Identification and characterization of the high-affinity choline transporter.
In cholinergic neurons, high-affinity choline uptake in presynaptic terminals is the rate-limiting step in acetylcholine synthesis. Using information provided by the Caenorhabditis elegans Genome Project, we cloned a cDNA encoding the high-affinity choline transporter from C. elegans (cho-1). We subsequently used this clone to isolate the corresponding cDNA from rat (CHT1). CHT1 is not homologous to neurotransmitter transporters, but is homologous to members of the Na+-dependent glucose transporter family. Expression of CHT1 mRNA is restricted to cholinergic neurons. The characteristics of CHT1-mediated choline uptake essentially match those of high-affinity choline uptake in rat brain synaptosomes.
Okuda
T
T
Department of Neurochemistry, Faculty of Medicine, University of Tokyo and CREST of Japan Science and Technology Corporation, Bunkyo-ku, Tokyo 113-0033, Japan. okuda@m.u-tokyo.ac.jp
Haga
T
T
Kanai
Y
Y
Endou
H
H
Ishihara
T
T
Katsura
I
I
D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D016466:CHO Cells; D017173:Caenorhabditis elegans; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002794:Choline / Q000378:metabolism / Q000493:pharmacokinetics; D003001:Cloning, Molecular; D006224:Cricetinae; D018076:DNA, Complementary / Q000235:genetics; D006426:Hemicholinium 3 / Q000494:pharmacology; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000235:genetics; D009474:Neurons / Q000378:metabolism; D014179:Neurotransmitter Uptake Inhibitors / Q000494:pharmacology; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D009928:Organ Specificity; D010802:Phylogeny; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017386:Sequence Homology, Amino Acid; D012964:Sodium / Q000378:metabolism
D002352:Carrier Proteins; D018076:DNA, Complementary; D026901:Membrane Transport Proteins; D009004:Monosaccharide Transport Proteins; D014179:Neurotransmitter Uptake Inhibitors; D012333:RNA, Messenger; C065637:choline transporter; D006426:Hemicholinium 3; D012964:Sodium; D002794:Choline