Protein kinase type A (PKA), is a cAMP-dependent intracellular serine/threonine kinase, an enzyme (transferase) that is involved in numerous reactions of energy metabolism, among others. When 4 cAMP bind to the regulatory unit of PKA, the active catalytic subunits are released, which bind to the various proteins and catalyze their phosphorylation. These catalyze the phosphorylation of various proteins. Substrates of the kinase include MAP kinases and transcription factors such as NF-κB.
Disorders of protein kinase A are the cause of the Carney complex.