-1 in this tissue involves actin-binding activities that are regulated by the C-terminal threonine residue and the organization of apical domain composition through NRFL-1.
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Affiliation(s)
- Jorian J Sepers
- Division of Developmental Biology, Department of Biology, Faculty of Science, Institute of Biodynamics and Biocomplexity, Utrecht University, Utrecht, Netherlands
| | - João J Ramalho
- Division of Developmental Biology, Department of Biology, Faculty of Science, Institute of Biodynamics and Biocomplexity, Utrecht University, Utrecht, Netherlands.,Laboratory of Biochemistry, Wageningen University and Research, Wageningen, Netherlands
| | - Jason R Kroll
- Division of Developmental Biology, Department of Biology, Faculty of Science, Institute of Biodynamics and Biocomplexity, Utrecht University, Utrecht, Netherlands
| | - Ruben Schmidt
- Division of Developmental Biology, Department of Biology, Faculty of Science, Institute of Biodynamics and Biocomplexity, Utrecht University, Utrecht, Netherlands
| | - Mike Boxem
- Division of Developmental Biology, Department of Biology, Faculty of Science, Institute of Biodynamics and Biocomplexity, Utrecht University, Utrecht, Netherlands
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3
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A biophysical perspective of the regulatory mechanisms of ezrin/radixin/moesin proteins. Biophys Rev 2022; 14:199-208. [PMID: 35340609 PMCID: PMC8921360 DOI: 10.1007/s12551-021-00928-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 12/14/2021] [Indexed: 02/08/2023] Open
Abstract
Many signal transductions resulting from ligand-receptor interactions occur at the cell surface. These signaling pathways play essential roles in cell polarization, membrane morphogenesis, and the modulation of membrane tension at the cell surface. However, due to the large number of membrane-binding proteins, including actin-membrane linkers, and transmembrane proteins present at the cell surface, the molecular mechanisms underlying the regulation at the cell surface are yet unclear. Here, we describe the molecular functions of one of the key players at the cell surface, ezrin/radixin/moesin (ERM) proteins from a biophysical point of view. We focus our discussion on biophysical properties of ERM proteins revealed by using biophysical tools in live cells and in vitro reconstitution systems. We first describe the structural properties of ERM proteins and then discuss the interactions of ERM proteins with PI(4,5)P2 and the actin cytoskeleton. These properties of ERM proteins revealed by using biophysical approaches have led to a better understanding of their physiological functions in cells and tissues. Supplementary Information The online version contains supplementary material available at 10.1007/s12551-021-00928-0.
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ROCK Inhibition as Potential Target for Treatment of Pulmonary Hypertension. Cells 2021; 10:cells10071648. [PMID: 34209333 PMCID: PMC8303917 DOI: 10.3390/cells10071648] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/17/2021] [Accepted: 06/23/2021] [Indexed: 02/07/2023] Open
Abstract
Pulmonary hypertension (PH) is a cardiovascular disease caused by extensive vascular remodeling in the lungs, which ultimately leads to death in consequence of right ventricle (RV) failure. While current drugs for PH therapy address the sustained vasoconstriction, no agent effectively targets vascular cell proliferation and tissue inflammation. Rho-associated protein kinases (ROCKs) emerged in the last few decades as promising targets for PH therapy, since ROCK inhibitors demonstrated significant anti-remodeling and anti-inflammatory effects. In this review, current aspects of ROCK inhibition therapy are discussed in relation to the treatment of PH and RV dysfunction, from cell biology to preclinical and clinical studies.
