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Villalobo A. Regulation of ErbB Receptors by the Ca2+ Sensor Protein Calmodulin in Cancer. Biomedicines 2023; 11:biomedicines11030661. [PMID: 36979639 PMCID: PMC10045772 DOI: 10.3390/biomedicines11030661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/17/2023] [Accepted: 02/19/2023] [Indexed: 02/24/2023] Open
Abstract
Overexpression and mutations of the epidermal growth factor receptor (EGFR/ErbB1/HER1) and other tyrosine kinase receptors of the ErbB family (ErbB2/HER2, ErbB3/HER3 and ErbB4/HER4) play an essential role in enhancing the proliferation, the migratory capacity and invasiveness of many tumor cells, leading to cancer progression and increased malignancy. To understand these cellular processes in detail is essential to understand at a molecular level the signaling pathways and regulatory mechanisms controlling these receptors. In this regard, calmodulin (CaM) is a Ca2+-sensor protein that directly interacts with and regulates ErbB receptors, as well as some CaM-dependent kinases that also regulate these receptors, particularly EGFR and ErbB2, adding an additional layer of CaM-dependent regulation to this system. In this short review, an update of recent advances in this area is presented, covering the direct action of Ca2+/CaM on the four ErbB family members mostly in tumor cells and the indirect action of Ca2+/CaM on the receptors via CaM-regulated kinases. It is expected that further understanding of the CaM-dependent mechanisms regulating the ErbB receptors in future studies could identify new therapeutic targets in these systems that could help to control or delay cancer progression.
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Affiliation(s)
- Antonio Villalobo
- Cancer and Human Molecular Genetics Area-Oto-Neurosurgery Research Group, University Hospital La Paz Research Institute (IdiPAZ), Paseo de la Castellana 261, E-28046 Madrid, Spain
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2
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Lin Z, Zhao Y, Li Q, Ci X, Ye X, Chen G, Tu Q, Feng W, Jiang P, Zhu S, Xue X, Saunders NA, Zhang L, Zhu X, Zhao KN. OUP accepted manuscript. Carcinogenesis 2022; 43:479-493. [PMID: 35134836 DOI: 10.1093/carcin/bgac010] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 01/19/2022] [Accepted: 02/02/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Zhongmin Lin
- Department of Pathology, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Yu Zhao
- Department of Obstetrics and Gynaecology, The Second Affiliated Hospital and Yuyin Children Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Qijia Li
- Department of Obstetrics and Gynaecology, The Second Affiliated Hospital and Yuyin Children Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, PR China
- School of Basic Medical Science, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Xingyuan Ci
- Department of Obstetrics and Gynaecology, The Second Affiliated Hospital and Yuyin Children Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, PR China
- School of Basic Medical Science, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Xiaoxian Ye
- School of Basic Medical Science, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Guorong Chen
- Department of Pathology, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Quanmei Tu
- School of Basic Medical Science, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Weixu Feng
- School of Basic Medical Science, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Pengfei Jiang
- School of Basic Medical Science, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Shanli Zhu
- School of Basic Medical Science, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Xiangyang Xue
- School of Basic Medical Science, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Nicholas A Saunders
- Diamantina Institute for Cancer Immunology and Metabolic Medicine, The University of Queensland, TRI, Woolloongabba, Queensland, Australia
| | - Lifang Zhang
- School of Basic Medical Science, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Xueqiong Zhu
- Department of Obstetrics and Gynaecology, The Second Affiliated Hospital and Yuyin Children Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, PR China
| | - Kong-Nan Zhao
- Department of Obstetrics and Gynaecology, The Second Affiliated Hospital and Yuyin Children Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, PR China
- School of Basic Medical Science, Wenzhou Medical University, Wenzhou, Zhejiang, PR China
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Queensland, Australia
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Yang CF, Tsai WC. Calmodulin: The switch button of calcium signaling. Tzu Chi Med J 2022; 34:15-22. [PMID: 35233351 PMCID: PMC8830543 DOI: 10.4103/tcmj.tcmj_285_20] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 03/17/2021] [Accepted: 05/06/2021] [Indexed: 11/25/2022] Open
Abstract
Calmodulin (CaM), a calcium sensor, decodes the critical calcium-dependent signals and converts them into the driving force to control various important cellular functions, such as ion transport. This small protein has a short central linker to connect two globular lobes and each unit is composed of a pair of homologous domains (HD) which are responsible for calcium binding. The conformation of each HD is sensitive to the levels of the intracellular Ca2+ concentrations while the flexible structure of the central domain enables its interactions with hundreds of cellular proteins. Apart from calcium binding, posttranslational modifications (PTMs) also contribute to the modulations of CaM functions by affecting its protein-protein interaction networks and hence drawing out the various downstream signaling cascades. In this mini-review, we first aim to elucidate the structural features of CaM and then overview the recent studies on the engagements of calcium binding and PTMs in Ca2+/CaM-mediated conformational alterations and signaling events. The mechanistic understanding of CaM working models is expected to be a key to decipher the precise role of CaM in cardiac physiology and disease pathology.
