**11.1. Phosphorylation of enzymes of the tricarboxylic acid cycle (TCA)**

Phosphoproteomic analyses revealed that most enzymes of the TCA cycle are phosphorylated/dephosphorylated [62]. These include aconitase, isocitrate and oxo-ketoglutarate dehydrogenases, succinyl-coenzyme A synthetase, succinate dehydrogenase, fumarate hydratase, and mitochondrial malate dehydrogenase [62, 63]. Although the functional role of these phosphorylations and the protein kinases that mediate them are not yet known, data suggest that phosphorylation regulates the activity of these enzymes.
