Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093-0116, USA.
Department of Molecular Biology, University of Wyoming, Laramie, Wyoming 82071, USA.
Nat Plants. 2015 Jan 26;1:14024. doi: 10.1038/nplants.2014.24.
Pre-mitotic establishment of polarity is a key event in the preparation of mother cells for asymmetric cell divisions that produce daughters of distinct fates, and ensures correct cellular patterning of tissues and eventual organ function. Previous work has shown that two receptor-like kinases, PANGLOSS2 (PAN2) and PAN1, and the small GTPase RHO GTPASE OF PLANTS (ROP) promote mother cell polarity and subsequent division asymmetry in developing maize stomata. PAN proteins become polarized prior to asymmetric cell division, however, the mechanism of this polarization is unknown. Here we show that the SCAR/WAVE regulatory complex, which activates the actin-nucleating ARP2/3 complex, is the first known marker of polarity in this asymmetric division model and is required for PAN polarization. These findings implicate actin, and specifically branched actin networks, in PAN polarization and asymmetric cell division.
有丝分裂前极性的建立是母细胞为产生不同命运的子细胞进行不对称细胞分裂做准备的一个关键事件，它确保了组织的正确细胞模式和最终的器官功能。先前的工作表明，两个受体样激酶 PANGLOSS2（PAN2）和 PAN1，以及小分子 G 蛋白 RHO GTPASE OF PLANTS（ROP）促进了玉米气孔发育过程中母细胞的极性和随后的分裂不对称性。PAN 蛋白在不对称细胞分裂之前就发生极化，然而，这种极化的机制尚不清楚。在这里，我们表明 SCAR/WAVE 调节复合物，它激活肌动蛋白成核 ARP2/3 复合物，是这个不对称分裂模型中第一个已知的极性标记物，并且是 PAN 极化所必需的。这些发现表明肌动蛋白，特别是分支肌动蛋白网络，参与了 PAN 的极化和不对称细胞分裂。
