Cloning and characterization of the choline acetyltransferase structural gene (cha-1) from C. elegans.
We have cloned the cha-1 gene from Caenorhabditis elegans using the method of transposon tagging, cha-1 is the structural gene for ChAT, the enzyme that synthesizes ACh. Sequence analysis of cDNAs predicts a protein of 71.5 kDa; comparison of the deduced amino acid sequence with ChAT sequences from other species confirms that cha-1 encodes ChAT. Comparison of cDNA and genomic sequences reveals that transcription is from right to left on the genetic map, and that some of the transcripts may result from trans-splicing of the 22-base spliced leader SL 1. The cha-1 gene is organized into 11 exons. The first exon contains only untranslated sequences, and is followed by an extremely long intron. The coding sequence of the cha-1 transcript is disrupted by mutations in the cha-1 gene. We have determined the sites of four transposon insertions and the end-points of two deletions that lead to the cha-1 mutant phenotype; one of the deletions appears to eliminate gene function completely. Comparison of the Drosophila, rat, and C. elegans genes reveals conserved motifs and conserved intron sites.
Alfonso
A
A
Program in Molecular and Cell Biology, Oklahoma Medical Research Foundation, Oklahoma City 73104.
Grundahl
K
K
McManus
J R
JR
Rand
J B
JB
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D017173:Caenorhabditis elegans / Q000201:enzymology* / Q000235:genetics*; D002795:Choline O-Acetyltransferase / Q000096:biosynthesis / Q000235:genetics*; D003001:Cloning, Molecular; D016384:Consensus Sequence; D004247:DNA / Q000032:analysis; D004330:Drosophila / Q000201:enzymology / Q000235:genetics; D005091:Exons; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010641:Phenotype; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D013552:Swine; D014158:Transcription, Genetic
D004247:DNA; D002795:Choline O-Acetyltransferase