Molecular cloning of a putative vesicular transporter for acetylcholine.
Classical neurotransmitters such as acetylcholine (ACh) require transport into synaptic vesicles for regulated exocytotic release. The Caenorhabditis elegans gene unc-17 encodes a protein with homology to mammalian transporters that concentrate monoamine neurotransmitters into synaptic vesicles. Mutations in unc-17 protect against organophosphorus toxicity, indicating a role in cholinergic neurotransmission. Using the relationship of unc-17 to the vesicular amine transporters, we first isolated a related sequence from the electric ray Torpedo californica [Torpedo vesicular ACh transporter (TorVAChT)] that is expressed by the electric lobe but not by peripheral tissues. Using the relationship of the Torpedo sequence to unc-17, we then isolated the cDNA for a rat homologue (rVAChT). Northern blot analysis shows expression of these sequences in the basal forebrain, basal ganglia, and spinal cord but not cerebellum or peripheral tissues. In situ hybridization shows expression of rVAChT mRNA in all cholinergic cell groups, including those in the basal forebrain, brainstem, and spinal cord that previously have been shown to express choline acetyltransferase mRNA. The human VAChT gene also localizes to chromosome 10 near the gene for choline acetyltransferase. Taken together, these observations support a role for rVAChT in vesicular ACh transport and indicate its potential as a novel marker for cholinergic neurons.
Roghani
A
A
Department of Neurology, University of California, Los Angeles, School of Medicine, CA 90024-1769.
Feldman
J
J
Kohan
S A
SA
Shirzadi
A
A
Gundersen
C B
CB
Brecha
N
N
Edwards
R H
RH
D000109:Acetylcholine / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D001921:Brain / Q000378:metabolism*; D001933:Brain Stem / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000378:metabolism; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000235:genetics; D002795:Choline O-Acetyltransferase / Q000096:biosynthesis; D003001:Cloning, Molecular; D017931:DNA Primers; D018076:DNA, Complementary / Q000302:isolation & purification; D017403:In Situ Hybridization; D026901:Membrane Transport Proteins; D008961:Models, Structural; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009928:Organ Specificity; D016133:Polymerase Chain Reaction / Q000379:methods; D016548:Prosencephalon / Q000378:metabolism; D011487:Protein Conformation; D051381:Rats; D017386:Sequence Homology, Amino Acid; D013116:Spinal Cord / Q000378:metabolism*; D014101:Torpedo; D014158:Transcription, Genetic; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins
D002352:Carrier Proteins; D017931:DNA Primers; D018076:DNA, Complementary; D026901:Membrane Transport Proteins; C493461:Slc18a3 protein, rat; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins; D002795:Choline O-Acetyltransferase; D000109:Acetylcholine