Aix Marseille Univ., CNRS, Institute of Developmental Biology of Marseille (IBDM), case 907, 13288 Marseille cedex 09, France.
Sci Rep. 2016 Sep 14;6:33420. doi: 10.1038/srep33420.
The localisation of apico-basal polarity proteins along the Z-axis of epithelial cells is well understood while their distribution in the plane of the epithelium is poorly characterised. Here we provide a systematic description of the planar localisation of apico-basal polarity proteins in the Drosophila ommatidial epithelium. We show that the adherens junction proteins Shotgun and Armadillo, as well as the baso-lateral complexes, are bilateral, i.e. present on both sides of cell interfaces. In contrast, we report that other key adherens junction proteins, Bazooka and the myosin regulatory light chain (Spaghetti squash) are unilateral, i.e. present on one side of cell interfaces. Furthermore, we demonstrate that planar cell polarity (PCP) and not the apical determinants Crumbs and Par-6 control Bazooka unilaterality in cone cells. Altogether, our work unravels an unexpected organisation and combination of apico-basal, cytoskeletal and planar polarity proteins that is different on either side of cell-cell interfaces and unique for the different contacts of the same cell.
上皮细胞中沿 Z 轴定位的顶端-基底极性蛋白的定位已经得到很好的理解，而它们在上皮细胞平面上的分布则特征描述较差。在这里，我们系统地描述了果蝇小眼上皮细胞中顶端-基底极性蛋白的平面定位。我们发现黏附连接蛋白 Shotgun 和 Armadillo 以及基底-侧复合物是双侧的，即在细胞界面的两侧都存在。相比之下，我们报告说其他关键的黏附连接蛋白 Bazooka 和肌球蛋白调节轻链（Spaghetti squash）是单侧的，即在细胞界面的一侧存在。此外，我们证明平面细胞极性（PCP）而不是顶端决定因素 Crumbs 和 Par-6 控制锥体细胞中 Bazooka 的单侧性。总之，我们的工作揭示了一种出乎意料的顶端-基底、细胞骨架和平坦极性蛋白的组织和组合，在细胞-细胞界面的两侧不同，并且对于同一细胞的不同接触是独特的。
