Biochemistry and Cell Biology Department, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA.
Biochemistry and Cell Biology Department, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
Life Sci Alliance. 2023 Oct 9;7(1). doi: 10.26508/lsa.202302287. Print 2024 Jan.
At the core of cilia are microtubules which establish length and assist ciliary assembly and disassembly; however, microtubules outside of the cilium can regulate ciliogenesis. The microtubule cytoskeleton polymerizes and depolymerizes rapidly. These processes have been studied across various organisms with chemical and genetic perturbations. However, these have generated conflicting data in terms of the role of cytoplasmic microtubules (CytoMTs) and free tubulin dynamics during ciliogenesis. Here, we look at the relationship between ciliogenesis and CytoMT dynamics in using chemical and mechanical perturbations. We find that not only can stabilized CytoMTs allow for normal ciliary assembly, but high calcium concentrations and low pH-induced deciliation cause CytoMTs to depolymerize separately from ciliary shedding. In addition, ciliary shedding through mechanical shearing allows cilia to regenerate earlier despite intact CytoMTs. Our data suggest that CytoMTs are not a sink for a limiting pool of cytoplasmic tubulin in , depolymerization after deciliation is a consequence rather than a requirement for ciliogenesis, and intact tubulin in the cytoplasm and proximal cilium support more efficient ciliary assembly.
纤毛的核心是微管，微管决定纤毛的长度并协助纤毛的组装和拆卸；然而，纤毛外的微管可以调节纤毛发生。微管细胞骨架快速聚合和解聚。这些过程已经在各种生物体中通过化学和遗传扰动进行了研究。然而，在细胞质微管（CytoMTs）和游离微管蛋白动力学在纤毛发生过程中的作用方面，这些研究产生了相互矛盾的数据。在这里，我们使用化学和机械扰动来研究纤毛发生和 CytoMT 动力学之间的关系。我们发现，稳定的 CytoMTs 不仅可以允许正常的纤毛组装，而且高钙浓度和低 pH 诱导的纤毛去极化会导致 CytoMTs 与纤毛脱落分别解聚。此外，通过机械剪切进行纤毛脱落可以使纤毛更早地再生，尽管 CytoMTs 完好无损。我们的数据表明，CytoMTs 不是细胞质中游离微管蛋白的限制池的汇，纤毛去极化后的解聚是结果而不是纤毛发生的要求，细胞质和近端纤毛中的完整微管蛋白支持更有效的纤毛组装。
