Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, the Netherlands.
Nat Rev Mol Cell Biol. 2022 Aug;23(8):541-558. doi: 10.1038/s41580-022-00473-y. Epub 2022 Apr 5.
Microtubules are polarized cytoskeletal filaments that serve as tracks for intracellular transport and form a scaffold that positions organelles and other cellular components and modulates cell shape and mechanics. In animal cells, the geometry, density and directionality of microtubule networks are major determinants of cellular architecture, polarity and proliferation. In dividing cells, microtubules form bipolar spindles that pull chromosomes apart, whereas in interphase cells, microtubules are organized in a cell type-specific fashion, which strongly correlates with cell physiology. In motile cells, such as fibroblasts and immune cells, microtubules are organized as radial asters, whereas in immotile epithelial and neuronal cells and in muscles, microtubules form parallel or antiparallel arrays and cortical meshworks. Here, we review recent work addressing how the formation of such microtubule networks is driven by the plethora of microtubule regulatory proteins. These include proteins that nucleate or anchor microtubule ends at different cellular structures and those that sever or move microtubules, as well as regulators of microtubule elongation, stability, bundling or modifications. The emerging picture, although still very incomplete, shows a remarkable diversity of cell-specific mechanisms that employ conserved building blocks to adjust microtubule organization in order to facilitate different cellular functions.
微管是极性细胞骨架丝，作为细胞内运输的轨道，并形成一个支架，定位细胞器和其他细胞成分，并调节细胞形状和力学。在动物细胞中，微管网络的几何形状、密度和方向性是细胞结构、极性和增殖的主要决定因素。在分裂的细胞中，微管形成双极纺锤体，将染色体拉开，而在间期中，微管以细胞类型特异性的方式组织，这与细胞生理学密切相关。在运动细胞中，如成纤维细胞和免疫细胞，微管组织成放射状星体，而在非运动的上皮细胞和神经元细胞以及肌肉中，微管形成平行或反平行的阵列和皮质网格。在这里，我们回顾了最近的研究工作，这些工作探讨了微管网络的形成是如何由大量的微管调节蛋白驱动的。这些蛋白包括在不同的细胞结构处起始或锚定微管末端的蛋白，以及切割或移动微管的蛋白，以及微管延伸、稳定性、成束或修饰的调节剂。尽管这个新兴的画面仍然非常不完整，但它显示了一种显著的细胞特异性机制多样性，这些机制利用保守的构建模块来调整微管组织，以促进不同的细胞功能。
