The effect of dichloroacetate on the phosphorylation of mitochondria proteins.

Succinyl-CoA synthetase and the alpha-subunit of pyruvate dehydrogenase are phosphorylated after incubation of mitochondria from brain, heart, and liver with [gamma-32P]ATP. Dichloroacetate, a known specific inhibitor for pyruvate dehydrogenase kinase, inhibits not only the phosphate incorporation into the alpha-subunit of pyruvate dehydrogenase but also the autophosphorylation of succinyl-CoA synthetase. AMP also inhibits the phosphorylation of both proteins. Phosphorylation of the alpha-subunit of pyruvate dehydrogenase in liver mitochondria is significantly lower than in mitochondria from other tissues.