Abstract

PKA belongs to the large set of related AGC kinases having a preference for phosphorylating basophilic sites. cAMP-dependent protein kinase A (PKA) is the major target for cAMP action in eukaryotic cells. The enzyme is allosterically activated by binding of cAMP to two regulatory ( R ) subunits which induces dissociation of two catalytic ( C ) subunits. The active kinase is then free to phosphorylate substrates on serine, or less commonly threonine residues in recognition motifs. The enzyme acts or a wide number of proteins involved in several biochemical processes. These include glucose metabolism (via activation and inactivation of glycogen phosphorylase b and glycogen synthase respectively), fatty acid synthesis (via acetyl-coA carboxylase), pyruvate oxidation (via pyruvate dehyrogenase complex).



This is therefore a vital signaling enzyme in a number of metabolic processes, affecting many cell functions by activating or inactivating substrate proteins in the presence of cAMP