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Bulthuis EP, Adjobo-Hermans MJW, de Potter B, Hoogstraten S, Wezendonk LHT, Tutakhel OAZ, Wintjes LT, van den Heuvel B, Willems PHGM, Kamsteeg EJ, Gozalbo MER, Sallevelt SCEH, Koudijs SM, Nicolai J, de Bie CI, Hoogendijk JE, Koopman WJH, Rodenburg RJ. SMDT1 variants impair EMRE-mediated mitochondrial calcium uptake in patients with muscle involvement. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166808. [PMID: 37454773 DOI: 10.1016/j.bbadis.2023.166808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/26/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023]
Abstract
Ionic calcium (Ca2+) is a key messenger in signal transduction and its mitochondrial uptake plays an important role in cell physiology. This uptake is mediated by the mitochondrial Ca2+ uniporter (MCU), which is regulated by EMRE (essential MCU regulator) encoded by the SMDT1 (single-pass membrane protein with aspartate rich tail 1) gene. This work presents the genetic, clinical and cellular characterization of two patients harbouring SMDT1 variants and presenting with muscle problems. Analysis of patient fibroblasts and complementation experiments demonstrated that these variants lead to absence of EMRE protein, induce MCU subcomplex formation and impair mitochondrial Ca2+ uptake. However, the activity of oxidative phosphorylation enzymes, mitochondrial morphology and membrane potential, as well as routine/ATP-linked respiration were not affected. We hypothesize that the muscle-related symptoms in the SMDT1 patients result from aberrant mitochondrial Ca2+ uptake.
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Affiliation(s)
- Elianne P Bulthuis
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Merel J W Adjobo-Hermans
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Bastiaan de Potter
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Saskia Hoogstraten
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands; Human and Animal Physiology, Wageningen University & Research, 6700 AH Wageningen, the Netherlands
| | - Lisanne H T Wezendonk
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Omar A Z Tutakhel
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Liesbeth T Wintjes
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Bert van den Heuvel
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Peter H G M Willems
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - Erik-Jan Kamsteeg
- Department of Human Genetics, Radboud University Medical Centre, 6525 GA Nijmegen, the Netherlands
| | - M Estela Rubio Gozalbo
- Department of Pediatrics, Maastricht University Medical Centre, 6229 HX Maastricht, the Netherlands; Department of Clinical Genetics, Maastricht University Medical Centre, 6229 HX Maastricht, the Netherlands
| | - Suzanne C E H Sallevelt
- Department of Clinical Genetics, Maastricht University Medical Centre, 6229 HX Maastricht, the Netherlands
| | - Suzanne M Koudijs
- Department of Neurology, Maastricht University Medical Centre, 6229 HX Maastricht, the Netherlands
| | - Joost Nicolai
- Department of Neurology, Maastricht University Medical Centre, 6229 HX Maastricht, the Netherlands
| | - Charlotte I de Bie
- Department of Genetics, University Medical Centre Utrecht, 3508 AB Utrecht, the Netherlands
| | - Jessica E Hoogendijk
- Rudolf Magnus Institute of Neuroscience, University Medical Centre Utrecht, 3584 CG Utrecht, the Netherlands
| | - Werner J H Koopman
- Human and Animal Physiology, Wageningen University & Research, 6700 AH Wageningen, the Netherlands; Department of Pediatrics, Amalia Children's Hospital, Radboud Center for Mitochondrial Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands.
| | - Richard J Rodenburg
- Department of Pediatrics, Amalia Children's Hospital, Radboud Center for Mitochondrial Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6500 HB Nijmegen, the Netherlands.
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