Solute carrier family 22, member 4, also known as SLC22A4, is a human 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...

; the encoded protein is an ergothioneine transporter.

Function

The encoded protein is an integral protein of the plasma membrane containing 12 transmembrane segments. The first functional designation of this protein was OCTN1 ("organic cation transporter, novel, type 1"), but efficiency of transport for organic cations (e.g., tetraethylammonium

Tetraethylammonium

Tetraethylammonium is a quaternary ammonium cation consisting of four ethyl groups attached to a central nitrogen atom. Like other members of its class, it can be used to alter a compound's solubility by displacing hard acids with this comparatively softer acid...

) is very low. The transport efficiency for carnitine is also negligible. Instead, the protein is responsible for the cotransport of sodium ions and ergothioneine

Ergothioneine

Ergothioneine is a naturally occurring amino acid and is a thiourea derivative of histidine, containing a sulfur atom in the imidazole ring. This compound is made in rather few organisms, notably Actinobacteria and filamentous fungi. Ergothioneine was discovered in 1909 and named after the ergot...

, which is an antioxidant

Antioxidant

An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...

, into cells. Thus, a more appropriate functional designation is ETT ("ergothioneine transporter").

Interactions

SLC22A4 has been shown to interact

Protein-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 PDZK1

PDZK1

Na/H exchange regulatory cofactor NHE-RF3 is a protein that in humans is encoded by the PDZK1 gene.-Interactions:PDZK1 has been shown to interact with AKAP10, FARP2, Sodium-hydrogen antiporter 3 regulator 1, SLC22A12, SLK, SLC22A4, CLCN3, PDZK1IP1, Cystic fibrosis transmembrane conductance...

.

Further reading