Folate receptor gamma is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...
that in humans is encoded by the FOLR3
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
. It is involved in up-take of
folic acid
Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing a ...
.
Gene location
The ''FOLR'' multi-gene family (''FOLR1'', ''FOLR2'' and ''FOLR3'') is localized to chromosome 11q13.3–q14.1, and encodes the gene products FRα, β and γ, respectively.
Tissue distribution
FOLR3 is localized in
haematopoietic tissue, such as spleen and bone marrow, and is present as a
secretory protein. FOLR3 expresses in humans rather than mice and rats.
Function
The ''FOLR3'' gene is polymorphic due to a nonsense mutation resulting in a truncated protein; FRγ, which can bind folic acid. ''FOLR3'' genes each consist of 5 exons, 4 introns and 1 promoter that encodes a single transcript.
Clinical significance
Expression of FOLR3 is correlated more strongly with plasma
homocysteine
Homocysteine is a non-proteinogenic α-amino acid. It is a homologue of the amino acid cysteine, differing by an additional methylene bridge (-CH2-). It is biosynthesized from methionine by the removal of its terminal Cε methyl group. In th ...
(Hcy) than
FOLR1
Folate receptor 1 (Folate receptor alpha, FOLR1) is a protein that in humans is encoded by the ''FOLR1'' gene.
The protein encoded by this gene is a member of the folate receptor (FOLR) family. Members of this family have a high affinity for folic ...
and
FOLR2
Folate receptor beta is a protein that in humans is encoded by the ''FOLR2'' gene.
The protein encoded by this gene is a member of the folate receptor (FOLR) family. Members of this gene family have a high affinity for folic acid and for several ...
. FOLR3 may decrease plasma Hcy compared with other FOLRs.
It was demonstrated that FOLR3 can metabolize both intracellular Hcy and extracellular Hcy. These results indicate that an increase in FOLR3 may effectively ameliorate Hcy in the blood and weaken Hcy-induced toxicity, even in tissues with the low level of FOLR1 and FOLR2 expression.
References
{{protein-stub
Membrane proteins