Ligand binds to G protein-coupled receptor → Activation of G protein → Activation of adenylyl cyclase → cAMP synthesis from ATP → Activation of protein kinase A → Phosphorylation of target proteins.

Ligand binds to G protein-coupled receptor → Activation of adenylyl cyclase → Activation of G protein → cAMP synthesis from ATP → Activation of protein kinase A → Phosphorylation of target proteins.

Ligand binds to G protein-coupled receptor → Activation of G protein → cAMP synthesis from ATP → Activation of adenylyl cyclase → Activation of protein kinase A → Phosphorylation of target proteins.

Ligand binds to G protein-coupled receptor → Activation of G protein → Activation of adenylyl cyclase → Activation of protein kinase A → cAMP synthesis from ATP → Phosphorylation of target proteins.