Integrin-mediated tyrosine phosphorylation and redistribution of paxillin during neuronal adhesion
Integrin-mediated tyrosine phosphorylation and redistribution of paxillin during neuronal adhesion
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DOI：
10.1006/excr.1996.3423
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发表时间：
1997-02-01
影响因子：
3.7
通讯作者：
Malanchini, B
中科院分区：
文献类型：
--
作者：
deCurtis, I;Malanchini, B
整合素是神经元与层粘连蛋白粘附的重要受体，层粘连蛋白是神经突起生长的最佳促进剂之一。本研究旨在了解整合素介导的神经突在层粘连蛋白上延伸的细胞内机制。在鸡视网膜神经元中，整合素介导的粘附层粘连蛋白和抗体诱导的整合素聚集引起桩蛋白和黏着斑激酶的酪氨酸磷酸化增加。与受体与抗整合素抗体聚集的神经元相比，这些蛋白的磷酸化和去磷酸化的动力学在层粘连蛋白上铺板的神经元中是不同的。蔗糖速度梯度分析不能显示桩蛋白和粘着斑激酶与整合素受体的任何关联。另一方面，通过使用毛地黄皂苷和温和的提取条件下，我们发现富集的酪氨酸磷酸化的多肽的细胞骨架，毛地黄皂苷不溶性馏分，此外，神经元粘附诱导的酪氨酸磷酸化桩蛋白的馏分与毛地黄皂苷不溶性馏分回收的显着增加，这表明这种蛋白质的重新分配后，神经元粘附层粘连蛋白。洗涤剂不溶性部分的定位研究表明，桩蛋白和粘着斑激酶与整合素的共分布。我们还发现，桩蛋白酪氨酸磷酸化，但不是桩蛋白的表达，是在视网膜发育调节。我们的研究结果表明，整合素介导的神经元粘附导致高度磷酸化的蛋白质在粘附位点的池的积累。在那里，它们可能负责细胞骨架的重组，这是神经突延伸过程的基础。(C)北京：科学出版社.
Integrins are important receptors for neuronal adhesion to laminin, which is one of the best promoters of neurite outgrowth. The present study was carried out to understand some of the intracellular mechanisms which allow integrin-mediated neurite extension on laminin. In chicken retinal neurons, integrin-mediated adhesion to laminin and antibody-induced integrin clustering caused an increase in tyrosine phosphorylation of paxillin and focal adhesion kinase, The kinetics of phosphorylation and dephosphorylation of these proteins were different in neurons plated on laminin, compared to neurons in which the receptors were clustered with anti-integrin antibodies. Analysis of sucrose velocity gradients could not show any association of paxillin and focal adhesion kinase with the integrin receptors. On the other hand, by using digitonin and milder extraction conditions, we found an enrichment of the tyrosine-phosphorylated polypeptides in the cytoskeletal, digitonin-insoluble fraction, Furthermore, neuronal adhesion induced a dramatic increase in the fraction of tyrosine-phosphorylated paxillin recovered with the digitonin-insoluble fraction, suggesting redistribution of this protein following adhesion of neurons to laminin. Localization studies on the detergent-insoluble fraction showed codistribution of both paxillin and focal adhesion kinase with integrins. We also found that paxillin tyrosine phosphorylation, but not paxillin expression, is developmentally regulated in the retina. Our results show that integrin-mediated neuronal adhesion leads to the accumulation of a pool of highly phosphorylated proteins at adhesion sites. There they may be responsible for the reorganization of the cytoskeleton, which underlies the process of neurite extension. (C) 1997 Academic Press.