6x4s

Publication Abstract from PubMed

The proteins MCU and EMRE form the minimal functional unit of the mitochondrial calcium uniporter complex in metazoans, a highly selective and tightly controlled Ca(2+) channel of the inner mitochondrial membrane that regulates cellular metabolism. Here we present functional reconstitution of an MCU-EMRE complex from the red flour beetle, Tribolium castaneum, and a cryo-EM structure of the complex at 3.5A resolution. Using a novel assay, we demonstrate robust Ca(2+) uptake into proteoliposomes containing the purified complex. Uptake is dependent on EMRE and also on the mitochondrial lipid cardiolipin. The structure reveals a tetrameric channel with a single ion pore. EMRE is located at the periphery of the transmembrane domain and associates primarily with the first transmembrane helix of MCU. Coiled coil and juxtamembrane domains within the matrix portion of the complex adopt markedly different conformations than in a structure of a human MCU-EMRE complex, suggesting that the structures represent different conformations of these functionally similar metazoan channels.

Structure and Reconstitution of a MCU-EMRE Mitochondrial Ca(2+) Uniporter Complex.,Wang C, Baradaran R, Long SB J Mol Biol. 2020 Aug 22. pii: S0022-2836(20)30507-6. doi:, 10.1016/j.jmb.2020.08.013. PMID:32841658^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.