Examples of different signals, receptors, Gα like-subunits, second messenger changes, and affected intracellular enzymes
| signal | vasopressin | epinephrine | light | odorant | odorant | sweet tastant |
| receptor | VR | β-adrenergic | rhodopsin | odorant recep. 1 | odorant recept. 2 | sweet receptor |
| Ga like- subunit | Gi | Gs | transducin | Golfactory | Golfactory | Ggustatory |
| coupled enzyme | adenylate cyclase | adenylate cyclase | phosphodiesterase | phopholipase C | adenylate cyclase | adenylate cyclase |
| 2nd messenger | decrease cAMP | increase cAMP | decrease cGMP | increase IP3 | increase cAMP | increase cAMP |
| protein affected | decrease PrK-A | increase PrK-A | dec. Ca, Na perm. | inc. Ca perm | inc.Ca, Na perm | dec. K perm |