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Vue Z, Murphy A, Le H, Neikirk K, Garza-Lopez E, Marshall AG, Mungai M, Jenkins B, Vang L, Beasley HK, Ezedimma M, Manus S, Whiteside A, Forni MF, Harris C, Crabtree A, Albritton CF, Jamison S, Demirci M, Prasad P, Oliver A, Actkins KV, Shao J, Zaganjor E, Scudese E, Rodriguez B, Koh A, Rabago I, Moore JE, Nguyen D, Aftab M, Kirk B, Li Y, Wandira N, Ahmad T, Saleem M, Kadam A, Katti P, Koh HJ, Evans C, Koo YD, Wang E, Smith Q, Tomar D, Williams CR, Sweetwyne MT, Quintana AM, Phillips MA, Hubert D, Kirabo A, Dash C, Jadiya P, Kinder A, Ajijola OA, Miller-Fleming TW, McReynolds MR, Hinton A. MICOS Complex Loss Governs Age-Associated Murine Mitochondrial Architecture and Metabolism in the Liver, While Sam50 Dictates Diet Changes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.20.599846. [PMID: 38979162 PMCID: PMC11230271 DOI: 10.1101/2024.06.20.599846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
The liver, the largest internal organ and a metabolic hub, undergoes significant declines due to aging, affecting mitochondrial function and increasing the risk of systemic liver diseases. How the mitochondrial three-dimensional (3D) structure changes in the liver across aging, and the biological mechanisms regulating such changes confers remain unclear. In this study, we employed Serial Block Face-Scanning Electron Microscopy (SBF-SEM) to achieve high-resolution 3D reconstructions of murine liver mitochondria to observe diverse phenotypes and structural alterations that occur with age, marked by a reduction in size and complexity. We also show concomitant metabolomic and lipidomic changes in aged samples. Aged human samples reflected altered disease risk. To find potential regulators of this change, we examined the Mitochondrial Contact Site and Cristae Organizing System (MICOS) complex, which plays a crucial role in maintaining mitochondrial architecture. We observe that the MICOS complex is lost during aging, but not Sam50. Sam50 is a component of the sorting and assembly machinery (SAM) complex that acts in tandem with the MICOS complex to modulate cristae morphology. In murine models subjected to a high-fat diet, there is a marked depletion of the mitochondrial protein SAM50. This reduction in Sam50 expression may heighten the susceptibility to liver disease, as our human biobank studies corroborate that Sam50 plays a genetically regulated role in the predisposition to multiple liver diseases. We further show that changes in mitochondrial calcium dysregulation and oxidative stress accompany the disruption of the MICOS complex. Together, we establish that a decrease in mitochondrial complexity and dysregulated metabolism occur with murine liver aging. While these changes are partially be regulated by age-related loss of the MICOS complex, the confluence of a murine high-fat diet can also cause loss of Sam50, which contributes to liver diseases. In summary, our study reveals potential regulators that affect age-related changes in mitochondrial structure and metabolism, which can be targeted in future therapeutic techniques.
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Affiliation(s)
- Zer Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Alexandria Murphy
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life Sciences, Pennsylvania State University, State College, PA 16801
| | - Han Le
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Edgar Garza-Lopez
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Andrea G. Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Margaret Mungai
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Brenita Jenkins
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life Sciences, Pennsylvania State University, State College, PA 16801
| | - Larry Vang
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Heather K. Beasley
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Mariaassumpta Ezedimma
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Sasha Manus
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Aaron Whiteside
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Maria Fernanda Forni
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06520
| | - Chanel Harris
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
- Department of Biomedical Sciences, School of Graduate Studies, Meharry Medical College, Nashville, TN 37208-3501, USA
| | - Amber Crabtree
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Claude F. Albritton
- Department of Biomedical Sciences, School of Graduate Studies, Meharry Medical College, Nashville, TN 37208-3501, USA
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Sydney Jamison
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Mert Demirci
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Praveena Prasad
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life Sciences, Pennsylvania State University, State College, PA 16801
| | - Ashton Oliver
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Ky’Era V. Actkins
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Jianqiang Shao
- Central Microscopy Research Facility, University of Iowa, Iowa City, IA, 52242, USA
| | - Elma Zaganjor
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Estevão Scudese
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Benjamin Rodriguez
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Alice Koh
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Izabella Rabago
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Johnathan E. Moore
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Desiree Nguyen
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Muhammad Aftab
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Benjamin Kirk
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Yahang Li
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Nelson Wandira
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Taseer Ahmad
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Department of Pharmacology, College of Pharmacy, University of Sargodha, Sargodha, Punjab,40100, Pakistan
| | - Mohammad Saleem
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Ashlesha Kadam
- Department of Internal Medicine, Section of Cardiovascular Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157 USA
| | - Prasanna Katti
- National Heart, Lung and Blood Institute, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, AP, 517619, India
| | - Ho-Jin Koh
- Department of Biological Sciences, Tennessee State University, Nashville, TN 37209, USA
| | - Chantell Evans
- Department of Cell Biology, Duke University School of Medicine, Durham, NC, 27708, USA
| | - Young Do Koo
- Department of Internal Medicine, University of Iowa, Iowa City, IA, 52242, USA
- Fraternal Order of Eagles Diabetes Research Center, Iowa City, Iowa, USA1
| | - Eric Wang
- Department of Chemical and Biomolecular Engineering, University of California, Irvine, CA, 92697, USA
| | - Quinton Smith
- Department of Chemical and Biomolecular Engineering, University of California, Irvine, CA, 92697, USA
| | - Dhanendra Tomar
- Department of Pharmacology, College of Pharmacy, University of Sargodha, Sargodha, Punjab,40100, Pakistan
| | - Clintoria R. Williams
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, OH 45435 USA
| | - Mariya T. Sweetwyne
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98195, USA
| | - Anita M. Quintana
- Department of Biological Sciences, Border Biomedical Research Center, The University of Texas at El Paso, El Paso, Texas, USA
| | - Mark A. Phillips
- Department of Integrative Biology, Oregon State University, Corvallis, OR, 97331, USA
| | - David Hubert
- Department of Integrative Biology, Oregon State University, Corvallis, OR, 97331, USA
| | - Annet Kirabo
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Vanderbilt Center for Immunobiology, Nashville, TN, 37232, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Nashville, TN, 37232, USA
- Vanderbilt Institute for Global Health, Nashville, TN, 37232, USA
| | - Chandravanu Dash
- Department of Microbiology, Immunology and Physiology, Meharry Medical College, Nashville, TN, United States
| | - Pooja Jadiya
- Department of Internal Medicine, Section of Gerontology and Geriatric Medicine, Sticht Center for Healthy Aging and Alzheimer’s Prevention, Wake Forest University School of Medicine, Winston-Salem, NC
| | - André Kinder
- Artur Sá Earp Neto University Center – UNIFASE-FMP, Petrópolis Medical School, Brazil
| | - Olujimi A. Ajijola
- UCLA Cardiac Arrhythmia Center, University of California, Los Angeles, CA, USA
| | - Tyne W. Miller-Fleming
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Melanie R. McReynolds
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life Sciences, Pennsylvania State University, State College, PA 16801
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
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Chen Y, Zhao C, Zheng J, Su N, Ji H. Discovery of the mechanism of n-propylparaben-promoting the proliferation of human breast adenocarcinoma cells by activating human estrogen receptors via metabolomics analysis. Hum Exp Toxicol 2023; 42:9603271231171648. [PMID: 37121592 DOI: 10.1177/09603271231171648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
BACKGROUND N-propylparaben (PP), a type of paraben, is commonly used as a preservative or antibacterial agent in daily chemicals, medicine, food, cosmetics, feed, and various industrial preservatives. Although PP promotes the growth of human breast adenocarcinoma (MCF-7) cells by activating the human estrogen receptor (ER), the mechanism responsible for this type of programmed cell proliferation is poorly understood. OBJECTIVE To clarify the effect of PP on cell metabolic function and the potential molecular mechanism of PP induced MCF-7 cell proliferation from a new perspective. METHODS To use high-resolution mass spectrometry-based metabolomics combined with bioinformatics analysis to analyze the molecular mechanism. RESULTS The results illustrated that differential endogenous compounds related to the effects of PP on cell metabolic functions were detected. PP was found to promote glycolysis in MCF-7 cells and enhance the tricarboxylic acid cycle (TCA cycle) in mitochondria, thus improving the energy supply to these tumor cells for metabolic function and promotion of rapid proliferation. Moreover, we found that PP promoted cell proliferation by affecting the mitogen-activated protein kinase (MAPK) signaling pathway of MCF-7 cells. CONCLUSION Our results revealed the molecular mechanism of low concentration PP promoting MCF-7 cell proliferation by activating ER.
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Affiliation(s)
- Yunxia Chen
- Chinese Academy of Inspection and Quarantine, Cosmetic Technology Center, Beijing, China
| | - Chan Zhao
- Chinese Academy of Inspection and Quarantine, Institute of Chemicals Safety, Beijing, China
| | - Jun Zheng
- Chinese Academy of Inspection and Quarantine, Cosmetic Technology Center, Beijing, China
| | - Ning Su
- Chinese Academy of Inspection and Quarantine, Cosmetic Technology Center, Beijing, China
| | - Hainan Ji
- Chinese Academy of Inspection and Quarantine, Institute of Chemicals Safety, Beijing, China
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McMahon DB, Kuek LE, Johnson ME, Johnson PO, Horn RL, Carey RM, Adappa ND, Palmer JN, Lee RJ. The bitter end: T2R bitter receptor agonists elevate nuclear calcium and induce apoptosis in non-ciliated airway epithelial cells. Cell Calcium 2022; 101:102499. [PMID: 34839223 PMCID: PMC8752513 DOI: 10.1016/j.ceca.2021.102499] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 10/21/2021] [Accepted: 10/31/2021] [Indexed: 01/03/2023]
Abstract
Bitter taste receptors (T2Rs) localize to airway motile cilia and initiate innate immune responses in retaliation to bacterial quorum sensing molecules. Activation of cilia T2Rs leads to calcium-driven NO production that increases cilia beating and directly kills bacteria. Several diseases, including chronic rhinosinusitis, COPD, and cystic fibrosis, are characterized by loss of motile cilia and/or squamous metaplasia. To understand T2R function within the altered landscape of airway disease, we studied T2Rs in non-ciliated airway cell lines and primary cells. Several T2Rs localize to the nucleus in de-differentiated cells that typically localize to cilia in differentiated cells. As cilia and nuclear import utilize shared proteins, some T2Rs may target to the nucleus in the absence of motile cilia. T2R agonists selectively elevated nuclear and mitochondrial calcium through a G-protein-coupled receptor phospholipase C mechanism. Additionally, T2R agonists decreased nuclear cAMP, increased nitric oxide, and increased cGMP, consistent with T2R signaling. Furthermore, exposure to T2R agonists led to nuclear calcium-induced mitochondrial depolarization and caspase activation. T2R agonists induced apoptosis in primary bronchial and nasal cells differentiated at air-liquid interface but then induced to a squamous phenotype by apical submersion. Air-exposed well-differentiated cells did not die. This may be a last-resort defense against bacterial infection. However, it may also increase susceptibility of de-differentiated or remodeled epithelia to damage by bacterial metabolites. Moreover, the T2R-activated apoptosis pathway occurs in airway cancer cells. T2Rs may thus contribute to microbiome-tumor cell crosstalk in airway cancers. Targeting T2Rs may be useful for activating cancer cell apoptosis while sparing surrounding tissue.
