A link between planar polarity and staircase-like bundle architecture in hair cells
A link between planar polarity and staircase-like bundle architecture in hair cells
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DOI：
10.1242/dev.139089
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发表时间：
2016-11-01
期刊：
影响因子：
4.6
通讯作者：
Cayouette, Michel
中科院分区：
文献类型：
--
作者：
Tarchini, Basile;Tadenev, Abigail L. D.;Cayouette, Michel
内耳的感官知觉依赖于毛束，即毛细胞顶部高度极化的运动探测器刷。我们之前表明，在小鼠耳蜗中，形成束的边缘由“裸区”定义，“裸区”是由 Insc-LGN-Gai 蛋白复合物指定的顶膜无微绒毛的子区域。我们现在报道 LGN 和 Gai 也占据直接毗邻裸露区域的静纤毛的最尖端。我们证明 LGN 和 Gai 对于促进跨行静纤毛的伸长和差异特性都是至关重要的。有趣的是，我们还发现总 LGN-Gai 蛋白量在裸露区和静纤毛尖端之间主动平衡，这表明裸露区蛋白质富集的早期平面不对称性赋予相邻静纤毛最高的身份。我们建议 LGN 和 Gai 参与源自束外部的长期推断信号，以对其阶梯状结构进行建模，这种特性对于机械偏转和听觉的方向敏感性至关重要。
Sensory perception in the inner ear relies on the hair bundle, the highly polarized brush of movement detectors that crowns hair cells. We previously showed that, in the mouse cochlea, the edge of the forming bundle is defined by the 'bare zone', a microvilli-free sub-region of apical membrane specified by the Insc-LGN-Gai protein complex. We now report that LGN and Gai also occupy the very tip of stereocilia that directly abut the bare zone. We demonstrate that LGN and Gai are both essential for promoting the elongation and differential identity of stereocilia across rows. Interestingly, we also reveal that total LGN-Gai protein amounts are actively balanced between the bare zone and stereocilia tips, suggesting that early planar asymmetry of protein enrichment at the bare zone confers adjacent stereocilia their tallest identity. We propose that LGN and Gai participate in a long-inferred signal that originates outside the bundle to model its staircase-like architecture, a property that is essential for direction sensitivity to mechanical deflection and hearing.