SYNTHETIC ALPHA MELANOCYTE STIMULATING HORMONE

This gene encodes a polypeptide hormone precursor that undergoes extensive, tissue-specific, post-translational processing via cleavage by subtilisin-like enzymes known as prohormone convertases. There are eight potential cleavage sites within the polypeptide precursor and, depending on tissue type and the available convertases, processing may yield as many as ten biologically active peptides involved in diverse cellular functions. The encoded protein is synthesized mainly in corticotroph cells of the anterior pituitary where four cleavage sites are used; adrenocorticotrophin, essential for normal steroidogenesis and the maintenance of normal adrenal weight, and lipotropin beta are the major end products. In other tissues, including the hypothalamus, placenta, and epithelium, all cleavage sites may be used, giving rise to peptides with roles in pain and energy homeostasis, melanocyte stimulation, and immune modulation. These include several distinct melanotropins, lipotropins, and endorphins that are contained within the adrenocorticotrophin and beta-lipotropin peptides. The antimicrobial melanotropin alpha peptide exhibits antibacterial and antifungal activity. Mutations in this gene have been associated with early onset obesity, adrenal insufficiency, and red hair pigmentation. Alternatively spliced transcript variants encoding the same protein have been described. [provided by RefSeq, Nov 2014]

POMC: ACTH stimulates the adrenal glands to release cortisol. Defects in POMC may be associated with susceptibility to obesity (OBESITY). It is a condition characterized by an increase of body weight beyond the limitation of skeletal and physical requirements, as the result of excessive accumulation of body fat. Defects in POMC are the cause of pro-opiomelanocortinin deficiency (POMCD). Affected individuals present early-onset obesity, adrenal insufficiency and red hair. Belongs to the POMC family.

Protein type: Secreted, signal peptide; Secreted

Chromosomal Location of Human Ortholog: 2p23.3

Cellular Component: extracellular space; peroxisomal matrix; cytoplasm; extracellular region; peroxisome; secretory granule

Molecular Function: type 3 melanocortin receptor binding; G-protein-coupled receptor binding; hormone activity; type 4 melanocortin receptor binding; receptor binding

Biological Process: generation of precursor metabolites and energy; cellular protein metabolic process; cell-cell signaling; neuropeptide signaling pathway; regulation of blood pressure; peptide hormone processing; regulation of appetite; positive regulation of transcription from RNA polymerase II promoter; negative regulation of tumor necrosis factor production; glucose homeostasis; signal transduction; cellular pigmentation

Disease: Obesity; Proopiomelanocortin Deficiency