Mitochondrial Ca2+ Uniporter Is a Mitochondrial Luminal Redox Sensor that Augments MCU Channel Activity

Zhiwei Dong; Santhanam Shanmughapriya; Dhanendra Tomar; Naveed Siddiqui; Solomon Lynch; Neeharika Nemani; Sarah L Breves; Xueqian Zhang; Aparna Tripathi; Palaniappan Palaniappan; Massimo F Riitano; Alison M Worth; Ajay Seelam; Edmund Carvalho; Ramasamy Subbiah; Fabián Jaña; Jonathan Soboloff; Yizhi Peng; Joseph Y Cheung; Suresh K Joseph; Jeffrey Caplan; Sudarsan Rajan; Peter B Stathopulos; Muniswamy Madesh

doi:10.1016/j.molcel.2017.01.032

Mitochondrial Ca²⁺ Uniporter Is a Mitochondrial Luminal Redox Sensor that Augments MCU Channel Activity

Mol Cell. 2017 Mar 16;65(6):1014-1028.e7. doi: 10.1016/j.molcel.2017.01.032. Epub 2017 Mar 2.

Authors

Zhiwei Dong¹, Santhanam Shanmughapriya², Dhanendra Tomar², Naveed Siddiqui³, Solomon Lynch⁴, Neeharika Nemani², Sarah L Breves², Xueqian Zhang⁵, Aparna Tripathi², Palaniappan Palaniappan², Massimo F Riitano², Alison M Worth², Ajay Seelam², Edmund Carvalho², Ramasamy Subbiah², Fabián Jaña², Jonathan Soboloff⁶, Yizhi Peng⁷, Joseph Y Cheung⁵, Suresh K Joseph⁸, Jeffrey Caplan⁴, Sudarsan Rajan⁹, Peter B Stathopulos³, Muniswamy Madesh¹⁰

Affiliations

¹ Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Institute of Burn Research, Southwest Hospital, Third Military Medical University, Chongqing 400038, PRC.
² Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA.
³ Department of Physiology and Pharmacology, Western University, London, ON N6A 5C1, Canada.
⁴ Department of Biological Sciences, Delaware Biotechnology Institute, University of Delaware, Newark, DE 19711, USA.
⁵ Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA.
⁶ Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA.
⁷ Institute of Burn Research, Southwest Hospital, Third Military Medical University, Chongqing 400038, PRC.
⁸ MitoCare Center, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
⁹ Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA. Electronic address: sudarsan@temple.edu.
¹⁰ Department of Medical Genetics and Molecular Biochemistry, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Center for Translational Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA. Electronic address: madeshm@temple.edu.

Abstract

Ca²⁺ dynamics and oxidative signaling are fundamental mechanisms for mitochondrial bioenergetics and cell function. The MCU complex is the major pathway by which these signals are integrated in mitochondria. Whether and how these coactive elements interact with MCU have not been established. As an approach toward understanding the regulation of MCU channel by oxidative milieu, we adapted inflammatory and hypoxia models. We identified the conserved cysteine 97 (Cys-97) to be the only reactive thiol in human MCU that undergoes S-glutathionylation. Furthermore, biochemical, structural, and superresolution imaging analysis revealed that MCU oxidation promotes MCU higher order oligomer formation. Both oxidation and mutation of MCU Cys-97 exhibited persistent MCU channel activity with higher [Ca²⁺]_m uptake rate, elevated mROS, and enhanced [Ca²⁺]_m overload-induced cell death. In contrast, these effects were largely independent of MCU interaction with its regulators. These findings reveal a distinct functional role for Cys-97 in ROS sensing and regulation of MCU activity.

Keywords: EMRE; MCU; MCUR1; MICU1; MICU2; bioenergetics; calcium; gluathionylation; mitochondria; reactive oxygen species.

MeSH terms

Animals
COS Cells
Calcium / metabolism*
Calcium Channels / chemistry
Calcium Channels / genetics
Calcium Channels / metabolism*
Calcium Signaling* / drug effects
Cell Death
Cell Hypoxia
Chlorocebus aethiops
Cysteine
Endothelial Cells / drug effects
Endothelial Cells / metabolism*
Endothelial Cells / pathology
Energy Metabolism
Glutathione / metabolism
HEK293 Cells
HeLa Cells
Humans
Ion Channel Gating* / drug effects
Lipopolysaccharides / pharmacology
Mice
Mice, Inbred C57BL
Mice, Knockout
Mitochondria / drug effects
Mitochondria / metabolism*
Mitochondria / pathology
Mitochondrial Membranes / drug effects
Mitochondrial Membranes / metabolism*
Mitochondrial Membranes / pathology
Mutation
Oxidation-Reduction
Protein Multimerization
Protein Processing, Post-Translational
Protein Structure, Quaternary
Reactive Oxygen Species / metabolism*
Structure-Activity Relationship
Thrombin / pharmacology
Time Factors
Transfection

Substances

Calcium Channels
Lipopolysaccharides
Reactive Oxygen Species
mitochondrial calcium uniporter
Thrombin
Glutathione
Cysteine
Calcium

Abstract

MeSH terms

Substances

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