Structural transport and inhibition mechanism of the mitochondrial pyruvate carrier

The mitochondrial pyruvate carrier (MPC), of the SLC54 family of solute carriers, has a critical role in eukaryotic energy metabolism by transporting pyruvate, the end-product of glycolysis, into the mitochondrial matrix. Recently, structures of the human MPC1/MPC2 and MPC1L/MPC2 heterodimers in the outward-open, occluded, and inward-open states have been determined by cryo-electron microscopy (cryo-EM) and by AlphaFold modeling. In this review we discuss the membrane orientation, substrate binding site properties, and structural features of the alternating access mechanism of the carrier, as well as the binding poses of three chemically distinct inhibitor classes, which exploit the same binding site in the outward-open state. These structural studies will support drug development efforts for the treatment of diabetes mellitus, neurodegeneration, metabolic dysfunction-associated steatotic liver disease (MASLD), and some types of cancers.