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Signal transduction in IgE receptor transfected mast cells

IgE 受体转染肥大细胞中的信号转导

基本信息

批准号：
07672409
负责人：
TESHIMA Reiko
金额：
$ 1.41万
依托单位：
National Institute of Health Sciences
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07672409/
关键词：
IgE receptor Mutant Mast cells Signal transduction CD63 antigen Tyrosine phosphorylation

项目摘要

We estabilshed the IgE receptor transfected-mouse mastocytoma P815 cells. The IgE receptors are composed of three types of polypeptides ; an IgE-biniding alpha subunit, a beta subunit, and two disulfide-linked gamma subunits. Three types of P815 transfectant were made ; cDNAs coding for each of whole three subunits were introduced (Wt) , cDNAs coding for whole alpha and gamma subunit and C-terminal depleted beta subunit were introduced (beta cd), cDNAs coding for whole alpha and beta subunit and C-terminal depleted gamma subunit were introduced (gamma cd). In Wt cells, endocytosis fo IgE receptors, tyrosine phosphorylation of beta and gamma subunit of IgE receptors, Lyn and Syk kinases and 42k protein ware increased. And the cytosolic Ca^<2+> concentration ([Ca^<2+>]i) and CD63 antigen expression on the cell surfaces were increased. However, in beta cd and gamma cd cells, the endocytosis of IgE receptor, tyrosine phosphorylation of above proteins, [Ca^<2+>]i increase and CD 63 antigen expression on the cells were not or little increased. In Wt cells, CD63 antigen expression on the cell surfaces was mostly blocked by the preteatment of herbimycin A.The surface expression of CD63 antigen reflected the degranulation in RBL-2H3 cells. Therefore, these results suggested that tyrosing phosphorylation of the C-terminal cytoplasmic domains of beta and gamma subunits was essential for IgE receptor endo cytosis, [Ca^<2+>]i increase and degranulation.

我们建立了IgE受体转染的小鼠肥大细胞瘤P815细胞。IgE受体由三种类型的多肽组成：IgE结合的α亚基、β亚基和两个二硫键连接的γ亚基。制备了三种类型的P815转染子;引入编码全部三个亚基中的每一个的cDNA（Wt），引入编码全部α和γ亚基以及C末端耗尽的β亚基的cDNA（β cd），引入编码全部α和β亚基以及C末端耗尽的γ亚基的cDNA（γ cd）。在Wt细胞中，IgE受体的内吞作用、IgE受体β和γ亚基的酪氨酸磷酸化、林恩和Syk激酶以及42 k蛋白均增加。细胞内Ca^<2+>浓度（[Ca^<2+]i）和细胞表面CD 63抗原表达增加。而在β-CD和γ-CD细胞中，IgE受体的内吞、上述蛋白的酪氨酸磷酸化、[Ca^2+]i增加，细胞表面CD 63抗原表达无或略有增加。在Wt细胞中，除莠霉素A预处理主要阻断了细胞表面CD 63抗原的表达。CD 63抗原的表达反映了RBL-2 H3细胞的脱颗粒。因此，这些结果表明β和γ亚基的C末端胞质结构域的酪氨酸磷酸化对于IgE受体胞内吞、[Ca^2+]i增加和脱粒是必需的。