Spatial and temporal organization of cadherin in punctate adherens junctions
Spatial and temporal organization of cadherin in punctate adherens junctions
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DOI：
10.1073/pnas.1720826115
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发表时间：
2018-05-08
影响因子：
11.1
通讯作者：
Troyanovsky, Sergey M.
中科院分区：
文献类型：
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作者：
Indra, Indrajyoti;Choi, Jongho;Troyanovsky, Sergey M.
粘附连接（AJs）在组织完整性中起着重要作用;然而，AJs内部和外部的关键AJ跨膜蛋白E-钙粘蛋白的组织和动力学仍然存在争议。本文研究了E-cadherin在A431细胞点状AJs（pAJs）中的分布和运动。使用单分子定位显微镜，我们发现，在这些细胞中的pAJs达到超过1 μ m的长度和由几个钙粘蛋白集群与晶体样密度散布在稀疏的钙粘蛋白区域。值得注意的是，连接外钙粘蛋白似乎是单体的，其密度几乎是四个数量级小于在pAJ区域中观察到的。两种替代策略的跟踪钙粘蛋白运动在个别路口显示，pAJs进行肌动蛋白依赖的快速的顺序秒内部重组，在此期间，密集的集群解体和他们的钙粘蛋白立即重新用于新的集群。因此，我们的研究结果修改了经典的观点AJs描绘他们的马赛克的钙粘蛋白簇，短的寿命，使稳定的整体形态结合快速内部重排。
Adherens junctions (AJs) play a fundamental role in tissue integrity; however, the organization and dynamics of the key AJ transmembrane protein, E-cadherin, both inside and outside of AJs, remain controversial. Here we have studied the distribution and motility of E-cadherin in punctate AJs (pAJs) of A431 cells. Using single-molecule localization microscopy, we show that pAJs in these cells reach more than 1 mu m in length and consist of several cadherin clusters with crystal-like density interspersed within sparser cadherin regions. Notably, extrajunctional cadherin appears to be monomeric, and its density is almost four orders of magnitude less than observed in the pAJ regions. Two alternative strategies of tracking cadherin motion within individual junctions show that pAJs undergo actin-dependent rapid-on the order of seconds-internal reorganizations, during which dense clusters disassemble and their cadherins are immediately reused for new clusters. Our results thus modify the classical view of AJs by depicting them as mosaics of cadherin clusters, the short lifetimes of which enable stable overall morphology combined with rapid internal rearrangements.