melatonin receptor activity

Definition

Target type: molecularfunction

Combining with melatonin, N-acetyl-5-methoxytryptamine, to initiate a change in cell activity. Melatonin is a neuroendocrine substance that stimulates the aggregation of melanosomes in melanophores, thus lightening the skin. [GOC:ai, ISBN:0198506732]

Melatonin receptors are G protein-coupled receptors (GPCRs) that mediate the physiological effects of melatonin, a hormone produced by the pineal gland. Melatonin receptors are expressed in a variety of tissues, including the brain, retina, and immune system. There are two main subtypes of melatonin receptors: MT1 and MT2. Both receptors are activated by melatonin, leading to the activation of downstream signaling pathways. Upon activation, MT1 and MT2 receptors couple to G proteins, specifically Gi/o proteins. This coupling leads to the inhibition of adenylate cyclase, which in turn reduces the production of cyclic AMP (cAMP). The decreased cAMP levels then modulate the activity of various intracellular signaling pathways, such as the protein kinase A (PKA) pathway, which is involved in regulating cellular processes like gene expression, cell growth, and apoptosis. Furthermore, the activation of melatonin receptors can also activate other signaling pathways, such as the mitogen-activated protein kinase (MAPK) pathway, which plays a role in cell proliferation and differentiation. The overall effect of melatonin receptor activation is to regulate various physiological processes, including sleep-wake cycles, circadian rhythms, antioxidant defense, immune function, and neuroprotection. These diverse functions are achieved through the modulation of intracellular signaling pathways and the subsequent regulation of target gene expression.'
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Proteins (6)

Compounds (38)