Mitochondrial ca2+ uptake by the voltage-dependent anion channel 2 regulates cardiac rhythmicity

Hirohito Shimizu, Johann Schredelseker, Jie Huang, Kui Lu, Shamim Naghdi, Fei Lu, Sarah Franklin, Hannah D.G. Fiji, Kevin Wang, Huanqi Zhu, Cheng Tian, Billy Lin, Haruko Nakano, Amy Ehrlich, Junichi Nakai, Adam Z. Stieg, James K. Gimzewski, Atsushi Nakano, Joshua I. Goldhaber, Thomas M. VondriskaGyörgy Hajnóczky, Ohyun Kwon, Jau Nian Chen

Research output: Contribution to journalArticlepeer-review

66 Citations (Scopus)


Tightly regulated Ca2+ homeostasis is a prerequisite for proper cardiac function. To dissect the regulatory network of cardiac Ca2+ handling, we performed a chemical suppressor screen on zebrafish tremblor embryos, which suffer from Ca2+ extrusion defects. Efsevin was identified based on its potent activity to restore coordinated contractions in tremblor. We show that efsevin binds to VDAC2, potentiates mitochondrial Ca2+ uptake and accelerates the transfer of Ca2+ from intracellular stores into mitochondria. In cardiomyocytes, efsevin restricts the temporal and spatial boundaries of Ca2+ sparks and thereby inhibits Ca2+ overload-induced erratic Ca2+ waves and irregular contractions. We further show that overexpression of VDAC2 recapitulates the suppressive effect of efsevin on tremblor embryos whereas VDAC2 deficiency attenuates efsevin's rescue effect and that VDAC2 functions synergistically with MCU to suppress cardiac fibrillation in tremblor. Together, these findings demonstrate a critic l modulatory role for VDAC2-dependent mitochondrial Ca2+ uptake in the regulation of cardiac rhythmicity.

Original languageEnglish
Article numbere04801
Issue number4
Publication statusPublished - 2015 Jan 15


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