Peripherin 2
Encyclopedia
Peripherin-2 is a protein
, that in humans is encoded by the PRPH2 gene
. Peripherin-2 is found in the rod and cone cells of the retina
of the eye
. Defects in this protein result in one form of retinitis pigmentosa
, an incurable blindness.
Mutations in the PRPH2 gene are associated with Vitelliform macular dystrophy
.
family. Most of these members are cell-surface proteins that are characterized by the presence of four transmembrane helices. Tetraspanins mediate signal transduction events that play a role in the regulation of cell development, activation, growth and motility.
Peripherin 2 (sometimes referred to as peripherin/RDS or simply RDS) is a cell surface glycoprotein
found in the outer segment of both rod and cone photoreceptor cells. It is located in the rim regions of the flattened disks that contain rhodopsin
, which is the protein that is responsible for initiation of visual phototransduction upon reception of light. Peripherin 2 may function as an adhesion molecule
involved in stabilization and compaction of outer segment disks or in the maintenance of the curvature of the rim. This protein is essential for disk morphogenesis
.
, progressive macular degeneration
, macular dystrophy
and retinitis pigmentosa digenic.
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 PRPH2 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...
. Peripherin-2 is found in the rod and cone cells of the retina
Retina
The vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...
of the eye
Eye
Eyes are organs that detect light and convert it into electro-chemical impulses in neurons. The simplest photoreceptors in conscious vision connect light to movement...
. Defects in this protein result in one form of retinitis pigmentosa
Retinitis pigmentosa
Retinitis pigmentosa is a group of genetic eye conditions that leads to incurable blindness. In the progression of symptoms for RP, night blindness generally precedes tunnel vision by years or even decades. Many people with RP do not become legally blind until their 40s or 50s and retain some...
, an incurable blindness.
Mutations in the PRPH2 gene are associated with Vitelliform macular dystrophy
Vitelliform macular dystrophy
Vitelliform macular dystrophy or vitelliform dystrophy is a genetic eye disorder that can cause progressive vision loss. This disorder affects the retina, specifically cells in a small area near the center of the retina called the macula...
.
Function
The protein encoded by this gene is a member of the transmembrane 4 superfamily, also known as the tetraspaninTetraspanin
Tetraspanins are a family of membrane proteins found in all multicellular eukaryotes.Tetraspanins, also called tetraspans or the transmembrane 4 superfamily , have four transmembrane domains, intracellular N- and C-termini and two extracellular domains, one short and one longer, typically 100...
family. Most of these members are cell-surface proteins that are characterized by the presence of four transmembrane helices. Tetraspanins mediate signal transduction events that play a role in the regulation of cell development, activation, growth and motility.
Peripherin 2 (sometimes referred to as peripherin/RDS or simply RDS) is a cell surface glycoprotein
Glycoprotein
Glycoproteins are proteins that contain oligosaccharide chains covalently attached to polypeptide side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. In proteins that have segments extending...
found in the outer segment of both rod and cone photoreceptor cells. It is located in the rim regions of the flattened disks that contain rhodopsin
Rhodopsin
Rhodopsin, also known as visual purple, is a biological pigment of the retina that is responsible for both the formation of the photoreceptor cells and the first events in the perception of light. Rhodopsins belong to the G-protein coupled receptor family and are extremely sensitive to light,...
, which is the protein that is responsible for initiation of visual phototransduction upon reception of light. Peripherin 2 may function as an adhesion molecule
Cell adhesion molecule
Cell Adhesion Molecules are proteins located on the cell surface involved with the binding with other cells or with the extracellular matrix in the process called cell adhesion....
involved in stabilization and compaction of outer segment disks or in the maintenance of the curvature of the rim. This protein is essential for disk morphogenesis
Morphogenesis
Morphogenesis , is the biological process that causes an organism to develop its shape...
.
Clinical significance
Defects in this gene are associated with both central and peripheral retinal degenerations. Some of the various phenotypically different disorders are autosomal dominant retinitis pigmentosaRetinitis pigmentosa
Retinitis pigmentosa is a group of genetic eye conditions that leads to incurable blindness. In the progression of symptoms for RP, night blindness generally precedes tunnel vision by years or even decades. Many people with RP do not become legally blind until their 40s or 50s and retain some...
, progressive macular degeneration
Macular degeneration
Age-related macular degeneration is a medical condition which usually affects older adults and results in a loss of vision in the center of the visual field because of damage to the retina. It occurs in “dry” and “wet” forms. It is a major cause of blindness and visual impairment in older adults...
, macular dystrophy
Vitelliform macular dystrophy
Vitelliform macular dystrophy or vitelliform dystrophy is a genetic eye disorder that can cause progressive vision loss. This disorder affects the retina, specifically cells in a small area near the center of the retina called the macula...
and retinitis pigmentosa digenic.