GAMMA-GLUTAMYL-TRANSPEPTIDASE - WHAT DOES THE ORGANIZATION AND EXPRESSION OF A MULTIPROMOTER GENE TELL US ABOUT ITS FUNCTIONS

gamma-Glutamyl transpeptidase is a key enzyme in glutathione (GSH) sal vage, metabolism of endogenous mediators such as leukotrienes and pros taglandins, detoxification of xenobiotics including environmentally im portant compounds and carcinogens, and cellular processes dependent on the oxidation/reduction of glutathione. The enzyme is widely, distrib uted, and these functions often occur in separate tissues and in respo nse to different stimuli. Evidence indicates that gamma-glutamyl trans peptidase plays a direct role in some hepatic and renal responses to i njury. In the mouse gamma-glutamyl transpeptidase is a single copy gen e expressed from at least seven promoters, and many of the transcribed gamma-glutamyl transpeptidase RNAs are restricted in their expression , Studies that combine analyses of cellular processes with a knowledge of gene structure and expression hold promise for unravelling how the se two different levels of function are integrated.