Hepatocyte nuclear factors 1α and 4α control expression of proline oxidase in adult liver

Abstract
Adult liver functions are regulated by several hepatocyte nuclear factors (HNFs). HNF4α and HNF1α are involved in metabolic functions in the liver. The expression of proline oxidase (PO) and proline dehydrogenase was downregulated in the HNF4α liver‐specific null mice. In addition, the expression of PO was also diminished in the liver derived from HNF1α‐null mice. The −160 bp proximal promoter region of the PO gene has two HNF4α‐ and HNF1α‐binding consensus sites. Transactivation, electrophoretic mobility shift and chromatin immunoprecipitation studies revealed that these regions are important for PO promoter activity. These results suggested that HNF4α and HNF1α regulate proline metabolism in adult liver.