Department of Biological Sciences, Dartmouth College, Hanover, United States.
Elife. 2021 Mar 9;10:e65166. doi: 10.7554/eLife.65166.
SABRE, which is found throughout eukaryotes and was originally identified in plants, mediates cell expansion, division plane orientation, and planar polarity in plants. How and where SABRE mediates these processes remain open questions. We deleted in , an excellent model for cell biology. null mutants were stunted, similar to phenotypes in seed plants. Additionally, polarized growing cells were delayed in cytokinesis, sometimes resulting in catastrophic failures. A functional SABRE fluorescent fusion protein localized to dynamic puncta on regions of the endoplasmic reticulum (ER) during interphase and at the cell plate during cell division. Without , cells accumulated ER aggregates and the ER abnormally buckled along the developing cell plate. Notably, callose deposition was delayed in , and in cells that failed to divide, abnormal callose accumulations formed at the cell plate. Our findings revealed a surprising and fundamental role for the ER in cell plate maturation.
SABRE 广泛存在于真核生物中，最初在植物中被发现，它介导植物细胞的扩张、分裂面的定向和平面极性。SABRE 如何以及在何处介导这些过程仍然是悬而未决的问题。我们在 中删除了 SABRE，这是细胞生物学的一个很好的模型。 缺失突变体生长缓慢，类似于种子植物的表型。此外，极化生长的细胞在胞质分裂时延迟，有时导致灾难性的失败。功能 SABRE 荧光融合蛋白在有丝分裂间期定位于内质网 (ER) 区域的动态点状结构，在细胞分裂时定位于细胞板。没有 SABRE，细胞会积累 ER 聚集体，ER 沿着正在发育的细胞板异常弯曲。值得注意的是，在 中，纤维素沉积被延迟，在不能分裂的细胞中，异常的纤维素积累形成在细胞板上。我们的研究结果揭示了 ER 在细胞板成熟过程中的惊人而基本的作用。
