| Primary Identifier | IPR044109 | Type | Family |
| Short Name | STKc_PKA |
| description | The intracellular second messenger cyclic adenosine monophosphate (cAMP) exerts many of its physiological effects by activating cAMP-dependent protein kinase (PKA), which in turn phosphorylates and regulates the functions of downstream protein targets including ion channels, enzymes, and transcription factors. PKA is a tetrameric enzyme composed of a two regulatory (R) and two catalytic (C) subunits. Binding of 2 cAMP molecules to each R subunit leads to holoenzyme dissociation into the R dimer and two active subunits [, , ]. There are 4 different R sububits divided in two types, type I (RI-alpha and RI-beta), and type II (RII-alpha and RII-beta), and two main C subunits (C-alpha and C-beta) []. Type I PKA is predominantly cytoplasmic, whereas type II PKA usually associates with specific cellular structures and organelles. The intracellular organization of PKA is controlled through the association with AKAPs (A-kinase-anchoring proteins) [, , ].PKA plays a role in the regulation of diverse processes such as growth, development, memory, metabolism, gene expression, immunity, and lipolysis. The cAMP/PKA signaling pathway regulates glucose homeostasis at multiple levels including insulin and glucagon secretion, glucose uptake, glycogen synthesis and breakdown, gluconeogenesis []. The cAMP/PKA pathway acts downstream of GPCRs and regulates the activities of key molecules involved in insulin secretion, including GLUT2, KATP, and Cav [].This entry includes cAMP-dependent protein kinase catalytic subunit alpha/beta (C-alpha/C-beta) from animals and their homologue, C-gamma, found in higher primates. C-gamma appears to have no function as a mature protein []. |
