Fast structural responses of gap junction membrane domains to AB5 toxins.
Fast structural responses of gap junction membrane domains to AB5 toxins.
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间隙连接膜域对 AB5 毒素的快速结构响应。
DOI：
10.1073/pnas.1315850110
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发表时间：
2013
影响因子：
11.1
通讯作者：
Duden,Rainer
中科院分区：
文献类型：
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作者：
Majoul,IrinaV;Gao,Liang;Betzig,Eric;Onichtchouk,Daria;Butkevich,Eugenia;Kozlov,Yuri;Bukauskas,Feliksas;Bennett,MichaelVL;Lippincott-Schwartz,Jennifer;Duden,Rainer
间隙连接 (GJ) 代表富含连接蛋白的膜结构域，连接哺乳动物组织中相邻细胞的内部。此前尚不清楚 GJ 对细菌病原体的反应速度有多快。使用贝塞尔光束平面照明和共焦转盘显微镜，我们发现暴露于 AB5 毒素的细胞之间的 GJ 斑块内连接蛋白耗尽区域 (CDR) 快速（~500 ms）形成。 CDR 形成表现为 GJ 斑块内连接蛋白通道的快速重新分布，轮廓或几何形状发生微小变化。 CDR 形成不依赖于膜运输或膜下细胞骨架，并且对 GJ 电导没有影响。然而，CDR 反应取决于膜脂，可以通过胆固醇聚集剂和细胞外 K+ 离子浓度进行修改，并影响 cAMP 信号传导。 GJ 斑块对细菌毒素的 CDR 反应是在所有测试的连接蛋白亚型中观察到的现象。通过信号传导，CDR 反应可能使细胞能够感知 AB5 毒素的暴露。 CDR 的形成可能反映了 GJ 斑块生物膜中的脂相分离事件，导致连接蛋白堆积和脂质重组增加。我们的数据表明 GJ 斑块内具有非常快的动态（在毫秒到秒范围内），而 GJ 斑块以前被认为是相对稳定、寿命长的结构。
Gap junctions (GJs) represent connexin-rich membrane domains that connect interiors of adjoining cells in mammalian tissues. How fast GJs can respond to bacterial pathogens has not been known previously. Using Bessel beam plane illumination and confocal spinning disk microscopy, we found fast (∼500 ms) formation of connexin-depleted regions (CDRs) inside GJ plaques between cells exposed to AB5 toxins. CDR formation appears as a fast redistribution of connexin channels within GJ plaques with minor changes in outline or geometry. CDR formation does not depend on membrane trafficking or submembrane cytoskeleton and has no effect on GJ conductance. However, CDR responses depend on membrane lipids, can be modified by cholesterol-clustering agents and extracellular K+ion concentration, and influence cAMP signaling. The CDR response of GJ plaques to bacterial toxins is a phenomenon observed for all tested connexin isoforms. Through signaling, the CDR response may enable cells to sense exposure to AB5 toxins. CDR formation may reflect lipid-phase separation events in the biological membrane of the GJ plaque, leading to increased connexin packing and lipid reorganization. Our data demonstrate very fast dynamics (in the millisecond-to-second range) within GJ plaques, which previously were considered to be relatively stable, long-lived structures.