EGF信号:追踪癌症的路径

表皮生长因子（EGF）家族是一组结构相关的蛋白质，通过靶细胞上的酪氨酸激酶受体调节细胞增殖、迁移和分化。EGF受体有一个细胞质酪氨酸激酶结构域，一个跨膜结构域和一个与EGF结合的细胞外结构域。配体与EGF受体结合导致其二聚、自磷酸化和激活。一旦被激活，EGF受体通过几个蛋白质的磷酸化传递细胞内信号。

Ras被EGF受体激活是EGF信号转导的重要组成部分。鸟嘌呤核苷酸交换因子SOS激活Ras, Ras进而触发丝裂原激活蛋白(MAP)激酶通路。MAP激酶磷酸化转录因子，如激活蛋白1（AP-1;Fos-Jun二聚体）和Elk-1，导致细胞生长和发育。EGFR对Janus激酶(JAK)的磷酸化导致转录蛋白信号换能器和激活器(STATs)的激活，最终导致细胞的生长和分化。EGF信号的另一个关键方面涉及磷脂酶c - γ1 (PLCγ1)，它将PIP2裂解为IP3和DAG。IP3的产生导致内质网钙的释放，而DAG促进蛋白激酶C (PKC)的激活。PKC反过来磷酸化并激活转录因子Elk-1，导致细胞增殖。已知EGFR的突变影响其表达或活性，这使EGFR成为重要的药物靶点。

该通路强调了EGF信号转导的重要组成部分。

几个重要的表皮生长因子信号通路

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