TY - JOUR AU - Vetralla, Massimo AU - Wischhof, Lena AU - Kahsay, Asrat AU - Cadenelli, Vanessa AU - Scifo, Enzo AU - Xie, Beijia AU - Sbrissa, Miriana AU - Habert, Maelle AU - Ehninger, Dan AU - Rizzuto, Rosario AU - Bano, Daniele AU - De Stefani, Diego TI - TMEM65-dependent Ca2+ extrusion safeguards mitochondrial homeostasis. JO - Nature Communications VL - 17 IS - 1 SN - 2041-1723 CY - [London] PB - Springer Nature M1 - DZNE-2026-00112 SP - 923 PY - 2025 AB - The bidirectional transport of Ca2+ into and out of mitochondria regulates metabolism, signaling, and cell fate. While influx is mediated by the Mitochondrial Calcium Uniporter (MCU) complex, efflux mechanisms are more diversified, involving Na⁺ or H⁺ exchange pathways. We here demonstrate that TMEM65 is a fundamental component of the Ca2+ efflux machinery of mitochondria. Its overexpression specifically enhances Na⁺- and Li⁺-dependent mitochondrial Ca²⁺ extrusion. This effect is inhibited by CGP-37157 and does not depends on NCLX, currently considered the bona fide mitochondrial Na+/Ca2+ exchanger. Its downregulation chronically elevates basal [Ca²⁺]mt and impairs efflux upon stimulation. In Caenorhabditis elegans, deletion of TMEM65 homologs compromises embryonic development under mild thermal stress, causing necrotic lesions that are suppressed by genetic inhibition of MCU-1. These findings highlight a molecular component that may be relevant in pathological settings in which excessive mitochondrial Ca2+ accumulation critically contribute to degenerative pathways. KW - Animals KW - Mitochondria: metabolism KW - Caenorhabditis elegans: metabolism KW - Caenorhabditis elegans: genetics KW - Calcium: metabolism KW - Homeostasis KW - Caenorhabditis elegans Proteins: metabolism KW - Caenorhabditis elegans Proteins: genetics KW - Membrane Proteins: metabolism KW - Membrane Proteins: genetics KW - Calcium Channels: metabolism KW - Calcium Channels: genetics KW - Clonazepam: analogs & derivatives KW - Clonazepam: pharmacology KW - Sodium-Calcium Exchanger: metabolism KW - Sodium-Calcium Exchanger: genetics KW - Humans KW - Mitochondrial Proteins: metabolism KW - Mitochondrial Proteins: genetics KW - Thiazepines KW - Calcium (NLM Chemicals) KW - Caenorhabditis elegans Proteins (NLM Chemicals) KW - Membrane Proteins (NLM Chemicals) KW - Calcium Channels (NLM Chemicals) KW - Clonazepam (NLM Chemicals) KW - mitochondrial calcium uniporter (NLM Chemicals) KW - Sodium-Calcium Exchanger (NLM Chemicals) KW - CGP 37157 (NLM Chemicals) KW - Mitochondrial Proteins (NLM Chemicals) KW - Thiazepines (NLM Chemicals) LB - PUB:(DE-HGF)16 C6 - pmid:41408045 C2 - pmc:PMC12830682 DO - DOI:10.1038/s41467-025-67647-y UR - https://pub.dzne.de/record/284337 ER -