RAT SMALL-INTESTINE EXPRESSES PRIMARILY TYPE-VI GAMMA-GLUTAMYL-TRANSPEPTIDASE RNA

To clarify differences between gamma-glutamyl transpeptidase (gamma GT ) expression in the rat and the mouse small intestine, we cloned and s equenced 13 rat small intestine gamma GT cDNAs and compared them with those obtained from the mouse (Carter, et al. (1994) J. Biol. Chem. 26 9, 24581-24585). We found that all 13 were type VI, which in both spec ies accounts for 80-90% of intestinal gamma GT. However, rat type VI g amma GT is substantially longer than mouse type VI RNA and includes at least 67 additional nucleotides at the 5' end that are non-homologous with the 5' end of the mouse type VI RNA; further, these show no homo logy to another mouse exon (VII) that splices to type VI RNA. In addit ion, a 168 nucleotide stretch is present in the middle of rat RNA that is absent in mouse type VI RNA.