Asymmetric co-localization of Flamingo, a seven-pass transmembrane cadherin, and Dishevelled in planar cell polarization.

果蝇翅膀为研究平面细胞极性（PCP）遗传规划提供了一个合适的模型系统。每个翼细胞尊重近端远端（PD）轴；也就是说，它将肌动蛋白束的集合定位到它的远顶点，产生单个的前毛。这种PD极化需要火烈鸟蛋白（Fmi）重新分布到近端/远端细胞边界，这是一种跨膜钙粘蛋白；否则，细胞会使前毛定位错误。偏态Fmi模式的实现依赖于PCP信号通路中的两个上游成分：用于假设极性信号的卷曲（Fz）受体和细胞内蛋白disheveled （Dsh）。在这里，我们可视化了发育翼中的内源性Dsh。部分Dsh与Fmi共定位，两种蛋白的分布是相互依赖的。此外，Fz控制了Dsh与细胞边界的关联，这种关联与Dsh过度磷酸化形式的存在相关。我们的研究结果，以及最近对Fz分布的研究，支持了Fz、Dsh和Fmi构成一个信号复合体的可能性，其有限的定位仅在远端细胞边缘指导细胞骨架重组。

The Drosophila wing provides an appropriate model system to study genetic programming of planar cell polarity (PCP). Each wing cell respects the proximodistal (PD) axis ; i.e., it localizes an assembly of actin bundles to its distalmost vertex, producing a single prehair. This PD polarization requires re-distribution of Flamingo (Fmi), a seven-pass transmembrane cadherin, to proximal/distal cell boundaries ; otherwise the cell mislocalizes the prehair. Achievement of the biased Fmi pattern depends on two upstream components in the PCP signaling pathway : the Frizzled (Fz) receptor for a hypothetical polarity signal and the intracellular protein Dishevelled (Dsh). Here we visualized endogenous Dsh in the developing wing. A portion of Dsh co-localized with Fmi, and the distributions of both proteins were interdependent. Furthermore Fz controlled the association of Dsh with cell boundaries, which association was correlated with the presence of hyperphosphorylated forms of Dsh. Our results, together with a recent study on Fz distribution, support the possibility that Fz, Dsh, and Fmi constitute a signaling complex and that its restricted localization directs cytoskeletal reorganization only at the distal cell edge.