Molecular cloning of a cDNA for the glutamate transporter of the nematode Caenorhabditis elegans.

We cloned a cDNA for the glutamate transporter of the nematode Caenorhabditis elegans. The nucleotide sequence and Northern blotting indicated that the glutamate transporter gene is transcribed as a polycistronic mRNA in C. elegans and that subsequent trans-splicing yields two distinct monocistronic mRNAs for the glutamate transporter and the ATP synthase c subunit, respectively. The yields of these monocistronic mRNAs were quite different, suggesting that glutamate transport in C. elegans is regulated in the post-transcriptional phase. The glutamate transporter of C. elegans shows about 50-60% sequence similarity with those of mammals. This is the first description of invertebrate glutamate transporters.