Meta-Biol

• Pathways

Nuclear factor of activated T-cells (NFAT) is a transcription factor which induces genes responsible for cytokine production, for cell-cell interactions etc. NFAT transcription activity is modulated by calcium and Calcineurin concentration. In resting cells NFAT is phosphorylated and resides in the cytoplasm. Phosphorylation sites are located in NFAT's regulatory domain in three different serine rich motifs, termed SRR1, SP2 and SP. Upon stimulation, these serine residues are dephosphorylated by calcineurin, that thought to cause exposure of nuclear localization signal sequences triggering translocation of the dephosphorylated NFAT-CaN complex to the nucleus. Among all the phosphorylation sites one of the site in SRR-2 motif is not susceptable to dephosphorylation by CaN (Takeuchi et al. 2007, Hogan et al. 2003).