NCIt synonyms : PKA; cAMP-Dependent Protein Kinase; Protein Kinase-A;
NCIt definition : Most cellular effects of cAMP are mediated through PKA by serine or threonine phosphorylation
of target proteins. Human Protein Kinase A (cAMP Ser/Thr Protein Kinase Family) is
an inactive tetrameric cytoplasmic holoenzyme composed of homo- or heterodimeric regulatory
subunits associated with two catalytic subunits. cAMP causes dissociation of inactive
holoenzyme into a cAMP-bound dimer of regulatory subunits and two free monomeric catalytic
subunits that phosphorylate many cytoplasmic and nuclear substrates. In human, regulatory
PRKAR1A, PRKAR1B, PRKAR2A, and PRKAR2B subunits and catalytic PRKACA, PRKACB, and
PRKACG subunits have been identified. (NCI);