Abstract：
BACKGROUND: Calcium-dependent signaling in plants is responsible for several major cellular events, including the activation of the salinity-responsive pathways. Calcium binds to calcineurin B-like protein (CBL), and the resulting CBL-Ca2+ complex binds to CBL-interacting protein kinase (CIPK). The CBL-CIPK complex enhances the CIPK interaction with an upstream kinase. The upstream kinase phosphorylates CIPK that, in turn, phosphorylates membrane transporters. Phosphorylation influences transporter activity to kick-start many downstream functions, such as balancing the cytosolic Na+-to-K+ ratio. The CBL-CIPK interaction is pivotal for Ca2+-dependent salinity stress signaling.
METHODS: Computational methods are used to model the entire Arabidopsis thaliana CIPK24 protein structure in its autoinhibited and open-activated states. Arabidopsis thaliana CIPK24-CBL4 complex is predicted based on the protein-protein docking methods. The available structural and functional data support the CIPK24 and the CIPK24-CBL4 complex models. Models are energy-minimized and subjected to molecular dynamics (MD) simulations. MD simulations for 500 ns and 300 ns enabled us to predict the importance of conserved residues of the proteins. Finally, the work is extended to predict the CIPK24-CBL4 complex with the upstream kinase GRIK2. MD simulation for 300 ns on the ternary complex structure enabled us to identify the critical CIPK24-GRIK2 interactions. Together, these data could be used to engineer the CBL-CIPK interaction network for developing salt tolerance in crops.
METHODS: Computational methods are used to model the entire Arabidopsis thaliana CIPK24 protein structure in its autoinhibited and open-activated states. Arabidopsis thaliana CIPK24-CBL4 complex is predicted based on the protein-protein docking methods. The available structural and functional data support the CIPK24 and the CIPK24-CBL4 complex models. Models are energy-minimized and subjected to molecular dynamics (MD) simulations. MD simulations for 500 ns and 300 ns enabled us to predict the importance of conserved residues of the proteins. Finally, the work is extended to predict the CIPK24-CBL4 complex with the upstream kinase GRIK2. MD simulation for 300 ns on the ternary complex structure enabled us to identify the critical CIPK24-GRIK2 interactions. Together, these data could be used to engineer the CBL-CIPK interaction network for developing salt tolerance in crops.
摘要：
背景：植物中的钙依赖性信号是几个主要细胞事件的原因，包括盐度响应途径的激活。钙结合钙调磷酸酶B样蛋白（CBL），并且所得CBL-Ca2+复合物结合CBL-相互作用蛋白激酶(CIPK)。CBL-CIPK复合物增强了CIPK与上游激酶的相互作用。上游激酶磷酸化CIPK，反过来,磷酸化膜转运蛋白。磷酸化影响转运蛋白活性以启动许多下游功能，例如平衡细胞溶质Na+与K+的比率。CBL-CIPK相互作用对于Ca2+依赖性盐度胁迫信号传导至关重要。
方法：计算方法用于模拟整个拟南芥PK24蛋白在其自动抑制和开放活化状态下的结构。基于蛋白质-蛋白质对接方法预测拟南芥PK24-CBL4复合物。可用的结构和功能数据支持CIPK24和CIPK24-CBL4复杂模型。模型是能量最小化的，并进行分子动力学（MD）模拟。500ns和300ns的MD模拟使我们能够预测蛋白质保守残基的重要性。最后,这项工作被扩展到预测CIPK24-CBL4与上游激酶GRIK2的复合物。对三元复合物结构进行300ns的MD模拟使我们能够识别出关键的CIPK24-GRIK2相互作用。一起,这些数据可用于构建CBL-CIPK相互作用网络，以发展作物的耐盐性。
方法：计算方法用于模拟整个拟南芥PK24蛋白在其自动抑制和开放活化状态下的结构。基于蛋白质-蛋白质对接方法预测拟南芥PK24-CBL4复合物。可用的结构和功能数据支持CIPK24和CIPK24-CBL4复杂模型。模型是能量最小化的，并进行分子动力学（MD）模拟。500ns和300ns的MD模拟使我们能够预测蛋白质保守残基的重要性。最后,这项工作被扩展到预测CIPK24-CBL4与上游激酶GRIK2的复合物。对三元复合物结构进行300ns的MD模拟使我们能够识别出关键的CIPK24-GRIK2相互作用。一起,这些数据可用于构建CBL-CIPK相互作用网络，以发展作物的耐盐性。
