**8. Oxoglutarate carrier**

The OGC mediates transfer of oxoglutarate across MIM in exchange for dicarboxylate. OGC is a component of malate-aspartate shuttle; thus, dicarboxylate is usually malate. After export, malate is converted into oxaloacetate, which is in transamination reaction with glutamate converted into oxoglutarate and aspartate. The oxoglutarate is then transported by OGC. Binding the succinate to the matrix side of the carrier increases the affinity for malate, while phenylsuccinate, pyridoxalphosphate, retinoic acid, or alcohol was found to inhibit OGC [171, 172]. The OGC inhibition causes a decrease in mitochondrial reduced glutathione levels by 40–50% [138]. The carrier has also been proposed as a porphyrin transporter, and its inhibition blocks porphyrin conversion to heme in mitochondria. The downregulation of OGC has been reported in horse muscle with recurrent exertional rhabdomyolysis [173].
