151
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Garbincius JF, Luongo TS, Elrod JW. The debate continues - What is the role of MCU and mitochondrial calcium uptake in the heart? J Mol Cell Cardiol 2020; 143:163-174. [PMID: 32353353 DOI: 10.1016/j.yjmcc.2020.04.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/15/2020] [Accepted: 04/24/2020] [Indexed: 12/12/2022]
Abstract
Since the identification of the mitochondrial calcium uniporter (MCU) in 2011, several studies utilizing genetic models have attempted to decipher the role of mitochondrial calcium uptake in cardiac physiology. Confounding results in various mutant mouse models have led to an ongoing debate regarding the function of MCU in the heart. In this review, we evaluate and discuss the totality of evidence for mitochondrial calcium uptake in the cardiac stress response and highlight recent reports that implicate MCU in the control of homeostatic cardiac metabolism and function. This review concludes with a discussion of current gaps in knowledge and remaining experiments to define how MCU contributes to contractile function, cell death, metabolic regulation, and heart failure progression.
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Affiliation(s)
- Joanne F Garbincius
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.
| | - Timothy S Luongo
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.
| | - John W Elrod
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA 19140, USA.
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152
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Payne R, Li C, Foskett JK. Variable Assembly of EMRE and MCU Creates Functional Channels with Distinct Gatekeeping Profiles. iScience 2020; 23:101037. [PMID: 32315830 PMCID: PMC7170992 DOI: 10.1016/j.isci.2020.101037] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 02/24/2020] [Accepted: 04/01/2020] [Indexed: 10/29/2022] Open
Abstract
MCU is a Ca2+-selective channel that mediates mitochondrial Ca2+ influx. The human channel contains tetrameric pore-forming MCU, regulatory subunits MICU1/2, and EMRE that is required both for channel function and MICU1/2-mediated Ca2+ regulation. A structure of MCU with EMRE revealed a 4:4 stoichiometry, but the stoichiometry in vivo is unknown. Expression of tagged EMRE and MCU at a 1:10 ratio in cells lacking EMRE and MCU restored channel activity but not full channel gatekeeping. Increasing EMRE expression enhanced gatekeeping, raising the cytoplasmic Ca2+ concentration ([Ca2+]c) threshold for channel activation. MCU-EMRE concatemers creating channels with 1EMRE:4MCU restored Ca2+ uptake in cells, whereas cells expressing concatemers that enforced a 4EMRE:4MCU stoichiometry demonstrated enhanced channel gatekeeping. Concatemers enforcing 2EMRE/4MCU recapitulated the activity, gatekeeping, and size of endogenous channels. Thus, MCU does not require four EMRE, with most endogenous channels containing two, but complexes with 1-4 EMRE have activity with full or partial gatekeeping.
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Affiliation(s)
- Riley Payne
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Carmen Li
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - J Kevin Foskett
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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153
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Ponnalagu D, Singh H. Insights Into the Role of Mitochondrial Ion Channels in Inflammatory Response. Front Physiol 2020; 11:258. [PMID: 32327997 PMCID: PMC7160495 DOI: 10.3389/fphys.2020.00258] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 03/05/2020] [Indexed: 12/14/2022] Open
Abstract
Mitochondria are the source of many pro-inflammatory signals that cause the activation of the immune system and generate inflammatory responses. They are also potential targets of pro-inflammatory mediators, thus triggering a severe inflammatory response cycle. As mitochondria are a central hub for immune system activation, their dysfunction leads to many inflammatory disorders. Thus, strategies aiming at regulating mitochondrial dysfunction can be utilized as a therapeutic tool to cure inflammatory disorders. Two key factors that determine the structural and functional integrity of mitochondria are mitochondrial ion channels and transporters. They are not only important for maintaining the ionic homeostasis of the cell, but also play a role in regulating reactive oxygen species generation, ATP production, calcium homeostasis and apoptosis, which are common pro-inflammatory signals. The significance of the mitochondrial ion channels in inflammatory response is still not clearly understood and will need further investigation. In this article, we review the different mechanisms by which mitochondria can generate the inflammatory response as well as highlight how mitochondrial ion channels modulate these mechanisms and impact the inflammatory processes.
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Affiliation(s)
- Devasena Ponnalagu
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Wexner Medical Center, Columbus, OH, United States
| | - Harpreet Singh
- Department of Physiology and Cell Biology, Davis Heart and Lung Research Institute, The Ohio State University, Wexner Medical Center, Columbus, OH, United States
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154
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De Marchi U, Fernandez-Martinez S, de la Fuente S, Wiederkehr A, Santo-Domingo J. Mitochondrial ion channels in pancreatic β-cells: Novel pharmacological targets for the treatment of Type 2 diabetes. Br J Pharmacol 2020; 178:2077-2095. [PMID: 32056196 PMCID: PMC8246559 DOI: 10.1111/bph.15018] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/29/2020] [Accepted: 01/31/2020] [Indexed: 12/18/2022] Open
Abstract
Pancreatic beta‐cells are central regulators of glucose homeostasis. By tightly coupling nutrient sensing and granule exocytosis, beta‐cells adjust the secretion of insulin to the circulating blood glucose levels. Failure of beta‐cells to augment insulin secretion in insulin‐resistant individuals leads progressively to impaired glucose tolerance, Type 2 diabetes, and diabetes‐related diseases. Mitochondria play a crucial role in β‐cells during nutrient stimulation, linking the metabolism of glucose and other secretagogues to the generation of signals that promote insulin secretion. Mitochondria are double‐membrane organelles containing numerous channels allowing the transport of ions across both membranes. These channels regulate mitochondrial energy production, signalling, and cell death. The mitochondria of β‐cells express ion channels whose physio/pathological role is underappreciated. Here, we describe the mitochondrial ion channels identified in pancreatic β‐cells, we further discuss the possibility of targeting specific β‐cell mitochondrial channels for the treatment of Type 2 diabetes, and we finally highlight the evidence from clinical studies. LINKED ARTICLES This article is part of a themed issue on Cellular metabolism and diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.10/issuetoc
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Affiliation(s)
| | - Silvia Fernandez-Martinez
- Division of Clinical Pharmacology and Toxicology, Centre de Recherche Clinique, HUG, Genève, Switzerland
| | - Sergio de la Fuente
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania
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155
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Xing Y, Wang M, Wang J, Nie Z, Wu G, Yang X, Shen Y. Dimerization of MICU Proteins Controls Ca 2+ Influx through the Mitochondrial Ca 2+ Uniporter. Cell Rep 2020; 26:1203-1212.e4. [PMID: 30699349 DOI: 10.1016/j.celrep.2019.01.022] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 12/12/2018] [Accepted: 01/04/2019] [Indexed: 10/27/2022] Open
Abstract
The mitochondrial Ca2+ uniporter complex (MCUC) is responsible for Ca2+ influx into the mitochondrial matrix, playing critical roles in various mitochondrial functions. Eukaryotic MCUC consists of multiple subunits, and its Ca2+ influx activity is controlled by regulatory subunits, including mitochondrial Ca2+ uptake 1 (MICU1) and its paralogs (MICU2 and MICU3). However, the underlying mechanism remains unclear. Here, we determined multiple crystal structures of MICU2 and MICU3 from Homo sapiens. Our data demonstrate that distinct MICU protein N-domains determine the specific type of MICU dimers that perform the opposing roles in mitochondrial Ca2+ uptake at low cytosolic Ca2+ levels. In contrast, at high cytosolic Ca2+ levels, all MICU proteins undergo dimer rearrangement induced by Ca2+ binding, which releases the suppression of the MCUC pore-forming subunit and promotes the influx of large amounts of Ca2+. Altogether, our results elucidate the delicate mechanism of mitochondrial Ca2+ uptake regulation by MICU proteins.
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Affiliation(s)
- Yangfei Xing
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China
| | - Mingfei Wang
- State Key Laboratory of Medicinal Chemical Biology and College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China
| | - Jia Wang
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China
| | - Zhenzhen Nie
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China
| | - Guangyan Wu
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China
| | - Xue Yang
- State Key Laboratory of Medicinal Chemical Biology and College of Pharmacy, Nankai University, 38 Tongyan Road, Tianjin 300350, China.
| | - Yuequan Shen
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, 94 Weijin Road, Tianjin 300071, China; Synergetic Innovation Center of Chemical Science and Engineering, 94 Weijin Road, Tianjin 300071, China.
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156
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Park J, Lee Y, Park T, Kang JY, Mun SA, Jin M, Yang J, Eom SH. Structure of the MICU1-MICU2 heterodimer provides insights into the gatekeeping threshold shift. IUCRJ 2020; 7:355-365. [PMID: 32148862 PMCID: PMC7055370 DOI: 10.1107/s2052252520001840] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/10/2020] [Indexed: 06/10/2023]
Abstract
Mitochondrial calcium uptake proteins 1 and 2 (MICU1 and MICU2) mediate mitochondrial Ca2+ influx via the mitochondrial calcium uniporter (MCU). Its molecular action for Ca2+ uptake is tightly controlled by the MICU1-MICU2 heterodimer, which comprises Ca2+ sensing proteins which act as gatekeepers at low [Ca2+] or facilitators at high [Ca2+]. However, the mechanism underlying the regulation of the Ca2+ gatekeeping threshold for mitochondrial Ca2+ uptake through the MCU by the MICU1-MICU2 heterodimer remains unclear. In this study, we determined the crystal structure of the apo form of the human MICU1-MICU2 heterodimer that functions as the MCU gatekeeper. MICU1 and MICU2 assemble in the face-to-face heterodimer with salt bridges and me-thio-nine knobs stabilizing the heterodimer in an apo state. Structural analysis suggests how the heterodimer sets a higher Ca2+ threshold than the MICU1 homodimer. The structure of the heterodimer in the apo state provides a framework for understanding the gatekeeping role of the MICU1-MICU2 heterodimer.
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Affiliation(s)
- Jongseo Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
| | - Youngjin Lee
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Infection and Immunity Research Laboratory, Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Republic of Korea
| | - Taein Park
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Department of Chemistry, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
| | - Jung Youn Kang
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
| | - Sang A Mun
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
| | - Minwoo Jin
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
| | - Jihyeong Yang
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
| | - Soo Hyun Eom
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
- Department of Chemistry, Gwangju Institute of Science and Technology (GIST), Buk-gu, Gwangju 61005, Republic of Korea
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157
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Liu JC, Syder NC, Ghorashi NS, Willingham TB, Parks RJ, Sun J, Fergusson MM, Liu J, Holmström KM, Menazza S, Springer DA, Liu C, Glancy B, Finkel T, Murphy E. EMRE is essential for mitochondrial calcium uniporter activity in a mouse model. JCI Insight 2020; 5:134063. [PMID: 32017711 PMCID: PMC7101141 DOI: 10.1172/jci.insight.134063] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 01/29/2020] [Indexed: 11/17/2022] Open
Abstract
The mitochondrial calcium uniporter is widely accepted as the primary route of rapid calcium entry into mitochondria, where increases in matrix calcium contribute to bioenergetics but also mitochondrial permeability and cell death. Hence, regulation of uniporter activity is critical to mitochondrial homeostasis. The uniporter subunit EMRE is known to be an essential regulator of the channel-forming protein MCU in cell culture, but EMRE's impact on organismal physiology is less understood. Here we characterize a mouse model of EMRE deletion and show that EMRE is indeed required for mitochondrial calcium uniporter function in vivo. EMRE-/- mice are born less frequently; however, the mice that are born are viable, healthy, and do not manifest overt metabolic impairment, at rest or with exercise. Finally, to investigate the role of EMRE in disease processes, we examine the effects of EMRE deletion in a muscular dystrophy model associated with mitochondrial calcium overload.
