The Membrane-Associated Sec1/Munc18 KEULE is Required for Phragmoplast Microtubule Reorganization During Cytokinesis in Arabidopsis
The Membrane-Associated Sec1/Munc18 KEULE is Required for Phragmoplast Microtubule Reorganization During Cytokinesis in Arabidopsis
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DOI：
10.1016/j.molp.2015.12.005
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发表时间：
2016-04-04
期刊：
影响因子：
27.5
通讯作者：
Assaad, Farhah F.
中科院分区：
文献类型：
--
作者：
Steiner, Alexander;Mueller, Lin;Assaad, Farhah F.
胞质分裂，核分裂后的细胞质的分配，需要广泛的协调膜运输和细胞骨架动力学。在植物中，胞质分裂的开始以双极微管阵列（成膜体）和瞬时膜室（细胞板）的组装为特征。很少有人知道在细胞板的膜沉积和成膜体微管的动力学之间的协调。在这项研究中，我们监测整个胞质分裂微管和膜标记的本地化动态。我们的时空分辨率与微管动力学驱动膜运动的一般观点一致。尽管如此，我们提供的证据，在细胞板的主动分选，并表明，这是，至少部分地，介导的TRAPPII拴系复合物。我们还描述了成膜体微管组织和细胞板形成的一套pneuminesis-deficient突变体。在成膜体微管组织缺陷的四个突变株系中，只有mor 1微管相关突变株表现出异常的细胞板。相反，在成膜体微管重组中具有最强损伤的突变体是keule等位基因，其在膜融合中具有主要缺陷。我们的研究结果确定SEC 1/Munc 18蛋白KEULE作为一个中央调节节点在植物胞质分裂过程中的膜和微管动力学的协调。
Cytokinesis, the partitioning of the cytoplasm following nuclear division, requires extensive coordination between membrane trafficking and cytoskeletal dynamics. In plants, the onset of cytokinesis is characterized by the assembly of a bipolar microtubule array, the phragmoplast, and of a transient membrane compartment, the cell plate. Little is known about the coordination between membrane deposition at the cell plate and the dynamics of phragmoplast microtubules. In this study, we monitor the localization dynamics of microtubule and membrane markers throughout cytokinesis. Our spatiotemporal resolution is consistent with the general view that microtubule dynamics drive membrane movements. Nonetheless, we provide evidence for active sorting at the cell plate and show that this is, at least in part, mediated by the TRAPPII tethering complex. We also characterize phragmoplast microtubule organization and cell plate formation in a suite of cytokinesis-defective mutants. Of four mutant lines with defects in phragmoplast microtubule organization, only mor1 microtubule-associated mutants exhibited aberrant cell plates. Conversely, the mutants with the strongest impairment in phragmoplast microtubule reorganization are keule alleles, which have a primary defect in membrane fusion. Our findings identify the SEC1/Munc18 protein KEULE as a central regulatory node in the coordination of membrane and microtubule dynamics during plant cytokinesis.