Structure and Function of a Bacterial Gap Junction Analog
Structure and Function of a Bacterial Gap Junction Analog
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DOI：
10.1016/j.cell.2019.05.055
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发表时间：
2018-11
期刊：
影响因子：
64.5
通讯作者：
G. L. Weiss;Ann-Katrin Kieninger;I. Maldener;K. Forchhammer;M. Pilhofer
中科院分区：
文献类型：
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作者：
G. L. Weiss;Ann-Katrin Kieninger;I. Maldener;K. Forchhammer;M. Pilhofer
多细胞生活方式需要细胞间的连接。在多细胞蓝细菌中，隔连接使姐妹细胞之间的分子交换成为可能，并且是细胞分化所必需的。间隔连接的结构知之甚少，也不知道它们是否能够控制细胞间的通讯。在这里，我们通过冷冻聚焦离子束研磨的蓝细菌细丝的电子冷冻断层扫描来解决隔连接的原位结构。隔连接由一条穿过隔肽聚糖的管道组成。每个管端包含含有FraD的塞，其被细胞质帽覆盖。光漂白后的荧光恢复表明细胞间通讯在应激时被阻断。门控是伴随着一个可逆的构象变化的隔连接帽。我们提供了一个细胞连接的机制框架，早于真核间隙连接10亿年。门控动力学机制在不同生命领域的保守性强调了控制多细胞生物中分子交换的重要性。
Multicellular lifestyle requires cell-cell connections. In multicellular cyanobacteria, septal junctions enable molecular exchange between sister cells and are required for cellular differentiation. The structure of septal junctions is poorly understood, and it is unknown whether they are capable of controlling intercellular communication. Here, we resolved thein situarchitecture of septal junctions by electron cryotomography of cryo-focused ion beam-milled cyanobacterial filaments. Septal junctions consisted of a tube traversing the septal peptidoglycan. Each tube end comprised a FraD-containing plug, which was covered by a cytoplasmic cap. Fluorescence recovery after photobleaching showed that intercellular communication was blocked upon stress. Gating was accompanied by a reversible conformational change of the septal junction cap. We provide the mechanistic framework for a cell junction that predates eukaryotic gap junctions by a billion years. The conservation of a gated dynamic mechanism across different domains of life emphasizes the importance of controlling molecular exchange in multicellular organisms.