HNF1α activates the aminopeptidase N promoter in intestinal (Caco-2) cells

The importance of HNF1 binding proteins for intestinal aminopeptidase N expression was investigated using the Caco-2 cell-line. Aminopeptidase N promoter activity in Caco-2 cells depends on the HNF1 element (positions -85 to -58) and co-transfection with an HNF1α expression vector demonstrates a direct activation of the promoter by HNF1α through this element. Electrophoretic mobility shift assays using nuclear extracts from Caco-2 cells show the presence of high amounts of HNF1 binding proteins irrespective of their state of differentiation.