Stratifin (SFN)

Stratifin, was shown to be diffusely distributed in the cytoplasm and was present in cultured epithelial cells. It was most abundant in tissues enriched in stratified keratinizing epithelium.The induction of 14-3-3-sigma is mediated by a p53 -responsive element located 1.8 kb upstream of its transcription start site. Exogenous introduction of 14-3-3-sigma into cycling cells results in a G2 arrest. After DNA damage, these cells initially arrested in the G2 phase of the cell cycle, but unlike cells containing 14-3-3-sigma, the 14-3-3-sigma -/- cells were unable to maintain cell cycle arrest. The 14-3-3-sigma -/- cells died (mitotic catastrophe) as they entered mitosis. This process was associated with a failure of the 14-3-3-sigma-deficient cells to sequester the proteins that initiate mitosis and prevent them from entering the nucleus.