Figure 5

Principle of GPCR signaling. Acute agonist stimulation of GPCRs leads to activation of multiple signaling pathways, including second messengers cAMP, IP3 and Ca²⁺. GPCRs in the plasma membrane couple to these pathways via G proteins that connect the receptors to enzymes adenylyl cyclase, phospholipase C (PLC) or ionic conductance channels such as Ca²⁺ channels. Prolonged stimulation of the receptor leads to recruitment to the cell membrane of β-adrenergic receptor kinases and β-arrestin. Detected genes by microarray are presented in colored boxes corresponding to G protein isoforms (α, β, γ). The detected genes are upregulated (gray arrow) or downregulated (black arrow) vs. HuURNA through ontogeny. PKA, protein kinase A; PKC, protein kinase C.