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Affiliation(s)
- Derek B. McMahon
- Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA,Correspondence: Derek B. McMahon, PhD or Robert J. Lee, PhD, Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA USA, 215-573-9766, (D.B.M.) or (R.J.L)
| | - Li Eon Kuek
- Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Madeline E. Johnson
- Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Paige O. Johnson
- Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Rachel L.J. Horn
- Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Ryan M. Carey
- Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Nithin D. Adappa
- Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - James N. Palmer
- Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Robert J. Lee
- Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA,Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA,Correspondence: Derek B. McMahon, PhD or Robert J. Lee, PhD, Department of Otorhinolaryngology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA USA, 215-573-9766, (D.B.M.) or (R.J.L)
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Preston CC, Stoddard AC, Faustino RS. A Transient Mystery: Nucleolar Channel Systems. Results Probl Cell Differ 2022; 70:581-593. [PMID: 36348122 DOI: 10.1007/978-3-031-06573-6_20] [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] [Indexed: 06/16/2023]
Abstract
The nucleus is a complex organelle with functions beyond being a simple repository for genomic material. For example, its actions in biomechanical sensing, protein synthesis, and epigenomic regulation showcase how the nucleus integrates multiple signaling modalities to intricately regulate gene expression. This innate dynamism is underscored by subnuclear components that facilitate these roles, with elements of the nucleoskeleton, phase-separated nuclear bodies, and chromatin safeguarding by nuclear envelope proteins providing examples of this functional diversity. Among these, one of the lesser characterized nuclear organelles is the nucleolar channel system (NCS), first reported several decades ago in human endometrial biopsies. This tubular structure, believed to be derived from the inner nuclear membrane of the nuclear envelope, was first observed in secretory endometrial cells during a specific phase of the menstrual cycle. Reported as a consistent, yet transient, nuclear organelle, current interpretations of existing data suggest that it serves as a marker of a window for optimal implantation. In spite of this available data, the NCS remains incompletely characterized structurally and functionally, due in part to its transient spatial and temporal expression. As a further complication, evidence exists showing NCS expression in fetal tissue, suggesting that it may not act exclusively as a marker of uterine receptivity, but rather as a hormone sensor sensitive to estrogen and progesterone ratios. To gain a better understanding of the NCS, current technologies can be applied to profile rare cell populations or capture transient structural dynamics, for example, at a level of sensitivity and resolution not previously possible. Moving forward, advanced characterization of the NCS will shed light on an uncharacterized aspect of reproductive physiology, with the potential to refine assisted reproductive techniques.
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Affiliation(s)
- Claudia C Preston
- Biology Department, St. Mary's University of Minnesota, Winona, MN, USA
| | | | - Randolph S Faustino
- Genetics and Genomics Group, Sanford Research, Sioux Falls, SD, USA.
- Department of Pediatrics, Sanford School of Medicine of the University of South Dakota, Sioux Falls, SD, USA.
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Gilabert JA. Cytoplasmic Calcium Buffering: An Integrative Crosstalk. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:163-182. [PMID: 31646510 DOI: 10.1007/978-3-030-12457-1_7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Calcium (Ca2+) buffering is part of an integrative crosstalk between different mechanisms and elements involved in the control of free Ca2+ ions persistence in the cytoplasm and hence, in the Ca2+-dependence of many intracellular processes. Alterations of Ca2+ homeostasis and signaling from systemic to subcellular levels also play a pivotal role in the pathogenesis of many diseases.Compared with Ca2+ sequestration towards intracellular Ca2+ stores, Ca2+ buffering is a rapid process occurring in a subsecond scale. Any molecule (or binding site) with the ability to bind Ca2+ ions could be considered, at least in principle, as a buffer. However, the term Ca2+ buffer is applied only to a small subset of Ca2+ binding proteins containing acidic side-chain residues.Ca2+ buffering in the cytoplasm mainly relies on mobile and immobile or fixed buffers controlling the diffusion of free Ca2+ ions inside the cytosol both temporally and spatially. Mobility of buffers depends on their molecular weight, but other parameters as their concentration, affinity for Ca2+ or Ca2+ binding and dissociation kinetics next to their diffusional mobility also contribute to make Ca2+ signaling one of the most complex signaling activities of the cell.The crosstalk between all the elements involved in the intracellular Ca2+ dynamics is a process of extreme complexity due to the diversity of structural and molecular elements involved but permit a highly regulated spatiotemporal control of the signal mediated by Ca2+ ions. The basis of modeling tools to study Ca2+ dynamics are also presented.
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Affiliation(s)
- Juan A Gilabert
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Complutense University of Madrid, Madrid, Spain.
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Vogl W, Lyon K, Adams A, Piva M, Nassour V. The endoplasmic reticulum, calcium signaling and junction turnover in Sertoli cells. Reproduction 2017; 155:R93-R104. [PMID: 29066527 DOI: 10.1530/rep-17-0281] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 09/12/2017] [Accepted: 10/23/2017] [Indexed: 12/19/2022]
Abstract
The endoplasmic reticulum (ER) forms a continuous network throughout morphologically differentiated Sertoli cells. It is an integral component of intercellular adhesion junctions in this cell type, as well as forming membrane contact sites with the plasma membrane and intracellular organelles. One of the major functions of the ER in cells generally is maintaining calcium homeostasis and generating calcium signals. In this review, we discuss what is currently known about the overall pattern of distribution of the ER in Sertoli cells and the location of calcium regulatory machinery in the various subdomains of the organelle. Current data are consistent with the hypothesis that calcium signaling by the ER of Sertoli cells may play a significant role in events related to junction remodeling that occur in the seminiferous epithelium during spermatogenesis.
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Affiliation(s)
- Wayne Vogl
- Department of Cellular and Physiological SciencesUniversity of British Columbia, British Columbia, Canada .,Department of Obstetrics and GynaecologyUniversity of British Columbia, British Columbia, Canada
| | - Kevin Lyon
- Department of Obstetrics and GynaecologyUniversity of British Columbia, British Columbia, Canada
| | - Arlo Adams
- Department of Cellular and Physiological SciencesUniversity of British Columbia, British Columbia, Canada
| | - Matthew Piva
- Department of Cellular and Physiological SciencesUniversity of British Columbia, British Columbia, Canada
| | - Vanessa Nassour
- Department of Cellular and Physiological SciencesUniversity of British Columbia, British Columbia, Canada
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Tsuda T, Fitzgerald KK. Dystrophic Cardiomyopathy: Complex Pathobiological Processes to Generate Clinical Phenotype. J Cardiovasc Dev Dis 2017; 4:jcdd4030014. [PMID: 29367543 PMCID: PMC5715712 DOI: 10.3390/jcdd4030014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 08/27/2017] [Accepted: 08/30/2017] [Indexed: 02/06/2023] Open
Abstract
Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), and X-linked dilated cardiomyopathy (XL-DCM) consist of a unique clinical entity, the dystrophinopathies, which are due to variable mutations in the dystrophin gene. Dilated cardiomyopathy (DCM) is a common complication of dystrophinopathies, but the onset, progression, and severity of heart disease differ among these subgroups. Extensive molecular genetic studies have been conducted to assess genotype-phenotype correlation in DMD, BMD, and XL-DCM to understand the underlying mechanisms of these diseases, but the results are not always conclusive, suggesting the involvement of complex multi-layers of pathological processes that generate the final clinical phenotype. Dystrophin protein is a part of dystrophin-glycoprotein complex (DGC) that is localized in skeletal muscles, myocardium, smooth muscles, and neuronal tissues. Diversity of cardiac phenotype in dystrophinopathies suggests multiple layers of pathogenetic mechanisms in forming dystrophic cardiomyopathy. In this review article, we review the complex molecular interactions involving the pathogenesis of dystrophic cardiomyopathy, including primary gene mutations and loss of structural integrity, secondary cellular responses, and certain epigenetic and other factors that modulate gene expressions. Involvement of epigenetic gene regulation appears to lead to specific cardiac phenotypes in dystrophic hearts.
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Affiliation(s)
- Takeshi Tsuda
- Nemours Cardiac Center, Nemours/Alfred I. duPont Hospital for Children, Wilmington, 1600 Rockland Rd, DE 19803, USA.
| | - Kristi K Fitzgerald
- Nemours Cardiac Center, Nemours/Alfred I. duPont Hospital for Children, Wilmington, 1600 Rockland Rd, DE 19803, USA.
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Alonso MT, Rodríguez-Prados M, Navas-Navarro P, Rojo-Ruiz J, García-Sancho J. Using aequorin probes to measure Ca 2+ in intracellular organelles. Cell Calcium 2017; 64:3-11. [PMID: 28214023 DOI: 10.1016/j.ceca.2017.01.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 01/11/2017] [Indexed: 11/28/2022]
Abstract
Aequorins are excellent tools for measuring intra-organellar Ca2+ and assessing its role in physiological and pathological functions. Here we review targeting strategies to express aequorins in various organelles. We address critical topics such as probe affinity tuning as well as normalization and calibration of the signal. We also focus on bioluminescent Ca2+ imaging in nucleus or mitochondria of living cells. Finally, recent advances with a new chimeric GFP-aequorin protein (GAP), which can be used either as luminescent or fluorescent Ca2+ probe, are presented. GAP is robustly expressed in transgenic flies and mice, where it has proven to be a suitable Ca2+ indicator for monitoring physiological Ca2+ signaling ex vivo and in vivo.
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Affiliation(s)
- María Teresa Alonso
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), c/Sanz y Forés 3, 47003 Valladolid, Spain.
| | - Macarena Rodríguez-Prados
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), c/Sanz y Forés 3, 47003 Valladolid, Spain
| | - Paloma Navas-Navarro
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), c/Sanz y Forés 3, 47003 Valladolid, Spain
| | - Jonathan Rojo-Ruiz
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), c/Sanz y Forés 3, 47003 Valladolid, Spain
| | - Javier García-Sancho
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), c/Sanz y Forés 3, 47003 Valladolid, Spain.
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From Stores to Sinks: Structural Mechanisms of Cytosolic Calcium Regulation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 981:215-251. [PMID: 29594864 DOI: 10.1007/978-3-319-55858-5_10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
All eukaryotic cells have adapted the use of the calcium ion (Ca2+) as a universal signaling element through the evolution of a toolkit of Ca2+ sensor, buffer and effector proteins. Among these toolkit components, integral and peripheral proteins decorate biomembranes and coordinate the movement of Ca2+ between compartments, sense these concentration changes and elicit physiological signals. These changes in compartmentalized Ca2+ levels are not mutually exclusive as signals propagate between compartments. For example, agonist induced surface receptor stimulation can lead to transient increases in cytosolic Ca2+ sourced from endoplasmic reticulum (ER) stores; the decrease in ER luminal Ca2+ can subsequently signal the opening surface channels which permit the movement of Ca2+ from the extracellular space to the cytosol. Remarkably, the minuscule compartments of mitochondria can function as significant cytosolic Ca2+ sinks by taking up Ca2+ in a coordinated manner. In non-excitable cells, inositol 1,4,5 trisphosphate receptors (IP3Rs) on the ER respond to surface receptor stimulation; stromal interaction molecules (STIMs) sense the ER luminal Ca2+ depletion and activate surface Orai1 channels; surface Orai1 channels selectively permit the movement of Ca2+ from the extracellular space to the cytosol; uptake of Ca2+ into the matrix through the mitochondrial Ca2+ uniporter (MCU) further shapes the cytosolic Ca2+ levels. Recent structural elucidations of these key Ca2+ toolkit components have improved our understanding of how they function to orchestrate precise cytosolic Ca2+ levels for specific physiological responses. This chapter reviews the atomic-resolution structures of IP3R, STIM1, Orai1 and MCU elucidated by X-ray crystallography, electron microscopy and NMR and discusses the mechanisms underlying their biological functions in their respective compartments within the cell.
