Melatonin Receptor Type 1 (MT1)

The Melatonin MT1 receptor is a G protein-coupled receptor that binds the neurohormone melatonin. It plays a central role in regulating circadian rhythms, sleep, and various neuroendocrine functions. Upon binding melatonin, MT1 primarily couples to Gi proteins, leading to inhibition of adenylyl cyclase and decreased intracellular cAMP levels. It is expressed in several key tissues including the suprachiasmatic nucleus (SCN) of the hypothalamus, pars tuberalis of the pituitary gland, and retina. Drugs targeting MT1 are used for treating insomnia, non–24-hour sleep-wake disorder, depression, and jet lag.

Other names

Melatonin receptor 1AMTNR1AMelatonin receptor subtype 1

Agonist at MT1 receptor, leading to inhibition of adenylyl cyclase and decreased cAMP levels. Activation also increases phosphorylation of MAPK/ERK pathways and enhances potassium conductance via Kir channels.