Genomic sequence of human glyoxalase-I: analysis of promoter activity and its regulation

Glyoxalase-I is a glutathione-binding protein involved in the detoxificatio n of methylglyoxal, a by-product of glycolysis. Aberrations in the expressi on of human glyoxalase in cancer and diabetes have been reported. To gain a better understanding of the glyoxalase-I regulation under normal physiolog ical conditions and in disease processes, we have cloned 12 kb of genomic s equence, comprising five exons, separated by four introns. A fragment compr ising 982 bp of 5' flanking region was used in the pSEAP reporter system to identify the minimal promoter and to locate any cis-acting functional elem ents. This region contained a minimal promoter between -20 and -160 bp. Cel ls transfected with a construct containing the 5' flanking sequence exhibit ed a 45-fold higher activity over vector transfected cells. A twofold repro ducible increase in reporter activity was seen with insulin and ZnCl2 treat ments, indicating a functionally operative insulin response element (IRE) a nd metal response element (MRE). Knowledge regarding the regulation of glyo xalase-I may provide insights into the importance of this enzyme in human d iseases. (C) 1999 Published by Elsevier Science B.V. All rights reserved.