| A 21 mer peptide from the 3rd cytoplasmic domain of the murine MC1-R. Melanocortins are regulatory peptides formed by post-translational processing of pro-opiomelanocortin. Melanocortin peptides have been suggested to perform a variety of physiological roles ranging from control of behavior, memory, neurotrophic properties, antipyretic and modulation of immune system, etc. Their binding sites have been found distributed in tissues ranging from lachrymal and submandibular glands, pancreas, adipose tissue, bladder, duodenum, spleen, brain, gonadal tissues and malignant melanoma tumors. Five melanocortin receptors have been characterized to date. These include melanocyte-stimulating hormone receptor (MSH or MC1-R), corticoaderenal-specific ACTH receptor (MC2-R), melacortin-3 (MC3-R), melanocortin-4 (MC4-R) and melanocortin-5 receptor (MC5-R). MC3-R and MC4-R are distributed in brain whereas MC5-R has a broad distribution. Melanocyte Stimulating Hormone Receptor (MSH-R), also called Melanotropin Receptor, or Melanocortin-1 Receptor (MC1-R), is a 315 amino acid transmembrane protein belonging to the family 1 of G-Protein coupled receptors. It is a receptor for MSH (a,b,g) and ACTH. Its activity is mediated by G-proteins which activate adenylate cyclase. It is found in Melanocytes and corticoaderenal tissue as well as various tissues like adrenal gland, leukocytes, lung, lymph node, ovary, testis, pituitary, placenta, spleen and uterus. |
