cAMP-dependent protein kinase signaling pathway (PKA signaling pathway)

The cAMP-dependent protein kinase signaling pathway, commonly known as the PKA pathway, is a fundamental signal transduction mechanism that translates extracellular stimuli into diverse cellular responses (NIH, 2023). It begins with the activation of G protein-coupled receptors (GPCRs), which stimulate adenylyl cyclase to generate cyclic adenosine monophosphate (cAMP). Elevated cAMP levels activate Protein Kinase A (PKA), which then phosphorylates a wide array of substrates, including enzymes, ion channels, and the transcription factor CREB (UniProt, 2023). This pathway is critical for regulating glucose metabolism, cardiac contractility, and synaptic plasticity. Dysregulation of cAMP/PKA signaling is implicated in numerous pathologies, such as various cancers, endocrine disorders like Cushing's syndrome, and cardiovascular diseases (PubMed, 2020). While the pathway itself is a complex network rather than a single therapeutic target, many of its individual components—including GPCRs, adenylyl cyclases, and phosphodiesterases (PDEs)—are major targets for clinical drugs like beta-blockers and PDE inhibitors (StatPearls, 2023).

Other names

Protein kinase A signaling pathwayCyclic AMP signaling pathwaycAMP/PKA pathwaycAMP-dependent pathway

The pathway is initiated by ligand binding to G protein-coupled receptors (GPCRs), which activates adenylyl cyclase to produce the second messenger cAMP. cAMP then binds to the regulatory subunits of Protein Kinase A (PKA), inducing a conformational change that releases active catalytic subunits. These subunits phosphorylate various downstream targets, including metabolic enzymes and transcription factors like CREB, to regulate cellular processes (Wikipedia, 2023; StatPearls, 2023).