Department of Biology, The University of Saskatchewan, College of Arts and Science, Saskatoon, SK Canada.
PLoS One. 2018 Jun 12;13(6):e0198521. doi: 10.1371/journal.pone.0198521. eCollection 2018.
Following cytokinesis in plants, Endoplasmic MTs (EMTs) assemble on the nuclear surface, forming a radial network that extends out to the cell cortex, where they attach and incorporate into the cortical microtubule (CMT) array. We found that in these post-cytokinetic cells, the MT-associated protein CLASP is enriched at sites of EMT-cortex attachment, and is required for stable EMT tethering and growth into the cell cortex. Loss of EMT-cortex anchoring in clasp-1 mutants results in destabilized EMT arrays, and is accompanied by enhanced mobility of the cytoplasm, premature vacuolation, and precocious entry into cell elongation phase. Thus, EMTs appear to maintain cells in a meristematic state by providing a structural scaffold that stabilizes the cytoplasm to counteract actomyosin-based cytoplasmic streaming forces, thereby preventing premature establishment of a central vacuole and rapid cell elongation.
在植物细胞的胞质分裂之后，内质网微管（Endoplasmic MTs，EMTs）在核表面组装，形成一个延伸到细胞质皮层的放射状网络，它们附着在那里并整合到皮质微管（cortical microtubule，CMT）阵列中。我们发现，在这些胞质分裂后的细胞中，微管相关蛋白 CLASP 在 EMT-皮层附着的部位富集，并稳定 EMT 连接所必需的，并进入细胞质皮层。在 clasp-1 突变体中失去 EMT-皮层锚定导致 EMT 不稳定，同时细胞质的流动性增强，过早液泡化，以及过早进入细胞伸长阶段。因此，EMTs 通过提供一个稳定细胞质的结构支架，似乎可以维持细胞的分生组织状态，以抵抗肌动球蛋白为基础的细胞质流动，从而防止中央液泡的过早建立和细胞的快速伸长。