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Affiliation(s)
- Julia C. Liu
- Cardiovascular Branch and
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA
- Postdoctoral Research Associate Program, National Institute of General Medical Sciences, NIH, Bethesda, Maryland, USA
| | | | | | - Thomas B. Willingham
- Systems Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA
| | | | | | - Maria M. Fergusson
- Cardiovascular Branch and
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA
| | - Jie Liu
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA
- Aging Institute, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Kira M. Holmström
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA
| | | | | | - Chengyu Liu
- Transgenic Core, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA
| | - Brian Glancy
- Systems Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, Maryland, USA
| | - Toren Finkel
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA
- Aging Institute, University of Pittsburgh and University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
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158
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Mitochondrial Calcium Regulation of Redox Signaling in Cancer. Cells 2020; 9:cells9020432. [PMID: 32059571 PMCID: PMC7072435 DOI: 10.3390/cells9020432] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 02/05/2020] [Accepted: 02/10/2020] [Indexed: 02/07/2023] Open
Abstract
Calcium (Ca2+) uptake into the mitochondria shapes cellular Ca2+ signals and acts as a key effector for ATP generation. In addition, mitochondria-derived reactive oxygen species (mROS), produced as a consequence of ATP synthesis at the electron transport chain (ETC), modulate cellular signaling pathways that contribute to many cellular processes. Cancer cells modulate mitochondrial Ca2+ ([Ca2+]m) homeostasis by altering the expression and function of mitochondrial Ca2+ channels and transporters required for the uptake and extrusion of mitochondrial Ca2+. Regulated elevations in [Ca2+]m are required for the activity of several mitochondrial enzymes, and this in turn regulates metabolic flux, mitochondrial ETC function and mROS generation. Alterations in both [Ca2+]m and mROS are hallmarks of many tumors, and elevated mROS is a known driver of pro-tumorigenic redox signaling, resulting in the activation of pathways implicated in cellular proliferation, metabolic alterations and stress-adaptations. In this review, we highlight recent studies that demonstrate the interplay between [Ca2+]m and mROS signaling in cancer.
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159
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Gökerküçük EB, Tramier M, Bertolin G. Imaging Mitochondrial Functions: from Fluorescent Dyes to Genetically-Encoded Sensors. Genes (Basel) 2020; 11:E125. [PMID: 31979408 PMCID: PMC7073610 DOI: 10.3390/genes11020125] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 12/18/2022] Open
Abstract
Mitochondria are multifunctional organelles that are crucial to cell homeostasis. They constitute the major site of energy production for the cell, they are key players in signalling pathways using secondary messengers such as calcium, and they are involved in cell death and redox balance paradigms. Mitochondria quickly adapt their dynamics and biogenesis rates to meet the varying energy demands of the cells, both in normal and in pathological conditions. Therefore, understanding simultaneous changes in mitochondrial functions is crucial in developing mitochondria-based therapy options for complex pathological conditions such as cancer, neurological disorders, and metabolic syndromes. To this end, fluorescence microscopy coupled to live imaging represents a promising strategy to track these changes in real time. In this review, we will first describe the commonly available tools to follow three key mitochondrial functions using fluorescence microscopy: Calcium signalling, mitochondrial dynamics, and mitophagy. Then, we will focus on how the development of genetically-encoded fluorescent sensors became a milestone for the understanding of these mitochondrial functions. In particular, we will show how these tools allowed researchers to address several biochemical activities in living cells, and with high spatiotemporal resolution. With the ultimate goal of tracking multiple mitochondrial functions simultaneously, we will conclude by presenting future perspectives for the development of novel genetically-encoded fluorescent biosensors.
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Affiliation(s)
| | | | - Giulia Bertolin
- Univ Rennes, CNRS, IGDR [Institut de génétique et développement de Rennes] UMR 6290, F-35000 Rennes, France
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160
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161
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Vallese F, Barazzuol L, Maso L, Brini M, Calì T. ER-Mitochondria Calcium Transfer, Organelle Contacts and Neurodegenerative Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:719-746. [PMID: 31646532 DOI: 10.1007/978-3-030-12457-1_29] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
It is generally accepted that interorganellar contacts are central to the control of cellular physiology. Virtually, any intracellular organelle can come into proximity with each other and, by establishing physical protein-mediated contacts within a selected fraction of the membrane surface, novel specific functions are acquired. Endoplasmic reticulum (ER) contacts with mitochondria are among the best studied and have a major role in Ca2+ and lipid transfer, signaling, and membrane dynamics.Their functional (and structural) diversity, their dynamic nature as well as the growing number of new players involved in the tethering concurred to make their monitoring difficult especially in living cells. This review focuses on the most established examples of tethers/modulators of the ER-mitochondria interface and on the roles of these contacts in health and disease by specifically dissecting how Ca2+ transfer occurs and how mishandling eventually leads to disease. Additional functions of the ER-mitochondria interface and an overview of the currently available methods to measure/quantify the ER-mitochondria interface will also be discussed.
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Affiliation(s)
- Francesca Vallese
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Lucia Barazzuol
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Lorenzo Maso
- Department of Biology, University of Padua, Padua, Italy
| | - Marisa Brini
- Department of Biology, University of Padua, Padua, Italy.
| | - Tito Calì
- Department of Biomedical Sciences, University of Padua, Padua, Italy. .,Padua Neuroscience Center (PNC), Padua, Italy.
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162
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Ashrafi G, de Juan-Sanz J, Farrell RJ, Ryan TA. Molecular Tuning of the Axonal Mitochondrial Ca 2+ Uniporter Ensures Metabolic Flexibility of Neurotransmission. Neuron 2019; 105:678-687.e5. [PMID: 31862210 DOI: 10.1016/j.neuron.2019.11.020] [Citation(s) in RCA: 126] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/16/2019] [Accepted: 11/12/2019] [Indexed: 01/08/2023]
Abstract
The brain is a vulnerable metabolic organ and must adapt to different fuel conditions to sustain function. Nerve terminals are a locus of this vulnerability, but how they regulate ATP synthesis as fuel conditions vary is unknown. We show that synapses can switch from glycolytic to oxidative metabolism, but to do so, they rely on activity-driven presynaptic mitochondrial Ca2+ uptake to accelerate ATP production. We demonstrate that, whereas mitochondrial Ca2+ uptake requires elevated extramitochondrial Ca2+ in non-neuronal cells, axonal mitochondria readily take up Ca2+ in response to small changes in external Ca2+. We identified the brain-specific protein MICU3 as a critical driver of this tuning of Ca2+ sensitivity. Ablation of MICU3 renders axonal mitochondria similar to non-neuronal mitochondria, prevents acceleration of local ATP synthesis, and impairs presynaptic function under oxidative conditions. Thus, presynaptic mitochondria rely on MICU3 to facilitate mitochondrial Ca2+ uptake during activity and achieve metabolic flexibility.
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Affiliation(s)
- Ghazaleh Ashrafi
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
| | - Jaime de Juan-Sanz
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
| | - Ryan J Farrell
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA; David Rockefeller Graduate Program, Rockefeller University, New York, NY 10065, USA
| | - Timothy A Ryan
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA.
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163
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Boczek T, Radzik T, Ferenc B, Zylinska L. The Puzzling Role of Neuron-Specific PMCA Isoforms in the Aging Process. Int J Mol Sci 2019; 20:ijms20246338. [PMID: 31888192 PMCID: PMC6941135 DOI: 10.3390/ijms20246338] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 12/10/2019] [Accepted: 12/13/2019] [Indexed: 01/02/2023] Open
Abstract
The aging process is a physiological phenomenon associated with progressive changes in metabolism, genes expression, and cellular resistance to stress. In neurons, one of the hallmarks of senescence is a disturbance of calcium homeostasis that may have far-reaching detrimental consequences on neuronal physiology and function. Among several proteins involved in calcium handling, plasma membrane Ca2+-ATPase (PMCA) is the most sensitive calcium detector controlling calcium homeostasis. PMCA exists in four main isoforms and PMCA2 and PMCA3 are highly expressed in the brain. The overall effects of impaired calcium extrusion due to age-dependent decline of PMCA function seem to accumulate with age, increasing the susceptibility to neurotoxic insults. To analyze the PMCA role in neuronal cells, we have developed stable transfected differentiated PC12 lines with down-regulated PMCA2 or PMCA3 isoforms to mimic age-related changes. The resting Ca2+ increased in both PMCA-deficient lines affecting the expression of several Ca2+-associated proteins, i.e., sarco/endoplasmic Ca2+-ATPase (SERCA), calmodulin, calcineurin, GAP43, CCR5, IP3Rs, and certain types of voltage-gated Ca2+ channels (VGCCs). Functional studies also demonstrated profound changes in intracellular pH regulation and mitochondrial metabolism. Moreover, modification of PMCAs membrane composition triggered some adaptive processes to counterbalance calcium overload, but the reduction of PMCA2 appeared to be more detrimental to the cells than PMCA3.
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Affiliation(s)
- Tomasz Boczek
- Department of Molecular Neurochemistry, Medical University, 92-215 Lodz, Poland; (T.B.); (T.R.); (B.F.)
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Tomasz Radzik
- Department of Molecular Neurochemistry, Medical University, 92-215 Lodz, Poland; (T.B.); (T.R.); (B.F.)
| | - Bozena Ferenc
- Department of Molecular Neurochemistry, Medical University, 92-215 Lodz, Poland; (T.B.); (T.R.); (B.F.)
| | - Ludmila Zylinska
- Department of Molecular Neurochemistry, Medical University, 92-215 Lodz, Poland; (T.B.); (T.R.); (B.F.)
- Correspondence: ; Tel.: +48-42-272-5680
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164
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Wettmarshausen J, Goh V, Huang KT, Arduino DM, Tripathi U, Leimpek A, Cheng Y, Pittis AA, Gabaldón T, Mokranjac D, Hajnóczky G, Perocchi F. MICU1 Confers Protection from MCU-Dependent Manganese Toxicity. Cell Rep 2019; 25:1425-1435.e7. [PMID: 30403999 DOI: 10.1016/j.celrep.2018.10.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 08/09/2018] [Accepted: 10/08/2018] [Indexed: 12/17/2022] Open
Abstract
The mitochondrial calcium uniporter is a highly selective ion channel composed of species- and tissue-specific subunits. However, the functional role of each component still remains unclear. Here, we establish a synthetic biology approach to dissect the interdependence between the pore-forming subunit MCU and the calcium-sensing regulator MICU1. Correlated evolutionary patterns across 247 eukaryotes indicate that their co-occurrence may have conferred a positive fitness advantage. We find that, while the heterologous reconstitution of MCU and EMRE in vivo in yeast enhances manganese stress, this is prevented by co-expression of MICU1. Accordingly, MICU1 deletion sensitizes human cells to manganese-dependent cell death by disinhibiting MCU-mediated manganese uptake. As a result, manganese overload increases oxidative stress, which can be effectively prevented by NAC treatment. Our study identifies a critical contribution of MICU1 to the uniporter selectivity, with important implications for patients with MICU1 deficiency, as well as neurological disorders arising upon chronic manganese exposure.
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Affiliation(s)
- Jennifer Wettmarshausen
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München, 85764 Neuherberg, Germany; Department of Biochemistry, Gene Center Munich, Ludwig-Maximilians Universität München, 81377 Munich, Germany
| | - Valerie Goh
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München, 85764 Neuherberg, Germany; Department of Biochemistry, Gene Center Munich, Ludwig-Maximilians Universität München, 81377 Munich, Germany
| | - Kai-Ting Huang
- Department of Pathology, Anatomy, and Cell Biology, MitoCare Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Daniela M Arduino
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München, 85764 Neuherberg, Germany; Department of Biochemistry, Gene Center Munich, Ludwig-Maximilians Universität München, 81377 Munich, Germany
| | - Utkarsh Tripathi
- Department of Biochemistry, Gene Center Munich, Ludwig-Maximilians Universität München, 81377 Munich, Germany
| | - Anja Leimpek
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München, 85764 Neuherberg, Germany; Department of Biochemistry, Gene Center Munich, Ludwig-Maximilians Universität München, 81377 Munich, Germany
| | - Yiming Cheng
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München, 85764 Neuherberg, Germany; Department of Biochemistry, Gene Center Munich, Ludwig-Maximilians Universität München, 81377 Munich, Germany
| | - Alexandros A Pittis
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), 08003 Barcelona, Spain; Departament of Ciències Experimentals I de La Salut, Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Toni Gabaldón
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), 08003 Barcelona, Spain; Departament of Ciències Experimentals I de La Salut, Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| | - Dejana Mokranjac
- Biomedical Center Munich - Physiological Chemistry, Ludwig-Maximilians Universität München, 82152 Martinsried, Germany
| | - György Hajnóczky
- Department of Pathology, Anatomy, and Cell Biology, MitoCare Center, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Fabiana Perocchi
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center (HDC), Helmholtz Zentrum München, 85764 Neuherberg, Germany; Department of Biochemistry, Gene Center Munich, Ludwig-Maximilians Universität München, 81377 Munich, Germany; Munich Cluster for Systems Neurology, 81377 Munich, Germany.
