Pyruvate dehydrogenase kinase isozyme 4, mitochondrial is a member of the PDK/BCKDK protein kinase family and encodes a mitochondrial protein with a histidine kinase domain. This protein is located in the matrix of the mitrochondria and inhibits the pyruvate dehydrogenase complex by phosphorylating one of its subunits, thereby contributing to the regulation of glucose metabolism. Expression of this gene is regulated by glucocorticoids, retinoic acid and insulin.

The PDK4 gene encodes a protein with a calculated molecular weight of 46,466. PDK4 mRNA was detected in all tissues examined, with the highest levels in heart and skeletal muscle. The PDK4 gene consists of 11 exons spanning approximately 16 kb.