Institut für Neuro- und Verhaltensbiologie, Universität Münster, Badestraße 9, 48149 Münster, Germany.
Institut für Neuro- und Verhaltensbiologie, Universität Münster, Badestraße 9, 48149 Münster, Germany; Department of Biology, University of New Mexico, 219 Yale Boulevard NE, Albuquerque, NM 87131, USA.
Cell Rep. 2019 Feb 5;26(6):1641-1653.e4. doi: 10.1016/j.celrep.2019.01.046.
Occluding cell-cell junctions are pivotal during the development of many organs. One example is septate junction (SJ) strands, which are found in vertebrates and invertebrates. Although several proteins have been identified that are responsible for septate junction formation in Drosophila, it is presently unclear how these structures are formed or how they are positioned in a coordinated manner between two neighboring cells and within the tissue. Here, we identified a GPI-anchored protein called Undicht required for septate junction formation. Clonal analysis and rescue experiments show that Undicht acts in a non-cell-autonomous manner. It can be released from the plasma membrane by the proteolytic activity of two related ADAM10-like proteases, Kuzbanian and Kuzbanian-like. We propose that juxtacrine function of Undicht coordinates the formation of septate junction strands on two directly neighboring cells, whereas paracrine activity of Undicht controls the formation of occluding junctions within a tissue.
在许多器官的发育过程中，封闭细胞-细胞连接是至关重要的。一个例子是 有丝分裂后期（SJ）链，它存在于脊椎动物和无脊椎动物中。尽管已经鉴定出几种负责果蝇中 有丝分裂后期连接形成的蛋白质，但目前尚不清楚这些结构是如何形成的，或者它们如何在两个相邻细胞之间以及在组织内以协调的方式定位。在这里，我们鉴定了一种称为 Undicht 的 GPI-锚定蛋白，它是 有丝分裂后期连接形成所必需的。克隆分析和拯救实验表明，Undicht 以非细胞自主的方式发挥作用。它可以通过两种相关的 ADAM10 样蛋白酶 Kuzbanian 和 Kuzbanian-like 的蛋白水解活性从质膜中释放出来。我们提出，Undicht 的旁分泌功能协调两个直接相邻细胞上 有丝分裂后期连接链的形成，而 Undicht 的内分泌活性控制组织内封闭连接的形成。
