Lipoamide dehydrogenase is a component of the glycine cleavage system as well as an E3 component of three alpha-ketoacid dehydrogenase complexes (pyruvate-, alpha-ketoglutarate-, and branched-chain amino acid-dehydrogenase complex) (  , ). The 2-oxoglutarate dehydrogenase complex is mainly active in the mitochondrion . A fraction of the 2-oxoglutarate dehydrogenase complex also localizes in the nucleus and is required for lysine succinylation of histones: associates with KAT2A on chromatin and provides succinyl-CoA to histone succinyltransferase KAT2A . In monomeric form may have additional moonlighting function as serine protease . Involved in the hyperactivation of spermatazoa during capacitation and in the spermatazoal acrosome reaction (By similarity).
Subcellular locations: Mitochondrion matrix, Nucleus, Cell projection, Cilium, Flagellum, Cytoplasmic vesicle, Secretory vesicle, Acrosome
Mainly localizes in the mitochondrion. A small fraction localizes to the nucleus, where the 2-oxoglutarate dehydrogenase complex is required for histone succinylation.