The Activation of c-Src Tyrosine Kinase: Conformational Transition Pathway and Free Energy Landscape.
The Activation of c-Src Tyrosine Kinase: Conformational Transition Pathway and Free Energy Landscape.
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DOI：
10.1021/acs.jpcb.6b08409
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发表时间：
2017-04-20
期刊：
影响因子：
--
通讯作者：
Roux B
中科院分区：
文献类型：
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作者：
Fajer M;Meng Y;Roux B
酪氨酸激酶是调节细胞生长、增殖、代谢、分化和迁移的重要细胞信号变构酶。它们的活动必须受到严格的调节，这种调节的破坏可能导致各种疾病，特别是癌症。非受体酪氨酸激酶c-Src，一个原型模型系统和Src家族的代表性成员，作为复杂的多结构域变构分子开关起作用，包括调节催化结构域活性的SH 2和SH 3结构域。通过SH 2和SH 3调节结构域的c-Src的自抑制的广泛的图片是从结构的角度很好地表征，但仍然缺乏详细的分子机制的理解。在这里，我们使用先进的计算方法的基础上全原子分子动力学模拟与明确的溶剂，以提高我们的激酶激活的理解。为了阐明调节和自抑制的机制，我们计算了SH 2和SH 3结构域不同构型的c-Src“非活性到活性”构象转变的途径和自由能景观。使用分离的c-Src催化结构域作为比较的基线，观察到SH 2和SH 3结构域，取决于它们的结合取向，促进催化结构域的非活性或活性状态。来自SH 2-SH 3串联体的调节结构信息通过催化结构域的N-末端接头变构传递。构象转换途径的分析也说明了保守的色氨酸260在激活c-Src中的重要性，并揭示了在激活过程中的一系列协同事件。
Tyrosine kinases are important cellular signaling allosteric enzymes that regulate cell growth, proliferation, metabolism, differentiation and migration. Their activity must be tightly regulated, and disruption of this regulation can lead to a variety of diseases, particularly cancer. The non-receptor tyrosine kinase c-Src, a prototypical model system and a representative member of the Src-family, functions as complex multi-domain allosteric molecular switches comprising SH2 and SH3 domains regulating the activity of the catalytic domain. The broad picture of self-inhibition of c-Src via the SH2 and SH3 regulatory domains is well characterized from a structural point of view, but a detailed molecular mechanism understanding is nonetheless still lacking. Here, we use advanced computational methods based on all-atom molecular dynamics simulations with explicit solvent to advance our understanding of kinase activation. To elucidate the mechanism of regulation and self-inhibition, we have computed the pathway and the free energy landscapes for the “ inactive-to-active” conformational transition of c-Src for different configurations of the SH2 and SH3 domains. Using the isolated c-Src catalytic domain as a baseline for comparison, it is observed that the SH2 and SH3 domains, depending upon their bound orientation, either promote the inactive or the active state of the catalytic domain. The regulatory structural information from the SH2-SH3 tandem is allosterically transmitted via the N-terminal linker of the catalytic domain. Analysis of the conformational transition pathways also illustrates the importance of the conserved tryptophan 260 in activating c-Src, and reveals a series of concerted events during the activation process.