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165
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Duan N, Gao Z, Hu B, Ge D, Li W, Ye T, Geng X, Li X. Computational insights into the binding pattern of mitochondrial calcium uniporter inhibitor through homology modeling, molecular dynamics simulation, binding free energy prediction and density functional theory calculation. J Biomol Struct Dyn 2019; 38:5095-5107. [PMID: 31755365 DOI: 10.1080/07391102.2019.1695674] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The mitochondrial calcium uniporter (MCU) is the critical protein of the inner mitochondrial membrane that is the primary mediator for calcium uptake into the mitochondrial matrix. Herein we built the optimal homology model of human MCU which was refined through all-atom molecular dynamics simulation. Then, the binding mode of known inhibitor was predicted through molecular docking method, along with molecular dynamics simulation and binding free energy calculation to verify the docking result and stability of the protein-inhibitor complex. Finally, density functional theory (DFT) calculation enhanced our understanding of the molecular interaction of MCU inhibitor. Our research would provide a deeper insight into the interactions between human MCU and its inhibitor, which boosts to develop novel therapy against MCU related disease.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Na Duan
- Department of Cardiology, Shengjing Hospital of China Medical University, Shenyang, China.,Department of Cardiology, The People's Hospital of Liaoning Province, Shenyang, China
| | - Zisen Gao
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang, China
| | - Baichun Hu
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang, China
| | - Dandan Ge
- Key Laboratory of Structure-Based Drug Design & Discovery, Ministry of Education, Shenyang Pharmaceutical University, Shenyang, China.,International Office, Shenyang Pharmaceutical University, Shenyang, China
| | - Wei Li
- Yantai Branch of Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Yantai, China
| | - Tong Ye
- College of Arts, Sciences, Northeast Agricultural University, Harbin, Chinaand
| | - Xiaohui Geng
- School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, China
| | - Xiaodong Li
- Department of Cardiology, Shengjing Hospital of China Medical University, Shenyang, China
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166
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Brain activity regulates loose coupling between mitochondrial and cytosolic Ca 2+ transients. Nat Commun 2019; 10:5277. [PMID: 31754099 PMCID: PMC6872662 DOI: 10.1038/s41467-019-13142-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 10/21/2019] [Indexed: 01/08/2023] Open
Abstract
Mitochondrial calcium ([Ca2+]mito) dynamics plays vital roles in regulating fundamental cellular and organellar functions including bioenergetics. However, neuronal [Ca2+]mito dynamics in vivo and its regulation by brain activity are largely unknown. By performing two-photon Ca2+ imaging in the primary motor (M1) and visual cortexes (V1) of awake behaving mice, we find that discrete [Ca2+]mito transients occur synchronously over somatic and dendritic mitochondrial network, and couple with cytosolic calcium ([Ca2+]cyto) transients in a probabilistic, rather than deterministic manner. The amplitude, duration, and frequency of [Ca2+]cyto transients constitute important determinants of the coupling, and the coupling fidelity is greatly increased during treadmill running (in M1 neurons) and visual stimulation (in V1 neurons). Moreover, Ca2+/calmodulin kinase II is mechanistically involved in modulating the dynamic coupling process. Thus, activity-dependent dynamic [Ca2+]mito-to-[Ca2+]cyto coupling affords an important mechanism whereby [Ca2+]mito decodes brain activity for the regulation of mitochondrial bioenergetics to meet fluctuating neuronal energy demands as well as for neuronal information processing.
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167
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Affiliation(s)
- Nina Kaludercic
- Neuroscience Institute, National Research Council of Italy (CNR), Padua (N.K.)
| | - Luca Scorrano
- Department of Biology, University of Padua, Italy (L.S.)
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168
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Panga V, Kallor AA, Nair A, Harshan S, Raghunathan S. Mitochondrial dysfunction in rheumatoid arthritis: A comprehensive analysis by integrating gene expression, protein-protein interactions and gene ontology data. PLoS One 2019; 14:e0224632. [PMID: 31703070 PMCID: PMC6839853 DOI: 10.1371/journal.pone.0224632] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 10/17/2019] [Indexed: 02/07/2023] Open
Abstract
Several studies have reported mitochondrial dysfunction in rheumatoid arthritis (RA). Many nuclear DNA (nDNA) encoded proteins translocate to mitochondria, but their participation in the dysfunction of this cell organelle during RA is quite unclear. In this study, we have carried out an integrative analysis of gene expression, protein-protein interactions (PPI) and gene ontology data. The analysis has identified potential implications of the nDNA encoded proteins in RA mitochondrial dysfunction. Firstly, by analysing six synovial microarray datasets of RA patients and healthy controls obtained from the gene expression omnibus (GEO) database, we found differentially expressed nDNA genes that encode mitochondrial proteins. We uncovered some of the roles of these genes in RA mitochondrial dysfunction using literature search and gene ontology analysis. Secondly, by employing gene co-expression from microarrays and collating reliable PPI from seven databases, we created the first mitochondrial PPI network that is specific to the RA synovial joint tissue. Further, we identified hubs of this network, and moreover, by integrating gene expression and network analysis, we found differentially expressed neighbours of the hub proteins. The results demonstrate that nDNA encoded proteins are (i) crucial for the elevation of mitochondrial reactive oxygen species (ROS) and (ii) involved in membrane potential, transport processes, metabolism and intrinsic apoptosis during RA. Additionally, we proposed a model relating to mitochondrial dysfunction and inflammation in the disease. Our analysis presents a novel perspective on the roles of nDNA encoded proteins in mitochondrial dysfunction, especially in apoptosis, oxidative stress-related processes and their relation to inflammation in RA. These findings provide a plethora of information for further research.
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Affiliation(s)
- Venugopal Panga
- Institute of Bioinformatics and Applied Biotechnology (IBAB), Bengaluru, Karnataka, India
- Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Ashwin Adrian Kallor
- Institute of Bioinformatics and Applied Biotechnology (IBAB), Bengaluru, Karnataka, India
| | - Arunima Nair
- Institute of Bioinformatics and Applied Biotechnology (IBAB), Bengaluru, Karnataka, India
| | - Shilpa Harshan
- Institute of Bioinformatics and Applied Biotechnology (IBAB), Bengaluru, Karnataka, India
- Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Srivatsan Raghunathan
- Institute of Bioinformatics and Applied Biotechnology (IBAB), Bengaluru, Karnataka, India
- * E-mail:
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169
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Madreiter-Sokolowski CT, Ramadani-Muja J, Ziomek G, Burgstaller S, Bischof H, Koshenov Z, Gottschalk B, Malli R, Graier WF. Tracking intra- and inter-organelle signaling of mitochondria. FEBS J 2019; 286:4378-4401. [PMID: 31661602 PMCID: PMC6899612 DOI: 10.1111/febs.15103] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/19/2019] [Accepted: 10/22/2019] [Indexed: 12/15/2022]
Abstract
Mitochondria are as highly specialized organelles and masters of the cellular energy metabolism in a constant and dynamic interplay with their cellular environment, providing adenosine triphosphate, buffering Ca2+ and fundamentally contributing to various signaling pathways. Hence, such broad field of action within eukaryotic cells requires a high level of structural and functional adaptation. Therefore, mitochondria are constantly moving and undergoing fusion and fission processes, changing their shape and their interaction with other organelles. Moreover, mitochondrial activity gets fine-tuned by intra- and interorganelle H+ , K+ , Na+ , and Ca2+ signaling. In this review, we provide an up-to-date overview on mitochondrial strategies to adapt and respond to, as well as affect, their cellular environment. We also present cutting-edge technologies used to track and investigate subcellular signaling, essential to the understanding of various physiological and pathophysiological processes.
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Affiliation(s)
- Corina T Madreiter-Sokolowski
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria.,Department of Health Sciences and Technology, ETH Zurich, Schwerzenbach, Switzerland
| | - Jeta Ramadani-Muja
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Gabriela Ziomek
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Sandra Burgstaller
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Helmut Bischof
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Zhanat Koshenov
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Benjamin Gottschalk
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Roland Malli
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria.,BioTechMed, Graz, Austria
| | - Wolfgang F Graier
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria.,BioTechMed, Graz, Austria
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170
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Pathophysiology of Calcium Mediated Ventricular Arrhythmias and Novel Therapeutic Options with Focus on Gene Therapy. Int J Mol Sci 2019; 20:ijms20215304. [PMID: 31653119 PMCID: PMC6862059 DOI: 10.3390/ijms20215304] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 10/16/2019] [Accepted: 10/21/2019] [Indexed: 12/19/2022] Open
Abstract
Cardiac arrhythmias constitute a major health problem with a huge impact on mortality rates and health care costs. Despite ongoing research efforts, the understanding of the molecular mechanisms and processes responsible for arrhythmogenesis remains incomplete. Given the crucial role of Ca2+-handling in action potential generation and cardiac contraction, Ca2+ channels and Ca2+ handling proteins represent promising targets for suppression of ventricular arrhythmias. Accordingly, we report the different roles of Ca2+-handling in the development of congenital as well as acquired ventricular arrhythmia syndromes. We highlight the therapeutic potential of gene therapy as a novel and innovative approach for future arrhythmia therapy. Furthermore, we discuss various promising cellular and mitochondrial targets for therapeutic gene transfer currently under investigation.
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171
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Tarasova NV, Vishnyakova PA, Logashina YA, Elchaninov AV. Mitochondrial Calcium Uniporter Structure and Function in Different Types of Muscle Tissues in Health and Disease. Int J Mol Sci 2019; 20:ijms20194823. [PMID: 31569359 PMCID: PMC6801532 DOI: 10.3390/ijms20194823] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/12/2019] [Accepted: 09/26/2019] [Indexed: 02/07/2023] Open
Abstract
Calcium ions (Ca2+) influx to mitochondrial matrix is crucial for the life of a cell. Mitochondrial calcium uniporter (mtCU) is a protein complex which consists of the pore-forming subunit (MCU) and several regulatory subunits. MtCU is the main contributor to inward Ca2+ currents through the inner mitochondrial membrane. Extensive investigations of mtCU involvement into normal and pathological molecular pathways started from the moment of discovery of its molecular components. A crucial role of mtCU in the control of these pathways is now recognized in both health and disease. In particular, impairments of mtCU function have been demonstrated for cardiovascular and skeletal muscle-associated pathologies. This review summarizes the current state of knowledge on mtCU structure, regulation, and function in different types of muscle tissues in health and disease.
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Affiliation(s)
- Nadezhda V Tarasova
- Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Trubetskaya str. 8, bld. 2, Moscow 119991, Russia.
| | - Polina A Vishnyakova
- National Medical Research Center for Obstetrics, Gynecology and Perinatology Named after Academician V.I. Kulakov of Ministry of Healthcare of Russian Federation, 4 Oparina Street, Moscow 117997, Russia.
| | - Yulia A Logashina
- Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Trubetskaya str. 8, bld. 2, Moscow 119991, Russia.
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street 16/10, Moscow 117997, Russia.
| | - Andrey V Elchaninov
- National Medical Research Center for Obstetrics, Gynecology and Perinatology Named after Academician V.I. Kulakov of Ministry of Healthcare of Russian Federation, 4 Oparina Street, Moscow 117997, Russia.
- Scientific Research Institute of Human Morphology, 3 Tsurupa Street, Moscow 117418, Russia.
- Peoples' Friendship University of Russia, 6 Miklukho-Maklaya Street, Moscow 117198, Russia.
