Vesicular acetylcholine transporter

Last updated
SLC18A3
Identifiers
Aliases SLC18A3 , VACHT, solute carrier family 18 member A3, CMS21
External IDs OMIM: 600336 MGI: 1101061 HomoloGene: 11022 GeneCards: SLC18A3
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_003055

NM_021712

RefSeq (protein)

NP_003046

NP_068358

Location (UCSC) Chr 10: 49.61 – 49.61 Mb Chr 14: 32.18 – 32.19 Mb
PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

The Vesicular acetylcholine transporter (VAChT) is a neurotransmitter transporter which is responsible for loading acetylcholine (ACh) into secretory organelles in neurons making acetylcholine available for secretion. [5] [6] It is encoded by Solute carrier family 18, member 3 (SLC18A3) gene, located within the first intron of the choline acetyltransferase gene. VAChT is able to transport ACh into vesicles by relying on an exchange between protons (H+) that were previously pumped into the vesicle diffusing out, thus acting as an antiporter. ACh molecules are then carried into the vesicle by the action of exiting protons. [7] Acetylcholine transport utilizes a proton gradient established by a vacuolar ATPase.

Contents

VAChT uptake inhibitors

Radiolabeled compounds

PET imaging of the VAChT may provide insights into early diagnosis of Alzheimer's disease.

Related Research Articles

<span class="mw-page-title-main">Acetylcholine</span> Organic chemical and neurotransmitter

Acetylcholine (ACh) is an organic compound that functions in the brain and body of many types of animals as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Parts in the body that use or are affected by acetylcholine are referred to as cholinergic.

<span class="mw-page-title-main">Choline acetyltransferase</span> Protein-coding gene in the species Homo sapiens

Choline acetyltransferase is a transferase enzyme responsible for the synthesis of the neurotransmitter acetylcholine. ChAT catalyzes the transfer of an acetyl group from the coenzyme acetyl-CoA to choline, yielding acetylcholine (ACh). ChAT is found in high concentration in cholinergic neurons, both in the central nervous system (CNS) and peripheral nervous system (PNS). As with most nerve terminal proteins, ChAT is produced in the body of the neuron and is transported to the nerve terminal, where its concentration is highest. Presence of ChAT in a nerve cell classifies this cell as a "cholinergic" neuron. In humans, the choline acetyltransferase enzyme is encoded by the CHAT gene.

<span class="mw-page-title-main">Synaptic vesicle</span> Neurotransmitters that are released at the synapse

In a neuron, synaptic vesicles store various neurotransmitters that are released at the synapse. The release is regulated by a voltage-dependent calcium channel. Vesicles are essential for propagating nerve impulses between neurons and are constantly recreated by the cell. The area in the axon that holds groups of vesicles is an axon terminal or "terminal bouton". Up to 130 vesicles can be released per bouton over a ten-minute period of stimulation at 0.2 Hz. In the visual cortex of the human brain, synaptic vesicles have an average diameter of 39.5 nanometers (nm) with a standard deviation of 5.1 nm.

<span class="mw-page-title-main">Coluracetam</span> Chemical compound

Coluracetam is a purported nootropic agent of the racetam family. It is contains a chemical group that is a bioisostere of the 9-amino-tetrahydroacridine family. It was initially developed and tested by the Mitsubishi Tanabe Pharma Corporation for Alzheimer's disease. After the drug failed to reach endpoints in its clinical trials it was in-licensed by BrainCells Inc for investigations into major depressive disorder (MDD), which was preceded by being awarded a "Qualifying Therapeutic Discovery Program Grant" by the state of California. Findings from phase IIa clinical trials have suggested that it would be a potential medication for comorbid MDD with generalized anxiety disorder (GAD). BrainCells Inc is currently out-licensing the drug for this purpose. It may also have potential use in prevention and treatment of ischemic retinopathy and retinal and optic nerve injury.

