Mitochondrial calcium uniporter (MCU) is a highly selective Ca~(2+) channel protein of the mitochondria inner membrane [1], which allows divalent cations (Ca~(2+) ≈Sr~(2+) >>Mn~(2+) ≈Ba~(2+)) to permeate [2]. The MCU is a 40-kDa protein that contains a proteolytically cleaved mitochondrial import sequence, two coiled-coil domains, two transmembrane domains, and a short motif of amino acids between the two transmembrane domains critical for Ca~(2+) transport [3]. MCU is widely expressed in the mitochondrial inner membrane of various cells [4]....