The microtubule cytoskeleton serves as a dynamic structural framework for mitosis in eukaryotic cells. TANGLED1 (TAN1) is a microtubule-binding protein that localizes to the division site and mitotic microtubules and plays a critical role in division plane orientation in plants. Here, in vitro experiments demonstrate that TAN1 directly binds microtubules, mediating microtubule zippering or end-on microtubule interactions, depending on their contact angle. Maize tan1 mutant cells improperly position the preprophase band (PPB), which predicts the future division site. However, cell shape–based modeling indicates that PPB positioning defects are likely a consequence of abnormal cell shapes and not due to TAN1 absence. In telophase, colocalization of growing microtubules ends from the phragmoplast with TAN1 at the division site suggests that TAN1 interacts with microtubule tips end-on. Together, our results suggest that TAN1 contributes to microtubule organization to ensure proper division plane orientation.

中文翻译：

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TANGLED1 介导微管相互作用，可能促进玉米中分裂平面的定位

微管细胞骨架充当真核细胞有丝分裂的动态结构框架。TANGLED1 (TAN1) 是一种微管结合蛋白，定位于分裂位点和有丝分裂微管，在植物分裂平面方向中发挥关键作用。在这里，体外实验证明 TAN1 直接结合微管，介导微管拉链或末端微管相互作用，具体取决于它们的接触角。玉米 tan1 突变细胞未正确定位前期带 (PPB)，该带预测未来的分裂位点。然而，基于细胞形状的建模表明 PPB 定位缺陷可能是细胞形状异常的结果，而不是由于 TAN1 缺失造成的。在末期，来自成膜体的生长微管末端与分裂位点的 TAN1 共定位表明 TAN1 与微管尖端端对相互作用。总之，我们的结果表明 TAN1 有助于微管组织，以确保正确的分割平面方向。