Melatonin receptor type 1A (MT1)

Melatonin receptor type 1A is a high-affinity G protein-coupled receptor for melatonin, encoded by the MTNR1A gene. It is primarily expressed in the suprachiasmatic nucleus of the hypothalamus, pars tuberalis of the pituitary gland, retina, and other tissues. The main physiological roles include mediating melatonin’s effects on circadian rhythms—particularly sleep onset—and reproductive functions influenced by day length. Upon activation by melatonin or synthetic agonists such as tasimelteon or agomelatine, this membrane-bound seven-transmembrane domain protein inhibits adenylate cyclase activity through Gi/o proteins, leading to decreased intracellular cAMP levels. This action underlies its role in synchronizing biological clocks with environmental light-dark cycles and regulating sleep-wake patterns. Dysregulation or altered expression has been implicated in various conditions including insomnia, depression, cancer risk modulation, and metabolic diseases like type 2 diabetes[2][4][5][6].

Other names

MTNR1AMEL-1A-RMelatonin receptor 1AMel1a receptor[6][9]

Activation leads to inhibition of adenylate cyclase via G-protein coupling, reducing cAMP levels in target cells and modulating downstream signaling pathways involved in circadian rhythm and sleep regulation[5][7].