<span class="mw-page-title-main">End-plate potential</span>

End plate potentials (EPPs) are the voltages which cause depolarization of skeletal muscle fibers caused by neurotransmitters binding to the postsynaptic membrane in the neuromuscular junction. They are called "end plates" because the postsynaptic terminals of muscle fibers have a large, saucer-like appearance. When an action potential reaches the axon terminal of a motor neuron, vesicles carrying neurotransmitters are exocytosed and the contents are released into the neuromuscular junction. These neurotransmitters bind to receptors on the postsynaptic membrane and lead to its depolarization. In the absence of an action potential, acetylcholine vesicles spontaneously leak into the neuromuscular junction and cause very small depolarizations in the postsynaptic membrane. This small response (~0.4mV) is called a miniature end plate potential (MEPP) and is generated by one acetylcholine-containing vesicle. It represents the smallest possible depolarization which can be induced in a muscle.

The vesicular monoamine transporter (VMAT) is a transport protein integrated into the membranes of synaptic vesicles of presynaptic neurons. It transports monoamine neurotransmitters – such as dopamine, serotonin, norepinephrine, epinephrine, and histamine – into the vesicles, which release the neurotransmitters into synapses as chemical messages to postsynaptic neurons. VMATs utilize a proton gradient generated by V-ATPases in vesicle membranes to power monoamine import.

<span class="mw-page-title-main">Vesicular monoamine transporter 2</span> Mammalian protein found in Homo sapiens

The solute carrier family 18 member 2 (SLC18A2) also known as vesicular monoamine transporter 2 (VMAT2) is a protein that in humans is encoded by the SLC18A2 gene. SLC18A2 is an integral membrane protein that transports monoamines—particularly neurotransmitters such as dopamine, norepinephrine, serotonin, and histamine—from cellular cytosol into synaptic vesicles. In nigrostriatal pathway and mesolimbic pathway dopamine-releasing neurons, SLC18A2 function is also necessary for the vesicular release of the neurotransmitter GABA.

<span class="mw-page-title-main">Hemicholinium-3</span> Chemical compound

Hemicholinium-3 (HC3), also known as hemicholine, is a drug which blocks the reuptake of choline by the high-affinity choline transporter at the presynapse. The reuptake of choline is the rate-limiting step in the synthesis of acetylcholine; hence, hemicholinium-3 decreases the synthesis of acetylcholine. It is therefore classified as an indirect acetylcholine antagonist.

<span class="mw-page-title-main">Vesicular monoamine transporter 1</span> Protein-coding gene in the species Homo sapiens

Vesicular monoamine transporter 1 (VMAT1) also known as chromaffin granule amine transporter (CGAT) or solute carrier family 18 member 1 (SLC18A1) is a protein that in humans is encoded by the SLC18A1 gene. VMAT1 is an integral membrane protein, which is embedded in synaptic vesicles and serves to transfer monoamines, such as norepinephrine, epinephrine, dopamine, and serotonin, between the cytosol and synaptic vesicles. SLC18A1 is an isoform of the vesicular monoamine transporter.

Neurotransmitter transporters are a class of membrane transport proteins that span the cellular membranes of neurons. Their primary function is to carry neurotransmitters across these membranes and to direct their further transport to specific intracellular locations. There are more than twenty types of neurotransmitter transporters.

<span class="mw-page-title-main">Vesamicol</span> Chemical compound

Vesamicol is an experimental drug, acting presynaptically by inhibiting acetylcholine (ACh) uptake into synaptic vesicles and reducing its release. Vesamicol may have applications for the treatment of adenocarcinoma in situ of the lung.

<span class="mw-page-title-main">Acetylcholinesterase</span> Primary cholinesterase in the body

Acetylcholinesterase (HGNC symbol ACHE; EC 3.1.1.7; systematic name acetylcholine acetylhydrolase), also known as AChE, AChase or acetylhydrolase, is the primary cholinesterase in the body. It is an enzyme that catalyzes the breakdown of acetylcholine and some other choline esters that function as neurotransmitters:

An amino acid transporter is a membrane transport protein that transports amino acids. They are mainly of the solute carrier family.

<span class="mw-page-title-main">Choline transporter-like protein 1</span> Mammalian protein found in Homo sapiens

Choline transporter-like protein 1 is a protein that in humans is encoded by the SLC44A1 gene.

