Human 14-3-3 Sigma (SFN) Protein

Background

Stratifin (SFN) , also known as 14-3-3 sigma, is a member of the 14-3-3 protein family that acts as a critical regulator of cell cycle progression, DNA damage response, and cellular stress. It binds to phosphorylated serine/threonine residues on target proteins, facilitating their localization, stability, and activity. Stratifin is specifically involved in G2/M cell cycle checkpoint control by sequestering cyclin-dependent kinase complexes like CDC25C in the cytoplasm, preventing premature mitotic entry under DNA damage conditions. It is highly expressed in epithelial tissues and is essential for maintaining epithelial cell integrity, polarity, and stress responses. Stratifin acts as a tumor suppressor by inhibiting uncontrolled proliferation; its downregulation has been observed in breast, lung, and gastrointestinal cancers due to epigenetic silencing. Functional studies reveal its role in mediating stress-induced growth arrest and apoptosis, underscoring its importance in tumor suppression, DNA repair, and cell cycle regulation.