Beta-Melanocyte-stimulating hormone

Beta-Melanocyte-stimulating hormone (β-MSH) is a hormone produced by the pituitary gland. It is a member of the melanocortin family of peptides and plays a crucial role in the regulation of melanin production in melanocytes, the cells responsible for skin and hair color.

Structure

β-MSH is a 22-amino acid peptide derived from the proopiomelanocortin (POMC) precursor molecule. The POMC gene is expressed in the pituitary gland, where it is cleaved into several active peptides, including β-MSH, adrenocorticotropic hormone (ACTH), and beta-endorphin.

Function

β-MSH stimulates the production and release of melanin by melanocytes in skin and hair. This process, known as melanogenesis, is responsible for tanning of the skin in response to sunlight exposure. β-MSH binds to the melanocortin 1 receptor (MC1R) on the surface of melanocytes, triggering a cascade of intracellular events that ultimately leads to increased melanin production.

In addition to its role in skin pigmentation, β-MSH has been implicated in a variety of other physiological processes, including appetite regulation, sexual behavior, and immune response.

Clinical significance

Mutations in the POMC gene or the MC1R can lead to disorders of pigmentation, such as red hair and albinism. Additionally, abnormal β-MSH function has been implicated in a variety of conditions, including obesity, Addison's disease, and vitiligo.

See also

• Melanocyte
• Melanocortin
• Proopiomelanocortin
• Melanocortin 1 receptor