Integrative genomics identifies MCU as an essential component of the mitochondrial calcium uniporter

Central to the role of the mitochondrion in cellular metabolism is its ability to control the fluxes of the key signalling ion, Ca2+. This is done by a highly selective ion channel known as the mitochondrial calcium uniporter. The molecular nature of this channel has remained elusive, but now two groups report the identification of a 40-kilodalton protein in the inner membrane of mitochondria as the active channel of the uniporter. This protein contains two transmembrane domains and exhibits calcium-channel activity in vitro and in vivo.