CHARACTERIZATION OF THE HUMAN ALDOSE REDUCTASE GENE PROMOTER

The promoter region of the human aldose reductase gene has been identi fied upstream of the translation start ATG codon. The promoter contain s a TATA box, a CCAAT promoter element, and three Sp1 protein binding consensus sequences upstream of the capsite. A 640-base pair insert sp anning +31 to -609 directs expression of the reporter gene chloramphen icol acetyltransferase in an orientation-specific manner in transfecte d Hep G2 cells. The promoter activity remained constant with deletions from base pairs -609 to -186. The TATA and the CCAAT consensus sequen ces show significant promoter activity, whereas the three Sp1 binding consensus sequences, individually, have no significant promoter activi ty. A GA-rich region (-186 to -146) contains two CGGAAA/G motifs, whic h show promoter activity and interaction with Hep G2 nuclear extract a nd GA-binding proteins (GABPalpha and GABPbeta1) as shown by mobility shift assays and DNase I footprinting. Similar cis-elements in herpes simplex virus type 1 interact with rat liver GABP and the viral VP16 p rotein to mediate the induction of immediate early viral genes. A GC-r ich region (87 to -31) is identified by mobility shift assay, and a co nsensus sequence of an androgen response element is present at -396 to -382. The human aldose reductase promoter, thus, has regulatory respo nse elements that may be important during early development and pubert y. These regulatory elements may play a significant role in the develo pment of certain diabetic complications.