Melanocortin 4 receptor
Encyclopedia
Melanocortin receptor 4 is a protein
that in humans is encoded by the MC4R gene
. It encodes the MC4 protein, a G-protein coupled receptor that binds α-melanocyte stimulating hormone (α-MSH). In murine
models MC4 receptors have been found to be involved in feeding behaviour, the regulation of metabolism, sexual behaviour, and male erectile function
In 1998, it was reported that MC4R mutations were associated with inherited human obesity. They were found in heterozygotes, suggesting an autosomal dominant inheritance pattern. However, based on other research and observations, these mutations seem to have an incomplete penetrance and some degree of codominance. It has a prevalence of 1-2.5% in people with BMIs
of greater than 30, making it the most commonly known genetic defect predisposing people to obesity.
with Proopiomelanocortin
.
(BMI), confirmed the association of variants about 150 kilobases downstream of the MC4R gene with insulin resistance, obesity
and other anthropometric traits.
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
that in humans is encoded by the MC4R gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
. It encodes the MC4 protein, a G-protein coupled receptor that binds α-melanocyte stimulating hormone (α-MSH). In murine
Murinae
The Old World rats and mice, part of the subfamily Murinae in the family Muridae, comprise at least 519 species. This subfamily is larger than all mammal families except the Cricetidae and Muridae, and is larger than all mammal orders except the bats and the remainder of the...
models MC4 receptors have been found to be involved in feeding behaviour, the regulation of metabolism, sexual behaviour, and male erectile function
In 1998, it was reported that MC4R mutations were associated with inherited human obesity. They were found in heterozygotes, suggesting an autosomal dominant inheritance pattern. However, based on other research and observations, these mutations seem to have an incomplete penetrance and some degree of codominance. It has a prevalence of 1-2.5% in people with BMIs
Body mass index
The body mass index , or Quetelet index, is a heuristic proxy for human body fat based on an individual's weight and height. BMI does not actually measure the percentage of body fat. It was invented between 1830 and 1850 by the Belgian polymath Adolphe Quetelet during the course of developing...
of greater than 30, making it the most commonly known genetic defect predisposing people to obesity.
Interactions
Melanocortin 4 receptor has been shown to interactProtein-protein interaction
Protein–protein interactions occur when two or more proteins bind together, often to carry out their biological function. Many of the most important molecular processes in the cell such as DNA replication are carried out by large molecular machines that are built from a large number of protein...
with Proopiomelanocortin
Proopiomelanocortin
Pro-opiomelanocortin is a precursor polypeptide with 241 amino acid residues. POMC is synthesized from the 285-amino acid long polypeptide precursor, pre-pro-opiomelanocortin , by the removal of a 44-amino acid long signal peptide sequence during translation.The POMC gene is located on chromosome...
.
Clinical significance
In 2009, two very large genome wide association studies of body mass indexBody mass index
The body mass index , or Quetelet index, is a heuristic proxy for human body fat based on an individual's weight and height. BMI does not actually measure the percentage of body fat. It was invented between 1830 and 1850 by the Belgian polymath Adolphe Quetelet during the course of developing...
(BMI), confirmed the association of variants about 150 kilobases downstream of the MC4R gene with insulin resistance, 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...
and other anthropometric traits.