CHARACTERIZATION OF THE INTEGRIN ALPHA(V) GENE PROMOTER IN MICE

To characterize a promoter for integrin alpha(v), in mice, we cloned a 5'-flanking region of the mouse integrin alpha(v) gene. The nucleotid e sequence of the promoter region lacks both TATA or CCAAT boxes, and has the consensus sequence for Sp1, Ets, AP-2 and GATA-1. The transcri ption initiation site was mapped as 287 base pairs (bp) upstream from the translation initiation site by primer extension analysis. To analy ze the promoter activity of the integrin alpha(v) gene, the successive 5'-deletions which were cloned upstream of the luciferase reporter ge ne were transfected into mouse melanoma B16F10 cells with high metasta tic properties. The luciferase assay reveals that a region (positions -108 to +22) has important cis-acting elements for the promoter activi ty. Further, three distinct protein-DNA complexes in the promoter regi on were detected in a gel shift assay using nuclear extracts from B16F 10 cells. To identify positions where the complexes are formed, the pr omoter region (positions -108 to +97) was subjected to DNaseI footprin ting analysis. The analysis showed that a 17 bp-element (positions -31 to -15) interacts with putative transcription factors. Deletion of th e 17 bp-element from the promoter resulted in a reduction of about 80% in the promoter activity when compared with the wild type promoter, a nd a gel shift assay using the deleted mutant of the promoter showed o nly one protein-DNA complex. These results reveal that the 17 bp-eleme nt contains cis-acting elements, and plays an important role in the tr anscription initiation of the integrin alpha(v) gene. (C) 1998 Elsevie r Science B.V.