Review: Spatiotemporal dynamics of hCG/cAMP signaling and regulation of placental function.

The pregnancy hormone human chorionic gonadotropin (hCG) is essential to sustain early pregnancy and involved in regulation of progesterone production, decidualization, and cytotrophoblast differentiation. It binds to and activates the G-protein coupled luteinizing hormone/hCG-receptor, activating the cAMP/protein kinase A (PKA) pathway which results in the phosphorylation of specific intracellular target proteins. Specificity in cAMP signaling is ensured by generation of localized pools of cAMP controlled by phosphodiesterases and by discrete spatial and temporal activation of PKA in supramolecular signaling clusters inside the cell organized by A-kinase-anchoring proteins. Here we discuss spatiotemporal regulation of PKA signaling in response to hCG controlling placental function.