Phase Separation of Zonula Occludens Proteins Drives Formation of Tight Junctions
Phase Separation of Zonula Occludens Proteins Drives Formation of Tight Junctions
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DOI：
10.1016/j.cell.2019.10.011
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发表时间：
2019-10-31
期刊：
影响因子：
64.5
通讯作者：
Honigmann, Alf
中科院分区：
文献类型：
--
作者：
Beutel, Oliver;Maraspini, Riccardo;Honigmann, Alf
紧密连接是细胞粘附复合物，密封组织并参与细胞极性和信号传导。紧密连接作为粘附链的连续网络的超分子组装和定位依赖于膜相关支架蛋白ZO 1和ZO 2。为了了解封闭齿蛋白（ZO）是如何组织连接组装的，我们进行了定量细胞生物学和体外重建实验。我们发现ZO蛋白通过相分离自组织膜附着区室。我们确定了保守的PDZ-SH 3-GuK超结构域的多价相互作用作为相分离的驱动器。这些相互作用通过磷酸化和分子内结合来调节。形成浓缩ZO蛋白隔室是足够的，以具体丰富和本地化的紧密连接蛋白，包括粘附受体，细胞骨架适配器，和转录因子。我们的研究结果表明，一个活跃的相转变ZO蛋白到一个凝聚的膜结合室驱动claudin聚合和聚结的一个连续的紧密连接带。
Tight junctions are cell-adhesion complexes that seal tissues and are involved in cell polarity and signaling. Supra-molecular assembly and positioning of tight junctions as continuous networks of adhesion strands are dependent on the membrane-associated scaffolding proteins ZO1 and ZO2. To understand how zona occludens (ZO) proteins organize junction assembly, we performed quantitative cell biology and in vitro reconstitution experiments. We discovered that ZO proteins self-organize membrane-attached compartments via phase separation. We identified the multivalent interactions of the conserved PDZ-SH3-GuK supra-domain as the driver of phase separation. These interactions are regulated by phosphorylation and intra-molecular binding. Formation of condensed ZO protein compartments is sufficient to specifically enrich and localize tight-junction proteins, including adhesion receptors, cytoskeletal adapters, and transcription factors. Our results suggest that an active-phase transition of ZO proteins into a condensed membrane-bound compartment drives claudin polymerization and coalescence of a continuous tight-junction belt.