Based on studies in mice, FOXO1, in complex with PPARGC1A (PGC-1alpha), binds the promoter of the PCK1 gene, encoding Phosphoenolpyruvate carboxykinase, an enzyme in the gluconeogenesis pathway. Interaction of FOXO1 with PPARGC1A is inhibited by AKT-mediated phosphorylation of FOXO1, and binding of FOXO1 and PPARGC1A to the PKC1 promoter is inhibited by insulin (Puigserver et al. 2003).
FOXO3 (Hall et al. 2000) and FOXO4 (Yang et al. 2002) also bind the promoter of the PCK1 gene.