Forkhead box protein O (FOXO)

Forkhead box protein O (FOXO) refers to a family of evolutionarily conserved transcription factors, characterized by a 'forkhead' DNA-binding domain. In mammals, FOXO proteins (FOXO1, FOXO3, FOXO4, FOXO6) regulate key processes including cell cycle arrest, apoptosis, autophagy, stress resistance, metabolism, differentiation, and longevity. They are tightly controlled by upstream signaling, especially the PI3K/AKT pathway: phosphorylation causes their nuclear export and inactivation, while stress or growth factor deprivation promotes nuclear localization and gene regulation. FOXO function is context-dependent; these proteins generally act as tumor suppressors and maintain cellular homeostasis, but may also promote disease progression in certain cancers. Dysregulation of FOXO activity is implicated in cancer, metabolic diseases, aging-related decline, neurodegeneration, and inflammatory conditions. Because of their central role in diverse pathways, FOXO transcription factors are considered attractive but challenging therapeutic targets due to their extensive physiological relevance and complex regulation[1][2][3][4][5][6].

Other names

Forkhead box O proteinFOXO transcription factorFOXO family (with specific genes/proteins: FOXO1, FOXO3, FOXO4, FOXO6)Forkhead in rhabdomyosarcoma (FKHR, for FOXO1)Forkhead box protein O1/O3/O4/O6

Most drugs or molecular interventions act by modulating upstream regulation of FOXO, especially via: - Inhibition of PI3K/AKT pathway (to promote FOXO nuclear localization/activity) - Activating SIRT/AMPK/JNK signaling (to enhance FOXO transcriptional activity) - Post-translational modification (phosphorylation, acetylation, ubiquitination) to modify FOXO localization and DNA-binding