Casares-Arias Javier, González María Ujué, San Paulo Alvaro, Ventimiglia Leandro N, Sadler Jessica B A, Miguez David G, Labat-de-Hoz Leticia, Rubio-Ramos Armando, Rangel Laura, Bernabé-Rubio Miguel, Fernández-Barrera Jaime, Correas Isabel, Martín-Serrano Juan, Alonso Miguel A
Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, 28049 Madrid, Spain.
Instituto de Micro y Nanotecnología, Consejo Superior de Investigaciones Científicas, 28760 Madrid, Spain.
iScience. 2020 Jun 26;23(6):101244. doi: 10.1016/j.isci.2020.101244. Epub 2020 Jun 7.
The inheritance of the midbody remnant (MBR) breaks the symmetry of the two daughter cells, with functional consequences for lumen and primary cilium formation by polarized epithelial cells, and also for development and differentiation. However, despite its importance, neither the relationship between the plasma membrane and the inherited MBR nor the mechanism of MBR inheritance is well known. Here, the analysis by correlative light and ultra-high-resolution scanning electron microscopy reveals a membranous stalk that physically connects the MBR to the apical membrane of epithelial cells. The stalk, which derives from the uncleaved side of the midbody, concentrates the ESCRT machinery. The ESCRT CHMP4C subunit enables MBR inheritance, and its depletion dramatically reduces the percentage of ciliated cells. We demonstrate (1) that MBRs are physically connected to the plasma membrane, (2) how CHMP4C helps maintain the integrity of the connection, and (3) the functional importance of the connection.
中体残余物（MBR）的遗传打破了两个子细胞的对称性，对极化上皮细胞形成管腔和初级纤毛具有功能性影响，对发育和分化也有影响。然而，尽管其很重要，但质膜与遗传的MBR之间的关系以及MBR遗传机制都尚不为人所知。在这里，通过相关光和超高分辨率扫描电子显微镜分析揭示了一个膜性茎，它将MBR与上皮细胞的顶端膜物理连接起来。该茎源自中体未切割的一侧，富集了内体分选转运复合体（ESCRT）机制。ESCRT CHMP4C亚基促成MBR遗传，其缺失会显著降低有纤毛细胞的百分比。我们证明了（1）MBR与质膜物理连接，（2）CHMP4C如何帮助维持连接的完整性，以及（3）该连接的功能重要性。
