Solute carrier family 19 (folate transporter), member 1, also known as SLC19A1 or RFC1, is a protein

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...

 which in humans is encoded by the SLC19A1 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...

.

Function

Transport of folate

Folic acid

Folic acid and folate , as well as pteroyl-L-glutamic acid, pteroyl-L-glutamate, and pteroylmonoglutamic acid are forms of the water-soluble vitamin B9...

 compounds into mammalian cells can occur via receptor-mediated (see folate receptor 1

Folate receptor 1

Folate receptor alpha is a protein that in humans is encoded by the FOLR1 gene.-Clinical significance:FRA can be overexpressed by a number of epithelial-derived tumors including ovarian, breast, renal, lung, colorectal, and brain. Hence antibodies to it are used targeted therapies and diagnostic...

) or carrier-mediated mechanisms. A functional coordination between these 2 mechanisms has been proposed to be the method of folate uptake in certain cell types. Methotrexate

Methotrexate

Methotrexate , abbreviated MTX and formerly known as amethopterin, is an antimetabolite and antifolate drug. It is used in treatment of cancer, autoimmune diseases, ectopic pregnancy, and for the induction of medical abortions. It acts by inhibiting the metabolism of folic acid. Methotrexate...

 (MTX) is an antifolate chemotherapeutic agent that is actively transported by the carrier-mediated uptake system. RFC1 plays a role in maintaining intracellular concentrations of folate.

Clinical significance

Individuals carrying a specific polymorphism of SLC19A1 (c.80GG) have lower levels of folate. Other studies have also shown that individuals carrying the c.80AA polymrophism who are treated with methotrexate have higher levels of this anti-folate chemotherapeutic agent. Personalized dosing of the drug depending on the patient's genotype may therefore be required.

Further reading