A mechanism for exocyst-mediated tethering via Arf6 and PIP5K1C-driven phosphoinositide conversion.
A mechanism for exocyst-mediated tethering via Arf6 and PIP5K1C-driven phosphoinositide conversion.
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通过Arf6和PIP5K1C驱动的磷脂酰肌醇转化的胞外囊介导的系链机制。
DOI：
10.1016/j.cub.2022.04.089
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发表时间：
2022-07-11
期刊：
影响因子：
9.2
通讯作者：
Murray, David H.
中科院分区：
文献类型：
--
作者：
Maib, Hannes;Murray, David H.
极化运输是真核生物发育所必需的，并受到保守分子机制的调控。货物递送的后期步骤由外囊复合物介导，外囊复合物将脂质和蛋白质组分整合到系链囊泡以用于质膜融合。然而，这一过程的分子机制是不明确的。在这里，我们重建功能性八聚体人类外囊，证明了holocomplex聚结和生化稳定的亚复合物的基础。我们确定，每个子复合物独立地结合磷脂酰肌醇4，5-二磷酸（PI（4，5）P2），这是最低限度的膜束缚。通过重建和上皮细胞生物学实验，我们表明Arf 6介导的脂质激酶PIP 5 K1 C的募集迅速将磷脂酰肌醇4-磷酸（PI（4）P）转化为PI（4，5）P2，从而驱动囊外募集和膜束缚。这些结果提供了一个外囊介导的拴系的分子机制和一个独特的功能要求磷酸肌醇信号的后期囊泡附近的质膜。人外囊复合物的完全重构和亚基连接性每个亚复合物与PI（4，5）P2反式结合使膜束缚PI（4）P到PI（4，5）P2的转化足以用于外囊募集和束缚Arf 6控制细胞和体外PIP 5 K1 C的磷酸肌醇转化在极化膜运输过程中囊泡如何被束缚到质膜上？通过哺乳动物外囊复合物的完全重建，Maib和Murray表明，PI（4）P通过PIP 5 K1 C转化为PI（4，5）P2的磷酸肌醇由小GTd 6 Arf 6控制，并且该转化对于外囊介导的束缚是最低限度的。
Polarized trafficking is necessary for the development of eukaryotes and is regulated by a conserved molecular machinery. Late steps of cargo delivery are mediated by the exocyst complex, which integrates lipid and protein components to tether vesicles for plasma membrane fusion. However, the molecular mechanisms of this process are poorly defined. Here, we reconstitute functional octameric human exocyst, demonstrating the basis for holocomplex coalescence and biochemically stable subcomplexes. We determine that each subcomplex independently binds to phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), which is minimally sufficient for membrane tethering. Through reconstitution and epithelial cell biology experiments, we show that Arf6-mediated recruitment of the lipid kinase PIP5K1C rapidly converts phosphatidylinositol 4-phosphate (PI(4)P) to PI(4,5)P2, driving exocyst recruitment and membrane tethering. These results provide a molecular mechanism of exocyst-mediated tethering and a unique functional requirement for phosphoinositide signaling on late-stage vesicles in the vicinity of the plasma membrane. Complete reconstitution and subunit connectivity of the human exocyst complex Binding to PI(4,5)P2 in trans by each subcomplex enables membrane tethering PI(4)P to PI(4,5)P2 conversion is sufficient for exocyst recruitment and tethering Arf6 controls phosphoinositide conversion by PIP5K1C in cells and in vitro How are vesicles tethered to the plasma membrane during polarized membrane trafficking? Through complete reconstitution of the mammalian exocyst complex, Maib and Murray show that phosphoinositide conversion of PI(4)P into PI(4,5)P2 by PIP5K1C is controlled by the small GTPase Arf6, and the conversion is minimally sufficient for exocyst-mediated tethering.
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DOI：
10.1016/j.bbalip.2015.02.013
发表时间：
2015-06
期刊：
Biochimica et biophysica acta
影响因子：
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通讯作者：
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DOI：
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发表时间：
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影响因子：
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影响因子：
16.6
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DOI：
10.1126/science.1160617
发表时间：
2008-10-17
期刊：
Science (New York, N.Y.)
影响因子：
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