T Cell Activation Results in Conformational Changes in the Src Family Kinase Lck to Induce Its Activation
T Cell Activation Results in Conformational Changes in the Src Family Kinase Lck to Induce Its Activation
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DOI：
10.1126/scisignal.2003607
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发表时间：
2013-02-19
影响因子：
7.3
通讯作者：
Schraven, Burkhart
中科院分区：
文献类型：
--
作者：
Stirnweiss, Anja;Hartig, Roland;Schraven, Burkhart
淋巴细胞特异性Src家族蛋白酪氨酸激酶p56(Lck) （Lck）对T细胞的发育和激活至关重要，因此对适应性免疫反应至关重要。在T细胞受体（TCR）激活的情况下，Lck活性定向于特定底物的机制仍然是难以捉摸的。我们使用荧光寿命成像显微镜来评估活的人T细胞中Lck构象的激活依赖性时空变化。通过对Lck生物传感器荧光寿命的动力学分析，可以直接观察到抗CD3抗体或装载超抗原的抗原呈递细胞激活T细胞后Lck蛋白总量的20%的动态局部开放。对TCR复合物的平行生化分析表明，Lck的构象变化与Lck酶活性的诱导有关。这些数据表明，在TCR接合点处，Lck通过构象变化发生了动态的局部活化。
The lymphocyte-specific Src family protein tyrosine kinase p56(Lck) (Lck) is essential for T cell development and activation and, hence, for adaptive immune responses. The mechanism by which Lck activity is directed toward specific substrates in response to T cell receptor (TCR) activation remains elusive. We used fluorescence lifetime imaging microscopy to assess the activation-dependent spatiotemporal changes in the conformation of Lck in live human T cells. Kinetic analysis of the fluorescence lifetime of Lck biosensors enabled the direct visualization of the dynamic local opening of 20% of the total amount of Lck proteins after activation of T cells with antibody against CD3 or by superantigen-loaded antigen-presenting cells. Parallel biochemical analysis of TCR complexes revealed that the conformational changes in Lck correlated with the induction of Lck enzymatic activity. These data show the dynamic, local activation through conformational change of Lck at sites of TCR engagement.