Choline transporter

Source: Wikipedia, the free encyclopedia.
SLC5A7
Identifiers
Gene ontology
Molecular function
Cellular component
Biological process
Sources:Amigo / QuickGO
Ensembl

ENSG00000115665

ENSMUSG00000023945

UniProt

Q9GZV3
Q2T9H3

Q8BGY9

RefSeq (mRNA)

NM_001305005
NM_001305006
NM_001305007
NM_021815

NM_022025

RefSeq (protein)

NP_001291934
NP_001291935
NP_001291936
NP_068587
NP_001291936.1

NP_071308

Location (UCSC)Chr 2: 107.99 – 108.01 MbChr 17: 54.58 – 54.61 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/Edit Mouse

The high-affinity choline transporter (ChT) also known as solute carrier family 5 member 7 is a

cell membrane transporter and carries choline into acetylcholine-synthesizing neurons
.

Hemicholinium-3 is an inhibitor of the ChT and can be used to deplete acetylcholine stores, while coluracetam is an enhancer of the ChT and can increase cholinergic neurotransmission by enhancing acetylcholine synthesis.

Function

Choline is a direct precursor of acetylcholine (ACh), a neurotransmitter of the central and peripheral nervous system that regulates a variety of autonomic, cognitive, and motor functions. SLC5A7 is a Na(+)- and Cl(-)- dependent high-affinity transporter that mediates the uptake of choline for acetylcholine synthesis in cholinergic neurons.[5][6]

distal hereditary motor neuropathy type 7A).[7]

The ChT seems to be a site of action of some β-neurotoxins found in snake venoms, which disrupt peripheral cholinergic transmission by interfering with presynaptic acetylcholine synthesis. It is hypothesized that these toxins irreversibly block the ChT.[8][9]

Choline transporter in the human brain microvascular endothelial cells

Choline is a necessary reagent for the synthesis of

endothelial cells, two systems initiate the choline absorption. The first system is known as the Choline transporter-like protein 1, or CTL1. The second system is the Choline transporter-like protein 2, or CTL2. Those two systems are found on the plasma membrane of the brain microvascular endothelial cells. They are also found on the mitochondrial membrane. CTL2 was found to be highly expressed on the mitochondria. Meanwhile, CTL1 was mostly found on the plasma membrane of those microvascular cells.[10]

CTL2 is the main protein involved in the absorption of choline into the mitochondria for its oxidation, and CTL1 is the main protein for the choline uptake from the extracellular medium. CTL1 is a pH dependent protein. The absorption of choline through CTL1 proteins changes with the pH of the extracellular medium. When the pH of the medium is changed from 7.5 to 7.0-5.5, the rate of absorption of choline by CTL1 proteins decreases greatly. The choline uptake does not change upon the alkalinization of the extracellular medium. Moreover, it was found that the choline uptake is also influenced by the electronegativity of the plasma membrane. When the concentration of potassium ions is increased, the membrane becomes depolarized. The choline absorption decreases majorly as a result of the membrane depolarization by the potassium ions. The choline uptake was found to be only affected by the potassium ions. The sodium ions do not affect the affinity of CTL1 and CTL2 to choline.[10]

See also

References

  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000115665 – Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000023945 – 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. ^ a b "Entrez Gene: Solute carrier family 5 (choline transporter), member 7".
  6. PMID 11027560
    .
  7. PMID 23141292
    .
  8. S2CID 4287430
    .
  9. PMID 2260102
    .
  10. ^
    S2CID 45392318
    .

This article incorporates text from the United States National Library of Medicine, which is in the public domain.

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