In vivo Reconstitution of the Mitochondrial Uniporter

The mitochondrial uniporter is a highly selective calcium channel present broadly in eukaryotes, but absent in Saccharomyces cerevisiae. Therefore, we used yeast as a reconstitution system to identify the minimal components sufficient for in vivo uniporter activity. First, we considered Dictyostelium discoideum and showed that it has a highly simplified uniporter machinery: the expression of DdMCU, a single transmembrane component alone is sufficient to reconstitute mitochondrial calcium uniporter activity. Second, to establish human uniporter activity, the coexpression of MCU and - the animal specific protein - EMRE is necessary, whereas expression of MCU alone is insufficient. Our work established yeast as a powerful in vivo reconstitution system for the uniporter to study the evolution and function of this channel.