FCERI 介导的 Ca2+ 释放
中文名称
通路描述
肥大细胞内钙离子浓度的增加对于肥大细胞脱颗粒至关重要。通过激活 PLC-gamma 来实现内钙离子浓度的升高。肥大细胞表达 PLC-gamma1 和 PLC-gamma2 两种同工酶，这些酶被激活后，将磷脂酰肌醇 4,5-二磷酸 (PIP2) 转化为肌醇三磷酸 (IP3) 和二酰甘油 (DAG)。IP3 的产生导致内钙离子释放，随后导致持续的钙离子流响应，该响应由细胞外钙离子的内流维持。除了脱颗粒外，内钙离子浓度的增加还会激活钙调蛋白依赖的丝氨酸磷酸酶钙调蛋白激酶 (calcineurin)。钙调蛋白激酶去磷酸化 T 细胞激活因子核因子 (NFAT)，暴露出核定位信号序列，触发去磷酸化 NFAT-CaN 复合物转位至细胞核。一旦进入细胞核，NFAT 调节几种细胞因子基因的转录 (Kambayashi et al. 2007, Hoth & Penner 1992, Ebinu et al. 2000, Siraganian et al)。
英文描述
FCERI mediated Ca+2 mobilization 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).
所含基因
38 个基因