Review Note

GPCR with Gαs G-Protein: Step-by-Step

1. Ligand Binding: A ligand (e.g., hormone or neurotransmitter) binds to the {{c4::GPCR}} on the cell membrane.
2. Receptor Activation: The GPCR undergoes a {{c5::conformational}} change, activating the associated {{c5::Gαs}} protein.
3. GTP Exchange: Gαs exchanges GDP for GTP, causing it to dissociate from the Gβγ subunits.
4. Effector Activation: The activated Gαs-GTP complex binds to and activates {{c1::adenylate cyclase}}, an enzyme in the membrane.
5. cAMP Production: Adenylate cyclase converts {{c2::ATP}} to {{c2::cAMP}}, a second messenger.
6. Signal Amplification: cAMP activates protein {{c3::kinase A (PKA)}}, which phosphorylates target proteins, leading to cellular responses.
7. Termination: Gαs hydrolyzes GTP to GDP, reassociating with Gβγ, and returns to its inactive state, terminating the signal.