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Alonso MT, Navas-Navarro P, García-Sancho J. A Microplate-Based Bioluminescence Assay of Mitochondrial Calcium Uptake. Methods Mol Biol 2017; 1567:245-253. [PMID: 28276023 DOI: 10.1007/978-1-4939-6824-4_15] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Mitochondrial Ca2+ homeostasis is crucial for regulating vital functions such as respiration or apoptosis. Targeted aequorins are excellent probes to measure subcellular Ca2+. Ca2+ concentration in mitochondria ([Ca2+]M) is low at rest (about 10-7 M) and can increase to the micromolar or even approach the millimolar range, upon cell activation. Here we describe a new quantitative luminescent protocol to directly measure mitochondrial Ca2+ uptake, optimized for high throughput. The sensitivity of the method allows detection of changes in either the capacity or the affinity of mitochondrial Ca2+ transport.
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Affiliation(s)
- María Teresa Alonso
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), c/ Sanz y Forés 3, 47003, Valladolid, Spain.
| | - Paloma Navas-Navarro
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), c/ Sanz y Forés 3, 47003, Valladolid, Spain
| | - Javier García-Sancho
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), c/ Sanz y Forés 3, 47003, Valladolid, Spain
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11
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Alonso MT, Rojo-Ruiz J, Navas-Navarro P, Rodríguez-Prados M, García-Sancho J. Measuring Ca 2+ inside intracellular organelles with luminescent and fluorescent aequorin-based sensors. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:894-899. [PMID: 27939433 DOI: 10.1016/j.bbamcr.2016.12.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 12/05/2016] [Accepted: 12/06/2016] [Indexed: 02/06/2023]
Abstract
GFP-Aequorin Protein (GAP) can be used to measure [Ca2+] inside intracellular organelles, both by luminescence and by fluorescence. The low-affinity variant GAP3 is adequate for ratiometric imaging in the endoplasmic reticulum and Golgi apparatus, and it can be combined with conventional synthetic indicators for simultaneous measurements of cytosolic Ca2+. GAP is bioorthogonal as it does not have mammalian homologues, and it is robust and functionally expressed in transgenic flies and mice, where it can be used for Ca2+ measurements ex vivo and in vivo to explore animal models of health and disease. 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)
- María Teresa Alonso
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), C/Sanz y Forés 3, 47003, Valladolid, Spain.
| | - Jonathan Rojo-Ruiz
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), C/Sanz y Forés 3, 47003, Valladolid, Spain
| | - Paloma Navas-Navarro
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), C/Sanz y Forés 3, 47003, Valladolid, Spain
| | - Macarena Rodríguez-Prados
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), C/Sanz y Forés 3, 47003, Valladolid, Spain
| | - Javier García-Sancho
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas (CSIC), C/Sanz y Forés 3, 47003, Valladolid, Spain.
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12
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Villanueva J, Gimenez-Molina Y, Viniegra S, Gutiérrez LM. F-actin cytoskeleton and the fate of organelles in chromaffin cells. J Neurochem 2016; 137:860-6. [PMID: 26843469 DOI: 10.1111/jnc.13560] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 01/21/2016] [Accepted: 01/22/2016] [Indexed: 12/31/2022]
Abstract
In addition to playing a fundamental structural role, the F-actin cytoskeleton in neuroendocrine chromaffin cells has a prominent influence on governing the molecular mechanism and regulating the secretory process. Performing such roles, the F-actin network might be essential to first transport, and later locate the cellular organelles participating in the secretory cycle. Chromaffin granules are transported from the internal cytosolic regions to the cell periphery along microtubular and F-actin structures. Once in the cortical region, they are embedded in the F-actin network where these vesicles experience restrictions in motility. Similarly, mitochondria transport is affected by both microtubule and F-actin inhibitors and suffers increasing motion restrictions when they are located in the cortical region. Therefore, the F-actin cortex is a key factor in defining the existence of two populations of cortical and perinuclear granules and mitochondria which could be distinguished by their different location and mobility. Interestingly, other important organelles for controlling intracellular calcium levels, such as the endoplasmic reticulum network, present clear differences in distribution and much lower mobility than chromaffin vesicles and mitochondria. Nevertheless, both mitochondria and the endoplasmic reticulum appear to distribute in the proximity of secretory sites to fulfill a pivotal role, forming triads with calcium channels ensuring the fine tuning of the secretory response. This review presents the contributions that provide the basis for our current view regarding the influence that F-actin has on the distribution of organelles participating in the release of catecholamines in chromaffin cells, and summarizes this knowledge in simple models. In chromaffin cells, organelles such as granules and mitochondria distribute forming cortical and perinuclear populations whereas others like the ER present homogenous distributions. In the present review we discuss the role of transport systems and the existence of an F-actin cortical structure as the main factors behind the formation of organelle subpopulations in this neuroendocrine cell model. This article is part of a mini review series on Chromaffin cells (ISCCB Meeting, 2015). Cover image for this issue: doi: 10.1111/jnc.13322.
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Affiliation(s)
- José Villanueva
- Instituto de Neurociencias, Centro Mixto Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant (Alicante), Spain
| | - Yolanda Gimenez-Molina
- Instituto de Neurociencias, Centro Mixto Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant (Alicante), Spain
| | - Salvador Viniegra
- Instituto de Neurociencias, Centro Mixto Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant (Alicante), Spain
| | - Luis M Gutiérrez
- Instituto de Neurociencias, Centro Mixto Universidad Miguel Hernández-CSIC, Sant Joan d'Alacant (Alicante), Spain
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13
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Rodríguez-Prados M, Rojo-Ruiz J, Aulestia FJ, García-Sancho J, Alonso MT. A new low-Ca²⁺ affinity GAP indicator to monitor high Ca²⁺ in organelles by luminescence. Cell Calcium 2015; 58:558-64. [PMID: 26412347 DOI: 10.1016/j.ceca.2015.09.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 09/09/2015] [Accepted: 09/11/2015] [Indexed: 11/25/2022]
Abstract
We have recently described a new class of genetically encoded Ca(2+) indicators composed of two jellyfish proteins, a variant of green fluorescent protein (GFP) and the calcium binding protein apoaequorin, named GAP (Rodriguez-García et al., 2014). GAP is a unique dual-mode Ca(2+) indicator, able to function either as a fluorescent or a luminescent probe, depending on whether the photoprotein aequorin is in its apo-state or reconstituted with its cofactor coelenterazine. We describe here a novel application of GAP as a low affinity bioluminescent indicator, suitable for measurements of [Ca(2+)] in ER or in Golgi apparatus. We used the low affinity variant, GAP1, which carries mutations in two EF-hands of aequorin, reconstituted with coelenterazine n. In comparison to previous bioluminescent aequorin fusions, the decay rate of GAP1 was decreased 8 fold and the affinity for Ca(2+) was lowered one order of magnitude. This improvement allows long-term measurements in high Ca(2+) environments avoiding fast aequorin consumption. GAP1 was targeted to the ER of various cell types, where it monitored resting Ca(2+) concentrations in the range from 400 to 600 μM. ER could be emptied of calcium by stimulation with ATP, carbachol or histamine in intact cells, and by challenge with inositol tris-phosphate in permeabilized cells. GAP1 was also targeted to the Golgi apparatus where it was able to precisely monitor long-term calcium dynamics. GAP1 provides a novel and robust indicator applicable to bioluminescent high-throughput quantitative assays.
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Affiliation(s)
- Macarena Rodríguez-Prados
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas, Sanz y Forés 3, 47003 Valladolid, Spain
| | - Jonathan Rojo-Ruiz
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas, Sanz y Forés 3, 47003 Valladolid, Spain
| | - Francisco Javier Aulestia
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas, Sanz y Forés 3, 47003 Valladolid, Spain
| | - Javier García-Sancho
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas, Sanz y Forés 3, 47003 Valladolid, Spain
| | - María Teresa Alonso
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid and Consejo Superior de Investigaciones Científicas, Sanz y Forés 3, 47003 Valladolid, Spain.
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van Westering TLE, Betts CA, Wood MJA. Current understanding of molecular pathology and treatment of cardiomyopathy in duchenne muscular dystrophy. Molecules 2015; 20:8823-55. [PMID: 25988613 PMCID: PMC6272314 DOI: 10.3390/molecules20058823] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/08/2015] [Accepted: 05/11/2015] [Indexed: 12/27/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a genetic muscle disorder caused by mutations in the Dmd gene resulting in the loss of the protein dystrophin. Patients do not only experience skeletal muscle degeneration, but also develop severe cardiomyopathy by their second decade, one of the main causes of death. The absence of dystrophin in the heart renders cardiomyocytes more sensitive to stretch-induced damage. Moreover, it pathologically alters intracellular calcium (Ca2+) concentration, neuronal nitric oxide synthase (nNOS) localization and mitochondrial function and leads to inflammation and necrosis, all contributing to the development of cardiomyopathy. Current therapies only treat symptoms and therefore the need for targeting the genetic defect is immense. Several preclinical therapies are undergoing development, including utrophin up-regulation, stop codon read-through therapy, viral gene therapy, cell-based therapy and exon skipping. Some of these therapies are undergoing clinical trials, but these have predominantly focused on skeletal muscle correction. However, improving skeletal muscle function without addressing cardiac aspects of the disease may aggravate cardiomyopathy and therefore it is essential that preclinical and clinical focus include improving heart function. This review consolidates what is known regarding molecular pathology of the DMD heart, specifically focusing on intracellular Ca2+, nNOS and mitochondrial dysregulation. It briefly discusses the current treatment options and then elaborates on the preclinical therapeutic approaches currently under development to restore dystrophin thereby improving pathology, with a focus on the heart.
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Affiliation(s)
- Tirsa L E van Westering
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK
| | - Corinne A Betts
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.
| | - Matthew J A Wood
- Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford, OX1 3QX, UK.
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15
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Differential calcium handling by the cis and trans regions of the Golgi apparatus. Biochem J 2015; 466:455-65. [PMID: 25511127 DOI: 10.1042/bj20141358] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
High Ca2+ content in the Golgi apparatus (Go) is essential for protein processing and sorting. In addition, the Go can shape the cytosolic Ca2+ signals by releasing or sequestering Ca2+. We generated two new aequorin-based Ca2+ probes to specifically measure Ca2+ in the cis/cis-to-medial-Go (cGo) or the trans-Go (tGo). Ca2+ homoeostasis in these compartments and in the endoplasmic reticulum (ER) has been studied and compared. Moreover, the relative size of each subcompartment was estimated from aequorin consumption. We found that the cGo accumulates Ca2+ to high concentrations (150-300 μM) through the sarco plasmic/endoplasmic reticulum Ca2+-ATPase (SERCA). The tGo, in turn, is divided into two subcompartments: tGo1 and tGo2. The subcompartment tGo1 contains 20% of the aequorin and has a high internal [Ca2+]; Ca2+ is accumulated in this subcompartment via the secretory pathway Ca2+-ATPase 1 (SPCA-1) at a very high affinity (K50=30 nM). The subcompartment tGo2 contains 80% of aequorin, has a lower [Ca2+] and no SPCA-1 activity; Ca2+ uptake happens through SERCA and is slower than in tGo1. The two tGo subcompartments, tGo1 and tGo2, are diffusionally isolated. Inositol trisphosphate mobilizes Ca2+ from the cGo and tGo2, but not from tGo1, whereas caffeine releases Ca2+ from all the Golgi regions, and nicotinic acid dinucleotide phosphate and cADP ribose from none.
