Letting Pyruvate In Transport of pyruvate is an important event in metabolism whereby the pyruvate formed in glycolysis is transported into mitochondria to feed into the tricarboxylic acid cycle (see the Perspective by Murphy and Divakaruni ). Two groups have now identified proteins that are components of the mitochondrial pyruvate transporter. Bricker et al. (p. 96 , published online 24 May) found that the proteins mitochondrial pyruvate carrier 1 and 2 (MPC1 and MPC2) are required for full pyruvate transport in yeast and Drosophila cells and that humans with mutations in MPC1 have metabolic defects consistent with loss of the transporter. Herzig et al. (p. 93 , published online 24 May) identified the same proteins as components of the carrier in yeast. Furthermore, expression of the mouse proteins in bacteria conferred increased transport of pyruvate into bacterial cells.