Induction of the antigen receptor expression on B lymphocytes results in rapid competence for signaling of SLP-65 and Syk
Induction of the antigen receptor expression on B lymphocytes results in rapid competence for signaling of SLP-65 and Syk
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DOI：
10.1093/emboj/17.24.7304
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发表时间：
1998-12-15
期刊：
影响因子：
11.4
通讯作者：
Reth, M
中科院分区：
文献类型：
--
作者：
Zhang, Y;Wienands, J;Reth, M
抗原与B细胞抗原受体（BCR）的结合导致蛋白酪氨酸激酶（PTK）如林恩和Syk的活化，以及包括HS 1和SLP-65在内的几种底物蛋白的磷酸化。使用他莫昔芬调节的Cre重组酶的表达载体，我们已经开发了一种允许BCR的诱导型表达的方法。通过Cre介导的DNA重组克服了免疫球蛋白重链的VH前导阅读框被两个loxP位点破坏，并导致BCR在转染的B细胞暴露于他莫昔芬后4小时开始在细胞表面表达。可用于任何分泌的或I型跨膜蛋白的诱导型表达。通过监测过钒酸盐刺激的表达不同水平BCR的B细胞中的信号元件的激活，我们在这里表明，SLP-65和Syk的磷酸化，而不是林恩的磷酸化，是严格依赖于细胞表面上的BCR的表达。这些数据表明，BCR一旦出现在细胞表面，就会重组其信号分子。
The binding of antigen to the B cell antigen receptor (BCR) results in the activation of protein tyrosine kinases (PTKs) such as Lyn and Syk, and the phosphorylation of several substrate proteins including HS1 and SLP-65, How these signaling elements are connected to the BCR is not well understood. Using an expression vector for a tamoxifen-regulated Cre recombinase, we have developed a method that allows the inducible expression of the BCR, Disruption of the VH leader reading frame of the immunoglobulin heavy chain by two loxP sites is overcome by Cre-mediated DNA recombination and results in the cell surface expression of the BCR starting 4 h after exposure of transfected B cells to tamoxifen, This method can, in principle, be employed for the inducible expression of any secreted or type I transmembrane protein. By monitoring the activation of signaling elements in pervanadate-stimulated B cells expressing different levels of the BCR, we show here that phosphorylation of SLP-65 and Syk, but not of Lyn, is strictly dependent on the expression of the BCR on the cell surface. These data suggest that the BCR reorganizes its signaling molecules as soon as it appears on the cell surface.