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172
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Lambert JP, Luongo TS, Tomar D, Jadiya P, Gao E, Zhang X, Lucchese AM, Kolmetzky DW, Shah NS, Elrod JW. MCUB Regulates the Molecular Composition of the Mitochondrial Calcium Uniporter Channel to Limit Mitochondrial Calcium Overload During Stress. Circulation 2019; 140:1720-1733. [PMID: 31533452 DOI: 10.1161/circulationaha.118.037968] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The mitochondrial calcium uniporter (mtCU) is an ≈700-kD multisubunit channel residing in the inner mitochondrial membrane required for mitochondrial Ca2+ (mCa2+) uptake. Here, we detail the contribution of MCUB, a paralog of the pore-forming subunit MCU, in mtCU regulation and function and for the first time investigate the relevance of MCUB to cardiac physiology. METHODS We created a stable MCUB knockout cell line (MCUB-/-) using CRISPR-Cas9n technology and generated a cardiac-specific, tamoxifen-inducible MCUB mutant mouse (CAG-CAT-MCUB x MCM; MCUB-Tg) for in vivo assessment of cardiac physiology and response to ischemia/reperfusion injury. Live-cell imaging and high-resolution spectrofluorometery were used to determine intracellular Ca2+ exchange and size-exclusion chromatography; blue native page and immunoprecipitation studies were used to determine the molecular function and impact of MCUB on the high-molecular-weight mtCU complex. RESULTS Using genetic gain- and loss-of-function approaches, we show that MCUB expression displaces MCU from the functional mtCU complex and thereby decreases the association of mitochondrial calcium uptake 1 and 2 (MICU1/2) to alter channel gating. These molecular changes decrease MICU1/2-dependent cooperative activation of the mtCU, thereby decreasing mCa2+ uptake. Furthermore, we show that MCUB incorporation into the mtCU is a stress-responsive mechanism to limit mCa2+ overload during cardiac injury. Indeed, overexpression of MCUB is sufficient to decrease infarct size after ischemia/reperfusion injury. However, MCUB incorporation into the mtCU does come at a cost; acute decreases in mCa2+ uptake impair mitochondrial energetics and contractile function. CONCLUSIONS We detail a new regulatory mechanism to modulate mtCU function and mCa2+ uptake. Our results suggest that MCUB-dependent changes in mtCU stoichiometry are a prominent regulatory mechanism to modulate mCa2+ uptake and cellular physiology.
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Affiliation(s)
- Jonathan P Lambert
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | - Timothy S Luongo
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | - Dhanendra Tomar
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | - Pooja Jadiya
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | - Erhe Gao
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | - Xueqian Zhang
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | - Anna Maria Lucchese
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | - Devin W Kolmetzky
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | - Neil S Shah
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
| | - John W Elrod
- Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA
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173
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Abstract
In heart failure, alterations of Na+ and Ca2+ handling, energetic deficit, and oxidative stress in cardiac myocytes are important pathophysiological hallmarks. Mitochondria are central to these processes because they are the main source for ATP, but also reactive oxygen species (ROS), and their function is critically controlled by Ca2+ During physiological variations of workload, mitochondrial Ca2+ uptake is required to match energy supply to demand but also to keep the antioxidative capacity in a reduced state to prevent excessive emission of ROS. Mitochondria take up Ca2+ via the mitochondrial Ca2+ uniporter, which exists in a multiprotein complex whose molecular components were identified only recently. In heart failure, deterioration of cytosolic Ca2+ and Na+ handling hampers mitochondrial Ca2+ uptake and the ensuing Krebs cycle-induced regeneration of the reduced forms of NADH (nicotinamide adenine dinucleotide) and NADPH (nicotinamide adenine dinucleotide phosphate), giving rise to energetic deficit and oxidative stress. ROS emission from mitochondria can trigger further ROS release from neighboring mitochondria termed ROS-induced ROS release, and cross talk between different ROS sources provides a spatially confined cellular network of redox signaling. Although low levels of ROS may serve physiological roles, higher levels interfere with excitation-contraction coupling, induce maladaptive cardiac remodeling through redox-sensitive kinases, and cell death through mitochondrial permeability transition. Targeting the dysregulated interplay between excitation-contraction coupling and mitochondrial energetics may ameliorate the progression of heart failure.
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Affiliation(s)
- Edoardo Bertero
- From the Comprehensive Heart Failure Center, University Clinic Würzburg, Germany
| | - Christoph Maack
- From the Comprehensive Heart Failure Center, University Clinic Würzburg, Germany.
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174
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Wu W, Shen Q, Lei Z, Qiu Z, Li D, Pei H, Zheng J, Jia Z. The crystal structure of MICU2 provides insight into Ca 2+ binding and MICU1-MICU2 heterodimer formation. EMBO Rep 2019; 20:e47488. [PMID: 31397067 PMCID: PMC6726906 DOI: 10.15252/embr.201847488] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 06/12/2019] [Accepted: 07/12/2019] [Indexed: 11/09/2022] Open
Abstract
The mitochondrial calcium uniporter (MCU) complex mediates the uptake of Ca2+ into mitochondria. Its activity is regulated by a heterodimer of MICU1 and MICU2, two EF-hand-containing proteins that act as the main gatekeeper of the uniporter. Herein we report the crystal structure of human MICU2 at 1.96 Å resolution. Our structure reveals a dimeric architecture of MICU2, in which each monomer adopts the canonical two-lobe structure with a pair of EF-hands in each lobe. Both Ca2+ -bound and Ca2+ -free EF-hands are observed in our structure. Moreover, we characterize the interaction sites within the MICU2 homodimer, as well as the MICU1-MICU2 heterodimer in both Ca2+ -free and Ca2+ -bound conditions. Glu242 in MICU1 and Arg352 in MICU2 are crucial for apo heterodimer formation, while Phe383 in MICU1 and Glu196 in MICU2 significantly contribute to the interaction in the Ca2+ -bound state. Based on our structural and biochemical analyses, we propose a model for MICU1-MICU2 heterodimer formation and its conformational transition from apo to a more compact Ca2+ -bound state, which expands our understanding of this co-regulatory mechanism critical for MCU's mitochondrial calcium uptake function.
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Affiliation(s)
- Wenping Wu
- College of ChemistryBeijing Normal UniversityBeijingChina
| | - Qingya Shen
- College of ChemistryBeijing Normal UniversityBeijingChina
| | - Zhen Lei
- College of ChemistryBeijing Normal UniversityBeijingChina
| | - Zhiyu Qiu
- College of ChemistryBeijing Normal UniversityBeijingChina
| | - Dan Li
- College of ChemistryBeijing Normal UniversityBeijingChina
| | - Hairun Pei
- College of ChemistryBeijing Normal UniversityBeijingChina
| | - Jimin Zheng
- College of ChemistryBeijing Normal UniversityBeijingChina
| | - Zongchao Jia
- Department of Biomedical and Molecular SciencesQueen's UniversityKingstonONCanada
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175
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Dubinin MV, Belosludtsev KN. Taxonomic Features of Specific Ca2+ Transport Mechanisms in Mitochondria. BIOCHEMISTRY MOSCOW SUPPLEMENT SERIES A-MEMBRANE AND CELL BIOLOGY 2019. [DOI: 10.1134/s1990747819030127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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176
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Gottschalk B, Klec C, Leitinger G, Bernhart E, Rost R, Bischof H, Madreiter-Sokolowski CT, Radulović S, Eroglu E, Sattler W, Waldeck-Weiermair M, Malli R, Graier WF. MICU1 controls cristae junction and spatially anchors mitochondrial Ca 2+ uniporter complex. Nat Commun 2019; 10:3732. [PMID: 31427612 PMCID: PMC6700202 DOI: 10.1038/s41467-019-11692-x] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 07/30/2019] [Indexed: 12/15/2022] Open
Abstract
Recently identified core proteins (MICU1, MCU, EMRE) forming the mitochondrial Ca2+ uniporter complex propelled investigations into its physiological workings. Here, we apply structured illumination microscopy to visualize and localize these proteins in living cells. Our data show that MICU1 localizes at the inner boundary membrane (IBM) due to electrostatic interaction of its polybasic domain. Moreover, this exclusive localization of MICU1 is important for the stability of cristae junctions (CJ), cytochrome c release and mitochondrial membrane potential. In contrast to MICU1, MCU and EMRE are homogeneously distributed at the inner mitochondrial membrane under resting conditions. However, upon Ca2+ elevation MCU and EMRE dynamically accumulate at the IBM in a MICU1-dependent manner. Eventually, our findings unveil an essential function of MICU1 in CJ stabilization and provide mechanistic insights of how sophistically MICU1 controls the MCU-Complex while maintaining the structural mitochondrial membrane framework.
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Affiliation(s)
- Benjamin Gottschalk
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Christiane Klec
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Gerd Leitinger
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Cell Biology, Histology and Embryology, Medical University of Graz, Neue Stiftingtalstraße 6/2, 8010 Graz, Austria
| | - Eva Bernhart
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - René Rost
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Helmut Bischof
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Corina T. Madreiter-Sokolowski
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Snježana Radulović
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria ,0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Cell Biology, Histology and Embryology, Medical University of Graz, Neue Stiftingtalstraße 6/2, 8010 Graz, Austria
| | - Emrah Eroglu
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Wolfgang Sattler
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria ,grid.452216.6BioTechMed Graz, Mozartgasse 12/2, Graz, 8010 Austria
| | - Markus Waldeck-Weiermair
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Roland Malli
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria ,grid.452216.6BioTechMed Graz, Mozartgasse 12/2, Graz, 8010 Austria
| | - Wolfgang F. Graier
- 0000 0000 8988 2476grid.11598.34Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria ,grid.452216.6BioTechMed Graz, Mozartgasse 12/2, Graz, 8010 Austria
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Yamamoto T, Ozono M, Watanabe A, Maeda K, Nara A, Hashida M, Ido Y, Hiroshima Y, Yamada A, Terada H, Shinohara Y. Functional analysis of coiled-coil domains of MCU in mitochondrial calcium uptake. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:148061. [PMID: 31394096 DOI: 10.1016/j.bbabio.2019.148061] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 07/20/2019] [Accepted: 08/02/2019] [Indexed: 11/30/2022]
Abstract
The mitochondrial calcium uniporter (MCU) complex is a highly-selective calcium channel. This complex consists of MCU, mitochondrial calcium uptake proteins (MICUs), MCU regulator 1 (MCUR1), essential MCU regulator element (EMRE), etc. MCU, which is the pore-forming subunit, has 2 highly conserved coiled-coil domains (CC1 and CC2); however, their functional roles are unknown. The yeast expression system of mammalian MCU and EMRE enables precise reconstitution of the properties of the mammalian MCU complex in yeast mitochondria. Using the yeast expression system, we here showed that, when MCU mutant lacking CC1 or CC2 was expressed together with EMRE in yeast, their mitochondrial Ca2+-uptake function was lost. Additionally, point mutations in CC1 or CC2, which were expected to prevent the formation of the coiled coil, also disrupted the Ca2+-uptake function. Thus, it is essential for the Ca2+ uptake function of MCU that the coiled-coil structure be formed in CC1 and CC2. The loss of function of those mutated MCUs was also observed in the mitochondria of a yeast strain lacking the yeast MCUR1 homolog. Also, in the D. discoideum MCU, which has EMRE-independent Ca2+-uptake function, the deletion of either CC1 or CC2 caused the loss of function. These results indicated that the critical functions of CC1 and CC2 were independent of other regulatory subunits such as MCUR1 and EMRE, suggesting that CC1 and CC2 might be essential for pore formation by MCUs themselves. Based on the tetrameric structure of MCU, we discussed the functional roles of the coiled-coil domains of MCU.
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Affiliation(s)
- Takenori Yamamoto
- Institute for Genome Research, Tokushima University, Kuramotocho-3, Tokushima 770-8503, Japan; Faculty of Pharmaceutical Sciences, Tokushima University, Shomachi-1, Tokushima 770-8505, Japan.
| | - Mizune Ozono
- Institute for Genome Research, Tokushima University, Kuramotocho-3, Tokushima 770-8503, Japan; Faculty of Pharmaceutical Sciences, Tokushima University, Shomachi-1, Tokushima 770-8505, Japan
| | - Akira Watanabe
- Institute for Genome Research, Tokushima University, Kuramotocho-3, Tokushima 770-8503, Japan; Faculty of Pharmaceutical Sciences, Tokushima University, Shomachi-1, Tokushima 770-8505, Japan
| | - Kosuke Maeda
- Institute for Genome Research, Tokushima University, Kuramotocho-3, Tokushima 770-8503, Japan; Faculty of Pharmaceutical Sciences, Tokushima University, Shomachi-1, Tokushima 770-8505, Japan
| | - Atsushi Nara
- Institute for Genome Research, Tokushima University, Kuramotocho-3, Tokushima 770-8503, Japan; Faculty of Pharmaceutical Sciences, Tokushima University, Shomachi-1, Tokushima 770-8505, Japan
| | - Mei Hashida
- Institute for Genome Research, Tokushima University, Kuramotocho-3, Tokushima 770-8503, Japan; Faculty of Pharmaceutical Sciences, Tokushima University, Shomachi-1, Tokushima 770-8505, Japan
| | - Yusuke Ido
- Institute for Genome Research, Tokushima University, Kuramotocho-3, Tokushima 770-8503, Japan; Faculty of Pharmaceutical Sciences, Tokushima University, Shomachi-1, Tokushima 770-8505, Japan
| | - Yuka Hiroshima
- Institute for Genome Research, Tokushima University, Kuramotocho-3, Tokushima 770-8503, Japan
| | - Akiko Yamada
- School of Dentistry, Tokushima University, Kuramotocho-3, Tokushima 770-8504, Japan
| | - Hiroshi Terada
- Niigata University of Pharmacy and Applied Life Sciences, Niigata City 956-8603, Japan
| | - Yasuo Shinohara
- Institute for Genome Research, Tokushima University, Kuramotocho-3, Tokushima 770-8503, Japan; Faculty of Pharmaceutical Sciences, Tokushima University, Shomachi-1, Tokushima 770-8505, Japan.