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Fukusumi Y, Yasuda H, Zhang Y, Kawachi H. Nephrin-Ephrin-B1-Na +/H + Exchanger Regulatory Factor 2-Ezrin-Actin Axis Is Critical in Podocyte Injury. THE AMERICAN JOURNAL OF PATHOLOGY 2021; 191:1209-1226. [PMID: 33887216 DOI: 10.1016/j.ajpath.2021.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/13/2021] [Accepted: 04/05/2021] [Indexed: 10/21/2022]
Abstract
Ephrin-B1 is one of the critical components of the slit diaphragm of kidney glomerular podocyte. However, the precise function of ephrin-B1 is unclear. To clarify the function of ephrin-B1, ephrin-B1-associated molecules were studied. RNA-sequencing analysis suggested that Na+/H+ exchanger regulatory factor 2 (NHERF2), a scaffolding protein, is associated with ephrin-B1. NHERF2 was expressed at the apical area and the slit diaphragm, and interacted with the nephrin-ephrin-B1 complex at the slit diaphragm. The nephrin-ephrin-B1-NHERF2 complex interacted with ezrin bound to F-actin. NHERF2 bound ephrin-B1 via its first postsynaptic density protein-95/disks large/zonula occludens-1 domain, and podocalyxin via its second postsynaptic density protein-95/disks large/zonula occludens-1 domain. Both in vitro analyses with human embryonic kidney 293 cells and in vivo study with rat nephrotic model showed that stimulaiton of the slit diaphragm, phosphorylation of nephrin and ephrin-B1, and dephosphorylation of NHERF2 and ezrin, disrupted the linkages of ephrin-B1-NHERF2 and NHERF2-ezrin. It is conceivable that the linkage of nephrin-ephrin-B1-NHERF2-ezrin-actin is a novel critical axis in the podocytes. Ephrin-B1 phosphorylation also disrupted the linkage of an apical transmembrane protein, podocalyxin, with NHERF2-ezrin-actin. The phosphorylation of ephrin-B1 and the consequent dephosphorylation of NHERF2 are critical initiation events leading to podocyte injury.
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Affiliation(s)
- Yoshiyasu Fukusumi
- Department of Cell Biology, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Hidenori Yasuda
- Department of Cell Biology, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Ying Zhang
- Department of Cell Biology, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Hiroshi Kawachi
- Department of Cell Biology, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
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6
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Duran CL, Howell DW, Dave JM, Smith RL, Torrie ME, Essner JJ, Bayless KJ. Molecular Regulation of Sprouting Angiogenesis. Compr Physiol 2017; 8:153-235. [PMID: 29357127 DOI: 10.1002/cphy.c160048] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The term angiogenesis arose in the 18th century. Several studies over the next 100 years laid the groundwork for initial studies performed by the Folkman laboratory, which were at first met with some opposition. Once overcome, the angiogenesis field has flourished due to studies on tumor angiogenesis and various developmental models that can be genetically manipulated, including mice and zebrafish. In addition, new discoveries have been aided by the ability to isolate primary endothelial cells, which has allowed dissection of various steps within angiogenesis. This review will summarize the molecular events that control angiogenesis downstream of biochemical factors such as growth factors, cytokines, chemokines, hypoxia-inducible factors (HIFs), and lipids. These and other stimuli have been linked to regulation of junctional molecules and cell surface receptors. In addition, the contribution of cytoskeletal elements and regulatory proteins has revealed an intricate role for mobilization of actin, microtubules, and intermediate filaments in response to cues that activate the endothelium. Activating stimuli also affect various focal adhesion proteins, scaffold proteins, intracellular kinases, and second messengers. Finally, metalloproteinases, which facilitate matrix degradation and the formation of new blood vessels, are discussed, along with our knowledge of crosstalk between the various subclasses of these molecules throughout the text. Compr Physiol 8:153-235, 2018.