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HPV16 E7-impaired keratinocyte differentiation leads to tumorigenesis via cell cycle/pRb/involucrin/spectrin/adducin cascade. Appl Microbiol Biotechnol 2020; 104:4417-4433. [PMID: 32215704 DOI: 10.1007/s00253-020-10492-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/14/2020] [Accepted: 02/20/2020] [Indexed: 12/26/2022]
Abstract
Here, we used codon usage technology to generate two codon-modified human papillomavirus (HPV)16 E7 genes and, together with wild-type E7, to construct three HPV16 E7 gene plasmids: Wt-E7, HB1-E7, and HB2-E7. The three HPV 16 E7 plasmids were used to investigate how HPV16 E7 protein was expressed in different cells and how this oncoprotein deregulated cellular and molecular events in human keratinocytes to induce carcinogenesis. We discovered that codon usage of HPV16 E7 gene played a key role in determining expression of E7 oncoprotein in all tested cells. HPV16 E7 inhibited significantly expression of pRb to impair keratinocyte differentiation and disrupted development of skin epidermis in mice. HPV16 E7 increased substantially the number of G0/G1 cells associated with upregulation of cyclin D2 and downregulation of cyclin B1 in keratinocytes. HPV16 E7 not only inhibited expression of involucrin and α-spectrin but also disrupted the organization of involucrin filaments and spectrin cytoskeleton. Furthermore, HPV16 E7 inhibited expression of β-adducin, destroyed its cytoskeletal structure and induced phosphorylation of β-adducin(Ser662) in keratinocytes. Importantly, HPV16 E7 induced carcinogenesis in mice associated with expression of phosphorylated β-adducin(Ser662) and its nucleus-translocation. In conclusion, we provided evidence that HPV16 E7 oncoprotein inhibited keratinocyte differentiation in vitro and in vivo leading to carcinogenesis through cell cycle arrest and disruption of pRb/involucrin/spectrin/adducin cascade.
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Machnicka B, Grochowalska R, Bogusławska DM, Sikorski AF. The role of spectrin in cell adhesion and cell-cell contact. Exp Biol Med (Maywood) 2019; 244:1303-1312. [PMID: 31226892 DOI: 10.1177/1535370219859003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Spectrins are proteins that are responsible for many aspects of cell function and adaptation to changing environments. Primarily the spectrin-based membrane skeleton maintains cell membrane integrity and its mechanical properties, together with the cytoskeletal network a support cell shape. The occurrence of a variety of spectrin isoforms in diverse cellular environments indicates that it is a multifunctional protein involved in numerous physiological pathways. Participation of spectrin in cell–cell and cell–extracellular matrix adhesion and formation of dynamic plasma membrane protrusions and associated signaling events is a subject of interest for researchers in the fields of cell biology and molecular medicine. In this mini-review, we focus on data concerning the role of spectrins in cell surface activities such as adhesion, cell–cell contact, and invadosome formation. We discuss data on different adhesion proteins that directly or indirectly interact with spectrin repeats. New findings support the involvement of spectrin in cell adhesion and spreading, formation of lamellipodia, and also the participation in morphogenetic processes, such as eye development, oogenesis, and angiogenesis. Here, we review the role of spectrin in cell adhesion and cell–cell contact.Impact statementThis article reviews properties of spectrins as a group of proteins involved in cell surface activities such as, adhesion and cell–cell contact, and their contribution to morphogenesis. We show a new area of research and discuss the involvement of spectrin in regulation of cell–cell contact leading to immunological synapse formation and in shaping synapse architecture during myoblast fusion. Data indicate involvement of spectrins in adhesion and cell–cell or cell–extracellular matrix interactions and therefore in signaling pathways. There is evidence of spectrin’s contribution to the processes of morphogenesis which are connected to its interactions with adhesion molecules, membrane proteins (and perhaps lipids), and actin. Our aim was to highlight the essential role of spectrin in cell–cell contact and cell adhesion.
