Phospho-FoxO3a (Ser253) Recombinant Rabbit mAb (S-3814)

Phospho-FoxO3a (Ser253) refers to the forkhead box O3a (FoxO3a) transcription factor specifically phosphorylated at the serine 253 residue, a critical post-translational modification primarily mediated by the Akt/PKB kinase pathway in response to growth factors and insulin signaling. This phosphorylation event serves as a key regulatory switch that dictates the subcellular localization and functional activity of FoxO3a; upon phosphorylation at Ser253, along with other sites such as Thr32 and Ser318, FoxO3a undergoes a conformational change that facilitates its binding to 14-3-3 proteins, leading to its nuclear export and subsequent cytoplasmic sequestration. Consequently, this modification inhibits FoxO3a’s ability to bind DNA and activate the transcription of target genes involved in crucial cellular processes including apoptosis, cell cycle arrest, oxidative stress resistance, and autophagy, thereby promoting cell survival and proliferation while suppressing tumor-suppressive functions under conditions of active PI3K/Akt signaling.