Folate receptors bind folate and reduced folic acid derivatives and mediates delivery of tetrahydrofolate to the interior of cells. It is then converted from monoglutamate to polyglutamate forms - such as 5-methyltetrahydrofolate - as only monoglutamate forms can be transported across cell membranes. Polyglutamate forms are biologically active enzymatic cofactors required for many folate-dependent processes such as folate-dependent one-carbon metabolism. These proteins are attached to the membrane by a GPI anchor. A riboflavin-binding protein required for the transport of riboflavin to the developing oocyte in chicken also belong to this family.
Human proteins from this family include:
- FOLR1: folate receptor 1 (adult),
- FOLR2: folate receptor 2 (fetal), and
- FOLR3: folate receptor gamma.
References
Wibowo AS, Singh M, Reeder KM, Carter JJ, Kovach AR, Meng W, et al. (September 2013). "Structures of human folate receptors reveal biological trafficking states and diversity in folate and antifolate recognition". Proceedings of the National Academy of Sciences of the United States of America. 110 (38): 15180–8. Bibcode:2013PNAS..11015180W. doi:10.1073/pnas.1308827110. PMC 3780903. PMID 23934049. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3780903 ↩
Antony AC (1996). "Folate receptors". Annual Review of Nutrition. 16: 501–21. doi:10.1146/annurev.nu.16.070196.002441. PMID 8839936. /wiki/Doi_(identifier) ↩