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178
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Hutto RA, Bisbach CM, Abbas F, Brock DC, Cleghorn WM, Parker ED, Bauer BH, Ge W, Vinberg F, Hurley JB, Brockerhoff SE. Increasing Ca 2+ in photoreceptor mitochondria alters metabolites, accelerates photoresponse recovery, and reveals adaptations to mitochondrial stress. Cell Death Differ 2019; 27:1067-1085. [PMID: 31371786 PMCID: PMC7206026 DOI: 10.1038/s41418-019-0398-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 06/19/2019] [Accepted: 07/11/2019] [Indexed: 11/09/2022] Open
Abstract
Photoreceptors are specialized neurons that rely on Ca2+ to regulate phototransduction and neurotransmission. Photoreceptor dysfunction and degeneration occur when intracellular Ca2+ homeostasis is disrupted. Ca2+ homeostasis is maintained partly by mitochondrial Ca2+ uptake through the mitochondrial Ca2+ uniporter (MCU), which can influence cytosolic Ca2+ signals, stimulate energy production, and trigger apoptosis. Here we discovered that zebrafish cone photoreceptors express unusually low levels of MCU. We expected that this would be important to prevent mitochondrial Ca2+ overload and consequent cone degeneration. To test this hypothesis, we generated a cone-specific model of MCU overexpression. Surprisingly, we found that cones tolerate MCU overexpression, surviving elevated mitochondrial Ca2+ and disruptions to mitochondrial ultrastructure until late adulthood. We exploited the survival of MCU overexpressing cones to additionally demonstrate that mitochondrial Ca2+ uptake alters the distributions of citric acid cycle intermediates and accelerates recovery kinetics of the cone response to light. Cones adapt to mitochondrial Ca2+ stress by decreasing MICU3, an enhancer of MCU-mediated Ca2+ uptake, and selectively transporting damaged mitochondria away from the ellipsoid toward the synapse. Our findings demonstrate how mitochondrial Ca2+ can influence physiological and metabolic processes in cones and highlight the remarkable ability of cone photoreceptors to adapt to mitochondrial stress.
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Affiliation(s)
- Rachel A Hutto
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA
| | - Celia M Bisbach
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA
| | - Fatima Abbas
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, 84132, USA
| | - Daniel C Brock
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA
| | - Whitney M Cleghorn
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA
| | - Edward D Parker
- Opthalmology Department, University of Washington, Seattle, WA, 98109, USA
| | - Benjamin H Bauer
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA
| | - William Ge
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA
| | - Frans Vinberg
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, 84132, USA
| | - James B Hurley
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA.,Opthalmology Department, University of Washington, Seattle, WA, 98109, USA
| | - Susan E Brockerhoff
- Biochemistry Department, University of Washington, Seattle, WA, 98109, USA. .,Opthalmology Department, University of Washington, Seattle, WA, 98109, USA.
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179
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Jaña F, Bustos G, Rivas J, Cruz P, Urra F, Basualto-Alarcón C, Sagredo E, Ríos M, Lovy A, Dong Z, Cerda O, Madesh M, Cárdenas C. Complex I and II are required for normal mitochondrial Ca 2+ homeostasis. Mitochondrion 2019; 49:73-82. [PMID: 31310854 DOI: 10.1016/j.mito.2019.07.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 04/01/2019] [Accepted: 07/12/2019] [Indexed: 01/03/2023]
Abstract
Cytosolic calcium (cCa2+) entry into mitochondria is facilitated by the mitochondrial membrane potential (ΔΨm), an electrochemical gradient generated by the electron transport chain (ETC). Is has been assumed that as long as mutations that affect the ETC do not affect the ΔΨm, the mitochondrial Ca2+ (mCa2+) homeostasis remains normal. We show that knockdown of NDUFAF3 and SDHB reduce ETC activity altering mCa2+ efflux and influx rates while ΔΨm remains intact. Shifting the equilibrium toward lower [Ca2+]m accumulation renders cells resistant to death. Our findings reveal an unexpected relationship between complex I and II with the mCa2+ homeostasis independent of ΔΨm.
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Affiliation(s)
- Fabian Jaña
- Departamento de Ciencias de la Salud, Universidad de Aysén, Coyhaique, Chile; Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Galdo Bustos
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile
| | - José Rivas
- Departamento de Ciencias de la Salud, Universidad de Aysén, Coyhaique, Chile; Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Pablo Cruz
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Felix Urra
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Carla Basualto-Alarcón
- Departamento de Ciencias de la Salud, Universidad de Aysén, Coyhaique, Chile; Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Anatomy and Legal Medicine Department, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Eduardo Sagredo
- Centro de Investigación y Tratamiento del Cáncer, Facultad de Medicina, Universidad de Chile, Chile
| | - Melany Ríos
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile
| | - Alenka Lovy
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile; Center for Neuroscience Research, Tufts University School of Medicine, Boston, MA, USA
| | - Zhiwei Dong
- Department of Medicine, Center for Precision Medicine, University of Texas Health San Antonio, TX, USA
| | - Oscar Cerda
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago, Chile; Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Santiago, Chile.; The Wound Repair, Treatment and Health (WoRTH), Chile
| | - Muniswamy Madesh
- Department of Medicine, Center for Precision Medicine, University of Texas Health San Antonio, TX, USA.
| | - César Cárdenas
- Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile; Buck Institute for Research on Aging, Novato, CA, USA; Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, United States.
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180
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Abstract
MICU2 is a Ca2+ sensor protein of mitochondrial uniporter which is a highly selective Ca2+ channel mediating mitochondrial Ca2+ uptake to regulate cell death, metabolism, and cytoplasmic Ca2+ signaling. Here we describe the procedures for protein preparation of various MICU2 constructs, which have enabled successful in vitro characterizations of MICU2 including interaction with MICU1 using pull-down assays and oligomerization using multi-angle laser light scattering.
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Affiliation(s)
- Wenping Wu
- College of Chemistry, Beijing Normal University, Beijing, China
| | - Jimin Zheng
- College of Chemistry, Beijing Normal University, Beijing, China.
| | - Zongchao Jia
- Department of Biochemical and Molecular Science, Queen University, Kingston, ON, Canada.
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181
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Belosludtsev KN, Dubinin MV, Belosludtseva NV, Mironova GD. Mitochondrial Ca2+ Transport: Mechanisms, Molecular Structures, and Role in Cells. BIOCHEMISTRY. BIOKHIMIIA 2019; 84:593-607. [PMID: 31238859 DOI: 10.1134/s0006297919060026] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 03/18/2019] [Accepted: 03/19/2019] [Indexed: 11/29/2023]
Abstract
Mitochondria are among the most important cell organelles involved in the regulation of intracellular calcium homeostasis. During the last decade, a number of molecular structures responsible for the mitochondrial calcium transport have been identified including the mitochondrial Ca2+ uniporter (MCU), Na+/Ca2+ exchanger (NCLX), and Ca2+/H+ antiporter (Letm1). The review summarizes the data on the structure, regulation, and physiological role of such structures. The pathophysiological mechanism of Ca2+ transport through the cyclosporine A-sensitive mitochondrial permeability transition pore is discussed. An alternative mechanism for the mitochondrial pore opening, namely, formation of the lipid pore induced by saturated fatty acids, and its role in Ca2+ transport are described in detail.
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Affiliation(s)
- K N Belosludtsev
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
- Mari State University, Yoshkar-Ola, 424000, Russia
| | - M V Dubinin
- Mari State University, Yoshkar-Ola, 424000, Russia
| | - N V Belosludtseva
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
| | - G D Mironova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
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182
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Chiurillo MA, Lander N, Bertolini MS, Vercesi AE, Docampo R. Functional analysis and importance for host cell infection of the Ca 2+-conducting subunits of the mitochondrial calcium uniporter of Trypanosoma cruzi. Mol Biol Cell 2019; 30:1676-1690. [PMID: 31091170 PMCID: PMC6727756 DOI: 10.1091/mbc.e19-03-0152] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We report here that Trypanosoma cruzi, the etiologic agent of Chagas disease, possesses two unique paralogues of the mitochondrial calcium uniporter complex TcMCU subunit that we named TcMCUc and TcMCUd. The predicted structure of the proteins indicates that, as predicted for the TcMCU and TcMCUb paralogues, they are composed of two helical membrane-spanning domains and contain a WDXXEPXXY motif. Overexpression of each gene led to a significant increase in mitochondrial Ca2+ uptake, while knockout (KO) of either TcMCUc or TcMCUd led to a loss of mitochondrial Ca2+ uptake, without affecting the mitochondrial membrane potential. TcMCUc-KO and TcMCUd-KO epimastigotes exhibited reduced growth rate in low-glucose medium and alterations in their respiratory rate, citrate synthase activity, and AMP/ATP ratio, while trypomastigotes had reduced ability to efficiently infect host cells and replicate intracellularly as amastigotes. By gene complementation of KO cell lines or by a newly developed CRISPR/Cas9-mediated knock-in approach, we also studied the importance of critical amino acid residues of the four paralogues on mitochondrial Ca2+ uptake. In conclusion, the results predict a hetero-oligomeric structure for the T. cruzi MCU complex, with structural and functional differences, as compared with those in the mammalian complex.
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Affiliation(s)
- Miguel A Chiurillo
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo 13083, Brazil
| | - Noelia Lander
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo 13083, Brazil
| | - Mayara S Bertolini
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo 13083, Brazil
| | - Anibal E Vercesi
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo 13083, Brazil
| | - Roberto Docampo
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, São Paulo 13083, Brazil.,Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Athens, GA 30602
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183
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Marchi S, Vitto VAM, Danese A, Wieckowski MR, Giorgi C, Pinton P. Mitochondrial calcium uniporter complex modulation in cancerogenesis. Cell Cycle 2019; 18:1068-1083. [PMID: 31032692 DOI: 10.1080/15384101.2019.1612698] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Aberrations in mitochondrial Ca2+ homeostasis have been associated with different pathological conditions, including neurological defects, cardiovascular diseases, and, in the last years, cancer. With the recent molecular identification of the mitochondrial calcium uniporter (MCU) complex, the channel that allows Ca2+ accumulation into the mitochondrial matrix, alterations in the expression levels or functioning in one or more MCU complex members have been linked to different cancers and cancer-related phenotypes. In this review, we will analyze the role of the uniporter and mitochondrial Ca2+ derangements in modulating cancer cell sensitivity to death, invasiveness, and migratory capacity, as well as cancer progression in vivo. We will also discuss some critical points and contradictory results to highlight the consequence of MCU complex modulation in tumor development.
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Affiliation(s)
- Saverio Marchi
- a Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology , Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara , Ferrara , Italy.,b Department of Clinical and Molecular Sciences, Polytechnical University of Marche , Ancona , Italy
| | - Veronica Angela Maria Vitto
- a Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology , Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara , Ferrara , Italy
| | - Alberto Danese
- a Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology , Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara , Ferrara , Italy
| | | | - Carlotta Giorgi
- a Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology , Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara , Ferrara , Italy
| | - Paolo Pinton
- a Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology , Laboratory for Technologies of Advanced Therapies (LTTA), University of Ferrara , Ferrara , Italy.,d Maria Cecilia Hospital, GVM Care & Research, 48033 , Cotignola , Ravenna , Italy
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184
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Wang Y, Nguyen NX, She J, Zeng W, Yang Y, Bai XC, Jiang Y. Structural Mechanism of EMRE-Dependent Gating of the Human Mitochondrial Calcium Uniporter. Cell 2019; 177:1252-1261.e13. [PMID: 31080062 DOI: 10.1016/j.cell.2019.03.050] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 02/09/2019] [Accepted: 03/27/2019] [Indexed: 01/06/2023]
Abstract
Mitochondrial calcium uptake is crucial to the regulation of eukaryotic Ca2+ homeostasis and is mediated by the mitochondrial calcium uniporter (MCU). While MCU alone can transport Ca2+ in primitive eukaryotes, metazoans require an essential single membrane-spanning auxiliary component called EMRE to form functional channels; however, the molecular mechanism of EMRE regulation remains elusive. Here, we present the cryo-EM structure of the human MCU-EMRE complex, which defines the interactions between MCU and EMRE as well as pinpoints the juxtamembrane loop of MCU and extended linker of EMRE as the crucial elements in the EMRE-dependent gating mechanism among metazoan MCUs. The structure also features the dimerization of two MCU-EMRE complexes along an interface at the N-terminal domain (NTD) of human MCU that is a hotspot for post-translational modifications. Thus, the human MCU-EMRE complex, which constitutes the minimal channel components among metazoans, provides a framework for future mechanistic studies on MCU.
