Molecular cloning of a human, hemicholinium-3-sensitive choline transporter

Subbu Apparsundaram*, Shawn M. Ferguson, Alfred L. George, Randy D. Blakely

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

145 Scopus citations

Abstract

Under many physiological circumstances, Na+-and Cl--dependent, hemicholinium-3 (HC-3)-sensitive, high-affinity choline uptake (HACU) in cholinergic neurons is thought to be rate-limiting in the biosynthesis of acetylcholine (ACh). Based on sequence information provided by the Human Genome Project and the recently reported rat CHT1 (rCHT1), we cloned a human CHT cDNA from spinal cord. The hCHT cDNA encodes a protein of 580 amino acids having 93% identity to rCHT1 and 51% identity to the Caenorhabditis elegans homolog CHO-1, and is distantly related to members of the Na+-coupled glucose transporter (SGLT) gene family of Na+-coupled glucose (SGLT), nucleoside and iodide transporters. Northern blot analysis reveals the expression of a ~5 kb transcript in human brain regions rich in cholinergic neurons including the putamen, spinal cord, and medulla. Expression of hCHT cDNA in COS-7 cells results in saturable, Na+/Cl--dependent choline uptake (K(m) = 1.2 μM) in membrane vesicles and [3H] HC-3 binding (K(d) = 4 nM) in membrane fractions, consistent with characteristics reported in mammalian cholinergic neurons. Using radiation hybrid mapping techniques, we localized the hCHT gene to human chromosome 2q12. These studies elucidate the primary structure and chromosomal localization of hCHT and provide a basis for mechanistic analysis of ILhCU regulation and an investigation of the role ofhCHT in disease states. (C) 2000 Academic Press.

Original languageEnglish (US)
Pages (from-to)862-867
Number of pages6
JournalBiochemical and Biophysical Research Communications
Volume276
Issue number3
DOIs
StatePublished - Oct 5 2000

Keywords

  • Acetylcholine
  • Choline
  • Cholinergic
  • Chromosomal mapping
  • Gene expression
  • Hemicholinium-3
  • Membrane protein
  • Transporter

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

Fingerprint Dive into the research topics of 'Molecular cloning of a human, hemicholinium-3-sensitive choline transporter'. Together they form a unique fingerprint.

Cite this