Figure 3.

Activating and repressing function of Foxo1. Many transcription factors have dual effects on gene expression, turning some genes on and others off. In the case of Foxo regulation of G6pc and Gck, the activation mechanism is based on direct DNA binding through the protein’s namesake, forkhead domain. The repressor mechanism is based on the recruitment of Sin3a, a large component of the gene repressor complex, as the Foxo corepressor of Gck. This opens up the possibility of identifying drugs that act selectively on a specific function.