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Affiliation(s)
- Yan Wang
- Howard Hughes Medical Institute and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Nam X Nguyen
- Howard Hughes Medical Institute and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Ji She
- Howard Hughes Medical Institute and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Weizhong Zeng
- Howard Hughes Medical Institute and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yi Yang
- Howard Hughes Medical Institute and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Youxing Jiang
- Howard Hughes Medical Institute and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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185
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MICU1 and MICU2 Play an Essential Role in Mitochondrial Ca 2+ Uptake, Growth, and Infectivity of the Human Pathogen Trypanosoma cruzi. mBio 2019; 10:mBio.00348-19. [PMID: 31064825 PMCID: PMC6509184 DOI: 10.1128/mbio.00348-19] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The mitochondrial Ca2+ uptake in trypanosomatids, which belong to the eukaryotic supergroup Excavata, shares biochemical characteristics with that of animals, which, together with fungi, belong to the supergroup Opisthokonta. However, the composition of the mitochondrial calcium uniporter (MCU) complex in trypanosomatids is quite peculiar, suggesting lineage-specific adaptations. In this work, we used Trypanosoma cruzi to study the role of orthologs for mitochondrial calcium uptake 1 (MICU1) and MICU2 in mitochondrial Ca2+ uptake. T. cruzi MICU1 (TcMICU1) and TcMICU2 have mitochondrial targeting signals, two canonical EF-hand calcium-binding domains, and localize to the mitochondria. Using the CRISPR/Cas9 system (i.e., clustered regularly interspaced short palindromic repeats with Cas9), we generated TcMICU1 and TcMICU2 knockout (-KO) cell lines. Ablation of either TcMICU1 or TcMICU2 showed a significantly reduced mitochondrial Ca2+ uptake in permeabilized epimastigotes without dissipation of the mitochondrial membrane potential or effects on the AMP/ATP ratio or citrate synthase activity. However, none of these proteins had a gatekeeper function at low cytosolic Ca2+ concentrations ([Ca2+]cyt), as occurs with their mammalian orthologs. TcMICU1-KO and TcMICU2-KO epimastigotes had a lower growth rate and impaired oxidative metabolism, while infective trypomastigotes have a reduced capacity to invade host cells and to replicate within them as amastigotes. The findings of this work, which is the first to study the role of MICU1 and MICU2 in organisms evolutionarily distant from animals, suggest that, although these components were probably present in the last eukaryotic common ancestor (LECA), they developed different roles during evolution of different eukaryotic supergroups. The work also provides new insights into the adaptations of trypanosomatids to their particular life styles.IMPORTANCE Trypanosoma cruzi is the etiologic agent of Chagas disease and belongs to the early-branching eukaryotic supergroup Excavata. Its mitochondrial calcium uniporter (MCU) subunit shares similarity with the animal ortholog that was important to discover its encoding gene. In animal cells, the MICU1 and MICU2 proteins act as Ca2+ sensors and gatekeepers of the MCU, preventing Ca2+ uptake under resting conditions and favoring it at high cytosolic Ca2+ concentrations ([Ca2+]cyt). Using the CRISPR/Cas9 technique, we generated TcMICU1 and TcMICU2 knockout cell lines and showed that MICU1 and -2 do not act as gatekeepers at low [Ca2+]cyt but are essential for normal growth, host cell invasion, and intracellular replication, revealing lineage-specific adaptations.
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186
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Crosstalk between Calcium and ROS in Pathophysiological Conditions. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:9324018. [PMID: 31178978 PMCID: PMC6507098 DOI: 10.1155/2019/9324018] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 04/01/2019] [Indexed: 12/12/2022]
Abstract
Calcium ions are highly versatile intracellular signals that regulate many cellular processes. The key to achieving this pleiotropic role is the spatiotemporal control of calcium concentration evoked by an extensive molecular repertoire of signalling components. Among these, reactive oxygen species (ROS) signalling, together with calcium signalling, plays a crucial role in controlling several physiopathological events. Although initially considered detrimental by-products of aerobic metabolism, it is now widely accepted that ROS, in subtoxic levels, act as signalling molecules. However, dysfunctions in the mechanisms controlling the physiological ROS concentration affect cellular homeostasis, leading to the pathogenesis of various disorders.
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187
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Cui C, Yang J, Fu L, Wang M, Wang X. Progress in understanding mitochondrial calcium uniporter complex-mediated calcium signalling: A potential target for cancer treatment. Br J Pharmacol 2019; 176:1190-1205. [PMID: 30801705 DOI: 10.1111/bph.14632] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 01/02/2019] [Accepted: 01/29/2019] [Indexed: 12/15/2022] Open
Abstract
Due to its Ca2+ buffering capacity, the mitochondrion is one of the most important intracellular organelles in regulating Ca2+ dynamic oscillation. Mitochondrial calcium uniporter (MCU) is the primary mediator of Ca2+ influx into mitochondria, manipulating cell energy metabolism, ROS production, and programmed cell death, all of which are critical for carcinogenesis. The understanding of the uniporter complex was significantly boosted by recent groundbreaking discoveries that identified the uniporter pore-forming subunit MCU and its regulatory molecules, including MCU-dominant negative β subunit (MCUb), essential MCU regulator (EMRE), MCU regulator 1 (MCUR1), mitochondrial calcium uptake (MICU) 1, MICU2, and MICU3. These provide the means and molecular platform to investigate MCU complex (uniplex)-mediated impaired Ca2+ signalling in physiology and pathology. This review aims to summarize the progress of the understanding regulatory mechanisms of uniplex, roles of uniplex-mediated Ca2+ signalling in cancer, and potential pharmacological inhibitors of MCU.
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Affiliation(s)
- Chaochu Cui
- Henan Key Laboratory of Medical Tissue Regeneration, College of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China.,Henan Key Laboratory of Neurorestoratology, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, China.,State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Jianbo Yang
- Henan Key Laboratory of Medical Tissue Regeneration, College of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
| | - Liwu Fu
- State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Mingyong Wang
- School of Laboratory Medicine, Xinxiang Medical University, Xinxiang, China
| | - Xianwei Wang
- Henan Key Laboratory of Medical Tissue Regeneration, College of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China
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188
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Nickel AG, Kohlhaas M, Bertero E, Wilhelm D, Wagner M, Sequeira V, Kreusser MM, Dewenter M, Kappl R, Hoth M, Dudek J, Backs J, Maack C. CaMKII does not control mitochondrial Ca 2+ uptake in cardiac myocytes. J Physiol 2019; 598:1361-1376. [PMID: 30770570 DOI: 10.1113/jp276766] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 02/13/2019] [Indexed: 01/26/2023] Open
Abstract
KEY POINTS Mitochondrial Ca2+ uptake stimulates the Krebs cycle to regenerate the reduced forms of pyridine nucleotides (NADH, NADPH and FADH2 ) required for ATP production and reactive oxygen species (ROS) elimination. Ca2+ /calmodulin-dependent protein kinase II (CaMKII) has been proposed to regulate mitochondrial Ca2+ uptake via mitochondrial Ca2+ uniporter phosphorylation. We used two mouse models with either global deletion of CaMKIIδ (CaMKIIδ knockout) or cardiomyocyte-specific deletion of CaMKIIδ and γ (CaMKIIδ/γ double knockout) to interrogate whether CaMKII controls mitochondrial Ca2+ uptake in isolated mitochondria and during β-adrenergic stimulation in cardiac myocytes. CaMKIIδ/γ did not control Ca2+ uptake, respiration or ROS emission in isolated cardiac mitochondria, nor in isolated cardiac myocytes, during β-adrenergic stimulation and pacing. The results of the present study do not support a relevant role of CaMKII for mitochondrial Ca2+ uptake in cardiac myocytes under physiological conditions. ABSTRACT Mitochondria are the main source of ATP and reactive oxygen species (ROS) in cardiac myocytes. Furthermore, activation of the mitochondrial permeability transition pore (mPTP) induces programmed cell death. These processes are essentially controlled by Ca2+ , which is taken up into mitochondria via the mitochondrial Ca2+ uniporter (MCU). It was recently proposed that Ca2+ /calmodulin-dependent protein kinase II (CaMKII) regulates Ca2+ uptake by interacting with the MCU, thereby affecting mPTP activation and programmed cell death. In the present study, we investigated the role of CaMKII under physiological conditions in which mitochondrial Ca2+ uptake matches energy supply to the demand of cardiac myocytes. Accordingly, we measured mitochondrial Ca2+ uptake in isolated mitochondria and cardiac myocytes harvested from cardiomyocyte-specific CaMKII δ and γ double knockout (KO) (CaMKIIδ/γ DKO) and global CaMKIIδ KO mice. To simulate a physiological workload increase, cardiac myocytes were subjected to β-adrenergic stimulation (by isoproterenol superfusion) and an increase in stimulation frequency (from 0.5 to 5 Hz). No differences in mitochondrial Ca2+ accumulation were detected in isolated mitochondria or cardiac myocytes from both CaMKII KO models compared to wild-type littermates. Mitochondrial redox state and ROS production were unchanged in CaMKIIδ/γ DKO, whereas we observed a mild oxidation of mitochondrial redox state and an increase in H2 O2 emission from CaMKIIδ KO cardiac myocytes exposed to an increase in workload. In conclusion, the results obtained in the present study do not support the regulation of mitochondrial Ca2+ uptake via the MCU or mPTP activation by CaMKII in cardiac myocytes under physiological conditions.
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Affiliation(s)
- Alexander G Nickel
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany.,Affiliation when/at which experiments were performed: Clinic III for Internal Medicine, University Clinic Homburg, Homburg, Germany
| | - Michael Kohlhaas
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany.,Affiliation when/at which experiments were performed: Clinic III for Internal Medicine, University Clinic Homburg, Homburg, Germany
| | - Edoardo Bertero
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany
| | - Daniel Wilhelm
- Affiliation when/at which experiments were performed: Clinic III for Internal Medicine, University Clinic Homburg, Homburg, Germany
| | - Michael Wagner
- Affiliation when/at which experiments were performed: Clinic III for Internal Medicine, University Clinic Homburg, Homburg, Germany.,Institute for Molecular Cell Biology, Saarland University, Homburg, Germany
| | - Vasco Sequeira
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany
| | - Michael M Kreusser
- Institute of Experimental Cardiology, Heidelberg University Hospital, Heidelberg, Germany.,German Center for Cardiovascular Research (DZHK), partner site Heidelberg/Mannheim, Germany.,Department of Cardiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Matthias Dewenter
- Institute of Experimental Cardiology, Heidelberg University Hospital, Heidelberg, Germany.,German Center for Cardiovascular Research (DZHK), partner site Heidelberg/Mannheim, Germany
| | - Reinhard Kappl
- Department of Biophysics, CIPMM, School of Medicine, Saarland University, Homburg, Germany
| | - Markus Hoth
- Department of Biophysics, CIPMM, School of Medicine, Saarland University, Homburg, Germany
| | - Jan Dudek
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany
| | - Johannes Backs
- Institute of Experimental Cardiology, Heidelberg University Hospital, Heidelberg, Germany.,German Center for Cardiovascular Research (DZHK), partner site Heidelberg/Mannheim, Germany
| | - Christoph Maack
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Würzburg, Germany
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189
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Cao JL, Adaniya SM, Cypress MW, Suzuki Y, Kusakari Y, Jhun BS, O-Uchi J. Role of mitochondrial Ca 2+ homeostasis in cardiac muscles. Arch Biochem Biophys 2019; 663:276-287. [PMID: 30684463 PMCID: PMC6469710 DOI: 10.1016/j.abb.2019.01.027] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 01/10/2019] [Accepted: 01/22/2019] [Indexed: 12/22/2022]
Abstract
Recent discoveries of the molecular identity of mitochondrial Ca2+ influx/efflux mechanisms have placed mitochondrial Ca2+ transport at center stage in views of cellular regulation in various cell-types/tissues. Indeed, mitochondria in cardiac muscles also possess the molecular components for efficient uptake and extraction of Ca2+. Over the last several years, multiple groups have taken advantage of newly available molecular information about these proteins and applied genetic tools to delineate the precise mechanisms for mitochondrial Ca2+ handling in cardiomyocytes and its contribution to excitation-contraction/metabolism coupling in the heart. Though mitochondrial Ca2+ has been proposed as one of the most crucial secondary messengers in controlling a cardiomyocyte's life and death, the detailed mechanisms of how mitochondrial Ca2+ regulates physiological mitochondrial and cellular functions in cardiac muscles, and how disorders of this mechanism lead to cardiac diseases remain unclear. In this review, we summarize the current controversies and discrepancies regarding cardiac mitochondrial Ca2+ signaling that remain in the field to provide a platform for future discussions and experiments to help close this gap.
