IDG/McGovern Institute for Brain Research, School of Life Sciences, Tsinghua University, Beijing, China.
Guangzhou Laboratory , Guangzhou, China.
J Cell Biol. 2023 Oct 2;222(10). doi: 10.1083/jcb.202209116. Epub 2023 Aug 31.
Mechanoreceptor cells develop specialized mechanosensory organelles (MOs), where force-sensitive channels and supporting structures are organized in an orderly manner to detect forces. It is intriguing how MOs are formed. Here, we address this issue by studying the MOs of fly ciliated mechanoreceptors. We show that the main structure of the MOs is a compound cytoskeleton formed of short microtubules and electron-dense materials (EDMs). In a knock-out mutant of DCX-EMAP, this cytoskeleton is nearly absent, suggesting that DCX-EMAP is required for the formation of the MOs and in turn fly mechanotransduction. Further analysis reveals that DCX-EMAP expresses in fly ciliated mechanoreceptors and localizes to the MOs. Moreover, it plays dual roles by promoting the assembly/stabilization of the microtubules and the accumulation of the EDMs in the MOs. Therefore, DCX-EMAP serves as a core ultrastructural organizer of the MOs, and this finding provides novel molecular insights as to how fly MOs are formed.
机械感受器细胞会发育出具有特殊机械感受功能的细胞器（MOs），在这些细胞器中，力敏通道和支撑结构以有序的方式排列，从而能够检测力。MOs 是如何形成的这一点很有趣。在这里，我们通过研究果蝇纤毛机械感受器的 MOs 来解决这个问题。我们发现，MOs 的主要结构是由短微管和电子致密物质（EDMs）组成的复合细胞骨架。在 DCX-EMAP 的敲除突变体中，这种细胞骨架几乎不存在，这表明 DCX-EMAP 对于 MOs 的形成以及果蝇的机械转导是必需的。进一步的分析表明，DCX-EMAP 在果蝇纤毛机械感受器中表达，并定位于 MOs。此外，它通过促进微管的组装/稳定以及 EDMs 在 MOs 中的积累发挥双重作用。因此，DCX-EMAP 是 MOs 的核心超微结构组织者，这一发现为果蝇 MOs 的形成提供了新的分子见解。