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16
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Weinberg SH, Smith GD. The influence of Ca²⁺ buffers on free [Ca²⁺] fluctuations and the effective volume of Ca²⁺ microdomains. Biophys J 2015; 106:2693-709. [PMID: 24940787 DOI: 10.1016/j.bpj.2014.04.045] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 04/28/2014] [Accepted: 04/30/2014] [Indexed: 02/06/2023] Open
Abstract
Intracellular calcium (Ca(2+)) plays a significant role in many cell signaling pathways, some of which are localized to spatially restricted microdomains. Ca(2+) binding proteins (Ca(2+) buffers) play an important role in regulating Ca(2+) concentration ([Ca(2+)]). Buffers typically slow [Ca(2+)] temporal dynamics and increase the effective volume of Ca(2+) domains. Because fluctuations in [Ca(2+)] decrease in proportion to the square-root of a domain's physical volume, one might conjecture that buffers decrease [Ca(2+)] fluctuations and, consequently, mitigate the significance of small domain volume concerning Ca(2+) signaling. We test this hypothesis through mathematical and computational analysis of idealized buffer-containing domains and their stochastic dynamics during free Ca(2+) influx with passive exchange of both Ca(2+) and buffer with bulk concentrations. We derive Langevin equations for the fluctuating dynamics of Ca(2+) and buffer and use these stochastic differential equations to determine the magnitude of [Ca(2+)] fluctuations for different buffer parameters (e.g., dissociation constant and concentration). In marked contrast to expectations based on a naive application of the principle of effective volume as employed in deterministic models of Ca(2+) signaling, we find that mobile and rapid buffers typically increase the magnitude of domain [Ca(2+)] fluctuations during periods of Ca(2+) influx, whereas stationary (immobile) Ca(2+) buffers do not. Also contrary to expectations, we find that in the absence of Ca(2+) influx, buffers influence the temporal characteristics, but not the magnitude, of [Ca(2+)] fluctuations. We derive an analytical formula describing the influence of rapid Ca(2+) buffers on [Ca(2+)] fluctuations and, importantly, identify the stochastic analog of (deterministic) effective domain volume. Our results demonstrate that Ca(2+) buffers alter the dynamics of [Ca(2+)] fluctuations in a nonintuitive manner. The finding that Ca(2+) buffers do not suppress intrinsic domain [Ca(2+)] fluctuations raises the intriguing question of whether or not [Ca(2+)] fluctuations are a physiologically significant aspect of local Ca(2+) signaling.
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Affiliation(s)
- Seth H Weinberg
- Department of Applied Science, The College of William & Mary, Williamsburg, Virginia
| | - Gregory D Smith
- Department of Applied Science, The College of William & Mary, Williamsburg, Virginia.
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17
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Turnbull DM, Rustin P. Genetic and biochemical intricacy shapes mitochondrial cytopathies. Neurobiol Dis 2015; 92:55-63. [PMID: 25684538 DOI: 10.1016/j.nbd.2015.02.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 01/22/2015] [Accepted: 02/03/2015] [Indexed: 12/17/2022] Open
Abstract
The major progress made in the identification of the molecular bases of mitochondrial disease has revealed the huge diversity of their origin. Today up to 300 mutations were identified in the mitochondrial genome and about 200 nuclear genes are possibly mutated. In this review, we highlight a number of features specific to mitochondria which possibly participate in the complexity of these diseases. These features include both the complexity of mitochondrial genetics and the multiplicity of the roles ensured by the organelles in numerous aspects of cell life and death. This spectacular complexity presumably accounts for the present lack of an efficient therapy in the vast majority of cases.
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Affiliation(s)
- Douglass M Turnbull
- Wellcome Trust Centre for Mitochondrial Research, Institute for Neuroscience, Newcastle University, Framlington Road, Newcastle upon Tyne NE2 4HH, UK
| | - Pierre Rustin
- INSERM UMR 1141, Hôpital Robert Debré, Paris, France; Université Paris 7, Faculté de Médecine Denis Diderot, Paris, France.
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18
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Ibarra C, Vicencio JM, Varas-Godoy M, Jaimovich E, Rothermel BA, Uhlén P, Hill JA, Lavandero S. An integrated mechanism of cardiomyocyte nuclear Ca(2+) signaling. J Mol Cell Cardiol 2014; 75:40-8. [PMID: 24997440 PMCID: PMC4626248 DOI: 10.1016/j.yjmcc.2014.06.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 06/11/2014] [Accepted: 06/26/2014] [Indexed: 01/05/2023]
Abstract
In cardiomyocytes, Ca(2+) plays a central role in governing both contraction and signaling events that regulate gene expression. Current evidence indicates that discrimination between these two critical functions is achieved by segregating Ca(2+) within subcellular microdomains: transcription is regulated by Ca(2+) release within nuclear microdomains, and excitation-contraction coupling is regulated by cytosolic Ca(2+). Accordingly, a variety of agonists that control cardiomyocyte gene expression, such as endothelin-1, angiotensin-II or insulin-like growth factor-1, share the feature of triggering nuclear Ca(2+) signals. However, signaling pathways coupling surface receptor activation to nuclear Ca(2+) release, and the phenotypic responses to such signals, differ between agonists. According to earlier hypotheses, the selective control of nuclear Ca(2+) signals by activation of plasma membrane receptors relies on the strategic localization of inositol trisphosphate receptors at the nuclear envelope. There, they mediate Ca(2+) release from perinuclear Ca(2+) stores upon binding of inositol trisphosphate generated in the cytosol, which diffuses into the nucleus. More recently, identification of such receptors at nuclear membranes or perinuclear sarcolemmal invaginations has uncovered novel mechanisms whereby agonists control nuclear Ca(2+) release. In this review, we discuss mechanisms for the selective control of nuclear Ca(2+) signals with special focus on emerging models of agonist receptor activation.
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Affiliation(s)
- Cristián Ibarra
- Cardiovascular and Metabolic Diseases, Innovative Medicines and Early Development, AstraZeneca R&D, Mölndal, Sweden.
| | - Jose Miguel Vicencio
- Hatter Cardiovascular Institute, University College London, London, United Kingdom
| | - Manuel Varas-Godoy
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Enrique Jaimovich
- Centro de Estudios Moleculares de la Célula, Facultad de Ciencias Químicas y Farmacéuticas & Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Beverly A Rothermel
- Department of Internal Medicine, Cardiology Division, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Per Uhlén
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Joseph A Hill
- Department of Internal Medicine, Cardiology Division, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sergio Lavandero
- Centro de Estudios Moleculares de la Célula, Facultad de Ciencias Químicas y Farmacéuticas & Facultad de Medicina, Universidad de Chile, Santiago, Chile; Department of Internal Medicine, Cardiology Division, University of Texas Southwestern Medical Center, Dallas, TX, USA; Advanced Center for Chronic Diseases, Facultad de Ciencias Químicas y Farmacéuticas & Facultad de Medicina, Universidad de Chile, Santiago, Chile.
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19
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Vygodina TV, Kirichenko A, Konstantinov AA. Cation binding site of cytochrome c oxidase: progress report. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1188-95. [PMID: 24607866 DOI: 10.1016/j.bbabio.2014.02.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 02/18/2014] [Accepted: 02/24/2014] [Indexed: 12/15/2022]
Abstract
Cytochrome c oxidase from bovine heart binds Ca(2+) reversibly at a specific Cation Binding Site located near the outer face of the mitochondrial membrane. Ca(2+) shifts the absorption spectrum of heme a, which allowed earlier the determination of the kinetic and equilibrium characteristics of the binding, and, as shown recently, the binding of calcium to the site inhibits cytochrome oxidase activity at low turnover rates of the enzyme [Vygodina, Т., Kirichenko, A., Konstantinov, A.A (2013). Direct Regulation of Cytochrome c Oxidase by Calcium Ions. PloS ONE 8, e74436]. This paper summarizes further progress in the studies of the Cation Binding Site in this group presenting the results to be reported at 18th EBEC Meeting in Lisbon, 2014. The paper revises specificity of the bovine oxidase Cation Binding Site for different cations, describes dependence of the Ca(2+)-induced inhibition on turnover rate of the enzyme and reports very high affinity binding of calcium with the "slow" form of cytochrome oxidase. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference. Guest Editors: Manuela Pereira and Miguel Teixeira.
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Affiliation(s)
- Tatiana V Vygodina
- A.N. Belozersky Research Institute of Physico-Chemical Biology, Moscow State University, Russia
| | - Anna Kirichenko
- A.N. Belozersky Research Institute of Physico-Chemical Biology, Moscow State University, Russia
| | - Alexander A Konstantinov
- A.N. Belozersky Research Institute of Physico-Chemical Biology, Moscow State University, Russia.
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20
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Calderón JC, Bolaños P, Caputo C. The excitation-contraction coupling mechanism in skeletal muscle. Biophys Rev 2014; 6:133-160. [PMID: 28509964 PMCID: PMC5425715 DOI: 10.1007/s12551-013-0135-x] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 12/06/2013] [Indexed: 12/27/2022] Open
Abstract
First coined by Alexander Sandow in 1952, the term excitation-contraction coupling (ECC) describes the rapid communication between electrical events occurring in the plasma membrane of skeletal muscle fibres and Ca2+ release from the SR, which leads to contraction. The sequence of events in twitch skeletal muscle involves: (1) initiation and propagation of an action potential along the plasma membrane, (2) spread of the potential throughout the transverse tubule system (T-tubule system), (3) dihydropyridine receptors (DHPR)-mediated detection of changes in membrane potential, (4) allosteric interaction between DHPR and sarcoplasmic reticulum (SR) ryanodine receptors (RyR), (5) release of Ca2+ from the SR and transient increase of Ca2+ concentration in the myoplasm, (6) activation of the myoplasmic Ca2+ buffering system and the contractile apparatus, followed by (7) Ca2+ disappearance from the myoplasm mediated mainly by its reuptake by the SR through the SR Ca2+ adenosine triphosphatase (SERCA), and under several conditions movement to the mitochondria and extrusion by the Na+/Ca2+ exchanger (NCX). In this text, we review the basics of ECC in skeletal muscle and the techniques used to study it. Moreover, we highlight some recent advances and point out gaps in knowledge on particular issues related to ECC such as (1) DHPR-RyR molecular interaction, (2) differences regarding fibre types, (3) its alteration during muscle fatigue, (4) the role of mitochondria and store-operated Ca2+ entry in the general ECC sequence, (5) contractile potentiators, and (6) Ca2+ sparks.
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Affiliation(s)
- Juan C Calderón
- Physiology and Biochemistry Research Group-Physis, Department of Physiology and Biochemistry, Faculty of Medicine, University of Antioquia UdeA, Calle 70 No 52-21, Medellín, Colombia.
- Laboratory of Cellular Physiology, Centre of Biophysics and Biochemistry, Venezuelan Institute for Scientific Research (IVIC), Caracas, Venezuela.
