Protocadherin-15 is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
that in humans is encoded by the ''PCDH15''
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
.
Function
This gene is a member of the
cadherin superfamily. Family members encode integral membrane proteins that mediate
calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...
-dependent cell-cell
adhesion
Adhesion is the tendency of dissimilar particles or surfaces to cling to one another ( cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another).
The forces that cause adhesion and cohesion can b ...
. The protein product of this gene consists of a
signal peptide, 11 extracellular calcium-binding domains, a
transmembrane domain
A transmembrane domain (TMD) is a membrane-spanning protein domain. TMDs generally adopt an alpha helix topological conformation, although some TMDs such as those in porins can adopt a different conformation. Because the interior of the lipid bi ...
and a unique
cytoplasmic domain. It plays an essential role in maintenance of normal
retina
The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which then ...
l and
cochlea
The cochlea is the part of the inner ear involved in hearing. It is a spiral-shaped cavity in the bony labyrinth, in humans making 2.75 turns around its axis, the modiolus. A core component of the cochlea is the Organ of Corti, the sensory or ...
r function.
It is thought to interact with
CDH23
Cadherin-23 is a protein that in humans is encoded by the ''CDH23'' gene.
Function
This gene is a member of the cadherin superfamily, genes encoding calcium dependent cell-cell adhesion glycoproteins. The protein encoded by this gene is a larg ...
to form
tip-link filaments.
Clinical significance
Mutations in this gene have been associated with hearing loss, which is consistent with its location at the
Usher syndrome
Usher syndrome, also known as Hallgren syndrome, Usher–Hallgren syndrome, retinitis pigmentosa–dysacusis syndrome or dystrophia retinae dysacusis syndrome, is a rare genetic disorder caused by a mutation in any one of at least 11 genes result ...
type 1F (USH1F) critical region on chromosome 10.
Variation within it has also been found to be associated with normal differences in human facial appearance.
References
Further reading
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External links
GeneReviews/NCBI/NIH/UW entry on Usher Syndrome Type IPDBe-KBprovides an overview of all the structure information available in the PDB for Human Protocadherin-15 (PCDH15)
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