Structural analysis and modeling reveals new mechanisms governing ESCRT-III spiral filament assembly.
Structural analysis and modeling reveals new mechanisms governing ESCRT-III spiral filament assembly.
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DOI：
10.1083/jcb.201403108
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发表时间：
2014-09-15
期刊：
影响因子：
--
通讯作者：
Audhya A
中科院分区：
文献类型：
--
作者：
Shen QT;Schuh AL;Zheng Y;Quinney K;Wang L;Hanna M;Mitchell JC;Otegui MS;Ahlquist P;Cui Q;Audhya A
Cryo-EM和分子动力学模拟揭示了单个单体的意外灵活性和ESCRT-III亚基Vps 32/CHMP 4 B形成的螺旋丝中单体之间的稳定界面。生物膜的断裂是由结合和操纵脂质双层的各种蛋白质复合物促进的。ESCRT-III（运输III所需的内体分选复合物）细丝在多泡内体生物发生、胞质分裂和逆转录病毒出芽的表面上不同的过程中介导膜断裂。然而，ESCRT-III亚基组装成聚合物的机制仍然未知。使用低温电子显微镜（cryo-EM），我们发现全长ESCRT-III亚基Vps 32/CHMP 4 B自发形成单链螺旋丝。由二维cryo-EM结合分子动力学模拟提供的分辨率显示，细丝内的单个Vps 32/CHMP 4 B单体是柔性的，并且能够适应一定范围的弯曲角度。相比之下，单体之间的界面是稳定的，并且对构象的变化是难治的。我们还发现Vps 32/CHMP 4 B的羧基端在限制纤维的侧向结合中起着关键作用。我们的研究结果强调了ESCRT-III细丝组装产生能够在多种细胞环境中进行膜重塑的独特聚合物的新机制。
Cryo-EM and molecular dynamics simulations reveal unexpected flexibility in individual monomers and a stable interface between monomers in the spiral filaments formed by the ESCRT-III subunit Vps32/CHMP4B. The scission of biological membranes is facilitated by a variety of protein complexes that bind and manipulate lipid bilayers. ESCRT-III (endosomal sorting complex required for transport III) filaments mediate membrane scission during the ostensibly disparate processes of multivesicular endosome biogenesis, cytokinesis, and retroviral budding. However, mechanisms by which ESCRT-III subunits assemble into a polymer remain unknown. Using cryogenic electron microscopy (cryo-EM), we found that the full-length ESCRT-III subunit Vps32/CHMP4B spontaneously forms single-stranded spiral filaments. The resolution afforded by two-dimensional cryo-EM combined with molecular dynamics simulations revealed that individual Vps32/CHMP4B monomers within a filament are flexible and able to accommodate a range of bending angles. In contrast, the interface between monomers is stable and refractory to changes in conformation. We additionally found that the carboxyl terminus of Vps32/CHMP4B plays a key role in restricting the lateral association of filaments. Our findings highlight new mechanisms by which ESCRT-III filaments assemble to generate a unique polymer capable of membrane remodeling in multiple cellular contexts.
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影响因子：
3.3
作者：
Dobro MJ;Samson RY;Yu Z;McCullough J;Ding HJ;Chong PL;Bell SD;Jensen GJ
通讯作者：
Jensen GJ
DOI：
10.1126/science.1161070
发表时间：
2008-09-05
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Lata S;Schoehn G;Jain A;Pires R;Piehler J;Gottlinger HG;Weissenhorn W
通讯作者：
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影响因子：
5.5
作者：
Goetz, Andreas W.;Williamson, Mark J.;Xu, Dong;Poole, Duncan;Le Grand, Scott;Walker, Ross C.
通讯作者：
Walker, Ross C.
DOI：
10.1038/nrm2937
发表时间：
2010-08
期刊：
Nature reviews. Molecular cell biology
影响因子：
--
作者：
通讯作者：
--
影响因子：
5.5
作者：
Beauchamp, Kyle A.;Lin, Yu-Shan;Das, Rhiju;Pande, Vijay S.
通讯作者：
Pande, Vijay S.