Anti-MTNR1B from rabbit, purified by affinity chromatography

Melatonin receptor type 1B (UniProt: P49286; also known as Mel-1B-R, Mel1b receptor) is encoded by the MTNR1B gene (Gene ID: 4544) in human. Mel-1B-R is a member of the G-protein coupled 1 family that is predominantly expressed in retina and to lesser extent in brain tissue. Mel-1B-R activity is mediated by pertussis toxin sensitive G proteins that inhibit adenylate cyclase activity. Mel-1B-R mediates the reproductive and circadian actions of melatonin. Melatonin is shown to be involved in body mass regulation in mammals and this effect is suggest to be mediated by a direct action of melatonin on Mel-1B receptors on brown adipocytes. Melatonin is reported to act as a chemopreventive agent and its levels inversely correlate with the risk of developing cancer. In this regard melatonin induces p38-dependent phosphorylation of both p53 and histone H2AX. Activation of the p53-dependent DNA damage response by melatonin is mediated by both Mel-1A and Mel-1B receptors. The absence of either receptor impairs melatonin's ability to reduce both cell proliferation and clonogenic potential of cancer cells. A variant in MTNR1B gene is reported to worsen the deleterious effect of melatonin on glucose tolerance in humans. (Ref.: Brydon, L. et al. (2001). Endocrinology. 142(10):4264-4271; Santoro, R., et al. (2013). Carcinogenesis. 34(5):1051-1061).