Institut Laue-Langevin, Grenoble, France.
Biophys J. 2010 Nov 17;99(10):3473-82. doi: 10.1016/j.bpj.2010.09.058.
NHERF1 is a multidomain scaffolding protein that assembles signaling complexes, and regulates the cell surface expression and endocytic recycling of a variety of membrane proteins. The ability of the two PDZ domains in NHERF1 to assemble protein complexes is allosterically modulated by the membrane-cytoskeleton linker protein ezrin, whose binding site is located as far as 110 Ångstroms away from the PDZ domains. Here, using neutron spin echo (NSE) spectroscopy, selective deuterium labeling, and theoretical analyses, we reveal the activation of interdomain motion in NHERF1 on nanometer length-scales and on submicrosecond timescales upon forming a complex with ezrin. We show that a much-simplified coarse-grained model suffices to describe interdomain motion of a multidomain protein or protein complex. We expect that future NSE experiments will benefit by exploiting our approach of selective deuteration to resolve the specific domain motions of interest from a plethora of global translational and rotational motions. Our results demonstrate that the dynamic propagation of allosteric signals to distal sites involves changes in long-range coupled domain motions on submicrosecond timescales, and that these coupled motions can be distinguished and characterized by NSE.
NHERF1 是一种多功能支架蛋白，可组装信号复合物，并调节多种膜蛋白的细胞表面表达和内吞循环。NHERF1 中的两个 PDZ 结构域组装蛋白复合物的能力受到膜-细胞骨架连接蛋白 ezrin 的变构调节，其结合位点位于距离 PDZ 结构域 110Å 之遥。在这里，我们使用中子自旋回波 (NSE) 光谱学、选择性氘标记和理论分析，揭示了 ezrin 形成复合物后，NHERF1 中在纳米长度尺度和亚微秒时间尺度上的结构域间运动的激活。我们表明，一个简化的粗粒化模型足以描述多结构域蛋白或蛋白复合物的结构域间运动。我们预计，未来的 NSE 实验将受益于我们的选择性氘标记方法，该方法可将大量的全局平移和旋转运动中的特定感兴趣的结构域运动分辨出来。我们的结果表明，变构信号的远程传播涉及亚微秒时间尺度上长程耦合结构域运动的变化，并且这些耦合运动可以通过 NSE 来区分和描述。
