SLP-76 is a substrate of the high affinity IgE receptor-stimulated protein tyrosine kinases in rat basophilic leukemia cells
SLP-76 is a substrate of the high affinity IgE receptor-stimulated protein tyrosine kinases in rat basophilic leukemia cells
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DOI：
10.1074/jbc.272.2.1363
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发表时间：
1997-01-10
影响因子：
4.8
通讯作者：
Koretzky, GA
中科院分区：
文献类型：
--
作者：
HendricksTaylor, LR;Motto, DG;Koretzky, GA
在大鼠嗜碱性白血病RBL-2H3细胞上刺激IgE高亲和受体导致蛋白酪氨酸激酶的激活和几种底物的酪氨酸快速磷酸化，其中许多底物尚未确定。在这篇报告中，我们证明了Grb2适配蛋白，当作为谷胱甘肽s转移酶融合蛋白表达时，与四个酪氨酸磷酸化分子（116、76、36和31 kDa）结合，这些分子来自受刺激的RBL-2H3细胞的裂解物。我们进一步证明了76-kDa蛋白是SLP-76，一种造血细胞特异性蛋白，最初在T细胞中被鉴定为Grb2结合蛋白，在IgE高亲和力受体的刺激下，SLP 76经历快速酪氨酸磷酸化，并通过SLP-76的SH2结构域与另外两个62和130 kDa的酪氨酸磷酸化蛋白结合。进一步的研究表明，SLP-76 SH2结构域还能结合来自刺激的RBL-2H3细胞裂解物的蛋白激酶。此外，SLP-76的磷酸化需要Syk活性，但不依赖于Ca+2的动员。这些数据，连同我们之前记录其在T细胞活化中的作用，表明SLP-76及其相关蛋白可能在免疫系统中多种细胞类型的偶联信号事件中发挥基本作用。
Stimulation of the IgE high affinity receptor on rat basophilic leukemia RBL-2H3 cells results in activation of protein tyrosine kinases and rapid tyrosine phosphorylation of several substrates, many of which remain unidentified. In this report, we demonstrate that the Grb2 adapter protein, when expressed as a glutathione S-transferase fusion protein, associates with four tyrosine-phosphorylated molecules (116, 76, 36, and 31 kDa) from lysates of stimulated RBL-2H3 cells, We show further that the 76-kDa protein is SLP-76, a hematopoietic cell-specific protein first identified as a Grb2-binding protein in T cells, Upon stimulation of the high affinity receptor for IgE, SLP 76 undergoes rapid tyrosine phosphorylation and associates with two additional tyrosine phosphoproteins of 62 and 130 kDa via the SH2 domain of SLP-76. Additional studies demonstrate that the SLP-76 SH2 domain also binds a protein kinase from stimulated RBL-2H3 cell lysates. Furthermore, the phosphorylation of SLP-76 requires Syk activity but is not dependent on Ca+2 mobilization, These data, together with our previous work documenting its role in T cell activation, suggest that SLP-76 and the proteins with which it associates may play a fundamental role in coupling signaling events in multiple cell types in the immune system.