Kappa Opioid Receptor - Signal Transduction

Signal Transduction

κ-Opioid receptor activation by agonists is coupled to the G protein G_i/G₀, which subsequently increases phosphodiesterase activity. Phosphodiesterases break down cAMP, producing an inhibitory effect in neurons. κ-Opioid receptors also couple to inward-rectifier potassium and to N-type calcium ion channels. Recent studies have also demonstrated that agonist-induced stimulation of the κ-Opioid receptor, like other G-protein coupled receptors, can result in the activation of mitogen-activated protein kinases (MAPK). These include extracellular signal-regulated kinase, p38 MAP kinases, and c-Jun N-terminal kinases.