Autoinhibited kinesin-1 adopts a hierarchical folding pattern.
Autoinhibited kinesin-1 adopts a hierarchical folding pattern.
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自抑制驱动蛋白-1采用分层折叠模式。
DOI：
10.1101/2023.01.26.525761
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Cianfrocco,MichaelA
中科院分区：
文献类型：
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作者：
Tan,Zhenyu;Yue,Yang;daVeigaLeprevost,Felipe;Haynes,SarahE;Basrur,Venkatesha;Nesvizhskii,AlexeyI;Verhey,KristenJ;Cianfrocco,MichaelA
传统的驱动蛋白-1 是细胞中用于运输细胞货物的主要顺行马达。虽然人们一致认为驱动蛋白 1 的 C 末端尾部抑制运动，但全长自抑制驱动蛋白 1 的分子结构仍然未知。在这里，我们结合交联质谱 (XL-MS)、电子显微镜 (EM) 和 AlphaFold 结构预测来确定全长自抑制驱动蛋白-1 同二聚体（驱动蛋白-1 重链 [KHC]）和驱动蛋白-1 异四聚体（KHC 与驱动蛋白轻链 1 [KLC1] 结合）的结构。我们的综合分析表明，驱动蛋白-1 通过卷曲螺旋 3 的断裂形成紧凑、弯曲的构象。此外，我们的 XL-MS 分析表明，驱动蛋白轻链稳定了折叠的抑制状态，而不是诱导新的结构状态。使用我们的结构模型，我们表明，激活全长驱动蛋白-1 需要破坏运动域、茎域和尾域之间的多重相互作用。我们的工作提供了一个概念框架，用于理解货物接头和微管相关蛋白如何解除自抑制以促进激活。
Conventional kinesin-1 is the primary anterograde motor in cells for transporting cellular cargo. While there is a consensus that the C-terminal tail of kinesin-1 inhibits motility, the molecular architecture of a full-length autoinhibited kinesin-1 remains unknown. Here, we combine crosslinking mass spectrometry (XL-MS), electron microscopy (EM), and AlphaFold structure prediction to determine the architecture of the full-length autoinhibited kinesin-1 homodimer (kinesin-1 heavy chain [KHC]) and kinesin-1 heterotetramer (KHC bound to kinesin light chain 1 [KLC1]). Our integrative analysis shows that kinesin-1 forms a compact, bent conformation through a break in coiled-coil 3. Moreover, our XL-MS analysis demonstrates that kinesin light chains stabilize the folded inhibited state rather than inducing a new structural state. Using our structural model, we show that disruption of multiple interactions between the motor, stalk, and tail domains is required to activate the full-length kinesin-1. Our work offers a conceptual framework for understanding how cargo adaptors and microtubule-associated proteins relieve autoinhibition to promote activation.