This entry represents a group of calcium uptake proteins, including MICU1/2/3 from humans. They contain the conserved EF-hand Ca2+-binding domains. MICU1 and MICU2 are the main regulators of the mitochondrial Ca(2+)-uniporter (MCU) []. MICU2 forms a heterodimer with MICU1 to modulate MCU channel activity []. MICU3 a tissue-specific enhancer of mitochondrial calcium uptake [].
Essential MCU regulator (EMRE) is a component of the mitochondrial calcium uniporter complex in metazoa, a complex that mediates calcium uptake into mitochondria. It bridges the calcium-sensing components of the complex, MICU1 and MICU2, and the pore-forming subunit MCU, and it is essential for the complex uniporter activity [].
Mitochondrial intermembrane space import and assembly protein 40 (CHCHD4) is a chaperone and catalyses the formation of disulfide bonds in proteins within the mitochondrial intermembrane space (IMS) such as COX17 [], COX19 [], MICU1 []and GFER []. A precursor of one of these proteins in a reduced state is imported into the mitochondrion where it associates with CHCHD4 forming a transient intermolecular disulfide bridge. This leads to oxidation of the precursor, formation of an intramolecular disulfide bond and the folding in the IMS [].This entry also includes the uncharacterized protein F42H10.2 from Caenorhabditis elegans.