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Affiliation(s)
- Jessica L Cao
- Cardiovascular Research Center, Rhode Island Hospital, Providence, RI, USA; Department of Medicine, Division of Cardiology, The Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Stephanie M Adaniya
- Cardiovascular Research Center, Rhode Island Hospital, Providence, RI, USA; Department of Medicine, Division of Cardiology, The Warren Alpert Medical School of Brown University, Providence, RI, USA; Lillehei Heart Institute, Department of Medicine, Cardiovascular Division, University of Minnesota, Minneapolis, MN, USA
| | - Michael W Cypress
- Lillehei Heart Institute, Department of Medicine, Cardiovascular Division, University of Minnesota, Minneapolis, MN, USA
| | - Yuta Suzuki
- Lillehei Heart Institute, Department of Medicine, Cardiovascular Division, University of Minnesota, Minneapolis, MN, USA
| | - Yoichiro Kusakari
- Department of Cell Physiology, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Bong Sook Jhun
- Lillehei Heart Institute, Department of Medicine, Cardiovascular Division, University of Minnesota, Minneapolis, MN, USA
| | - Jin O-Uchi
- Lillehei Heart Institute, Department of Medicine, Cardiovascular Division, University of Minnesota, Minneapolis, MN, USA.
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190
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Crystal structure of MICU2 and comparison with MICU1 reveal insights into the uniporter gating mechanism. Proc Natl Acad Sci U S A 2019; 116:3546-3555. [PMID: 30755530 DOI: 10.1073/pnas.1817759116] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The mitochondrial uniporter is a Ca2+-channel complex resident within the organelle's inner membrane. In mammalian cells the uniporter's activity is regulated by Ca2+ due to concerted action of MICU1 and MICU2, two paralogous, but functionally distinct, EF-hand Ca2+-binding proteins. Here we present the X-ray structure of the apo form of Mus musculus MICU2 at 2.5-Å resolution. The core structure of MICU2 is very similar to that of MICU1. It consists of two lobes, each containing one canonical Ca2+-binding EF-hand (EF1, EF4) and one structural EF-hand (EF2, EF3). Two molecules of MICU2 form a symmetrical dimer stabilized by highly conserved hydrophobic contacts between exposed residues of EF1 of one monomer and EF3 of another. Similar interactions stabilize MICU1 dimers, allowing exchange between homo- and heterodimers. The tight EF1-EF3 interface likely accounts for the structural and functional coupling between the Ca2+-binding sites in MICU1, MICU2, and their complex that leads to the previously reported Ca2+-binding cooperativity and dominant negative effect of mutation of the Ca2+-binding sites in either protein. The N- and C-terminal segments of the two proteins are distinctly different. In MICU2 the C-terminal helix is significantly longer than in MICU1, and it adopts a more rigid structure. MICU2's C-terminal helix is dispensable in vitro for its interaction with MICU1 but required for MICU2's function in cells. We propose that in the MICU1-MICU2 oligomeric complex the C-terminal helices of both proteins form a central semiautonomous assembly which contributes to the gating mechanism of the uniporter.
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191
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Woods J, Nemani N, Shanmughapriya S, Kumar A, Zhang M, Nathan SR, Thomas M, Carvalho E, Ramachandran K, Srikantan S, Stathopulos PB, Wilson JJ, Madesh M. A Selective and Cell-Permeable Mitochondrial Calcium Uniporter (MCU) Inhibitor Preserves Mitochondrial Bioenergetics after Hypoxia/Reoxygenation Injury. ACS CENTRAL SCIENCE 2019; 5:153-166. [PMID: 30693334 PMCID: PMC6346394 DOI: 10.1021/acscentsci.8b00773] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Indexed: 05/10/2023]
Abstract
Mitochondrial Ca2+ (mCa2+) uptake mediated by the mitochondrial calcium uniporter (MCU) plays a critical role in signal transduction, bioenergetics, and cell death, and its dysregulation is linked to several human diseases. In this study, we report a new ruthenium complex Ru265 that is cell-permeable, minimally toxic, and highly potent with respect to MCU inhibition. Cells treated with Ru265 show inhibited MCU activity without any effect on cytosolic Ca2+ dynamics and mitochondrial membrane potential (ΔΨm). Dose-dependent studies reveal that Ru265 is more potent than the currently employed MCU inhibitor Ru360. Site-directed mutagenesis of Cys97 in the N-terminal domain of human MCU ablates the inhibitory activity of Ru265, suggesting that this matrix-residing domain is its target site. Additionally, Ru265 prevented hypoxia/reoxygenation injury and subsequent mitochondrial dysfunction, demonstrating that this new inhibitor is a valuable tool for studying the functional role of the MCU in intact biological models.
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Affiliation(s)
- Joshua
J. Woods
- Robert
F. Smith School for Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
- Department
of Chemistry and Chemical Biology, Cornell
University, Ithaca, New York 14853, United
States
| | - Neeharika Nemani
- Department
of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania 19140, United States
- Center
for Translational Medicine, Lewis Katz School
of Medicine at Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Santhanam Shanmughapriya
- Department
of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania 19140, United States
- Center
for Translational Medicine, Lewis Katz School
of Medicine at Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Akshay Kumar
- Department
of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania 19140, United States
- Center
for Translational Medicine, Lewis Katz School
of Medicine at Temple University, Philadelphia, Pennsylvania 19140, United States
| | - MengQi Zhang
- Department
of Physiology and Pharmacology, Western
University, London, Ontario N6A 5C1, Canada
| | - Sarah R. Nathan
- Department
of Chemistry and Chemical Biology, Cornell
University, Ithaca, New York 14853, United
States
| | - Manfred Thomas
- Department
of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania 19140, United States
- Center
for Translational Medicine, Lewis Katz School
of Medicine at Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Edmund Carvalho
- Department
of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania 19140, United States
- Center
for Translational Medicine, Lewis Katz School
of Medicine at Temple University, Philadelphia, Pennsylvania 19140, United States
| | - Karthik Ramachandran
- Department
of Medicine/Nephrology, Institute for Precision Medicine and Health, University of Texas Health San Antonio, San Antonio, Texas 78229, United States
| | - Subramanya Srikantan
- Department
of Medicine/Nephrology, Institute for Precision Medicine and Health, University of Texas Health San Antonio, San Antonio, Texas 78229, United States
| | - Peter B. Stathopulos
- Department
of Physiology and Pharmacology, Western
University, London, Ontario N6A 5C1, Canada
| | - Justin J. Wilson
- Department
of Chemistry and Chemical Biology, Cornell
University, Ithaca, New York 14853, United
States
| | - Muniswamy Madesh
- Department
of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania 19140, United States
- Center
for Translational Medicine, Lewis Katz School
of Medicine at Temple University, Philadelphia, Pennsylvania 19140, United States
- Department
of Medicine/Nephrology, Institute for Precision Medicine and Health, University of Texas Health San Antonio, San Antonio, Texas 78229, United States
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192
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Phillips CB, Tsai CW, Tsai MF. The conserved aspartate ring of MCU mediates MICU1 binding and regulation in the mitochondrial calcium uniporter complex. eLife 2019; 8:41112. [PMID: 30638448 PMCID: PMC6347451 DOI: 10.7554/elife.41112] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 01/07/2019] [Indexed: 01/09/2023] Open
Abstract
The mitochondrial calcium uniporter is a Ca2+ channel that regulates intracellular Ca2+ signaling, oxidative phosphorylation, and apoptosis. It contains the pore-forming MCU protein, which possesses a DIME sequence thought to form a Ca2+ selectivity filter, and also regulatory EMRE, MICU1, and MICU2 subunits. To properly carry out physiological functions, the uniporter must stay closed in resting conditions, becoming open only when stimulated by intracellular Ca2+ signals. This Ca2+-dependent activation, known to be mediated by MICU subunits, is not well understood. Here, we demonstrate that the DIME-aspartate mediates a Ca2+-modulated electrostatic interaction with MICU1, forming an MICU1 contact interface with a nearby Ser residue at the cytoplasmic entrance of the MCU pore. A mutagenesis screen of MICU1 identifies two highly-conserved Arg residues that might contact the DIME-Asp. Perturbing MCU-MICU1 interactions elicits unregulated, constitutive Ca2+ flux into mitochondria. These results indicate that MICU1 confers Ca2+-dependent gating of the uniporter by blocking/unblocking MCU.
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Affiliation(s)
| | - Chen-Wei Tsai
- Department of Biochemistry, Brandeis University, Waltham, United States.,Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, United States
| | - Ming-Feng Tsai
- Department of Biochemistry, Brandeis University, Waltham, United States.,Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, United States
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193
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Leanza L, Checchetto V, Biasutto L, Rossa A, Costa R, Bachmann M, Zoratti M, Szabo I. Pharmacological modulation of mitochondrial ion channels. Br J Pharmacol 2019; 176:4258-4283. [PMID: 30440086 DOI: 10.1111/bph.14544] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 10/15/2018] [Accepted: 10/22/2018] [Indexed: 12/17/2022] Open
Abstract
The field of mitochondrial ion channels has undergone a rapid development during the last three decades, due to the molecular identification of some of the channels residing in the outer and inner membranes. Relevant information about the function of these channels in physiological and pathological settings was gained thanks to genetic models for a few, mitochondria-specific channels. However, many ion channels have multiple localizations within the cell, hampering a clear-cut determination of their function by pharmacological means. The present review summarizes our current knowledge about the ins and outs of mitochondrial ion channels, with special focus on the channels that have received much attention in recent years, namely, the voltage-dependent anion channels, the permeability transition pore (also called mitochondrial megachannel), the mitochondrial calcium uniporter and some of the inner membrane-located potassium channels. In addition, possible strategies to overcome the difficulties of specifically targeting mitochondrial channels versus their counterparts active in other membranes are discussed, as well as the possibilities of modulating channel function by small peptides that compete for binding with protein interacting partners. Altogether, these promising tools along with large-scale chemical screenings set up to identify new, specific channel modulators will hopefully allow us to pinpoint the actual function of most mitochondrial ion channels in the near future and to pharmacologically affect important pathologies in which they are involved, such as neurodegeneration, ischaemic damage and cancer. LINKED ARTICLES: This article is part of a themed section on Mitochondrial Pharmacology: Featured Mechanisms and Approaches for Therapy Translation. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.22/issuetoc.
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Affiliation(s)
- Luigi Leanza
- Department of Biology, University of Padova, Padova, Italy
| | | | - Lucia Biasutto
- CNR Institute of Neurosciences, Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Andrea Rossa
- Department of Chemical Sciences, University of Padova, Padova, Italy
| | - Roberto Costa
- Department of Biology, University of Padova, Padova, Italy
| | | | - Mario Zoratti
- CNR Institute of Neurosciences, Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Ildiko Szabo
- Department of Biology, University of Padova, Padova, Italy.,CNR Institute of Neurosciences, Department of Biomedical Sciences, University of Padova, Padova, Italy
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194
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Checchetto V, Szabò I. Electrophysiological Characterization of Calcium-Permeable Channels Using Planar Lipid Bilayer. Methods Mol Biol 2019; 1925:65-73. [PMID: 30674017 DOI: 10.1007/978-1-4939-9018-4_6] [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: 06/09/2023]
Abstract
Numerous researchers tried to identify the key players of calcium signaling in mitochondria using molecular and cell biology techniques for more than five decades. However, only an integrated approach involving also electrophysiological techniques has finally allowed to define the components of the protein complex responsible for the uptake of this ion into mitochondria.Here we describe the protocol used for the electrophysiological characterization of the mitochondrial calcium uniporter (MCU) complex: the following outline indicates step-by-step the setup of planar lipid bilayer experiments.
