Forkhead Box Protein O6 (FOXO6)

Human FOXO6 was identified in ESTs originating from brain tissue and tumor cell lines, and it shares about 95% amino acid identity with mouse Foxo6. In situ hybridization in mouse revealed restricted expression in the developing and adult brain, particularly in cortical and hippocampal structures. After stimulation with IGF1 or insulin, Foxo6 was predominantly localized to the nucleus, while Foxo1 and Foxo3 were mainly cytosolic, and nuclear export of Foxo6 was mediated by the PI3-kinase pathway.

Luciferase reporter assay showed that Foxo6 functions as a transcription factor, and phosphorylation of ser184 was found to be important in regulating the transactivating properties of Foxo6, independent of its subcellular localization.