- Departamento de Fisiología y Bioquímica, Grupo de Investigación en Fisiología y Bioquímica-Physis, Facultad de Medicina, Universidad de Antioquia, Calle 70 No 52-21, Medellín, Colombia.
| | - Pura Bolaños
- Laboratory of Cellular Physiology, Centre of Biophysics and Biochemistry, Venezuelan Institute for Scientific Research (IVIC), Caracas, Venezuela
| | - Carlo Caputo
- Laboratory of Cellular Physiology, Centre of Biophysics and Biochemistry, Venezuelan Institute for Scientific Research (IVIC), Caracas, Venezuela
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21
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Lozić I, Bartlett CA, Shaw JA, Iyer KS, Dunlop SA, Kilburn MR, Fitzgerald M. Changes in subtypes of Ca microdomains following partial injury to the central nervous system. Metallomics 2014; 6:455-64. [PMID: 24425149 DOI: 10.1039/c3mt00336a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rapid changes in Ca(2+) concentration and location in response to injury play key roles in a range of biological systems. However, quantitative analysis of changes in size and distribution of Ca(2+) microdomains in specific cell types in whole tissue samples has been limited by analytical resolution and reliance on indirect Ca(2+) indicator systems. Here, we combine the unique advantages of nanoscale secondary ion mass spectrometry (NanoSIMS) with immunohistochemistry to directly quantify changes in number, size and intensity of Ca microdomains specific to axonal or glial regions vulnerable to spreading damage following neurotrauma. Furthermore, using NanoSIMS allows separate quantification of Ca microdomains according to their co-localization with areas enriched in P. We rapidly excise and cryopreserve optic nerve segments from adult rat at time points ranging from 5 minutes to 3 months after injury, allowing assessment of Ca microdomains dynamics with minimal disruption due to tissue processing. We demonstrate significantly more non-P co-localized Ca microdomains in glial than axonal regions in normal optic nerve. The density of Ca microdomains not co-localized with areas enriched in P rapidly, selectively and significantly decreases after injury; densities of Ca microdomains co-localized with P enriched areas are unchanged. An efflux of Ca(2+) from microdomains not co-localized with P may contribute to the structural and functional deficits observed in nerve vulnerable to spreading damage following neurotrauma. NanoSIMS analyses of Ca microdomains allow quantitative and novel insights into Ca dynamics, applicable to a range of normal, as well as diseased or injured mammalian systems.
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Affiliation(s)
- Ivan Lozić
- BioNano, School of Chemistry and Biochemistry, The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009, Australia
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Villanueva J, Viniegra S, Gimenez-Molina Y, García-Martinez V, Expósito-Romero G, del Mar Frances M, García-Sancho J, Gutiérrez LM. The distribution of mitochondria and endoplasmic reticulum in relation with secretory sites in chromaffin cells. J Cell Sci 2014; 127:5105-14. [DOI: 10.1242/jcs.160242] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The distribution of mitochondria and ER in relation to exocytotic sites is relevant to understand the influence of these organelles in tuning calcium signals and secretion. Confocal images of probes tagged to mitochondria and F-actin cytoskeleton revealed the existence of two populations of mitochondria, one cortical and the other perinuclear. This mitochondrial distribution was also confirmed by using electron microscopy. In contrast, ER was sparse in the cortex and more abundant in deep cytoplasmic regions. The mitochondrial distribution may be due to organellar transport, which experiences increasing restrictions in the cell cortex. Further study of organelle distribution in relation to SNARE microdomains or the granule fusion sites revealed that 1/3 of the cortical mitochondria co-localized with exocytotic sites whereas another 1/3 located at a distance smaller than 2 vesicle diameters. ER structures were also present in the vicinity of secretory sites but at a lower density. Therefore, mitochondria and ER have a spatial distribution that suggests a specialized role in modulation of exocytosis and fits with cytosolic Ca2+ microdomains described before.
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Berchtold MW, Villalobo A. The many faces of calmodulin in cell proliferation, programmed cell death, autophagy, and cancer. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1843:398-435. [PMID: 24188867 DOI: 10.1016/j.bbamcr.2013.10.021] [Citation(s) in RCA: 230] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Revised: 10/24/2013] [Accepted: 10/26/2013] [Indexed: 12/21/2022]
Abstract
Calmodulin (CaM) is a ubiquitous Ca(2+) receptor protein mediating a large number of signaling processes in all eukaryotic cells. CaM plays a central role in regulating a myriad of cellular functions via interaction with multiple target proteins. This review focuses on the action of CaM and CaM-dependent signaling systems in the control of vertebrate cell proliferation, programmed cell death and autophagy. The significance of CaM and interconnected CaM-regulated systems for the physiology of cancer cells including tumor stem cells, and processes required for tumor progression such as growth, tumor-associated angiogenesis and metastasis are highlighted. Furthermore, the potential targeting of CaM-dependent signaling processes for therapeutic use is discussed.
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Key Words
- (4-[3,5-bis-[2-(4-hydroxy-3-methoxy-phenyl)-ethyl]-4,5-dihydro-pyrazol-1-yl]-benzoic acid
- (4-[3,5-bis-[2-(4-hydroxy-3-methoxy-phenyl)-vinyl]-4,5-dihydro-pyrazol-1-yl]-phenyl)-(4-methyl-piperazin-1-yl)-methanone
- (−) enantiomer of dihydropyrine 3-methyl-5-3-(4,4-diphenyl-1-piperidinyl)-propyl-1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-piridine-3,5-dicarboxylate-hydrochloride (niguldipine)
- 1-[N,O-bis(5-isoquinolinesulfonyl)-N-methyl-l-tyrosyl]-4-phenylpiperazine
- 12-O-tetradecanoyl-phorbol-13-acetate
- 2-chloro-(ε-amino-Lys(75))-[6-(4-(N,N′-diethylaminophenyl)-1,3,5-triazin-4-yl]-CaM adduct
- 3′-(β-chloroethyl)-2′,4′-dioxo-3,5′-spiro-oxazolidino-4-deacetoxy-vinblastine
- 7,12-dimethylbenz[a]anthracene
- Apoptosis
- Autophagy
- B859-35
- CAPP(1)-CaM
- Ca(2+) binding protein
- Calmodulin
- Cancer biology
- Cell proliferation
- DMBA
- EBB
- FL-CaM
- FPCE
- HBC
- HBCP
- J-8
- KAR-2
- KN-62
- KN-93
- N-(4-aminobutyl)-2-naphthalenesulfonamide
- N-(4-aminobutyl)-5-chloro-2-naphthalenesulfonamide
- N-(6-aminohexyl)-1-naphthalenesulfonamide
- N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide
- N-8-aminooctyl-5-iodo-naphthalenesulfonamide
- N-[2-[N-(4-chlorocinnamyl)-N-methylaminomethyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulfonamide
- O-(4-ethoxyl-butyl)-berbamine
- RITC-CaM
- TA-CaM
- TFP
- TPA
- W-12
- W-13
- W-5
- W-7
- fluorescein-CaM adduct
- fluphenazine-N-2-chloroethane
- norchlorpromazine-CaM adduct
- rhodamine isothiocyanate-CaM adduct
- trifluoperazine
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Affiliation(s)
- Martin W Berchtold
- Department of Biology, University of Copenhagen, Copenhagen Biocenter 4-2-09 Ole Maaløes Vej 5, DK-2200 Copenhagen N, Denmark.
| | - Antonio Villalobo
- Instituto de Investigaciones Biomédicas, Department of Cancer Biology, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, c/Arturo Duperier 4, E-28029 Madrid, Spain.
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Garland J. Energy management – a critical role in cancer induction? Crit Rev Oncol Hematol 2013; 88:198-217. [DOI: 10.1016/j.critrevonc.2013.04.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 03/08/2013] [Accepted: 04/05/2013] [Indexed: 12/18/2022] Open
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Paula-Lima AC, Hidalgo C. Amyloid β-peptide oligomers, ryanodine receptor-mediated Ca(2+) release, and Wnt-5a/Ca(2+) signaling: opposing roles in neuronal mitochondrial dynamics? Front Cell Neurosci 2013; 7:120. [PMID: 23908603 PMCID: PMC3727079 DOI: 10.3389/fncel.2013.00120] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 07/10/2013] [Indexed: 01/08/2023] Open
Affiliation(s)
- Andrea C Paula-Lima
- Faculty of Dentistry, Department of Basic and Communitarian Sciences, Universidad de Chile Santiago, Chile ; Centro de Estudios Moleculares de la Célula, Universidad de Chile Santiago, Chile ; Biomedical Neuroscience Institute, Universidad de Chile Santiago, Chile
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García-Sancho J. The coupling of plasma membrane calcium entry to calcium uptake by endoplasmic reticulum and mitochondria. J Physiol 2013; 592:261-8. [PMID: 23798493 DOI: 10.1113/jphysiol.2013.255661] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Cross-talk between organelles and plasma membrane Ca(2+) channels is essential for modulation of the cytosolic Ca(2+) ([Ca(2+)]C) signals, but such modulation may differ among cells. In chromaffin cells Ca(2+) entry through voltage-operated channels induces calcium release from the endoplasmic reticulum (ER) that amplifies the signal. [Ca(2+)]C microdomains as high as 20-50 μm are sensed by subplasmalemmal mitochondria, which accumulate large amounts of Ca(2+) through the mitochondrial Ca(2+) uniporter (MCU). Mitochondria confine the high-Ca(2+) microdomains (HCMDs) to beneath the plasma membrane, where exocytosis of secretory vesicles happens. Cell core [Ca(2+)]C is much smaller (1-2 μm). By acting as a Ca(2+) sink, mitochondria stabilise the HCMD in space and time. In non-excitable HEK293 cells, activation of store-operated Ca(2+) entry, triggered by ER Ca(2+) emptying, also generated subplasmalemmal HCMDs, but, in this case, most of the Ca(2+) was taken up by the ER rather than by mitochondria. The smaller size of the [Ca(2+)]C peak in this case (about 2 μm) may contribute to this outcome, as the sarco-endoplasmic reticulum Ca(2+) ATPase has much higher Ca(2+) affinity than MCU. It is also possible that the relative positioning of organelles, channels and effectors, as well as cytoskeleton and accessory proteins plays an important role.
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Don-Salu-Hewage AS, Chan SY, McAndrews KM, Chetram MA, Dawson MR, Bethea DA, Hinton CV. Cysteine (C)-x-C receptor 4 undergoes transportin 1-dependent nuclear localization and remains functional at the nucleus of metastatic prostate cancer cells. PLoS One 2013; 8:e57194. [PMID: 23468933 PMCID: PMC3585330 DOI: 10.1371/journal.pone.0057194] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 01/18/2013] [Indexed: 01/01/2023] Open
Abstract
The G-protein coupled receptor (GPCR), Cysteine (C)-X-C Receptor 4 (CXCR4), plays an important role in prostate cancer metastasis. CXCR4 is generally regarded as a plasma membrane receptor where it transmits signals that support transformation, progression and eventual metastasis. Due to the central role of CXCR4 in tumorigenesis, therapeutics approaches such as antagonist and monoclonal antibodies have focused on receptors that exist on the plasma membrane. An emerging concept for G-protein coupled receptors is that they may localize to and associate with the nucleus where they retain function and mediate nuclear signaling. Herein, we demonstrate that CXCR4 associated with the nucleus of malignant prostate cancer tissues. Likewise, expression of CXCR4 was detected in nuclear fractions among several prostate cancer cell lines, compared to normal prostate epithelial cells. Our studies identified a nuclear pool of CXCR4 and we defined a nuclear transport pathway for CXCR4. We reveal a putative nuclear localization sequence (NLS), ‘RPRK’, within CXCR4 that contributed to nuclear localization. Additionally, nuclear CXCR4 interacted with Transportinβ1 and Transportinβ1-binding to CXCR4 promoted its nuclear translocation. Importantly, Gαi immunoprecipitation and calcium mobilization studies indicated that nuclear CXCR4 was functional and participated in G-protein signaling, revealing that the nuclear pool of CXCR4 retained function. Given the suggestion that functional, nuclear CXCR4 may be a mechanism underlying prostate cancer recurrence, increased metastatic ability and poorer prognosis after tumors have been treated with therapy that targets plasma membrane CXCR4, these studies addresses a novel mechanism of nuclear signaling for CXCR4, a novel mechanism of clinical targeting, and demonstrate an active nuclear pool that provides important new information to illuminate what has been primarily clinical reports of nuclear CXCR4.
