Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, College of Life Science, Beijing Normal University, 100875, Beijing, China.
Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education, Instrumentation and Service Center for Science and Technology, Beijing Normal University, 519087, Zhuhai, China.
Nat Commun. 2023 Nov 17;14(1):7442. doi: 10.1038/s41467-023-43325-9.
As one of the major components of plant cell walls, cellulose is crucial for plant growth and development. Cellulose is synthesized by cellulose synthase (CesA) complexes (CSCs), which are trafficked and delivered from the Golgi apparatus to the plasma membrane. How CesAs are released from Golgi remains largely unclear. In this study, we observed that STELLO (STL) family proteins localized at a group of small CesA-containing compartments called Small CesA compartments (SmaCCs) or microtubule-associated CesA compartments (MASCs). The STL-labeled SmaCCs/MASCs were directly derived from Golgi through a membrane-stretching process: membrane-patches of Golgi attached to cortical microtubules, which led to emergence of membrane-tails that finally ruptured to generate SmaCCs/MASCs associated with the cortical microtubules. While myosin propelled the movement of Golgi along actin filaments to stretch the tails, the CesA-microtubule linker protein, CSI1/POM2 was indispensable for the tight anchor of the membrane-tail ends at cortical microtubules. Together, our data reveal a non-canonical delivery route to the plasma membrane of a major enzyme complex in plant biology.
作为植物细胞壁的主要成分之一，纤维素对植物的生长和发育至关重要。纤维素由纤维素合酶（CesA）复合物（CSC）合成，这些复合物从高尔基体运输并递送到质膜。CesA 如何从高尔基体释放仍然很大程度上不清楚。在这项研究中，我们观察到 STELLO（STL）家族蛋白定位于一组称为小 CesA 区室（SmaCCs）或微管相关 CesA 区室（MASCs）的小 CesA 包含区室。STL 标记的 SmaCCs/MASCs 是通过膜拉伸过程直接从高尔基体衍生而来的：高尔基体的膜片附着在皮质微管上，导致膜尾的出现，最终破裂产生与皮质微管相关的 SmaCCs/MASCs。虽然肌球蛋白推动着高尔基体沿着肌动蛋白丝运动以拉伸尾部，但 CesA-微管连接蛋白 CSI1/POM2 对于膜尾末端在皮质微管上的紧密锚定是必不可少的。总之，我们的数据揭示了植物生物学中主要酶复合物向质膜的非典型递呈途径。
