Eiseman E, Bolen J B
Department of Molecular Biology, Bristol-Myers Squibb Pharmaceutical, Research Institute, Princeton, New Jersey 08543-4000.
Nature. 1992 Jan 2;355(6355):78-80. doi: 10.1038/355078a0.
The high-affinity IgE receptor (Fc epsilon RI), which is expressed on the surface of mast cells and basophils, has a central role in immediate allergic responses. In the rat basophilic leukaemia cell line RBL-2H3, which is a model system for the analysis of Fc epsilon RI-mediated signal transduction, surface engagement of Fc epsilon RI induces histamine release and the tyrosine phosphorylation of several distinct proteins. Although the alpha, beta, and gamma subunits of Fc epsilon RI lack intrinsic tyrosine protein kinase (TPK) activity, a kinase that copurifies with Fc epsilon RI phosphorylates the beta and gamma subunits of the receptor on tyrosine residues. We report here that in RBL-2H3 cells, p56lyn and pp60c-src are activated after Fc epsilon RI crosslinking, and p56lyn coimmunoprecipitates with Fc epsilon RI. In the mouse mast-cell line PT-18, another cell type used to study FC epsilon RI-mediated signalling, tyrosine phosphorylation of proteins is also an immediate consequence of receptor crosslinking. Notably, the only detectable src protein-related TPK in PT-18 cells is p62c-yes, and it is this TPK that is activated on Fc epsilon RI engagement and coimmunoprecipitates with the receptor. Therefore, it seems that different src protein-related TPKs can associate with the same receptor and become activated after receptor engagement.
高亲和力IgE受体（FcεRI）表达于肥大细胞和嗜碱性粒细胞表面，在速发型过敏反应中起核心作用。在大鼠嗜碱性白血病细胞系RBL - 2H3（一种用于分析FcεRI介导的信号转导的模型系统）中，FcεRI的表面结合可诱导组胺释放以及几种不同蛋白质的酪氨酸磷酸化。尽管FcεRI的α、β和γ亚基缺乏内在的酪氨酸蛋白激酶（TPK）活性，但一种与FcεRI共纯化的激酶可使受体的β和γ亚基在酪氨酸残基上发生磷酸化。我们在此报告，在RBL - 2H3细胞中，FcεRI交联后p56lyn和pp60c - src被激活，且p56lyn与FcεRI共免疫沉淀。在小鼠肥大细胞系PT - 18（另一种用于研究FcεRI介导的信号传导的细胞类型）中，蛋白质的酪氨酸磷酸化也是受体交联的直接结果。值得注意的是，PT - 18细胞中唯一可检测到的src蛋白相关TPK是p62c - yes，正是这种TPK在FcεRI结合后被激活并与受体共免疫沉淀。因此，似乎不同的src蛋白相关TPK可以与同一受体结合并在受体结合后被激活。