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Affiliation(s)
- Camille L Duran
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - David W Howell
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - Jui M Dave
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - Rebecca L Smith
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - Melanie E Torrie
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Jeffrey J Essner
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Kayla J Bayless
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
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Boratkó A, Péter M, Csortos C. Regulation of merlin by protein phosphatase 1-TIMAP and EBP50 in endothelial cells. Int J Biochem Cell Biol 2016; 82:10-17. [PMID: 27871951 DOI: 10.1016/j.biocel.2016.11.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 10/18/2016] [Accepted: 11/14/2016] [Indexed: 11/16/2022]
Abstract
Merlin (moesin-ezrin-radixin like protein), the product of neurofibromatosis type 2 gene, was primarily recognized as a tumor suppressor, but it also functions as a membrane-cytoskeletal linker and regulator of multiple signaling pathways. The activity and localization of merlin is regulated by head to tail folding that is controlled by phosphorylation of the Ser518 side chain. Merlin localizes in the nucleus when the Ser518 side chain is not phosphorylated, while the phosphorylated form is present in the cytoplasm and the plasma membrane. In this work interactions and their impact on the subcellular localization and phosphorylation state of the Ser518 side chain of merlin were investigated in endothelial cells. It is shown that merlin (dephospho-Ser518 form) interacts in the nucleus of endothelial cells with the scaffolding protein EBP50, a member of the Na+/H+exchanger regulatory factor family. Upon EBP50 depletion, merlin translocated from the nucleus, suggesting that binding of merlin to EBP50 is critical in the nuclear localization of merlin. Along with the translocation, the phosphorylation level of phospho-Ser518-merlin was increased in EBP50 depleted cells. TIMAP (TGFβ-inhibited membrane-associated protein), a type 1 protein phosphatase (PP1) regulatory subunit, was newly recognized as an interacting partner for merlin. Domain mapping using truncated mutant forms in GST pull down revealed that the N-terminal half of TIMAP (aa 1-290) and the FERM domain of merlin are the regions responsible for the interaction.The catalytic subunit of PP1 (PP1c) was present in all merlin-TIMAP pull down or immunoprecipitation samples demonstrating that merlin actually interacts with the PP1c-TIMAP holoenzyme. On the other hand, from TIMAP depleted cells, without its targeting protein, PP1c could not bind to merlin. Also, when the phosphatase activity of PP1c-TIMAP was inhibited either with depletion of TIMAP or by treatment of the cells with specific PP1 inhibitor, there was an increase in the amount of phospho-Ser518 form of merlin in the membrane of the cells. These data strongly suggest that the PP1c-TIMAP- complex dephosphorylates phospho-Ser518-merlin. ECIS measurements indicate that phospho-merlin accelerates in vitro wound healing of the endothelial monolayer. In conclusion, in endothelial cells, EBP50 is required for the nuclear localization of merlin and the PP1c-TIMAP holoenzyme plays an important role in the dephosphorylation of merlin on its Ser518 side chain, which influence cell migration and proliferation.
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Affiliation(s)
- Anita Boratkó
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Egyetem tér 1., Debrecen H-4032, Hungary
| | - Margit Péter
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Egyetem tér 1., Debrecen H-4032, Hungary
| | - Csilla Csortos
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Egyetem tér 1., Debrecen H-4032, Hungary.
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Tsolis KC, Bagli E, Kanaki K, Zografou S, Carpentier S, Bei ES, Christoforidis S, Zervakis M, Murphy C, Fotsis T, Economou A. Proteome Changes during Transition from Human Embryonic to Vascular Progenitor Cells. J Proteome Res 2016; 15:1995-2007. [DOI: 10.1021/acs.jproteome.6b00180] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Konstantinos C. Tsolis
