Substrates and regulation mechanisms for the human mitochondrial sirtuins Sirt3 and Sirt5.

It is shown that Sirt3 can deacetylate and thereby activate a central metabolic regulator in the mitochondrial matrix, glutamate dehydrogenase, and that the N- and C-terminal regions of Sirt 3 regulate its activity against glutamate dehydrogensase and a peptide substrate, indicating roles for these regions in substrate recognition and Sirtuin regulation.