Different transcription termination sequences of gastrin genes

Abstract

We have isolated genomic clones that contain monkey, sheep and mouse gastrin genes. The terminator-like sequence of monkey gastrin gene for RNA polymerase II was similar to the previously shown human terminator [Sato, K, Ito, R, Baek, K，H., and Agarwal, K. (1986) Mol Cell. Biol. 6, 1032-1043]. To identify the termination element in m이ise and sheep gastrin genes, we employed an in vivo transiently expressing system. The GT-repeat sequence at the 3' flanking region of mouse gastrin gene, acted as a transcription terminator. When the element was deleted, the effect of termination disappeared perfectly. When the element was artificially inserted into the 3' flanking region of sheep gastrin gene that had not shown any transcription termination, the effect of termination newly appeared. The GT-repeat element responsible for transcription termination functioned with orientation-dependent fashion. An adenine stretch (A)10 found at the 3' flanking region of sheep gastrin gene, however, did not function as a terminator. Thus, mechanisms of transcription termination by RNA polymerase II appear to vary from species to species even for the same eukaryotic gene.