CHRNA4 : cholinergic receptor nicotinic alpha 4 subunit
Description
The CHRNA4 (cholinergic receptor nicotinic alpha 4 subunit) is a protein-coding gene located on chromosome 20.
The CHRNA4 gene provides instructions for making a subunit of a larger protein called the neuronal nicotinic acetylcholine receptor (nAChR). Each nAChR protein is made up of five subunits, usually two alpha (α) and three beta (β) subunits. Many different combinations are possible, and the characteristics of each nAChR protein depend on which subunits it contains. In the brain, nAChR proteins most commonly consist of two α4 subunits and three β2 subunits. The CHRNA4 gene is responsible for producing the α4 subunit. In the brain, nAChR proteins are widely distributed and play an important role in chemical signaling between nerve cells (neurons). The nAChR proteins act as channels, allowing charged atoms (ions) including calcium, sodium, and potassium to cross the cell membrane. These channels open when attached to a brain chemical (neurotransmitter) called acetylcholine. The channels also open in response to nicotine, the addictive substance in tobacco.Communication between neurons depends on neurotransmitters, which are released from one neuron and taken up by neighboring neurons. The release and uptake of these chemicals are tightly regulated to ensure that signals are passed efficiently and accurately between neurons. Researchers believe that nAChR channels play an important role in controlling the normal release and uptake of neurotransmitters. A wide range of brain functions depend on nAChR channels, including sleep and arousal, fatigue, anxiety, attention, pain perception, and memory. The channels are also active before birth, which suggests that they are involved in early brain development. At least one drug that targets nAChR channels in the brain has been developed to help people quit smoking; other medications targeting these channels are under study for the treatment of schizophrenia, Alzheimer disease, and pain.
CHRNA4 is also known as BFNC, EBN, EBN1, NACHR, NACHRA4, NACRA4.
