Interaction between MyRIP and the actin cytoskeleton regulates Weibel-Palade body trafficking and exocytosis.
Interaction between MyRIP and the actin cytoskeleton regulates Weibel-Palade body trafficking and exocytosis.
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DOI：
10.1242/jcs.178285
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发表时间：
2016-02-01
影响因子：
4
通讯作者：
Carter T
中科院分区：
文献类型：
--
作者：
Conte IL;Hellen N;Bierings R;Mashanov GI;Manneville JB;Kiskin NI;Hannah MJ;Molloy JE;Carter T
韦伯-帕拉德体（WPB）-肌动蛋白相互作用是必不可少的贩运和分泌的血管性血友病因子，然而，这种相互作用的分子基础仍然不清楚。肌球蛋白Va（MyoVa或MYO 5A）被Rab 27 A-MyRIP复合物募集到WPB，被认为是肌动蛋白结合的主要介质，但也可能发生直接的MyRIP-肌动蛋白相互作用。为了评估MyRIP-肌动蛋白和MyRIP-MyoVa结合在WPB运输和Ca 2+驱动的胞吐中的具体贡献，我们使用了具有破坏的MyoVa和/或肌动蛋白结合的EGFP-MyRIP点突变体和高速活细胞荧光显微镜。我们现在表明，MyRIP限制WPB运动的能力取决于其肌动蛋白结合，而不是其MyoVa结合特性。我们还表明，虽然MyRIP在Ca 2+驱动的胞吐作用需要MyoVa和肌动蛋白结合潜力，它是后者起着主导作用。鉴于这些结果，并与肌动蛋白破坏或稳定实验的分析，我们建议，MyRIP在调节WPB贩运和胞吐作用的作用，主要是通过其与肌动蛋白，而不是与MyoVa的相互作用介导的。总结：MyRIP在限制内皮细胞中韦伯-帕拉德小体的运动和胞吐中的作用主要是通过其肌动蛋白而不是肌球蛋白Va结合特性介导的。
Weibel–Palade body (WPB)–actin interactions are essential for the trafficking and secretion of von Willebrand factor; however, the molecular basis for this interaction remains poorly defined. Myosin Va (MyoVa or MYO5A) is recruited to WPBs by a Rab27A–MyRIP complex and is thought to be the prime mediator of actin binding, but direct MyRIP–actin interactions can also occur. To evaluate the specific contribution of MyRIP–actin and MyRIP–MyoVa binding in WPB trafficking and Ca2+-driven exocytosis, we used EGFP–MyRIP point mutants with disrupted MyoVa and/or actin binding and high-speed live-cell fluorescence microscopy. We now show that the ability of MyRIP to restrict WPB movement depends upon its actin-binding rather than its MyoVa-binding properties. We also show that, although the role of MyRIP in Ca2+-driven exocytosis requires both MyoVa- and actin-binding potential, it is the latter that plays a dominant role. In view of these results and together with the analysis of actin disruption or stabilisation experiments, we propose that the role of MyRIP in regulating WPB trafficking and exocytosis is mediated largely through its interaction with actin rather than with MyoVa. Summary: The role of MyRIP in restricting the movement and exocytosis of Weibel–Palade bodies in endothelial cells is mediated primarily through its actin- rather than myosin-Va-binding properties.