Cryo-EM of the dynamin polymer assembled on lipid membrane.
Cryo-EM of the dynamin polymer assembled on lipid membrane.
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DOI：
10.1038/s41586-018-0378-6
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发表时间：
2018-08
期刊：
影响因子：
64.8
通讯作者：
Hinshaw JE
中科院分区：
文献类型：
--
作者：
Kong L;Sochacki KA;Wang H;Fang S;Canagarajah B;Kehr AD;Rice WJ;Strub MP;Taraska JW;Hinshaw JE
膜分裂是细胞膜调节和重塑的基本过程。发动蛋白是一种大的GTP酶，通过聚集、收缩和分裂出芽囊泡的颈部来介导膜分裂。在这里，我们报告了一个3.75 μ m分辨率的cryo-EM结构的膜相关的螺旋聚合物的人动力蛋白-1在GMPPCP结合状态。该结构定义了发动蛋白聚合物的螺旋对称性和寡聚体界面的位置，这通过基于细胞的内吞测定法进行了验证。与无脂质的四聚体形式相比，膜相关发动蛋白与其普列克底物蛋白同源结构域（PHD）结合到脂质双层，并通过GT3结构域跨螺旋梯级自组装。值得注意的是，与膜和螺旋装配的相互作用是由严重弯曲的束信号元件（BSE）调节的，该元件将GT3结构域与蛋白质的其余部分连接。BSE构象是不对称的跨梯级间GTdR接口，是唯一的相比，所有已知的核苷酸结合状态的发动蛋白。该结构表明BSE从GTdR二聚体相互作用产生的力弯曲，所述力通过茎转移到PHD和脂质膜。破坏BSE扭结的突变损害了内吞作用。我们还报告了一个10.1 μ m分辨率的cryo-EM地图的超收缩发动蛋白聚合物显示本地化的构象变化，在BSE和GTP水解，驱动膜收缩诱导的GTdR域。这些结果为动力蛋白对脂膜的作用机制提供了结构基础。
Membrane fission is a fundamental process in the regulation and remodeling of cell membranes. Dynamin, a large GTPase, mediates membrane fission by assembling around, constricting and cleaving the necks of budding vesicles. Here, we report a 3.75 Å resolution cryo-EM structure of the membrane-associated helical polymer of human dynamin-1 in the GMPPCP bound state. The structure defines the helical symmetry of the dynamin polymer and the positions of the oligomeric interfaces, which were validated by cell-based endocytosis assays. Compared to the lipid-free tetramer form, membrane-associated dynamin binds to the lipid bilayer with its pleckstrin homology domain (PHD) and self-assembles across the helical rungs via the GTPase domain. Notably, interaction with the membrane and helical assembly is accommodated by a severely bent bundle signaling element (BSE), which connects the GTPase domain with the rest of the protein. The BSE conformation is asymmetric across the inter-rung GTPase interface, and is unique compared to all known nucleotide-bound states of dynamin. The structure suggests that the BSE bends from forces generated from the GTPase dimer interaction that are transferred across the stalk to the PHD and lipid membrane. Mutations disrupting the BSE kink impaired endocytosis. We also report a 10.1 Å resolution cryo-EM map of a super-constricted dynamin polymer showing localized conformational changes at the BSE and GTPase domains induced by GTP hydrolysis that drive membrane constriction. Altogether, the results provide a structural basis for dynamin’s mechanism of action on lipid membrane.
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影响因子：
21.3
作者：
Sochacki KA;Dickey AM;Strub MP;Taraska JW
通讯作者：
Taraska JW
影响因子：
3.4
作者：
Petrache, HI;Tristram-Nagle, S;Nagle, JF
通讯作者：
Nagle, JF
影响因子：
2.9
作者：
Daumke, Oliver;Praefcke, Gerrit J. K.
通讯作者：
Praefcke, Gerrit J. K.
DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH
影响因子：
3
作者：
Pettersen, EF;Goddard, TD;Ferrin, TE
通讯作者：
Ferrin, TE