Several well-studied GPCRs illustrate their catalytic roles:
- Beta-Adrenergic Receptors: These are involved in the fight-or-flight response by activating adenylyl cyclase, thereby increasing cAMP levels and triggering a range of physiological responses. - Rhodopsin: This GPCR is involved in the visual process. Upon absorbing light, rhodopsin activates a G protein called transducin, leading to a cascade of events that ultimately result in vision. - Opioid Receptors: These receptors bind endogenous opioids and are involved in modulating pain and reward pathways. Their activation can inhibit adenylate cyclase and reduce cAMP levels, leading to analgesic effects.