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Affiliation(s)
| | - Ildikò Szabò
- Department of Biology, University of Padua, Padua, Italy
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195
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Marchi S, Corricelli M, Branchini A, Vitto VAM, Missiroli S, Morciano G, Perrone M, Ferrarese M, Giorgi C, Pinotti M, Galluzzi L, Kroemer G, Pinton P. Akt-mediated phosphorylation of MICU1 regulates mitochondrial Ca 2+ levels and tumor growth. EMBO J 2018; 38:embj.201899435. [PMID: 30504268 DOI: 10.15252/embj.201899435] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 10/08/2018] [Accepted: 10/15/2018] [Indexed: 12/13/2022] Open
Abstract
Although mitochondria play a multifunctional role in cancer progression and Ca2+ signaling is remodeled in a wide variety of tumors, the underlying mechanisms that link mitochondrial Ca2+ homeostasis with malignant tumor formation and growth remain elusive. Here, we show that phosphorylation at the N-terminal region of the mitochondrial calcium uniporter (MCU) regulatory subunit MICU1 leads to a notable increase in the basal mitochondrial Ca2+ levels. A pool of active Akt in the mitochondria is responsible for MICU1 phosphorylation, and mitochondrion-targeted Akt strongly regulates the mitochondrial Ca2+ content. The Akt-mediated phosphorylation impairs MICU1 processing and stability, culminating in reactive oxygen species (ROS) production and tumor progression. Thus, our data reveal the crucial role of the Akt-MICU1 axis in cancer and underscore the strategic importance of the association between aberrant mitochondrial Ca2+ levels and tumor development.
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Affiliation(s)
- Saverio Marchi
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Mariangela Corricelli
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Alessio Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Veronica Angela Maria Vitto
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Sonia Missiroli
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Giampaolo Morciano
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy.,Maria Cecilia Hospital, GVM Care & Research, Cotignola, Italy
| | - Mariasole Perrone
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Mattia Ferrarese
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Carlotta Giorgi
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Mirko Pinotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Lorenzo Galluzzi
- Department of Radiation Oncology, Weill Cornell Medical College, New York, NY, USA.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Guido Kroemer
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,Equipe 11 Labellisée Ligue Nationale Contre le Cancer, Centre de Recherche des Cordeliers, Paris, France.,Institut National de la Santé et de la Recherche Médicale, U1138, Paris, France.,Université Pierre et Marie Curie, Paris, France.,Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France.,Center of Clinical Investigations in Biotherapies of Cancer (CICBT), Villejuif, France.,Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, Paris, France.,Department of Women's and Children's Health, Karolinska University Hospital, Stockholm, Sweden
| | - Paolo Pinton
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy .,Maria Cecilia Hospital, GVM Care & Research, Cotignola, Italy
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196
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Abstract
In the last few decades, a large body of experimental evidence has highlighted the complex role for mitochondria in eukaryotic cells: they are not only the site of aerobic metabolism (thus providing most of the ATP supply for endergonic processes) but also a crucial checkpoint of cell death processes (both necrosis and apoptosis) and autophagy. For this purpose, mitochondria must receive and decode the wide variety of physiological and pathological stimuli impacting on the cell. The “old” notion that mitochondria possess a sophisticated machinery for accumulating and releasing Ca
2+, the most common and versatile second messenger of eukaryotic cells, is thus no surprise. What may be surprising is that the identification of the molecules involved in mitochondrial Ca
2+ transport occurred only in the last decade for both the influx (the mitochondrial Ca
2+ uniporter, MCU) and the efflux (the sodium calcium exchanger, NCX) pathways. In this review, we will focus on the description of the amazing molecular complexity of the MCU complex, highlighting the numerous functional implications of the tissue-specific expression of the variants of the channel pore components (MCU/MCUb) and of the associated proteins (MICU 1, 2, and 3, EMRE, and MCUR1).
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Affiliation(s)
- Giorgia Pallafacchina
- Department of Biomedical Sciences, University of Padua, Padua, 35131, Italy.,Italian National Research Council (CNR), Neuroscience Institute, Padua, 35131, Italy
| | - Sofia Zanin
- Department of Medicine, University of Padua, Padua, 35128, Italy
| | - Rosario Rizzuto
- Department of Biomedical Sciences, University of Padua, Padua, 35131, Italy
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197
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Kwong JQ, Huo J, Bround MJ, Boyer JG, Schwanekamp JA, Ghazal N, Maxwell JT, Jang YC, Khuchua Z, Shi K, Bers DM, Davis J, Molkentin JD. The mitochondrial calcium uniporter underlies metabolic fuel preference in skeletal muscle. JCI Insight 2018; 3:121689. [PMID: 30429366 DOI: 10.1172/jci.insight.121689] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 10/04/2018] [Indexed: 01/17/2023] Open
Abstract
The mitochondrial Ca2+ uniporter (MCU) complex mediates acute mitochondrial Ca2+ influx. In skeletal muscle, MCU links Ca2+ signaling to energy production by directly enhancing the activity of key metabolic enzymes in the mitochondria. Here, we examined the role of MCU in skeletal muscle development and metabolic function by generating mouse models for the targeted deletion of Mcu in embryonic, postnatal, and adult skeletal muscle. Loss of Mcu did not affect muscle growth and maturation or otherwise cause pathology. Skeletal muscle-specific deletion of Mcu in mice also did not affect myofiber intracellular Ca2+ handling, but it did inhibit acute mitochondrial Ca2+ influx and mitochondrial respiration stimulated by Ca2+, resulting in reduced acute exercise performance in mice. However, loss of Mcu also resulted in enhanced muscle performance under conditions of fatigue, with a preferential shift toward fatty acid metabolism, resulting in reduced body fat with aging. Together, these results demonstrate that MCU-mediated mitochondrial Ca2+ regulation underlies skeletal muscle fuel selection at baseline and under enhanced physiological demands, which affects total homeostatic metabolism.
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Affiliation(s)
- Jennifer Q Kwong
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, USA.,Department of Pediatrics, Division of Cardiovascular Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Jiuzhou Huo
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, USA
| | - Michael J Bround
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, USA
| | - Justin G Boyer
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, USA
| | - Jennifer A Schwanekamp
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, USA
| | - Nasab Ghazal
- Department of Pediatrics, Division of Cardiovascular Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Joshua T Maxwell
- Department of Pediatrics, Division of Cardiovascular Biology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Young C Jang
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Zaza Khuchua
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, USA.,Sechenov University, Moscow, Russia
| | - Kevin Shi
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis, California, USA
| | - Jennifer Davis
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Jeffery D Molkentin
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, USA.,Howard Hughes Medical Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
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198
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Paillard M, Csordás G, Huang KT, Várnai P, Joseph SK, Hajnóczky G. MICU1 Interacts with the D-Ring of the MCU Pore to Control Its Ca 2+ Flux and Sensitivity to Ru360. Mol Cell 2018; 72:778-785.e3. [PMID: 30454562 PMCID: PMC6251499 DOI: 10.1016/j.molcel.2018.09.008] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 07/20/2018] [Accepted: 09/06/2018] [Indexed: 01/04/2023]
Abstract
Proper control of the mitochondrial Ca2+ uniporter's pore (MCU) is required to allow Ca2+-dependent activation of oxidative metabolism and to avoid mitochondrial Ca2+ overload and cell death. The MCU's gatekeeping and cooperative activation is mediated by the Ca2+-sensing MICU1 protein, which has been proposed to form dimeric complexes anchored to the EMRE scaffold of MCU. We unexpectedly find that MICU1 suppresses inhibition of MCU by ruthenium red/Ru360, which bind to MCU's DIME motif, the selectivity filter. This led us to recognize in MICU1's sequence a putative DIME interacting domain (DID), which is required for both gatekeeping and cooperative activation of MCU and for cell survival. Thus, we propose that MICU1 has to interact with the D-ring formed by the DIME domains in MCU to control the uniporter.
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Affiliation(s)
- Melanie Paillard
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - György Csordás
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Kai-Ting Huang
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Peter Várnai
- Department of Physiology, Semmelweis University, Budapest, 1094 Hungary
| | - Suresh K Joseph
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - György Hajnóczky
- MitoCare Center, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
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199
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Wang P, Fernandez-Sanz C, Wang W, Sheu SS. Why don't mice lacking the mitochondrial Ca 2+ uniporter experience an energy crisis? J Physiol 2018; 598:1307-1326. [PMID: 30218574 DOI: 10.1113/jp276636] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 08/28/2018] [Indexed: 01/15/2023] Open
Abstract
Current dogma holds that the heart balances energy demand and supply effectively and sustainably by sequestering enough Ca2+ into mitochondria during heartbeats to stimulate metabolic enzymes in the tricarboxylic acid (TCA) cycle and electron transport chain (ETC). This process is called excitation-contraction-bioenergetics (ECB) coupling. Recent breakthroughs in identifying the mitochondrial Ca2+ uniporter (MCU) and its associated proteins have opened up new windows for interrogating the molecular mechanisms of mitochondrial Ca2+ homeostasis regulation and its role in ECB coupling. Despite remarkable progress made in the past 7 years, it has been surprising, almost disappointing, that germline MCU deficiency in mice with certain genetic background yields viable pups, and knockout of the MCU in adult heart does not cause lethality. Moreover, MCU deficiency results in few adverse phenotypes, normal performance, and preserved bioenergetics in the heart at baseline. In this review, we briefly assess the existing literature on mitochondrial Ca2+ homeostasis regulation and then we consider possible explanations for why MCU-deficient mice are spared from energy crises under physiological conditions. We propose that MCU and/or mitochondrial Ca2+ may have limited ability to set ECB coupling, that other mitochondrial Ca2+ handling mechanisms may play a role, and that extra-mitochondrial Ca2+ may regulate ECB coupling. Since the heart needs to regenerate a significant amount of ATP to assure the perpetuation of heartbeats, multiple mechanisms are likely to work in concert to match energy supply with demand.
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Affiliation(s)
- Pei Wang
- Mitochondria and Metabolism Center, Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, 98109, USA
| | - Celia Fernandez-Sanz
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Wang Wang
- Mitochondria and Metabolism Center, Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, 98109, USA
| | - Shey-Shing Sheu
- Center for Translational Medicine, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 19107, USA
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200
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Wang L, Wang L, Chen Q, Chen G, Zhang S, Wu J, Tao S. Identification and comparative analysis of the MCU gene family in pear and its functions during fruit ripening. JOURNAL OF PLANT PHYSIOLOGY 2018; 229:53-62. [PMID: 30036746 DOI: 10.1016/j.jplph.2018.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 07/10/2018] [Accepted: 07/10/2018] [Indexed: 06/08/2023]
Abstract
Mitochondrial calcium uniporter (MCU) plays an important role in cell senescence and aging in mammals. However, the function of MCU homologs during the ripening and senescence of postharvest fruit had not been characterized until recently. In this study, a comprehensive study was conducted on the characteristics of the MCU family genes in the pear genome. In total, seven PbrMCU genes were identified and classified into two subgroups. Whole-genome duplication (WGD)/segmental duplication is the main driving force behind their expansion. The genes contained various conserved motifs and cis-acting elements, and the correspondent proteins possessed a serial of conserved motifs. A total of six PbrMCUs with diverse expression patterns were detected as the pear fruit ripened. Following the results of the impact of postharvest treatments (ethrel and 1-methylcyclopropene) and transient overexpression of 1-aminocyclopropane-1-carboxylate oxidase 1 gene (PbrACO1), the candidate genes PbrMCU3, PbrMCU4, and PbrMCU7 were determined to be involved in pear ripening. Moreover, the response of mitochondrial calcium uptake 1 (PbrMICU1) transcription to the postharvest treatments was similar to that of PbrMCU4.
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Affiliation(s)
- Li Wang
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Libin Wang
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Qian Chen
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Guodong Chen
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Shaoling Zhang
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China
| | - Juyou Wu
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China.
| | - Sutian Tao
- Centre of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China.
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