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Affiliation(s)
- Ayesha S. Don-Salu-Hewage
- Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, Georgia, United States of America
- Department of Biological Sciences, Clark Atlanta University, Atlanta, Georgia, United States of America
| | - Siu Yuen Chan
- Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, University of Hong Kong, Hong Kong, PRC
| | - Kathleen M. McAndrews
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Mahandranauth A. Chetram
- Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, Georgia, United States of America
- Department of Biological Sciences, Clark Atlanta University, Atlanta, Georgia, United States of America
| | - Michelle R. Dawson
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Danaya A. Bethea
- Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, Georgia, United States of America
| | - Cimona V. Hinton
- Center for Cancer Research and Therapeutic Development, Clark Atlanta University, Atlanta, Georgia, United States of America
- * E-mail:
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Alonso MT, Manjarrés IM, García-Sancho J. Privileged coupling between Ca(2+) entry through plasma membrane store-operated Ca(2+) channels and the endoplasmic reticulum Ca(2+) pump. Mol Cell Endocrinol 2012; 353:37-44. [PMID: 21878366 DOI: 10.1016/j.mce.2011.08.021] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Revised: 08/10/2011] [Accepted: 08/15/2011] [Indexed: 12/17/2022]
Abstract
The sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA) is the third element of capacitative calcium entry. It colocalizes with STIM1 and Orai1 at puncta, where couples plasma membrane store-operated Ca(2+) channels (SOC) to Ca(2+) pumping into the ER. The efficiency of this calcium entry-calcium refilling (CECR) coupling is comparable to the classic excitation-response transduction mechanisms. This allows efficient filling of the endoplasmic reticulum (ER) with the Ca(2+) entering through SOC channels with little progression of the Ca(2+) wave towards the cell core. CECR coupling is very sensitive to changes in stoichiometry among STIM, Orai and SERCA, with excess Orai antagonizing ER refilling. ER takes up most of the calcium load that enters through SOC, whereas mitochondria take up a very small fraction. This difference is due to the spatial positioning with regard to SOC, the amplitude of the high Ca(2+) microdomains, and the differences in the Ca(2+) affinity of the uptake mechanisms.
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Affiliation(s)
- María Teresa Alonso
- Instituto de Biología y Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas, c/ Sanz y Forés s/n, 47003 Valladolid, Spain
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Zampese E, Pizzo P. Intracellular organelles in the saga of Ca2+ homeostasis: different molecules for different purposes? Cell Mol Life Sci 2012; 69:1077-104. [PMID: 21968921 PMCID: PMC11114864 DOI: 10.1007/s00018-011-0845-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 09/15/2011] [Accepted: 09/19/2011] [Indexed: 11/28/2022]
Abstract
An increase in the concentration of cytosolic free Ca(2+) is a key component regulating different cellular processes ranging from egg fertilization, active secretion and movement, to cell differentiation and death. The multitude of phenomena modulated by Ca(2+), however, do not simply rely on increases/decreases in its concentration, but also on specific timing, shape and sub-cellular localization of its signals that, combined together, provide a huge versatility in Ca(2+) signaling. Intracellular organelles and their Ca(2+) handling machineries exert key roles in this complex and precise mechanism, and this review will try to depict a map of Ca(2+) routes inside cells, highlighting the uniqueness of the different Ca(2+) toolkit components and the complexity of the interactions between them.
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Affiliation(s)
- Enrico Zampese
- Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy
| | - Paola Pizzo
- Department of Biomedical Sciences, University of Padova, Viale G. Colombo 3, 35121 Padova, Italy
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30
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Cytosolic organelles shape calcium signals and exo–endocytotic responses of chromaffin cells. Cell Calcium 2012; 51:309-20. [DOI: 10.1016/j.ceca.2011.12.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 12/02/2011] [Accepted: 12/05/2011] [Indexed: 01/09/2023]
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Mitochondria and chromaffin cell function. Pflugers Arch 2012; 464:33-41. [PMID: 22278417 DOI: 10.1007/s00424-012-1074-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 01/05/2012] [Accepted: 01/09/2012] [Indexed: 10/14/2022]
Abstract
Chromaffin cells are an excellent model for stimulus-secretion coupling. Ca(2+) entry through plasma membrane voltage-operated Ca(2+) channels (VOCC) is the trigger for secretion, but the intracellular organelles contribute subtle nuances to the Ca(2+) signal. The endoplasmic reticulum amplifies the cytosolic Ca(2+) ([Ca(2+)](C)) signal by Ca(2+)-induced Ca(2+) release (CICR) and helps generation of microdomains with high [Ca(2+)](C) (HCMD) at the subplasmalemmal region. These HCMD induce exocytosis of the docked secretory vesicles. Mitochondria close to VOCC take up large amounts of Ca(2+) from HCMD and stop progression of the Ca(2+) wave towards the cell core. On the other hand, the increase of [Ca(2+)] at the mitochondrial matrix stimulates respiration and tunes energy production to the increased needs of the exocytic activity. At the end of stimulation, [Ca(2+)](C) decreases rapidly and mitochondria release the Ca(2+) accumulated in the matrix through the Na(+)/Ca(2+) exchanger. VOCC, CICR sites and nearby mitochondria form functional triads that co-localize at the subplasmalemmal area, where secretory vesicles wait ready for exocytosis. These triads optimize stimulus-secretion coupling while avoiding propagation of the Ca(2+) signal to the cell core. Perturbation of their functioning in neurons may contribute to the genesis of excitotoxicity, ageing mental retardation and/or neurodegenerative disorders.
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Sanmartin CD, Adasme T, Hidalgo C, Paula-Lima AC. The antioxidant N-acetylcysteine prevents the mitochondrial fragmentation induced by soluble amyloid-β peptide oligomers. NEURODEGENER DIS 2012; 10:34-7. [PMID: 22286146 DOI: 10.1159/000334901] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Soluble amyloid-β peptide oligomers (AβOs), which are centrally involved in the pathogenesis of Alzheimer's disease, trigger Ca(2+) influx through N-methyl-D-aspartate receptors and stimulate reactive oxygen species generation in primary hippocampal neurons. We have previously reported that AβOs promote Ca(2+) release mediated by ryanodine receptors (RyR), which in turn triggers mitochondrial fragmentation. We have also reported that the antioxidant N-acetylcysteine (NAC) prevents AβOs-induced Ca(2+) signal generation. OBJECTIVES To determine if RyR-mediated Ca(2+) release activated by the specific agonist 4-chloro-m-cresol (4-CMC) induces fragmentation of the mitochondrial network, and to ascertain if NAC prevents the mitochondrial fragmentation induced by AβOs and/or 4-CMC. METHODS Mature primary rat hippocampal neurons were incubated for 24 h with sublethal concentrations of AβOs (500 nM) or for 1-3 h with 4-CMC (0.5-1 mM), ± 10 mM NAC. Mitochondrial morphology was assessed by confocal microscopy of fixed neurons stained with anti-mHsp70. Intracellular Ca(2+) levels were determined by time series microscopy of neurons preloaded with Fluo-4 AM. RESULTS Preincubation of neurons for 30 min with NAC prevented the mitochondrial fragmentation induced by AβOs or 4-CMC. In addition, we confirmed that preincubation with NAC abolished the stimulation of RyR-mediated Ca(2+) release induced by AβOs or 4-CMC. CONCLUSION The present results strongly suggest that the general antioxidant NAC prevents AβO-induced mitochondrial fragmentation by preventing RyR-mediated Ca(2+)-induced Ca(2+) release.
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Affiliation(s)
- C D Sanmartin
- Center for Molecular Studies of the Cell, Faculty of Medicine, Universidad de Chile, Santiago, Chile
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Weiss JL. Ca(2+) signaling mechanisms in bovine adrenal chromaffin cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:859-72. [PMID: 22453973 DOI: 10.1007/978-94-007-2888-2_38] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Calcium (Ca(2+)) is a crucial intracellular messenger in physiological aspects of cell signaling. Adrenal chromaffin cells are the secretory cells from the adrenal gland medulla that secrete catecholamines, which include epinephrine and norepinephrine important in the 'fight or flight' response. Bovine adrenal chromaffin cells have long been used as an important model for secretion -(exocytosis) not only due to their importance in the short-term stress response, but also as a neuroendocrine model of neurotransmtter release, as they have all the same exocytotic proteins as neurons but are easier to prepare, culture and use in functional assays. The components of the Ca(2+) signal transduction cascade and it role in secretion has been extensively characterized in bovine adrenal chromaffin cells. The Ca(2+) sources, signaling molecules and how this relates to the short-term stress response are reviewed in this book chapter in an endeavor to generally -overview these mechanisms in a concise and uncomplicated manner.
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Affiliation(s)
- Jamie L Weiss
- Department of Biology, William Paterson University, 300 Pompton Road, Wayne, NJ 07470, USA.
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Ramadan JW, Steiner SR, O'Neill CM, Nunemaker CS. The central role of calcium in the effects of cytokines on beta-cell function: implications for type 1 and type 2 diabetes. Cell Calcium 2011; 50:481-90. [PMID: 21944825 DOI: 10.1016/j.ceca.2011.08.005] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 07/20/2011] [Accepted: 08/16/2011] [Indexed: 12/29/2022]
Abstract
The appropriate regulation of intracellular calcium is a requirement for proper cell function and survival. This review focuses on the effects of proinflammatory cytokines on calcium regulation in the insulin-producing pancreatic beta-cell and how normal stimulus-secretion coupling, organelle function, and overall beta-cell viability are impacted. Proinflammatory cytokines are increasingly thought to contribute to beta-cell dysfunction not only in type 1 diabetes (T1D), but also in the progression of type 2 diabetes (T2D). Cytokine-induced disruptions in calcium handling result in reduced insulin release in response to glucose stimulation. Cytokines can alter intracellular calcium levels by depleting calcium from the endoplasmic reticulum (ER) and by increasing calcium influx from the extracellular space. Depleting ER calcium leads to protein misfolding and activation of the ER stress response. Disrupting intracellular calcium may also affect organelles, including the mitochondria and the nucleus. As a chronic condition, cytokine-induced calcium disruptions may lead to beta-cell death in T1D and T2D, although possible protective effects are also discussed. Calcium is thus central to both normal and pathological cell processes. Because the tight regulation of intracellular calcium is crucial to homeostasis, measuring the dynamics of calcium may serve as a good indicator of overall beta-cell function.
