Regulation of mammalian pyruvate dehydrogenase kinase.

It is generally believed that mammalian pyruvate dehydrogenase kinase is a heterodimer consisting of catalytic and regulatory subunits. However, the contribution of the two subunits to the kinase-mediated signal transduction has remained undefined. In the present study recombinant components of mammalian pyruvate dehydrogenase complex were employed in order to characterize the role of the kinase catalytic subunit in the regulation of pyruvate dehydrogenase reaction. The results provide the first evidence strongly suggesting that the catalytic subunit of pyruvate dehydrogenase kinase is competent to respond to known effectors of kinase activity as well as to interact with the E2-core without assistance of a regulatory subunit.