The Microtubule-Associated Protein IQ67 DOMAIN5 Modulates Microtubule Dynamics and Pavement Cell Shape
The Microtubule-Associated Protein IQ67 DOMAIN5 Modulates Microtubule Dynamics and Pavement Cell Shape
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DOI：
10.1104/pp.18.00558
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发表时间：
2018-08-01
期刊：
影响因子：
7.4
通讯作者：
Yang, Zhenbiao
中科院分区：
文献类型：
--
作者：
Liang, Hong;Zhang, Yi;Yang, Zhenbiao
皮质微管（MT）的动态排列在控制植物细胞生长和形状形成方面发挥着关键作用，但皮质MT组织起来调节这些过程的机制尚未得到很好的表征。特别是，皮质MT的动态行为是其空间组织的关键，但控制MT动态的分子机制仍然知之甚少。在这项研究中，我们使用的拼图块状路面细胞的拟南芥（拟南芥）叶片作为模型系统，研究皮层MT组织。我们分离出一个甲基磺酸乙酯突变体，其子叶中铺路细胞的交错排列减少。该品系携带IQ67 DOMAIN 5（IQD5）突变，其编码植物特异性IQ基序蛋白家族的成员。活细胞成像和生化分析表明，IQD5结合MT和促进MT组装。MT解聚药物治疗和体内MT动力学测定表明，IQD5的功能，以稳定MT。因此，我们的研究结果提供了遗传，细胞生物学和生化证据，证明IQD5调节MT动力学，影响MT组织和随后的细胞形状形成。
The dynamic arrangement of cortical microtubules (MTs) plays a pivotal role in controlling cell growth and shape formation in plants, but the mechanisms by which cortical MTs are organized to regulate these processes are not well characterized. In particular, the dynamic behavior of cortical MTs is critical for their spatial organization, yet the molecular mechanisms controlling MT dynamics remain poorly understood. In this study, we used the puzzle piece-shaped pavement cells of Arabidopsis (Arabidopsis thaliana) leaves as a model system in which to study cortical MT organization. We isolated an ethyl methanesulfonate mutant with reduced interdigitation of pavement cells in cotyledons. This line carried a mutation in IQ67 DOMAIN5 (IQD5), which encodes a member of the plant-specific IQ motif protein family. Live-cell imaging and biochemical analyses demonstrated that IQD5 binds to MTs and promotes MT assembly. MT-depolymerizing drug treatment and in vivo MT dynamics assays suggested that IQD5 functions to stabilize MTs. Hence, our findings provide genetic, cell biological, and biochemical evidence that IQD5 regulates MT dynamics that affect MT organization and subsequent cell shape formation.