Medicine and Health Sciences Commons^™

Micu1 Interacts With The D-Ring Of The Mcu Pore To Control Its Ca2+ Flux And Sensitivity To Ru360, Melanie Paillard, György Csordás, Kai-Ting Huang, Peter Várnai, Suresh K. Joseph, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

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 …