The 5' untranslated region of the human gamma-glutamyl transferase mRNA contains a tissue-specific active translational enhancer.

We report the functional and structural analysis of the 5' untranslated region (5'UTR) of human hepatoma HepG2 gamma-glutamyltransferase (GGT) mRNA. Transient expression of a hybrid GGT-luciferase gene in HepG2, MIA-Pa-Ca-2 and MG 63 cell lines shows that this 5'UTR acts as a tissue-specific translational enhancer. Evidence for transcripts with multiple 5'UTR coding for HepG2 GGT was obtained by RNase protection. Computer analysis of this 5'UTR detected the existence of a stable stem and loop structure containing multiple steroid modulatory elements.