A plasma membrane template for macropinocytic cups
A plasma membrane template for macropinocytic cups
复制标题
DOI：
10.7554/elife.20085
复制
发表时间：
2016-12-13
期刊：
影响因子：
7.7
通讯作者：
Kay, Robert R.
中科院分区：
文献类型：
--
作者：
Veltman, Douwe M.;Williams, Thomas D.;Kay, Robert R.
巨胞饮作用是细胞将细胞外液吸收到大囊泡中的基本机制。它主要依赖于质膜下形成的一个环状的肌动蛋白，它发展成巨胞饮杯。我们发现，巨胞饮杯在Dictyosteoblasts周围一致的PIP 3，活性Ras和活性Rac激烈的补丁组织。这些信号斑块总是与其外周的活性SCAR/WAVE环相关，所有基于PIP 3斑块的检查结构也是如此，包括吞噬杯和基底波。斑块的形成不依赖于封闭的F-肌动蛋白环，当RasGAP NF 1突变时，斑块会变大，这表明Ras起着指导作用。新的巨胞饮杯主要通过从现有的巨胞饮杯分裂而形成。我们认为杯状质膜结构是由活性Ras/PIP 3的自组织斑块形成的，这些活性Ras/PIP 3在其外周招募了一圈肌动蛋白成核剂。
Macropinocytosis is a fundamental mechanism that allows cells to take up extracellular liquid into large vesicles. It critically depends on the formation of a ring of protrusive actin beneath the plasma membrane, which develops into the macropinocytic cup. We show that macropinocytic cups in Dictyostelium are organised around coincident intense patches of PIP3, active Ras and active Rac. These signalling patches are invariably associated with a ring of active SCAR/WAVE at their periphery, as are all examined structures based on PIP3 patches, including phagocytic cups and basal waves. Patch formation does not depend on the enclosing F-actin ring, and patches become enlarged when the RasGAP NF1 is mutated, showing that Ras plays an instructive role. New macropinocytic cups predominantly form by splitting from existing ones. We propose that cup-shaped plasma membrane structures form from self-organizing patches of active Ras/PIP3, which recruit a ring of actin nucleators to their periphery.