Microtubules are required for the maintenance of planar cell polarity in monociliated floorplate cells.
Microtubules are required for the maintenance of planar cell polarity in monociliated floorplate cells.
复制标题
微管对于维持单纤毛底板细胞的平面细胞极性是必需的。
DOI：
10.1016/j.ydbio.2019.04.007
复制
发表时间：
2019
影响因子：
2.7
通讯作者：
Moens,CeciliaB
中科院分区：
文献类型：
--
作者：
Mathewson,AndrewW;Berman,DanielG;Moens,CeciliaB
平面细胞极性（PCP）蛋白的不对称定位对于许多平面极化细胞过程的建立至关重要，但维持这些不对称分布的机制仍然知之甚少。大量证据已将定向的顶端下微管 (MT) 与 PCP 蛋白质极性的建立联系起来，但最近的研究表明，MT 细胞骨架后来对于维持这种不对称性是可有可无的。由于 MT 是细胞内膜结合蛋白的囊泡运输的基础，因此维持 PCP 中对 MT 的需求值得进一步研究。我们研究了斑马鱼神经管底板极化背景下 PCP 蛋白和 MT 细胞骨架之间复杂的相互作用。我们证明底板细胞初级纤毛的渐进后极化不仅需要 Vangl2，还需要 Fzd3a。我们确定 GFP-Vangl2 不对称地定位于前膜，而 Fzd3a-GFP 不会在前膜或后膜上极化，但在初级纤毛的基部保持胞质富集。在 PCP 维持期间，囊泡 Fzd3a-GFP 沿着 MT 快速运输，主要流向顶膜，而囊泡 GFP-Vangl2 很少观察到。诺考达唑诱导的 MT 聚合丧失会破坏基底体定位以及 GFP-Vangl2 定位，并减少胞质 Fzd3a-GFP 运动。 MT 破坏后去除诺考达唑可恢复 MT 聚合，但不会恢复基础体极性。有趣的是，即使在未极化的基体的情况下，GFP-Vangl2 也会重新极化到前膜，并且在恢复数小时后，囊泡 Fzd3a-GFP 动力学也会恢复。我们的发现共同挑战了之前的工作，揭示了 PCP 蛋白的 MT 依赖性转运在维持发育过程中细胞和 PCP 蛋白不对称性方面的持续作用。
The asymmetric localization of planar cell polarity (PCP) proteins is essential for the establishment of many planar polarized cellular processes, but the mechanisms that maintain these asymmetric distributions remain poorly understood. A body of evidence has tied oriented subapical microtubules (MTs) to the establishment of PCP protein polarity, yet recent studies have suggested that the MT cytoskeleton is later dispensable for the maintenance of this asymmetry. As MTs underlie the vesicular trafficking of membrane-bound proteins within cells, the requirement for MTs in the maintenance of PCP merited further investigation. We investigated the complex interactions between PCP proteins and the MT cytoskeleton in the polarized context of the floorplate of the zebrafish neural tube. We demonstrated that the progressive posterior polarization of the primary cilia of floorplate cells requires not only Vangl2 but also Fzd3a. We determined that GFP-Vangl2 asymmetrically localizes to anterior membranes whereas Fzd3a-GFP does not polarize on anterior or posterior membranes but maintains a cytosolic enrichment at the base of the primary cilium. Vesicular Fzd3a-GFP is rapidly trafficked along MTs primarily toward the apical membrane during a period of PCP maintenance, whereas vesicular GFP-Vangl2 is less frequently observed. Nocodazole-induced loss of MT polymerization disrupts basal body positioning as well as GFP-Vangl2 localization and reduces cytosolic Fzd3a-GFP movements. Removal of nocodazole after MT disruption restores MT polymerization but does not restore basal body polarity. Interestingly, GFP-Vangl2 repolarizes to anterior membranes and vesicular Fzd3a-GFP dynamics recover after multiple hours of recovery, even in the context of unpolarized basal bodies. Together our findings challenge previous work by revealing an ongoing role for MT-dependent transport of PCP proteins in maintaining both cellular and PCP protein asymmetry during development.