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Affiliation(s)
- Beata Machnicka
- Department of Biochemistry and Bioinformatics, Faculty of Biological Sciences, University of Zielona Góra, Zielona Góra 65-516, Poland
| | - Renata Grochowalska
- Department of Biochemistry and Bioinformatics, Faculty of Biological Sciences, University of Zielona Góra, Zielona Góra 65-516, Poland
| | - Dżamila M Bogusławska
- Department of Biochemistry and Bioinformatics, Faculty of Biological Sciences, University of Zielona Góra, Zielona Góra 65-516, Poland
| | - Aleksander F Sikorski
- Department of Cytobiochemistry, Faculty of Biotechnology, University of Wrocław, Wrocław 50-383, Poland
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The multifunctional role of phospho-calmodulin in pathophysiological processes. Biochem J 2018; 475:4011-4023. [PMID: 30578290 PMCID: PMC6305829 DOI: 10.1042/bcj20180755] [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: 09/18/2018] [Revised: 11/23/2018] [Accepted: 11/30/2018] [Indexed: 02/06/2023]
Abstract
Calmodulin (CaM) is a versatile Ca2+-sensor/transducer protein that modulates hundreds of enzymes, channels, transport systems, transcription factors, adaptors and other structural proteins, controlling in this manner multiple cellular functions. In addition to its capacity to regulate target proteins in a Ca2+-dependent and Ca2+-independent manner, the posttranslational phosphorylation of CaM by diverse Ser/Thr- and Tyr-protein kinases has been recognized as an important additional manner to regulate this protein by fine-tuning its functionality. In this review, we shall cover developments done in recent years in which phospho-CaM has been implicated in signalling pathways that are relevant for the onset and progression of diverse pathophysiological processes. These include diverse systems playing a major role in carcinogenesis and tumour development, prion-induced encephalopathies and brain hypoxia, melatonin-regulated neuroendocrine disorders, hypertension, and heavy metal-induced cell toxicity.
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Lechuga S, Amin PH, Wolen AR, Ivanov AI. Adducins inhibit lung cancer cell migration through mechanisms involving regulation of cell-matrix adhesion and cadherin-11 expression. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1866:395-408. [PMID: 30290240 DOI: 10.1016/j.bbamcr.2018.10.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 09/16/2018] [Accepted: 10/01/2018] [Indexed: 12/31/2022]
Abstract
Cell migration is a critical mechanism controlling tissue morphogenesis, epithelial wound healing and tumor metastasis. Migrating cells depend on orchestrated remodeling of the plasma membrane and the underlying actin cytoskeleton, which is regulated by the spectrin-adducin-based membrane skeleton. Expression of adducins is altered during tumorigenesis, however, their involvement in metastatic dissemination of tumor cells remains poorly characterized. This study investigated the roles of α-adducin (ADD1) and γ-adducin (ADD3) in regulating migration and invasion of non-small cell lung cancer (NSCLC) cells. ADD1 was mislocalized, whereas ADD3 was markedly downregulated in NSCLC cells with the invasive mesenchymal phenotype. CRISPR/Cas9-mediated knockout of ADD1 and ADD3 in epithelial-type NSCLC and normal bronchial epithelial cells promoted their Boyden chamber migration and Matrigel invasion. Furthermore, overexpression of ADD1, but not ADD3, in mesenchymal-type NSCLC cells decreased cell migration and invasion. ADD1-overexpressing NSCLC cells demonstrated increased adhesion to the extracellular matrix (ECM), accompanied by enhanced assembly of focal adhesions and hyperphosphorylation of Src and paxillin. The increased adhesiveness and decreased motility of ADD1-overexpressing cells were reversed by siRNA-mediated knockdown of Src. By contrast, the accelerated migration of ADD1 and ADD3-depleted NSCLC cells was ECM adhesion-independent and was driven by the upregulated expression of pro-motile cadherin-11. Overall, our findings reveal a novel function of adducins as negative regulators of NSCLC cell migration and invasion, which could be essential for limiting lung cancer progression and metastasis.