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Affiliation(s)
- James W Ramadan
- Department of Medicine, University of Virginia, Charlottesville, United States
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Rosa JM, Torregrosa-Hetland CJ, Colmena I, Gutiérrez LM, García AG, Gandía L. Calcium entry through slow-inactivating L-type calcium channels preferentially triggers endocytosis rather than exocytosis in bovine chromaffin cells. Am J Physiol Cell Physiol 2011; 301:C86-98. [PMID: 21451100 DOI: 10.1152/ajpcell.00440.2010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Calcium (Ca(2+))-dependent endocytosis has been linked to preferential Ca(2+) entry through the L-type (α(1D), Ca(V)1.3) of voltage-dependent Ca(2+) channels (VDCCs). Considering that the Ca(2+)-dependent exocytotic release of neurotransmitters is mostly triggered by Ca(2+) entry through N-(α(1B), Ca(V)2.2) or PQ-VDCCs (α(1A), Ca(V)2.1) and that exocytosis and endocytosis are coupled, the supposition that the different channel subtypes are specialized to control different cell functions is attractive. Here we have explored this hypothesis in primary cultures of bovine adrenal chromaffin cells where PQ channels account for 50% of Ca(2+) current (I(Ca)), 30% for N channels, and 20% for L channels. We used patch-clamp and fluorescence techniques to measure the exo-endocytotic responses triggered by long depolarizing stimuli, in 1, 2, or 10 mM concentrations of extracellular Ca(2+) ([Ca(2+)](e)). Exo-endocytotic responses were little affected by ω-conotoxin GVIA (N channel blocker), whereas ω-agatoxin IVA (PQ channel blocker) caused 80% blockade of exocytosis as well as endocytosis. In contrast, nifedipine (L channel blocker) only caused 20% inhibition of exocytosis but as much as 90% inhibition of endocytosis. Conversely, FPL67146 (an activator of L VDCCs) notably augmented endocytosis. Photoreleased caged Ca(2+) caused substantially smaller endocytotic responses compared with those produced by K(+) depolarization. Using fluorescence antibodies, no colocalization between L, N, or PQ channels with clathrin was found; a 20-30% colocalization was found between dynamin and all three channel antibodies. This is incompatible with the view that L channels are coupled to the endocytotic machine. Data rather support a mechanism implying the different inactivation rates of L (slow-inactivating) and N/PQ channels (fast-inactivating). Thus a slow but more sustained Ca(2+) entry through L channels could be a requirement to trigger endocytosis efficiently, at least in bovine chromaffin cells.
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Affiliation(s)
- Juliana M Rosa
- Instituto Teófilo Hernando, IIS del Hospital Universitario de Princesa, Facultad de Medicina, Universidad Autónoma de Madrid, Madrid, Spain
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Calcium entry-calcium refilling (CECR) coupling between store-operated Ca(2+) entry and sarco/endoplasmic reticulum Ca(2+)-ATPase. Cell Calcium 2011; 49:153-61. [PMID: 21353305 DOI: 10.1016/j.ceca.2011.01.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 01/15/2011] [Accepted: 01/20/2011] [Indexed: 01/07/2023]
Abstract
Cross-talk between subcellular organelles is essential for cellular Ca(2+) homeostasis. We have studied the effects of knocking down STIM1, the Ca(2+) sensor of the endoplasmic reticulum (ER), on several homeostatic Ca(2+)-handling mechanisms, including plasma membrane Ca(2+) entry and transport by ER, mitochondria and nucleus. We have used targeted aequorins to selectively measure calcium fluxes in different organelles. Actions of STIM1 were extremely selective, restricted to store operated Ca(2+) channels (SOC) and Ca(2+) uptake by the ER. No interactions with uptake or release of Ca(2+) by mitochondria or nucleus were detected. Ca(2+) exit from the ER, including passive leak, release via inositol 1,4,5-trisphosphate and ryanodine receptors, was unaffected. STIM1 knock-down inhibited ER Ca(2+) uptake in intact but not in permeabilized cells, suggesting a privileged calcium entry-calcium refilling (CECR) coupling between plasma membrane SOC and ER calcium pump in the intact cell. As a result a large part of the entering Ca(2+) is taken up into the ER without reaching the bulk cytosol. The tightness of CECR, as measured by the slope of the stimulus-signal strength function, was comparable to classic excitation-response coupling mechanisms, such as excitation-contraction, excitation-secretion or excitation-transcription coupling.
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Alonso MT, García-Sancho J. Nuclear Ca(2+) signalling. Cell Calcium 2010; 49:280-9. [PMID: 21146212 DOI: 10.1016/j.ceca.2010.11.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Revised: 10/30/2010] [Accepted: 11/08/2010] [Indexed: 10/18/2022]
Abstract
Ca(2+) signalling is important for controlling gene transcription. Changes of the cytosolic Ca(2+) ([Ca(2+)](C)) may promote migration of transcription factors or transcriptional regulators to the nucleus. Changes of the nucleoplasmic Ca(2+) ([Ca(2+)](N)) can also regulate directly gene expression. [Ca(2+)](N) may change by propagation of [Ca(2+)](C) changes through the nuclear envelope or by direct release of Ca(2+) inside the nucleus. In the last case nuclear and cytosolic signalling can be dissociated. Phosphatidylinositol bisphosphate, phospholipase C and cyclic ADP-ribosyl cyclase are present inside the nucleus. Inositol trisphosphate receptors (IP(3)R) and ryanodine receptors (RyR) have also been found in the nucleus and can be activated by agonists. Furthermore, nuclear location of the synthesizing enzymes and receptors may be atypical, not associated to the nuclear envelope or other membranes. The possible role of nuclear subdomains such as speckles, nucleoplasmic reticulum, multi-macromolecular complexes and nuclear nanovesicles is discussed.
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Affiliation(s)
- Maria Teresa Alonso
- Instituto de Biología y Genética Molecular (IBGM), Universidad de Valladolid y Consejo Superior de Investigaciones Científicas (CSIC), c/Sanz y Forés 3, 47003 Valladolid, Spain
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He H, Kong SK, Chan KT. Identification of source of calcium in HeLa cells by femtosecond laser excitation. JOURNAL OF BIOMEDICAL OPTICS 2010; 15:057010. [PMID: 21054126 DOI: 10.1117/1.3485741] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Calcium is an important messenger in cells and whose store and diffusion dynamics at the subcellular level remain unclear. By inducing a controlled slow subcellular Ca2+ release through femtosecond laser irradiation in HeLa cells immersed in different media, cytoplasm is identified to be the major intracellular Ca2+ store, with the nucleus being the minor store and the extracellular Ca2+ also contributing to the total cellular Ca2+ level. Furthermore, Ca2+ released in either the cytoplasm or nucleus diffuses into the nucleus or cytoplasm, respectively, at different rates and influences the Ca2+ release in those regions.
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Affiliation(s)
- Hao He
- Chinese University of Hong Kong, Department of Electronic Engineering, Hong Kong
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40
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Matzke AJM, Weiger TM, Matzke M. Ion channels at the nucleus: electrophysiology meets the genome. MOLECULAR PLANT 2010; 3:642-52. [PMID: 20410254 PMCID: PMC2910552 DOI: 10.1093/mp/ssq013] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Accepted: 03/12/2010] [Indexed: 05/21/2023]
Abstract
The nuclear envelope is increasingly viewed from an electrophysiological perspective by researchers interested in signal transduction pathways that influence gene transcription and other processes in the nucleus. Here, we describe evidence for ion channels and transporters in the nuclear membranes and for possible ion gating by the nuclear pores. We argue that a systems-level understanding of cellular regulation is likely to require the assimilation of nuclear electrophysiology into molecular and biochemical signaling pathways.
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Affiliation(s)
- Antonius J M Matzke
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, A-1030 Vienna, Austria.
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41
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Abstract
The past two decades revealed a plethora of Ca2+-responsive proteins and downstream targets in plants, of which several are unique to plants. More recent high-throughput 'omics' approaches and bioinformatics are exposing Ca2+-responsive cis-elements and the corresponding Ca2+-responsive genes. Here, we review the current knowledge on Ca2+-signaling pathways that regulate gene expression in plants, and we link these to mechanisms by which plants respond to biotic and abiotic stresses.
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Affiliation(s)
- Yael Galon
- Department of Molecular Biology and Ecology of Plants, Faculty of Life Sciences, Tel-Aviv University 69978, Tel-Aviv, Israel
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42
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Manjarrés IM, Rodríguez-García A, Alonso MT, García-Sancho J. The sarco/endoplasmic reticulum Ca(2+) ATPase (SERCA) is the third element in capacitative calcium entry. Cell Calcium 2010; 47:412-8. [PMID: 20347143 DOI: 10.1016/j.ceca.2010.03.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2010] [Revised: 02/26/2010] [Accepted: 03/01/2010] [Indexed: 10/19/2022]
Abstract
STIM1 and Orai1 are the main players in capacitative calcium entry (CCE). STIM1 senses [Ca(2+)] inside the endoplasmic reticulum (ER) and, when it decreases, opens Orai1, a store-operated calcium channel (SOC) in the plasma membrane that promotes Ca(2+) entry and increases cytosolic Ca(2+). The final destination of the entering Ca(2+) is the ER, which refills very efficiently (capacitatively) with it. We propose here that SERCA is the third element of CCE, to which is tightly coupled to favour rapid Ca(2+) pumping from the high Ca(2+) microdomains, generated at the SOC's mouth, to the ER. We find that, on depletion of the intracellular Ca(2+) stores, SERCA co-localizes with STIM1 at puncta. Adequate coupling of CCE and ER Ca(2+) pumping requires correct proportions of STIM1, Orai1 and SERCA. Overexpression of Orai1 decreased modestly Ca(2+) entry, but produced a dramatic fall of Ca(2+) uptake into ER, which was rescued by STIM1 co-expression or by increasing external Ca(2+). In permeabilized cells, Ca(2+) uptake into the ER was indistinguishable in the Orai1-expressing and in the control cells. We propose that excess Orai1 uncouples SERCA from Ca(2+) entry in the intact cell by disturbing the fine topology of Ca(2+) pumping complexes within the ER-plasma membrane junctions.
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Affiliation(s)
- Isabel M Manjarrés
- Instituto de Biología y Genética Molecular, Universidad de Valladolid y Consejo Superior de Investigaciones Científicas, Spain
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43
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Presynaptic mitochondria in functionally different motor neurons exhibit similar affinities for Ca2+ but exert little influence as Ca2+ buffers at nerve firing rates in situ. J Neurosci 2010; 30:1869-81. [PMID: 20130196 DOI: 10.1523/jneurosci.4701-09.2010] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Mitochondria accumulate within nerve terminals and support synaptic function, most notably through ATP production. They can also sequester Ca(2+) during nerve stimulation, but it is unknown whether this limits presynaptic Ca(2+) levels at physiological nerve firing rates. Similarly, it is unclear whether mitochondrial Ca(2+) sequestration differs between functionally different nerve terminals. We addressed these questions using a combination of synthetic and genetically encoded Ca(2+) indicators to examine cytosolic and mitochondrial Ca(2+) levels in presynaptic terminals of tonic (MN13-Ib) and phasic (MNSNb/d-Is) motor neurons in Drosophila, which, as we determined, fire during fictive locomotion at approximately 42 Hz and approximately 8 Hz, respectively. Mitochondrial Ca(2+) sequestration starts in both terminals at approximately 250 nM, exhibits a similar Ca(2+)-uptake affinity (approximately 410 nM), and does not require Ca(2+) release from the endoplasmic reticulum. Nonetheless, mitochondrial Ca(2+) uptake in type Is terminals is more responsive to low-frequency nerve stimulation and this is due to higher cytosolic Ca(2+) levels. Since type Ib terminals have a higher mitochondrial density than Is terminals, it seemed possible that greater mitochondrial Ca(2+) sequestration may be responsible for the lower cytosolic Ca(2+) levels in Ib terminals. However, genetic and pharmacological manipulations of mitochondrial Ca(2+) uptake did not significantly alter nerve-stimulated elevations in cytosolic Ca(2+) levels in either terminal type within physiologically relevant rates of stimulation. Our findings indicate that presynaptic mitochondria have a similar affinity for Ca(2+) in functionally different nerve terminals, but do not limit cytosolic Ca(2+) levels within the range of motor neuron firing rates in situ.
