The cha-l transcript encodes choline acetyltransferase (ChAT), and is derived (mostly) from the left half of the cha-l
unc-17 gene complex (see abstract by Rand et al.). We have isolated and analyzed 4
cha-1 cDNAs (2 from the Kim library and 2 from the Barstead-Waterston library), and we have complete cDNA sequence information as well as virtually complete sequence data for the genomic region from which the transcripts are derived. The
cha-1 cDNAs contain a complete open reading frame encoding a deduced protein of 627 amino acids with a molecular weight of 71.5 kd, in excellent agreement with our measured 71 kd for the ChAT protein. Comparison of cDNA and genomic sequences indicates that
cha-1 transcripts consist of 11 exons. The first exon includes the entire 5' untranslated portion and is followed by a long (~5 kb) intron. (The
unc-17-encoded transcript is derived from this intron see abstract by Rand, et al.) The second exon starts with the protein initiation codon. Exon length ranges from 50-477, and intron length (not counting the first intron) ranges from 43-530. The deduced amino acid sequence shows 37% identity (58% similarity) with the porcine ChAT sequence, and 28% identity (50% similarity) with Drosophila ChAT. (The Drosophila and porcine sequences are 32% identical and 51% similar.) There are some regions which are highly conserved, e.g. a 25-amino acid stretch of the C. elegans deduced protein is 80% identical (88% similar) to the porcine sequence. We have also determined the insertion sites of 4 Tc1induced
cha-1 alleles as well as 2
cha-1 deletions. Supported by grants from NIGMS and NSF.