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Affiliation(s)
- Susana Lechuga
- Department of Inflammation and Immunity, Lerner Research Institute of Cleveland Clinic Foundation, Cleveland, OH 44195, United States of America; Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA 23298, United States of America
| | - Parth H Amin
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA 23298, United States of America
| | - Aaron R Wolen
- Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA 23298, United States of America
| | - Andrei I Ivanov
- Department of Inflammation and Immunity, Lerner Research Institute of Cleveland Clinic Foundation, Cleveland, OH 44195, United States of America; Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond, VA 23298, United States of America.
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Nussinov R, Zhang M, Tsai CJ, Jang H. Calmodulin and IQGAP1 activation of PI3Kα and Akt in KRAS, HRAS and NRAS-driven cancers. Biochim Biophys Acta Mol Basis Dis 2018; 1864:2304-2314. [DOI: 10.1016/j.bbadis.2017.10.032] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 10/24/2017] [Accepted: 10/27/2017] [Indexed: 02/06/2023]
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Nussinov R, Wang G, Tsai CJ, Jang H, Lu S, Banerjee A, Zhang J, Gaponenko V. Calmodulin and PI3K Signaling in KRAS Cancers. Trends Cancer 2017; 3:214-224. [PMID: 28462395 PMCID: PMC5408465 DOI: 10.1016/j.trecan.2017.01.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Calmodulin (CaM) uniquely promotes signaling of oncogenic K-Ras; but not N-Ras or H-Ras. How CaM interacts with K-Ras and how this stimulates cell proliferation are among the most challenging questions in KRAS-driven cancers. Earlier data pointed to formation of a ternary complex consisting of K-Ras, PI3Kα and CaM. Recent data point to phosphorylated CaM binding to the SH2 domains of the p85 subunit of PI3Kα and activating it. Modeling suggests that the high affinity interaction between the phosphorylated CaM tyrosine motif and PI3Kα, can promote full PI3Kα activation by oncogenic K-Ras. Our up-to-date review discusses CaM's role in PI3K signaling at the membrane in KRAS-driven cancers. This is significant since it may help development of K-Ras-specific pharmacology.
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Affiliation(s)
- Ruth Nussinov
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute at Frederick, Frederick, MD 21702, U.S.A
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Guanqiao Wang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Children’s Medical Center, Shanghai Jiao Tong University, School of Medicine, Shanghai, 200127, China
| | - Chung-Jung Tsai
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute at Frederick, Frederick, MD 21702, U.S.A
| | - Hyunbum Jang
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute at Frederick, Frederick, MD 21702, U.S.A
| | - Shaoyong Lu
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Children’s Medical Center, Shanghai Jiao Tong University, School of Medicine, Shanghai, 200127, China
| | - Avik Banerjee
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, IL 60607, U.S.A
| | - Jian Zhang
- Department of Pathophysiology, Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Children’s Medical Center, Shanghai Jiao Tong University, School of Medicine, Shanghai, 200127, China
| | - Vadim Gaponenko
- Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, IL 60607, U.S.A
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Anguita E, Villalobo A. Src-family tyrosine kinases and the Ca 2+ signal. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:915-932. [PMID: 27818271 DOI: 10.1016/j.bbamcr.2016.10.022] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 10/25/2016] [Accepted: 10/30/2016] [Indexed: 01/08/2023]
Abstract
In this review, we shall describe the rich crosstalk between non-receptor Src-family kinases (SFKs) and the Ca2+ transient generated in activated cells by a variety of extracellular and intracellular stimuli, resulting in diverse signaling events. The exchange of information between SFKs and Ca2+ is reciprocal, as it flows in both directions. These kinases are main actors in pathways leading to the generation of the Ca2+ signal, and reciprocally, the Ca2+ signal modulates SFKs activity and functions. We will cover how SFKs participate in the generation of the cytosolic Ca2+ rise upon activation of a series of receptors and the mechanism of clearance of this Ca2+ signal. The role of SFKs modulating Ca2+-translocating channels participating in these events will be amply discussed. Finally, the role of the Ca2+ sensor protein calmodulin on the activity of c-Src, and potentially on other SFKs, will be outlined as well. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech.
