Essential N-Terminal Insertion Motif Anchors the ESCRT-III Filament during MVB Vesicle Formation
Essential N-Terminal Insertion Motif Anchors the ESCRT-III Filament during MVB Vesicle Formation
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DOI：
10.1016/j.devcel.2013.09.009
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发表时间：
2013-10-28
影响因子：
11.8
通讯作者：
Emr, Scott D.
中科院分区：
文献类型：
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作者：
Buchkovich, Nicholas J.;Henne, William Mike;Emr, Scott D.
运输所需的内体分选复合物（ESCRT）已成为驱动拓扑独特的膜变形和分裂的关键细胞机器。了解 ESCRT-III 聚合物如何与膜相互作用、促进和/或稳定膜变形，是阐明这种雕刻机制的重要一步。通过结合体内和体外遗传和生化方法，我们确定了 ESCRT-III 膜关联所需的两个基本模块：静电簇和 N 末端插入基序。酵母中任一模块的突变都会导致 MVB 途径中的货物分选缺陷。我们表明，重要的 N 端插入基序为 ESCRT-III 聚合物提供了稳定的锚定。通过用充分表征的膜插入模块替换该 N 端基序，我们证明 Snf7 的 N 端已被调整以维持与 ESCRT-III 丝介导的膜内陷和囊泡形成相关的拓扑约束。我们的结果提供了对空间独特的、ESCRT-III 介导的膜重塑的见解。
The endosomal sorting complexes required for transport (ESCRTs) have emerged as key cellular machinery that drive topologically unique membrane deformation and scission. Understanding how the ESCRT-III polymer interacts with membrane, promoting and/or stabilizing membrane deformation, is an important step in elucidating this sculpting mechanism. Using a combination of genetic and biochemical approaches, both in vivo and in vitro, we identify two essential modules required for ESCRT-III-membrane association: an electrostatic cluster and an N-terminal insertion motif. Mutating either module in yeast causes cargo sorting defects in the MVB pathway. We show that the essential N-terminal insertion motif provides a stable anchor for the ESCRT-III polymer. By replacing this N-terminal motif with well-characterized membrane insertion modules, we demonstrate that the N terminus of Snf7 has been tuned to maintain the topological constraints associated with ESCRT-III-filament-mediated membrane invagination and vesicle formation. Our results provide insights into the spatially unique, ESCRT-III-mediated membrane remodeling.