- Department
of Protein structure and Proteomics Facility, Institute of Molecular Biology and Biotechnology - FORTH, 70013 Iraklio, Crete, Greece
- Department
of Biology, University of Crete, 70013 Iraklio, Crete, Greece
| | - Eleni Bagli
- Division
of Biomedical Research, Institute of Molecular Biology and Biotechnology - FORTH, 45110 Ioaninna, Greece
| | - Katerina Kanaki
- Department
of Protein structure and Proteomics Facility, Institute of Molecular Biology and Biotechnology - FORTH, 70013 Iraklio, Crete, Greece
| | - Sofia Zografou
- Division
of Biomedical Research, Institute of Molecular Biology and Biotechnology - FORTH, 45110 Ioaninna, Greece
| | - Sebastien Carpentier
- SYBIOMA, KU Leuven facility for Systems Biology Based Mass Spectrometry, B-3000 Leuven Belgium
| | - Ekaterini S. Bei
- School
of Electronic and Computer Engineering, Technical University of Crete, 73100 Chania, Greece
| | - Savvas Christoforidis
- Division
of Biomedical Research, Institute of Molecular Biology and Biotechnology - FORTH, 45110 Ioaninna, Greece
- Laboratory
of Biological Chemistry, Medical School, University of Ioannina, 45110 Ioannina, Greece
| | - Michalis Zervakis
- School
of Electronic and Computer Engineering, Technical University of Crete, 73100 Chania, Greece
| | - Carol Murphy
- Division
of Biomedical Research, Institute of Molecular Biology and Biotechnology - FORTH, 45110 Ioaninna, Greece
- School
of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K
| | - Theodore Fotsis
- Division
of Biomedical Research, Institute of Molecular Biology and Biotechnology - FORTH, 45110 Ioaninna, Greece
- Laboratory
of Biological Chemistry, Medical School, University of Ioannina, 45110 Ioannina, Greece
- School
of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K
| | - Anastassios Economou
- Department
of Protein structure and Proteomics Facility, Institute of Molecular Biology and Biotechnology - FORTH, 70013 Iraklio, Crete, Greece
- Department
of Biology, University of Crete, 70013 Iraklio, Crete, Greece
- SYBIOMA, KU Leuven facility for Systems Biology Based Mass Spectrometry, B-3000 Leuven Belgium
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Fodor T, Szántó M, Abdul-Rahman O, Nagy L, Dér Á, Kiss B, Bai P. Combined Treatment of MCF-7 Cells with AICAR and Methotrexate, Arrests Cell Cycle and Reverses Warburg Metabolism through AMP-Activated Protein Kinase (AMPK) and FOXO1. PLoS One 2016; 11:e0150232. [PMID: 26919657 PMCID: PMC4769015 DOI: 10.1371/journal.pone.0150232] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 02/10/2016] [Indexed: 12/17/2022] Open
Abstract
Cancer cells are characterized by metabolic alterations, namely, depressed mitochondrial oxidation, enhanced glycolysis and pentose phosphate shunt flux to support rapid cell growth, which is called the Warburg effect. In our study we assessed the metabolic consequences of a joint treatment of MCF-7 breast cancer cells with AICAR, an inducer of AMP-activated kinase (AMPK) jointly with methotrexate (MTX), a folate-analog antimetabolite that blunts de novo nucleotide synthesis. MCF7 cells, a model of breast cancer cells, were resistant to the individual application of AICAR or MTX, however combined treatment of AICAR and MTX reduced cell proliferation. Prolonged joint application of AICAR and MTX induced AMPK and consequently enhanced mitochondrial oxidation and reduced the rate of glycolysis. These metabolic changes suggest an anti-Warburg rearrangement of metabolism that led to the block of the G1/S and the G2/M transition slowing down cell cycle. The slowdown of cell proliferation was abolished when mitotropic transcription factors, PGC-1α, PGC-1β or FOXO1 were silenced. In human breast cancers higher expression of AMPKα and FOXO1 extended survival. AICAR and MTX exerts similar additive antiproliferative effect on other breast cancer cell lines, such as SKBR and 4T1 cells, too. Our data not only underline the importance of Warburg metabolism in breast cancer cells but nominate the AICAR+MTX combination as a potential cytostatic regime blunting Warburg metabolism. Furthermore, we suggest the targeting of AMPK and FOXO1 to combat breast cancer.
