Folate Transporter (FOLT)

Transport of folate compounds into mammalian cells can occur via receptor-mediated 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 (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.Northern blot analysis revealed that the IFC1 gene was expressed as a 3.3-kb mRNA at a high level in placenta and at lower levels in a variety of other tissues, including the small intestine. In situ hybridization of thin sections of intestinal epithelia demonstrated IFC1 expression localized to the villus and crypt cells, particularly the upper half of the villi.