Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands.
Institute of Science and Technology, Klosterneuburg, Austria.
Nat Plants. 2019 Feb;5(2):160-166. doi: 10.1038/s41477-019-0363-6. Epub 2019 Feb 8.
Multicellular development requires coordinated cell polarization relative to body axes, and translation to oriented cell division. In plants, it is unknown how cell polarities are connected to organismal axes and translated to division. Here, we identify Arabidopsis SOSEKI proteins that integrate apical-basal and radial organismal axes to localize to polar cell edges. Localization does not depend on tissue context, requires cell wall integrity and is defined by a transferrable, protein-specific motif. A Domain of Unknown Function in SOSEKI proteins resembles the DIX oligomerization domain in the animal Dishevelled polarity regulator. The DIX-like domain self-interacts and is required for edge localization and for influencing division orientation, together with a second domain that defines the polar membrane domain. Our work shows that SOSEKI proteins locally interpret global polarity cues and can influence cell division orientation. Furthermore, this work reveals that, despite fundamental differences, cell polarity mechanisms in plants and animals converge on a similar protein domain.
多细胞发育需要相对于体轴的细胞极化协调，以及定向细胞分裂的转化。在植物中，细胞极性如何与生物体轴相连并转化为分裂尚不清楚。在这里，我们鉴定了拟南芥 SOSEKI 蛋白，它们将顶端-基底和放射状生物体轴整合到极性细胞边缘。定位不依赖于组织背景，需要细胞壁完整性，并由可传递的、蛋白特异性的基序定义。SOSEKI 蛋白中的一个未知功能域类似于动物 Dishevelled 极性调节剂中的 DIX 寡聚化结构域。DIX 样结构域自身相互作用，对于边缘定位和影响分裂方向是必需的，与另一个定义极性膜结构域的结构域一起。我们的工作表明，SOSEKI 蛋白局部解释全局极性线索，并能影响细胞分裂方向。此外，这项工作表明，尽管存在根本差异，但植物和动物中的细胞极性机制在相似的蛋白结构域上趋同。
