Activation of a signaling cascade by cytoskeleton stretch
Activation of a signaling cascade by cytoskeleton stretch
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DOI：
10.1016/j.devcel.2004.08.021
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发表时间：
2004-11-01
影响因子：
11.8
通讯作者：
Sawada, Y
中科院分区：
文献类型：
--
作者：
Tamada, M;Sheetz, MP;Sawada, Y
细胞感知并响应机械力。然而，细胞外基质（ECM）的力量转导的生化信号的机制是未知的。通过Triton X-100提取去除细胞膜和可溶性蛋白后，我们发现剩余的复合物（Triton细胞骨架）在拉伸时激活Rap 1。Rap 1鸟嘌呤核苷酸交换因子，C3 G，需要这种激活; C3 G以及衔接蛋白，CrkII，在细胞提取物结合到Triton细胞骨架中的拉伸依赖性的方式。CrkII结合，这是Cas依赖，与伸展依赖性酪氨酸磷酸化的蛋白质在Triton细胞骨架，包括Cas在与ECM的接触。这些体外研究结果与体内观察到的拉伸增强的磷酸酪氨酸信号、细胞-ECM接触处CrkII的积累和CrkII-Cas共定位是相容的。我们认为，Triton细胞骨架上的机械力激活局部酪氨酸磷酸化，为胞质蛋白提供对接位点：并启动信号激活Rap 1。
Cells sense and respond to mechanical force. However, the mechanisms of transduction of extracellular matrix (ECM) forces to biochemical signals are not known. After removing the cell membrane and soluble proteins by Triton X-100 extraction, we found that the remaining complex (Triton cytoskeletons) activated Rap1 upon stretch. Rap1 guanine nucleotide exchange factor, C3G, was required for this activation; C3G as well as the adaptor protein, CrkII, in cell extract bound to Triton cytoskeletons in a stretch-dependent manner. CrkII binding, which was Cas dependent, correlated with stretch-dependent tyrosine phosphorylation of proteins in Triton cytoskeletons including Cas at the contacts with ECM. These in vitro findings were compatible with in vivo observations of stretch-enhanced phosphotyrosine signals, accumulation of CrkII at cell-ECM contacts, and CrkII-Cas colocalization. We suggest that mechanical force on Triton cytoskeletons activates local tyrosine phosphorylation which provides docking sites for cytosolic proteins: and initiates signaling to activate Rap1.