OCA2
Encyclopedia
P protein is a protein
that in humans is encoded by the OCA2 gene
.
OCA2 encodes the human homologue of the mouse p (pink-eyed dilution) gene. The P protein is believed to be an integral membrane protein
involved in small molecule transport, specifically tyrosine
- a precursor of melanin
. Certain mutations in OCA2 result in type 2 oculocutaneous albinism
.
A mutation in the HERC2
gene adjacent to OCA2, affecting OCA2's expression in the human iris, is found common to nearly all people with blue eyes. It has been hypothesized that all blue eyed humans share a single common ancestor with whom the mutation originated.
A study has found the His615Arg allele
of OCA2 is involved in the light skin tone in people of East Asian descent.
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 OCA2 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...
.
OCA2 encodes the human homologue of the mouse p (pink-eyed dilution) gene. The P protein is believed to be an integral membrane protein
Integral membrane protein
An integral membrane protein is a protein molecule that is permanently attached to the biological membrane. Proteins that cross the membrane are surrounded by "annular" lipids, which are defined as lipids that are in direct contact with a membrane protein...
involved in small molecule transport, specifically tyrosine
Tyrosine
Tyrosine or 4-hydroxyphenylalanine, is one of the 22 amino acids that are used by cells to synthesize proteins. Its codons are UAC and UAU. It is a non-essential amino acid with a polar side group...
- a precursor of melanin
Melanin
Melanin is a pigment that is ubiquitous in nature, being found in most organisms . In animals melanin pigments are derivatives of the amino acid tyrosine. The most common form of biological melanin is eumelanin, a brown-black polymer of dihydroxyindole carboxylic acids, and their reduced forms...
. Certain mutations in OCA2 result in type 2 oculocutaneous albinism
Oculocutaneous albinism
Oculocutaneous albinism is a form of albinism involving the eyes , skin , and in rare instances, the hair as well.Four types of oculocutaneous albinism have been described, all caused by a disruption of melanin synthesis and all autosomal recessive disorders.Common Albinism requires genes from both...
.
A mutation in the HERC2
HERC2
Probable E3 ubiquitin-protein ligase HERC2 is an enzyme that in humans is encoded by the HERC2 gene.A mutation in the HERC2 gene adjacent to OCA2, affecting OCA2's expression in the human iris, is found common to nearly all people with blue eyes...
gene adjacent to OCA2, affecting OCA2's expression in the human iris, is found common to nearly all people with blue eyes. It has been hypothesized that all blue eyed humans share a single common ancestor with whom the mutation originated.
A study has found the His615Arg allele
Allele
An allele is one of two or more forms of a gene or a genetic locus . "Allel" is an abbreviation of allelomorph. Sometimes, different alleles can result in different observable phenotypic traits, such as different pigmentation...
of OCA2 is involved in the light skin tone in people of East Asian descent.