The supramolecular architecture of junctional microdomains in native lens membranes
The supramolecular architecture of junctional microdomains in native lens membranes
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DOI：
10.1038/sj.embor.7400858
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发表时间：
2007-01-01
期刊：
影响因子：
7.7
通讯作者：
Scheuring, Simon
中科院分区：
文献类型：
--
作者：
Buzhynskyy, Nikolay;Hite, Richard K.;Scheuring, Simon
由连接子形成的间隙连接和由晶状体特异性水通道蛋白0（AQP0）形成的薄连接介导透镜透明度所必需的纤维细胞的紧密堆积。缝隙连接在细胞间传导水、离子和代谢物，而连接性AQP0似乎参与细胞粘附。高分辨率的原子力显微镜（AFM）显示，这些蛋白质的超分子组织在天然透镜核心膜，其中水通道蛋白0形成的二维阵列，被密集包装的间隙连接通道包围。这些连接微区同时提供纤维细胞之间的粘附和通信。AFM拓扑图还表明，在交界微区的水通道蛋白0的细胞外环采用的构象，非常类似的结构的交界水通道蛋白0，其中的水孔被认为是关闭的。最后，延时AFM成像提供了对AQP0阵列形成的见解。这是第一个多组分真核细胞膜的高分辨率视图，显示了膜蛋白如何自组装成功能性微区。
Gap junctions formed by connexons and thin junctions formed by lens-specific aquaporin 0 (AQP0) mediate the tight packing of fibre cells necessary for lens transparency. Gap junctions conduct water, ions and metabolites between cells, whereas junctional AQP0 seems to be involved in cell adhesion. High-resolution atomic force microscopy (AFM) showed the supramolecular organization of these proteins in native lens core membranes, in which AQP0 forms two-dimensional arrays that are surrounded by densely packed gap junction channels. These junctional microdomains simultaneously provide adhesion and communication between fibre cells. The AFM topographs also showed that the extracellular loops of AQP0 in junctional microdomains adopt a conformation that closely resembles the structure of junctional AQP0, in which the water pore is thought to be closed. Finally, time-lapse AFM imaging provided insights into AQP0 array formation. This first high-resolution view of a multicomponent eukaryotic membrane shows how membrane proteins self-assemble into functional microdomains.