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44
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Jong YJI, Kumar V, O'Malley KL. Intracellular metabotropic glutamate receptor 5 (mGluR5) activates signaling cascades distinct from cell surface counterparts. J Biol Chem 2010; 284:35827-38. [PMID: 19840937 DOI: 10.1074/jbc.m109.046276] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
G-protein-coupled receptors are thought to transmit extracellular signals to the cytoplasm from their position on the cell surface. Some receptors, including the metabotropic glutamate receptor 5 (mGluR5), are also highly expressed on intracellular membranes where they serve unknown functions. Here, we show that activation of cell surface versus intracellular mGluR5 results in unique Ca(2+) signatures leading to unique cellular responses. Specifically, activation of either cell surface or intracellular mGluR5 leads to JNK, Ca(2+)/calmodulin-dependent protein kinase (CaMK), and cyclic adenosine 3',5'-monophosphate-responsive element-binding protein phosphorylation, whereas activation of only intracellular mGluR5 leads to ERK1/2 and Elk-1 phosphorylation. Using pharmacological and genetic approaches, the present findings support a role for CaMK kinase in mediating mGluR5-dependent cyclic adenosine 3',5'-monophosphate-responsive element-binding protein phosphorylation, whereas CaMKII is upstream of intracellular mGluR5-mediated Elk-1 phosphorylation. Consistent with models showing Elk-1 regulating cascades of gene expression, the known Elk-1 targets c-fos and egr1 were up-regulated following intracellular mGluR5 activation, whereas a representative non-Elk-1 target, c-jun, was not. These findings emphasize that glutamate not only serves as a neurotransmitter for cell surface receptors but, when transported into the cell, can also activate intracellular receptors such as mGluR5. Glutamate activation of intracellular mGluR5 serves an important role in the regulation of nuclear Ca(2+), transcriptional activation, and gene expression necessary for physiological processes such as synaptic plasticity.
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Affiliation(s)
- Yuh-Jiin I Jong
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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45
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Bereiter-Hahn J, Jendrach M. Mitochondrial dynamics. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2010; 284:1-65. [PMID: 20875628 DOI: 10.1016/s1937-6448(10)84001-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mitochondrial dynamics is a key feature for the interaction of mitochondria with other organelles within a cell and also for the maintenance of their own integrity. Four types of mitochondrial dynamics are discussed: Movement within a cell and interactions with the cytoskeleton, fusion and fission events which establish coherence within the chondriome, the dynamic behavior of cristae and their components, and finally, formation and disintegration of mitochondria (mitophagy). Due to these essential functions, disturbed mitochondrial dynamics are inevitably connected to a variety of diseases. Localized ATP gradients, local control of calcium-based messaging, production of reactive oxygen species, and involvement of other metabolic chains, that is, lipid and steroid synthesis, underline that physiology not only results from biochemical reactions but, in addition, resides on the appropriate morphology and topography. These events and their molecular basis have been established recently and are the topic of this review.
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Affiliation(s)
- Jürgen Bereiter-Hahn
- Center of Excellence Macromolecular Complexes, Institute for Cell Biology and Neurosciences, Goethe University, Frankfurt am Main, Germany
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46
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Tracqui P, Ohayon J. An integrated formulation of anisotropic force-calcium relations driving spatio-temporal contractions of cardiac myocytes. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2009; 367:4887-4905. [PMID: 19884185 DOI: 10.1098/rsta.2009.0149] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Isolated cardiac myocytes exhibit spontaneous patterns of rhythmic contraction, driven by intracellular calcium waves. In order to study the coupling between spatio-temporal calcium dynamics and cell contraction in large deformation regimes, a new strain-energy function, describing the influence of sarcomere length on the calcium-dependent generation of active intracellular stresses, is proposed. This strain-energy function includes anisotropic passive and active contributions that were first validated separately from experimental stress-strain curves and stress-sarcomere length curves, respectively. An extended validation of this formulation was then conducted by considering this strain-energy function as the core of an integrated mechano-chemical three-dimensional model of cardiac myocyte contraction, where autocatalytic intracellular calcium dynamics were described by a representative two-variable model able to generate realistic intracellular calcium waves similar to those observed experimentally. Finite-element simulations of the three-dimensional cell model, conducted for different intracellular locations of triggering calcium sparks, explained very satisfactorily, both qualitatively and quantitatively, the contraction patterns of cardiac myocytes observed by time-lapse videomicroscopy. This integrative approach of the mechano-chemical couplings driving cardiac myocyte contraction provides a comprehensive framework for analysing active stress regulation and associated mechano-transduction processes that contribute to the efficiency of cardiac cell contractility in both physiological and pathological contexts.
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Affiliation(s)
- Philippe Tracqui
- Laboratoire Techniques de l'Ingéniere Médicale et da Complexité - Informatique, Mathématiques et Applications de Grenoble, Equipe DynaCell, Unité Mixte de Recherche, Centre National de Recherche Scientifique 5525, Institut d'Ingénierie et de l'Information de Santé (In3S), Université Joseph Fourier, Faculté de Médecine de Grenoble, 38706 La Tronche Cedex, France.
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47
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Matzke M, Weiger TM, Papp I, Matzke AJM. Nuclear membrane ion channels mediate root nodule development. TRENDS IN PLANT SCIENCE 2009; 14:295-298. [PMID: 19447668 DOI: 10.1016/j.tplants.2009.03.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Revised: 03/25/2009] [Accepted: 03/26/2009] [Indexed: 05/27/2023]
Abstract
Previous work has implicated two predicted ion channels in mediating perinuclear calcium spiking, which is essential for rhizobia-induced root nodule formation in legumes. A new study demonstrates that these ion channels are preferentially permeable to cations, such as potassium, and are located in the nuclear envelope. Here, we consider ways in which the ion channels influence perinuclear calcium spiking and discuss a potentially broader role for nuclear membrane ion channels in signal transduction in plants.
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Affiliation(s)
- Marjori Matzke
- Gregor Mendel Institute for Molecular Plant Biology, Austrian Academy of Sciences, Dr. Bohr-Gasse 3, A-1030 Vienna, Austria.
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48
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Korzeniowski MK, Szanda G, Balla T, Spät A. Store-operated Ca2+ influx and subplasmalemmal mitochondria. Cell Calcium 2009; 46:49-55. [PMID: 19427033 DOI: 10.1016/j.ceca.2009.04.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Revised: 04/02/2009] [Accepted: 04/06/2009] [Indexed: 12/11/2022]
Abstract
Calcium depletion of the endoplasmic reticulum (ER) induces oligomerisation, puncta formation and translocation of the ER Ca(2+) sensor proteins, STIM1 and -2 into plasma membrane (PM)-adjacent regions of the ER, where they activate the Orai1, -2 or -3 proteins present in the opposing PM. These proteins form ion channels through which store-operated Ca(2+) influx (SOC) occurs. Calcium ions exert negative feed-back on SOC. Here we examined whether subplasmalemmal mitochondria, which reduce this feed-back by Ca(2+) uptake, are located within or out of the high-Ca(2+) microdomains (HCMDs) formed between the ER and plasmalemmal Orai1 channels. For this purpose, COS-7 cells were cotransfected with Orai1, STIM1 labelled with YFP or mRFP and the mitochondrially targeted Ca(2+) sensitive fluorescent protein inverse-Pericam. Depletion of ER Ca(2+) with ATP+thapsigargin (in Ca(2+)-free medium) induced the appearance of STIM1 puncta in the < or =100 nm wide subplasmalemmal space, as examined with TIRF. Mitochondria were located either in the gaps between STIM1-tagged puncta or in remote, STIM1-free regions. After addition of Ca(2+) mitochondrial Ca(2+) concentration increased irrespective of the mitochondrion-STIM1 distance. These observations indicate that mitochondria are exposed to Ca(2+) diffused laterally from the HCMDs formed between the PM and the subplasmalemmal ER.
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Affiliation(s)
- Marek K Korzeniowski
- Section on Molecular Signal Transduction, Program on Developmental Neuroscience, NICHD, NIH, Bethesda, MD, USA
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49
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Rosa JM, Gandía L, García AG. Inhibition of N and PQ calcium channels by calcium entry through L channels in chromaffin cells. Pflugers Arch 2009; 458:795-807. [PMID: 19347353 DOI: 10.1007/s00424-009-0662-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Revised: 02/09/2009] [Accepted: 03/01/2009] [Indexed: 11/24/2022]
Abstract
Why adrenal chromaffin cells express various subtypes of voltage-dependent Ca(2+) channels and whether a given channel is specialized to perform a specific function are puzzling and unanswered questions. In this study, we have used the L Ca(2+) channel activator FPL64176 (FPL) to test the hypothesis that enhanced Ca(2+) entry through this channel favors the inhibition of N and PQ channels in voltage-clamped bovine adrenal chromaffin cells. Using 2 mM Ca(2+) as charge carrier and under the perforated-patch configuration (PPC) of the patch-clamp technique, FPL caused a paradoxical inhibition of the whole-cell inward Ca(2+) current (I (Ca)). Such inhibition turned on into an augmentation upon cell loading with EGTA-AM. Also, under the whole-cell configuration (WCC) of the patch-clamp technique, FPL decreased I (Ca) in the absence of EGTA from the pipette solution and increased the current in its presence. Using 2 mM Ba(2+) as charge carrier, FPL augmented the Ba(2+) current under both recording conditions, WCC and PPC. FPL augmented the residual current remaining after blockade of N and PQ channels with omega-conotoxin MVIIC or by holding the membrane potential at -50 mV. The data support the view that Ca(2+) entering the cell through the lesser inactivating L channels serves to modulate the more inactivating N and PQ channels. They also suggest a close colocalization of L and N/PQ Ca(2+) channels. This kind of L channel specialization may be relevant to cell excitability, exocytosis, and cell survival mechanisms.
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Affiliation(s)
- Juliana M Rosa
- Instituto Teófilo Hernando, Facultad de Medicina, Universidad Autónoma de Madrid, Arzobispo Morcillo, 4. 28029, Madrid, Spain
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50
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Botelho HM, Koch M, Fritz G, Gomes CM. Metal ions modulate the folding and stability of the tumor suppressor protein S100A2. FEBS J 2009; 276:1776-86. [PMID: 19267779 DOI: 10.1111/j.1742-4658.2009.06912.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The EF-hand protein S100A2 is a cell cycle regulator involved in tumorigenesis, acting through regulation of the p53 activation state. Metal ion-free S100A2 is homodimeric and contains two Ca(2+)-binding sites and two Zn(2+)-binding sites per subunit, whereby the Zn(2+) ion binding to one of the sites is coordinated by residues from two homodimers. The effect of selective binding of these metal ions was investigated using site-specific mutants which lacked one or both zinc sites. CD analysis of secondary structure changes on metallation showed that Zn(2+) binding was associated with a decrease in the secondary structure content, whereas Ca(2+) had the opposite effect in two of the three S100A2 mutants studied. The energy of unfolding (DeltaG(U)) of the apo wild-type S100A2 was determined to be 89.9 kJ mol(-1), and the apparent midpoint transition temperature (T(m)(app))) was 58.4 degrees C. In addition, a detailed study of the urea and thermal unfolding of the S100A2 mutants in different metallation states (apo, Zn(2+) and Ca(2+)) was performed. Thermal denaturation experiments showed that Zn(2+) acts as a destabilizer and Ca(2+) as a stabilizer of the protein conformation. This suggests a synergistic effect between metal binding, protein stability and S100A2 biological activity, according to which Ca(2+) activates and stabilizes the protein, the opposite being observed on Zn(2+) binding.
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Affiliation(s)
- Hugo M Botelho
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Portugal
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