<span class="mw-page-title-main">Vesicular glutamate transporter 1</span> Protein-coding gene in the species Homo sapiens

Vesicular glutamate transporter 1 (VGLUT1) is a protein that in humans is encoded by the SLC17A7 gene.

<span class="mw-page-title-main">CHRNA6</span> Protein-coding gene in the species Homo sapiens

Cholinergic receptor, nicotinic, alpha 6, also known as nAChRα6, is a protein that in humans is encoded by the CHRNA6 gene. The CHRNA6 gene codes for the α6 nicotinic receptor subunit that is found in certain types of nicotinic acetylcholine receptors found primarily in the brain. Neural nicotinic acetylcholine receptors containing α6 subunits are expressed on dopamine-releasing neurons in the midbrain, and dopamine release following activation of these neurons is thought to be involved in the addictive properties of nicotine. Due to their selective localisation on dopaminergic neurons, α6-containing nACh receptors have also been suggested as a possible therapeutic target for the treatment of Parkinson's disease. In addition to nicotine, research in animals has implicated alpha-6-containing nAChRs in the abusive and addictive properties of ethanol, with mecamylamine demonstrating a potent ability to block these properties.

<span class="mw-page-title-main">Reuptake inhibitor</span> Type of drug

Reuptake inhibitors (RIs) are a type of reuptake modulators. It is a drug that inhibits the plasmalemmal transporter-mediated reuptake of a neurotransmitter from the synapse into the pre-synaptic neuron. This leads to an increase in extracellular concentrations of the neurotransmitter and an increase in neurotransmission. Various drugs exert their psychological and physiological effects through reuptake inhibition, including many antidepressants and psychostimulants.

<span class="mw-page-title-main">Choline transporter</span> Protein-coding gene in the species Homo sapiens

The high-affinity choline transporter (ChT) also known as solute carrier family 5 member 7 is a protein in humans that is encoded by the SLC5A7 gene. It is a cell membrane transporter and carries choline into acetylcholine-synthesizing neurons.

<span class="mw-page-title-main">Vesicular glutamate transporter 3</span> Protein-coding gene in the species Homo sapiens

Vesicular glutamate transporter 3 (VGLUT3) is a protein that in humans is encoded by the SLC17A8 gene.

<span class="mw-page-title-main">Cholinergic neuron</span> Type of nerve cell

A cholinergic neuron is a nerve cell which mainly uses the neurotransmitter acetylcholine (ACh) to send its messages. Many neurological systems are cholinergic. Cholinergic neurons provide the primary source of acetylcholine to the cerebral cortex, and promote cortical activation during both wakefulness and rapid eye movement sleep. The cholinergic system of neurons has been a main focus of research in aging and neural degradation, specifically as it relates to Alzheimer's disease. The dysfunction and loss of basal forebrain cholinergic neurons and their cortical projections are among the earliest pathological events in Alzheimer's disease.

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000187714 - Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000100241 - Ensembl, May 2017
  3. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. Erickson JD, Varoqui H (Dec 2000). "Molecular analysis of vesicular amine transporter function and targeting to secretory organelles". FASEB Journal. 14 (15): 2450–8. doi:10.1096/fj.00-0206rev. PMID   11099462. S2CID   15305436.
  6. Weihe E, Tao-Cheng JH, Schäfer MK, Erickson JD, Eiden LE (Apr 1996). "Visualization of the vesicular acetylcholine transporter in cholinergic nerve terminals and its targeting to a specific population of small synaptic vesicles". Proceedings of the National Academy of Sciences of the United States of America. 93 (8): 3547–52. doi: 10.1073/pnas.93.8.3547 . PMC   39647 . PMID   8622973.
  7. Waymire J. "Storage of ACh". University of Texas Medical Center.
  8. Tu Z, Efange SM, Xu J, Li S, Jones LA, Parsons SM, Mach RH (Mar 2009). "Synthesis and in vitro and in vivo evaluation of 18F-labeled positron emission tomography (PET) ligands for imaging the vesicular acetylcholine transporter". Journal of Medicinal Chemistry. 52 (5): 1358–69. doi:10.1021/jm8012344. PMC   2765529 . PMID   19203271.

Further reading