[Organization of the human GLUT2 gene and regulation of the GLUT2 gene expression]

The high Km glucose transporter, termed GLUT2, is expressed in pancreatic beta-cells and hepatocytes in a tissue specific manner. Previous studies revealed that higher glucose levels cause increased GLUT2 gene expression in beta-cells and hepatocytes and that 11 exons of human GLUT2 gene are spanning around 30 kilobases in q26.1-->q26.3 region of was has been chromosome 3. While the putative transcriptional start site has been reported, we made a series of deletion analyses of the human GLUT2 gene promoter region and showed that the sequences located downstream of the putative transcriptional start site are essential for transcription not only in a hamster beta-cell line but also in primary cultured rat hepatocytes.