Increase of intracellular calcium in mast cells is most crucial for mast cell degranulation. Elevation of intracellular calcium is achieved by activation of PLC-gamma. Mast cells express both PLC-gamma1 and PLC-gamma2 isoforms and activation of these enzymes leads to conversion of phosphatidylinositol 4,5-bisphosphate (PIP2) into inositol triphosphate (IP3) and diacylglycerol (DAG). The production of IP3 leads to mobilization of intracellular Ca+2, which later results in a sustained Ca+2 flux response that is maintained by an influx of extracellular Ca+2. In addition to degranulation, an increase in intracellular calcium concentration also activates the Ca2+/calmodulin-dependent serine phosphatase calcineurin. Calcineurin dephosphorylates the nuclear factor for T cell activation (NFAT) which exposes nuclear-localization signal sequence triggering translocation of the dephosphorylated NFAT-CaN complex to the nucleus. Once in the nucleus, NFAT regulates the transcription of several cytokine genes (Kambayashi et al. 2007, Hoth & Penner 1992, Ebinu et al. 2000, Siraganian et al)

external resources

BTK , CALM1 , CALM2 , CALM3 , GRB2 , IGHE , IGLC1 , IGLC6 , ITK , ITPR1 , ITPR2 , ITPR3 , LCP2 , LYN , NFATC1 , NFATC2 , NFATC3 , PLCG1 , PLCG2 , PPP3CA , PPP3CB , PPP3R1 , SHC1 , SOS1 , SYK , TEC , TXK , VAV1 , VAV2 , GRAP2 , VAV3 , AHCYL1 , LAT , IGKV3D-11 , IGKV5-2 , IGKV4-1 ,