Department of Plant Biology, College of Biological Sciences, University of California, Davis, CA 95616, USA.
Department of Plant Biology, College of Biological Sciences, University of California, Davis, CA 95616, USA.
Dev Cell. 2024 Sep 9;59(17):2333-2346.e6. doi: 10.1016/j.devcel.2024.05.015. Epub 2024 Jun 6.
In plant vegetative tissues, cell division employs a mitotic microtubule array called the preprophase band (PPB) that marks the cortical division site. This transient cytoskeletal array imprints the spatial information to be read by the cytokinetic phragmoplast at later stages of mitotic cell division. In Arabidopsis thaliana, we discovered that the PPB recruited the Myosin XI motor MYA1/Myo11F to the cortical division site, where it joined microtubule-associated proteins and motors to form a ring of prominent cytoskeletal assemblies that received the expanding phragmoplast. Such a myosin localization pattern at the cortical division site was dependent on the POK1/2 Kinesin-12 motors. This regulatory function of MYA1/Myo11F in phragmoplast guidance was dependent on intact actin filaments. The discovery of these cytoskeletal motor assemblies pinpoints a mechanism underlying how two dynamic cytoskeletal networks work in concert to govern PPB-dependent division plane orientation in flowering plants.
在植物营养组织中，细胞分裂采用一种称为前期带（PPB）的有丝分裂微管阵列，该阵列标记皮质分裂位点。这种短暂的细胞骨架阵列将空间信息印刻下来，以便在有丝分裂细胞分裂的后期由胞质分裂纺锤体读取。在拟南芥中，我们发现 PPB 将肌球蛋白 XI 马达 MYA1/Myo11F 募集到皮质分裂位点，在那里它与微管相关蛋白和马达结合，形成一个突出的细胞骨架组装环，接收正在扩展的胞质分裂纺锤体。这种肌球蛋白在皮质分裂位点的定位模式依赖于 POK1/2 驱动蛋白-12 马达。MYA1/Myo11F 在胞质分裂纺锤体导向中的这种调节功能依赖于完整的肌动蛋白丝。这些细胞骨架马达组装的发现指出了一个机制，即两个动态细胞骨架网络如何协同工作，以控制有花植物中 PPB 依赖性分裂平面取向。