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Affiliation(s)
- Estefanía Anguita
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, c/ Arturo Duperier 4, E-28029 Madrid, Spain
| | - Antonio Villalobo
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, c/ Arturo Duperier 4, E-28029 Madrid, Spain.
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The activating role of phospho-(Tyr)-calmodulin on the epidermal growth factor receptor. Biochem J 2015; 472:195-204. [DOI: 10.1042/bj20150851] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 09/22/2015] [Indexed: 02/06/2023]
Abstract
The existence of a calmodulin (CaM)/phospho-(Tyr)-CaM cycle involved in the regulation of the epidermal growth factor receptor could have important consequences for the control of cell proliferation, as its alteration could potentially result in uncontrolled tumour growth.
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Stateva SR, Salas V, Anguita E, Benaim G, Villalobo A. Ca2+/Calmodulin and Apo-Calmodulin Both Bind to and Enhance the Tyrosine Kinase Activity of c-Src. PLoS One 2015; 10:e0128783. [PMID: 26058065 PMCID: PMC4461253 DOI: 10.1371/journal.pone.0128783] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 04/30/2015] [Indexed: 12/19/2022] Open
Abstract
Src family non-receptor tyrosine kinases play a prominent role in multiple cellular processes, including: cell proliferation, differentiation, cell survival, stress response, and cell adhesion and migration, among others. And when deregulated by mutations, overexpression, and/or the arrival of faulty incoming signals, its hyperactivity contributes to the development of hematological and solid tumors. c-Src is a prototypical member of this family of kinases, which is highly regulated by a set of phosphorylation events. Other factor contributing to the regulation of Src activity appears to be mediated by the Ca2+ signal generated in cells by different effectors, where the Ca2+-receptor protein calmodulin (CaM) plays a key role. In this report we demonstrate that CaM directly interacts with Src in both Ca2+-dependent and Ca2+-independent manners in vitro and in living cells, and that the CaM antagonist N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) inhibits the activation of this kinase induced by the upstream activation of the epidermal growth factor receptor (EGFR), in human carcinoma epidermoide A431 cells, and by hydrogen peroxide-induced oxidative stress, in both A431 cells and human breast adenocarcinoma SK-BR-3 cells. Furthermore, we show that the Ca2+/CaM complex strongly activates the auto-phosphorylation and tyrosine kinase activity of c-Src toward exogenous substrates, but most relevantly and for the first time, we demonstrate that Ca2+-free CaM (apo-CaM) exerts a far higher activatory action on Src auto-phosphorylation and kinase activity toward exogenous substrates than the one exerted by the Ca2+/CaM complex. This suggests that a transient increase in the cytosolic concentration of free Ca2+ is not an absolute requirement for CaM-mediated activation of Src in living cells, and that a direct regulation of Src by apo-CaM could be inferred.
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Affiliation(s)
- Silviya R. Stateva
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, c/ Arturo Duperier 4, E-28029, Madrid, Spain
| | - Valentina Salas
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, c/ Arturo Duperier 4, E-28029, Madrid, Spain
- Instituto de Biología Experimental, Facultad de Ciencias, Universidad Central de Venezuela, Caracas, Venezuela
| | - Estefanía Anguita
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, c/ Arturo Duperier 4, E-28029, Madrid, Spain
| | - Gustavo Benaim
- Instituto de Biología Experimental, Facultad de Ciencias, Universidad Central de Venezuela, Caracas, Venezuela
- Instituto de Estudios Avanzados (IDEA), Caracas, Venezuela
| | - Antonio Villalobo
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, c/ Arturo Duperier 4, E-28029, Madrid, Spain
- * E-mail:
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