Abstract：
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.
摘要：
在植物营养组织中，细胞分裂采用称为前前期带（PPB）的有丝分裂微管阵列，标记皮质分裂部位。这种瞬时细胞骨架阵列压印空间信息，以在有丝分裂细胞分裂的后期阶段由细胞动力学原生质体读取。在拟南芥中，我们发现PPB将肌球蛋白XI运动MYA1/Myo11F招募到皮质分裂部位，在那里，它连接了微管相关的蛋白质和马达，形成了一个突出的细胞骨架组件环，该组件接收了扩展的原生质体。皮质分裂部位的这种肌球蛋白定位模式取决于POK1/2Kinesin-12马达。MYA1/Myo11F在原生质体指导中的这种调节功能取决于完整的肌动蛋白丝。这些细胞骨架运动组件的发现指出了两个动态细胞骨架网络如何协同工作以控制开花植物中PPB依赖性分裂平面方向的潜在机制。
