Claudin-14 is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

that in humans is encoded by the ''CLDN14''

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

. It belongs to a related family of proteins called

claudin Claudins are a family of proteins which, along with occludin, are the most important components of the tight junctions ( zonulae occludentes). Tight junctions establish the paracellular barrier that controls the flow of molecules in the inter ...

s. The protein encoded by CLDN14 is an

integral membrane protein An integral, or intrinsic, membrane protein (IMP) is a type of membrane protein that is permanently attached to the biological membrane. All transmembrane proteins can be classified as IMPs, but not all IMPs are transmembrane proteins. IMPs comp ...

and a component of

tight junctions Tight junctions, also known as occluding junctions or ''zonulae occludentes'' (singular, ''zonula occludens''), are multiprotein junctional complexes between epithelial cells, sealing and preventing leakage of solutes and water. They also play a ...

, one mode of cell-to-cell adhesion in

epithelial Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of man ...

endothelial The endothelium (: endothelia) is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the res ...

cell sheets. Tight junctions form continuous seals around cells and serve as a physical barrier to prevent solutes and water from passing freely through the paracellular space. These junctions are composed of sets of continuous networking protein strands in the outer surface of the cell membrane, with complementary grooves in the inwardly facing extracytoplasmic leaflet. The CLDN14 protein also binds to

WW domain The WW domain (also known as the rsp5-domain or WWP repeating structural motif, motif) is a modular protein domain that mediates specific interactions with protein ligands. This domain is found in a number of unrelated signaling and structural pro ...

of Yes-associated protein. Defects in CLDN14 are the cause of an autosomal recessive form of nonsyndromic

sensorineural deafness Sensorineural hearing loss (SNHL) is a type of hearing loss in which the root cause lies in the inner ear, sensory organ (cochlea and associated structures), or the vestibulocochlear nerve (Cranial nerves, cranial nerve VIII). SNHL accounts for a ...

. Two

transcript variants Alternative splicing, alternative RNA splicing, or differential splicing, is an alternative splicing process during gene expression that allows a single gene to produce different splice variants. For example, some exons of a gene may be included ...

encoding the same protein have been found for this gene. There are also suggestions that CLDN14 plays a role in tumour

angiogenesis Angiogenesis is the physiological process through which new blood vessels form from pre-existing vessels, formed in the earlier stage of vasculogenesis. Angiogenesis continues the growth of the vasculature mainly by processes of sprouting and ...

(blood vessel formation), as deletion of a single copy of this gene leads to tight junction defects and leaky blood vessels in a

mouse model A model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workings of other organisms. Mod ...

. Polymorphisms in CLDN14 ar
associated with kidney stone
risk. It is likely that additional roles for claudins in the pathogenesis of other types of kidney diseases have yet to be uncovered.

See also

References

External links

Further reading