cAMPkaskad

cAMPkaskad, also known as the cyclic AMP (cAMP) cascade, is a fundamental signaling pathway in eukaryotic cells that plays a crucial role in various physiological processes, including cell growth, differentiation, and metabolism. The cascade is initiated by the binding of an extracellular ligand to a cell surface receptor, which activates a G protein-coupled receptor (GPCR). This activation leads to the exchange of GDP for GTP on the G protein, resulting in the dissociation of the G protein into its alpha (Galpha) and beta-gamma (Gbetagamma) subunits. The activated Galpha subunit then stimulates adenylate cyclase, an enzyme that converts ATP to cyclic AMP (cAMP). The increase in cAMP concentration within the cell leads to the activation of cAMP-dependent protein kinases (PKA), which phosphorylate various target proteins, ultimately resulting in the modulation of cellular processes. The cAMP cascade is tightly regulated by phosphodiesterases, enzymes that hydrolyze cAMP back to AMP, thereby terminating the signaling pathway. This cascade is a well-studied example of signal transduction and is a key target for various therapeutic interventions, including the treatment of diseases such as asthma, diabetes, and certain types of cancer.