Mechanistic insights into the interactions of dynein regulator Ndel1 with neuronal ankyrins and implications in polarity maintenance
Mechanistic insights into the interactions of dynein regulator Ndel1 with neuronal ankyrins and implications in polarity maintenance
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动力蛋白调节剂 Ndel1 与神经元锚蛋白相互作用的机制见解及其对极性维持的影响
DOI：
10.1073/pnas.1916987117
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发表时间：
2019-12
期刊：
影响因子：
--
通讯作者：
Wang Chao
中科院分区：
文献类型：
--
作者：
Ye Jin;Li Jianchao;Ye Fei;Zhang Yan;Zhang Mingjie;Wang Chao
轴突起始段是一个专门的领域，负责产生动作电位和维持轴突极性，其特征在于富集电压门控离子通道和支架蛋白，锚蛋白-G（AnkG）。AnkG与动力蛋白调节剂Ndel 1相互作用，以调节AIS的货物分拣。在这里，我们证明了一个特定的和高亲和力的相互作用介导的AnkG/Ndel 1复合物的形成，通过生物化学和结构的方法。我们进一步表明，几个体树突状细胞货物在AIS上的AnkG/Ndel 1复合物的破坏是错误的。我们的研究不仅建立了AnkG-Ndel 1相互作用和维持轴突极性的机制基础，而且还提供了对AnkB/Ndel 1复合物在远端轴突货物运输中潜在功能的深入了解。锚蛋白-G（AnkG）是神经元轴突起始段（AIS）中高度富集的支架蛋白，其功能是维持轴突极性和AIS的完整性。在AIS，AnkG通过与动力蛋白调节蛋白Ndel 1相互作用调节索马和轴突之间的选择性细胞内货物运输，但这种结合的分子机制仍然难以捉摸。在这里，我们报告说，Ndel 1的C-末端卷曲螺旋区（CT-CC）结合到巨大的神经元特异性插入区存在于AnkG和AnkB的2：1化学计量。与Ndel 1 CT-CC复合的AnkB的高分辨率晶体结构揭示了控制AnkB/Ndel 1复合物形成的详细分子基础。机械地，AnkB通过形成由分布在6个不同的相互作用层上的疏水相互作用主导的稳定的5螺旋束与Ndel 1结合。此外，我们发现AnkG对于AIS处的Ndel 1积累是必不可少的。最后，我们发现AIS的货物分选可以通过使用基于我们的结构数据设计的肽阻断AnkG/Ndel 1复合物的形成来破坏。总的来说，AnkB/Ndel 1复合物的原子结构以及通过AIS进行的货物分选的研究建立了AnkG/Ndel 1复合物形成和维持轴突极性的机制基础。我们的研究也将是有价值的AnkB和Ndel 1之间的相互作用的未来研究可能在远端轴突货物运输。
Significance The axon initial segment is a specialized domain responsible for the generation of action potential and maintenance of axonal polarity and is characterized by enrichment for voltage-gated ion channels and a scaffold protein, ankryin-G (AnkG). AnkG interacts with the dynein regulator Ndel1 to regulate cargo sorting at the AIS. Here we demonstrate that a specific and high-affinity interaction mediates AnkG/Ndel1 complex formation via biochemical and structural approaches. We further show that several somatodendritic cargoes are missorted at the AIS on disruption of the AnkG/Ndel1 complex. Our studies not only establish the mechanistic basis for AnkG–Ndel1 interaction and for the maintenance of the axonal polarity, but also provide insight into the AnkB/Ndel1 complex function potentially at distal axonal cargo transport. Ankyrin-G (AnkG), a highly enriched scaffold protein in the axon initial segment (AIS) of neurons, functions to maintain axonal polarity and the integrity of the AIS. At the AIS, AnkG regulates selective intracellular cargo trafficking between soma and axons via interaction with the dynein regulator protein Ndel1, but the molecular mechanism underlying this binding remains elusive. Here we report that Ndel1’s C-terminal coiled-coil region (CT-CC) binds to giant neuron-specific insertion regions present in both AnkG and AnkB with 2:1 stoichiometry. The high-resolution crystal structure of AnkB in complex with Ndel1 CT-CC revealed the detailed molecular basis governing the AnkB/Ndel1 complex formation. Mechanistically, AnkB binds with Ndel1 by forming a stable 5-helix bundle dominated by hydrophobic interactions spread across 6 distinct interaction layers. Moreover, we found that AnkG is essential for Ndel1 accumulation at the AIS. Finally, we found that cargo sorting at the AIS can be disrupted by blocking the AnkG/Ndel1 complex formation using a peptide designed based on our structural data. Collectively, the atomic structure of the AnkB/Ndel1 complex together with studies of cargo sorting through the AIS establish the mechanistic basis for AnkG/Ndel1 complex formation and for the maintenance of axonal polarity. Our study will also be valuable for future studies of the interaction between AnkB and Ndel1 perhaps at distal axonal cargo transport.
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影响因子：
4.5
作者：
Jegla T;Nguyen MM;Feng C;Goetschius DJ;Luna E;van Rossum DB;Kamel B;Pisupati A;Milner ES;Rolls MM
通讯作者：
Rolls MM
480/270-kD Ankyrin G对轴突近端段的限制需要多个Ankyrin G特异性域。
影响因子：
7.8
作者：
Zhang, X;Bennett, V
通讯作者：
Bennett, V
影响因子：
64.5
作者：
Galiano MR;Jha S;Ho TS;Zhang C;Ogawa Y;Chang KJ;Stankewich MC;Mohler PJ;Rasband MN
通讯作者：
Rasband MN
影响因子：
9.2
作者：
Vergnolle, Mailys A. S.;Taylor, Stephen S.
通讯作者：
Taylor, Stephen S.
DOI：
10.1073/pnas.1416544112
发表时间：
2015-01-27
影响因子：
11.1
作者：
Jenkins, Paul M.;Kim, Namsoo;Bennett, Vann
通讯作者：
Bennett, Vann