| First Author | Beaudry JB | Year | 2006 |
| Journal | Mol Cell Biol | Volume | 26 |
| Issue | 16 | Pages | 6037-46 |
| PubMed ID | 16880515 | Mgi Jnum | J:111407 |
| Mgi Id | MGI:3653960 | Doi | 10.1128/MCB.02445-05 |
| Citation | Beaudry JB, et al. (2006) Threshold levels of hepatocyte nuclear factor 6 (HNF-6) acting in synergy with HNF-4 and PGC-1alpha are required for time-specific gene expression during liver development. Mol Cell Biol 26(16):6037-46 |
| abstractText | During liver development, hepatocytes undergo a maturation process that leads to the fully differentiated state. This relies at least in part on the coordinated action of liver-enriched transcription factors (LETFs), but little is known about the dynamics of this coordination. In this context we investigate here the role of the LETF hepatocyte nuclear factor 6 (HNF-6; also called Onecut-1) during hepatocyte differentiation. We show that HNF-6 knockout mouse fetuses have delayed expression of glucose-6-phosphatase (g6pc), which catalyzes the final step of gluconeogenesis and is a late marker of hepatocyte maturation. Using a combination of in vivo and in vitro gain- and loss-of-function approaches, we demonstrate that HNF-6 stimulates endogenous g6pc gene expression directly via a synergistic and interdependent action with HNF-4 and that it involves coordinate recruitment of the coactivator PGC-1alpha. The expression of HNF-6, HNF-4, and PGC-1alpha rises steadily during liver development and precedes that of g6pc. We provide evidence that threshold levels of HNF-6 are required to allow synergism between HNF-6, HNF-4, and PGC-1alpha to induce time-specific expression of g6pc. Our observations on the regulation of g6pc by HNF-6 provide a model whereby synergism, interdependency, and threshold concentrations of LETFs and coactivators determine time-specific expression of genes during liver development. |
