Function
The human folate receptor(HFR) acts as a binder to folate in the body to reduce folic acid. HFR's are important for the absorbance of folic acid so that the body does not have an imbalance and can function properly. An improper imbalance in HFR can mainly effect the brain in the motor skills of a person. Human folate receptors also mediate the delivery of 5-methyltetrahydrofolate. As long as the HFR is in a neutral pH then it will have a high affinity for folic acid and folate. Expressed in the epithelial tissue of the brain, this is where the HFR is most effective; along with pregnant women who need HFR for the development of the baby in the uterus. If the mother does not have the proper HFR in the body while pregnant then it will effect the babies ability to function properly.<1>
Disease
Many of the diseases that carry out with an imbalance of HFR involve the brain. Not having the proper amount of HFR can cause a folate deficiency and cause brain damage, or known as neurodegeneration. The motor skills of the person will be effected and may cause movement disturbances such as epilepsy. The effects of low HFR can begin as soon as being in the uterus. If the carrier has an imbalance it can be passed down to the fetus while still in the uterus. Once born this imbalance and have developmental regression and the baby can have a reverse in the development. These changes can occur as loosing the ability to walk or talk at a young age. The folate deficiency can also cause leukodystrophy. This is a disruption of the white matter of the brain and the peripheral nerves.
Relevance
There are many studies done about HFR in the prevention of cancer and brain development.<2> The cancer studies have been done mainly in women of child bearing age in the breast tissue, cervical tissue and gastrointestinal tissue; all that come in connection with the baby. The HFR that are transferred from the mother to the baby can effect the balance of HFR that is in the mother and increase the change of cancer in these organs now due to a deficiency from passing the HFR onto the baby. This can then lead to the research of the brain development of children that may have problems growing to the full potential. The research in brain development can then be linked to the folate transfer to research in the blood-brain and blood-cerebrospinal fluid. This is the largest cause of the leukodystrophy in the brain and not being fully developed. Human folate receptors are relevant to the development of the body as a whole due to the impact that they can positively or negatively have on the brain and the neurological system of humans.
Structural highlights
In the folate receptors that are forms of alpha, beta, delta and gamma. The main difference between them all is on what binding properties that they possess between folic acid, 5-methyltetrahydrofolate and anti-folates. They are all expressed as a single chain or a single unit. Human folate receptors are classified as folate binging proteins because they only carry folate like structures through the blood. Folates have three major structural features; a bicyclic pterin head group, aminobenzoate, and glutamate. Most of the bindings are bound to the glutamate part of the receptors because of the charges between the receptor and the cargo. The folate receptor has a binding pocket that is negative and surrounding it is a positively charges entrance. This allows the cargo to be more easily bonded due to the difference in charges. These can be shown by the smaller bonds located on the outside of the molecule.<3>