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Affiliation(s)
- Tamás Fodor
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary
| | - Magdolna Szántó
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary
- MTA-DE Cell Biology and Signaling Research Group, Debrecen, H-4032, Hungary
| | - Omar Abdul-Rahman
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary
- MTA-DE Cell Biology and Signaling Research Group, Debrecen, H-4032, Hungary
| | - Lilla Nagy
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary
- MTA-DE Cell Biology and Signaling Research Group, Debrecen, H-4032, Hungary
| | - Ádám Dér
- Department of Oncology, Section of Radiation Therapy, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary
| | - Borbála Kiss
- Department of Dermatology, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary
| | - Peter Bai
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary
- MTA-DE Lendület Laboratory of Cellular Metabolism, Debrecen, H-4032, Hungary
- Research Center for Molecular Medicine, University of Debrecen, Debrecen, H-4032, Hungary
- * E-mail:
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Hartmann S, Ridley AJ, Lutz S. The Function of Rho-Associated Kinases ROCK1 and ROCK2 in the Pathogenesis of Cardiovascular Disease. Front Pharmacol 2015; 6:276. [PMID: 26635606 PMCID: PMC4653301 DOI: 10.3389/fphar.2015.00276] [Citation(s) in RCA: 209] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 11/03/2015] [Indexed: 01/26/2023] Open
Abstract
Rho-associated kinases ROCK1 and ROCK2 are serine/threonine kinases that are downstream targets of the small GTPases RhoA, RhoB, and RhoC. ROCKs are involved in diverse cellular activities including actin cytoskeleton organization, cell adhesion and motility, proliferation and apoptosis, remodeling of the extracellular matrix and smooth muscle cell contraction. The role of ROCK1 and ROCK2 has long been considered to be similar; however, it is now clear that they do not always have the same functions. Moreover, depending on their subcellular localization, activation, and other environmental factors, ROCK signaling can have different effects on cellular function. With respect to the heart, findings in isoform-specific knockout mice argue for a role of ROCK1 and ROCK2 in the pathogenesis of cardiac fibrosis and cardiac hypertrophy, respectively. Increased ROCK activity could play a pivotal role in processes leading to cardiovascular diseases such as hypertension, pulmonary hypertension, angina pectoris, vasospastic angina, heart failure, and stroke, and thus ROCK activity is a potential new biomarker for heart disease. Pharmacological ROCK inhibition reduces the enhanced ROCK activity in patients, accompanied with a measurable improvement in medical condition. In this review, we focus on recent findings regarding ROCK signaling in the pathogenesis of cardiovascular disease, with a special focus on differences between ROCK1 and ROCK2 function.
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Affiliation(s)
- Svenja Hartmann
- Institute of Pharmacology, University Medical Center Göttingen, Georg-August-University Göttingen, Göttingen, Germany
- German Center for Cardiovascular Research, Göttingen, Germany
- Randall Division of Cell and Molecular Biophysics, King’s College London, London, UK
| | - Anne J. Ridley
- Randall Division of Cell and Molecular Biophysics, King’s College London, London, UK
| | - Susanne Lutz
- Institute of Pharmacology, University Medical Center Göttingen, Georg-August-University Göttingen, Göttingen, Germany
- German Center for Cardiovascular Research, Göttingen, Germany
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The NHERF2 sequence adjacent and upstream of the ERM-binding domain affects NHERF2-ezrin binding and dexamethasone stimulated NHE3 activity. Biochem J 2015; 470:77-90. [PMID: 26251448 PMCID: PMC4613507 DOI: 10.1042/bj20150238] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 06/16/2015] [Indexed: 12/19/2022]
Abstract
The microvillar localization of Na+-H+ exchanger regulatory factor (NHERF)1/2 requires not only ezrin, radixin and moesin (ERM)-binding domain (EBD) but also a newly defined ERM-binding regulatory sequence (EBRS) that modulates NHERF1/2–ezrin binding. NHERF2 EBRS is also regulated by phosphorylation, which affects NHE3 (Na+-H+ exchanger 3) stimulation by dexamethasone. In the brush border of intestinal and kidney epithelial cells, scaffolding proteins ezrin, Na+-H+ exchanger regulatory factor (NHERF)1 and NHERF2 play important roles in linking transmembrane proteins to the cytoskeleton and assembling signalling regulatory complexes. The last 30 carboxyl residues of NHERF1 and NHERF2 form the EBDs [ezrin, radixin and moesin (ERM)-binding domain]. The current study found that NHERF1/2 contain an ERM-binding regulatory sequence (EBRS), which facilitates the interaction between the EBD and ezrin. The EBRSs are located within 24 and 19 residues immediately upstream of EBDs for NHERF1 and NHERF2 respectively. In OK (opossum kidney) epithelial cells, EBRSs are necessary along with the EBD to distribute NHERF1 and NHERF2 exclusively to the apical domain. Furthermore, phosphorylation of Ser303 located in the EBRS of NHERF2, decreases the binding affinity for ezrin, dislocates apical NHERF2 into the cytosol and increases the NHERF2 microvillar mobility rate. Moreover, increased phosphorylation of Ser303 was functionally significant preventing acute stimulation of NHE3 (Na+-H+ exchanger 3) activity by dexamethasone.
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