Agouti signalling peptide, a product of the Agouti gene

Agouti gene

The Agouti gene is responsible for determining whether a mammal's coat is banded or of a solid color . The chief product of the Agouti gene is Agouti signalling peptide , but there are a number of alternative splice products....

, is a peptide

Peptide

Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...

 consisting of 131 amino acids. Its discovery was published in 1994 in the scientific journal Nature where its functional properties were described. It acts as an inverse agonist

Inverse agonist

In the field of pharmacology, an inverse agonist is an agent that binds to the same receptor as an agonist but induces a pharmacological response opposite to that agonist....

 at melanocortin receptor

Melanocortin receptor

Melanocortin receptors are members of the rhodopsin family of 7-transmembrane, G protein-coupled receptors.There are five known members of the melanocortin receptor system each with differing specificities for melanocortins:...

s, specifically, MC1

Melanocortin 1 receptor

The melanocortin 1 receptor , also known as melanocyte-stimulating hormone receptor , melanin-activating peptide receptor, or melanotropin receptor, is a G protein-coupled receptor which binds to a class of pituitary peptide hormones known as the melanocortins, of which include adrenocorticotropic...

.
It is produced by the Agouti gene ASIP.

Function

In mice, the agouti gene encodes a paracrine signalling molecule that causes hair follicle melanocyte

Melanocyte

-External links: - "Eye: fovea, RPE" - "Integument: pigmented skin"...

s to synthesize pheomelanin, a yellow pigment, instead of the black or brown pigment, eumelanin. Pleiotropic effects of constitutive expression of the mouse gene include adult-onset obesity

Obesity

Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...

, increased tumor

Tumor

A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...

 susceptibility, and premature infertility. This gene is highly similar to the mouse gene and encodes a secreted protein that may (1) affect the quality of hair pigment

Pigment

A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.Many materials selectively absorb...

ation, (2) act as an inverse agonist of alpha-melanocyte-stimulating hormone

Melanocortin 1 receptor

The melanocortin 1 receptor , also known as melanocyte-stimulating hormone receptor , melanin-activating peptide receptor, or melanotropin receptor, is a G protein-coupled receptor which binds to a class of pituitary peptide hormones known as the melanocortins, of which include adrenocorticotropic...

, (3) play a role in neuroendocrine aspects of melanocortin

Melanocortin

The melanocortins are a group of peptide hormones which include adrenocorticotropic hormone and the different forms of melanocyte-stimulating hormone . They can be synthetic . In humans they can be endogenously produced from proopiomelanocortin in the pituitary gland...

 action, and (4) have a functional role in regulating lipid metabolism in adipocyte

Adipocyte

However, in some reports and textbooks, the number of fat cell increased in childhood and adolescence. The total number is constant in both obese and lean adult...

s.

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