MCUR1, CCDC90A, Is a Regulator of the Mitochondrial Calcium Uniporter

MCU is the pore-forming subunit of the mitochondrial inner membrane Ca2+ uniporter ion channel that mediates Ca2+ uptake into the matrix to regulate metabolism, cell death, and cytoplasmic Ca2+ signaling. We previously identified MCUR1 (Mitochondrial Calcium Uniporter Regulator 1) as an important regulator of MCU activity and showed that MCUR1 biochemically interacted with MCU (Mallilankaraman et al., 2012). MCUR1 regulated MCU-dependent mitochondrial Ca2+ uptake driven by the inner membrane voltage (ψm) generated by the electron transport chain, and MCUR1 knockdown abrogated Ca2+ uptake by mitochondria in intact and permeabilized cells, and disrupted oxidative phosphorylation (OXPHOS).