;Expression Patterns:The MT1 melatonin receptor sits on the cell membrane. In humans it consists of 351 amino acids that are encoded in chromosome 4. Its main function here is as an adenylate cyclase inhibitor, which works when MT1 binds to other G-proteins. In humans, The MT1 subtype is expressed in the pars tuberalis of the pituitary gland, the retina, and the suprachiasmatic nuclei of the hypothalamus, and are most likely found in human skin. As humans age, the expression of MT1 and the SCN decreases because MT1 reaction rate decreases and prolactin secretion decreases.
