National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
College of Agriculture and Biotechnology, Hunan University of Humanities, Science and Technology, Loudi, 417000, China.
Planta. 2023 Mar 2;257(4):71. doi: 10.1007/s00425-023-04106-2.
STD1 specifically interacts with MAP65-5 in rice and they cooperatively control microtubule bundles in phragmoplast expansion during cell division. Microtubules play critical roles during the cell cycle progression in the plant cell. We previously reported that STEMLESS DWARF 1 (STD1), a kinesin-related protein, was localized specifically to the phragmoplast midzone during telophase to regulate the lateral expansion of phragmoplast in rice (Oryza sativa). However, how STD1 regulates microtubule organization remains unknown. Here, we found that STD1 interacted directly with MAP65-5, a member of the microtubule-associated proteins (MAPs). Both STD1 and MAP65-5 could form homodimers and bundle microtubules individually. Compared with MAP65-5, the microtubules bundled by STD1 were disassembled completely into single microtubules after adding ATP. Conversely, the interaction of STD1 with MAP65-5 enhanced the microtubule bundling. These results suggest STD1 and MAP65-5 might cooperatively regulate microtubule organization in the phragmoplast at telophase.
STD1 特异性地与 MAP65-5 在水稻中相互作用，它们共同控制细胞分裂过程中胞质分裂时期微管束的扩展。微管在植物细胞的细胞周期进展中起着关键作用。我们之前曾报道过，类驱动蛋白蛋白 STD1 特异性定位于末期的胞质分裂板中间区，以调节水稻（Oryza sativa）胞质分裂板的横向扩展。然而，STD1 如何调节微管组织仍不清楚。在这里，我们发现 STD1 与微管相关蛋白（MAPs）家族的成员 MAP65-5 直接相互作用。STD1 和 MAP65-5 都可以形成同源二聚体并单独束集微管。与 MAP65-5 相比，加入 ATP 后，由 STD1 束集的微管完全解聚成单根微管。相反，STD1 与 MAP65-5 的相互作用增强了微管的束集。这些结果表明，STD1 和 MAP65-5 可能在末期共同调节胞质分裂板中的微管组织。
