Cell polarity is used to guide asymmetric divisions and create morphologically diverse cells. We find that two oppositely oriented cortical polarity domains present during the asymmetric divisions in the Arabidopsis stomatal lineage are reconfigured into polar domains marking ventral (pore-forming) and outward-facing domains of maturing stomatal guard cells. Proteins that define these opposing polarity domains were used as baits in miniTurboID-based proximity labeling. Among differentially enriched proteins, we find kinases, putative microtubule-interacting proteins, and polar SOSEKIs with their effector ANGUSTIFOLIA. Using AI-facilitated protein structure prediction models, we identify potential protein-protein interaction interfaces among them. Functional and localization analyses of the polarity protein OPL2 and its putative interaction partners suggest a positive interaction with mitotic microtubules and a role in cytokinesis. This combination of proteomics and structural modeling with live-cell imaging provides insights into how polarity is rewired in different cell types and cell-cycle stages.

细胞极性用于引导不对称分裂并创建形态多样化的细胞。我们发现，在拟南芥气孔谱系的不对称分裂过程中存在的两个方向相反的皮质极性域被重新配置为标记成熟气孔保卫细胞的腹侧（成孔）和外向域的极性域。定义这些相反极性域的蛋白质被用作基于 miniTurboID 的邻近标记的诱饵。在差异富集的蛋白质中，我们发现了激酶、推定的微管相互作用蛋白和极性 SOSEKI 及其效应子 ANGUSTIFOLIA。使用人工智能促进的蛋白质结构预测模型，我们确定了它们之间潜在的蛋白质-蛋白质相互作用界面。极性蛋白 OPL2 及其假定的相互作用伙伴的功能和定位分析表明，与有丝分裂微管存在积极的相互作用，并在胞质分裂中发挥作用。蛋白质组学和结构建模与活细胞成像的结合提供了关于极性在不同细胞类型和细胞周期阶段如何重新连接的见解。