PDK3/PDHK3

PDK3 is the most restricted member of the pyruvate dehydrogenase kinase family, showing its highest expression in testis with appreciable levels in brain and skeletal muscle. Like PDK1, PDK2 and PDK4, it inactivates the PDH complex through phosphorylation of the E1alpha subunit, but it differs from its siblings in sensitivity to allosteric effectors and in its tissue-limited expression profile, which links it to specialized metabolic programs in germ cells and neurons. Its phosphorylation sites and effector responses overlap with other isozymes, yet isozyme-selective PDK3 inhibitors offer a route to dissecting isoform-specific PDH control. Recombinant PDK3 supports such selectivity and tissue-specific metabolism studies.