Ultrastructure of the zonula adherens revealed by rapid-freeze deep-etching
Ultrastructure of the zonula adherens revealed by rapid-freeze deep-etching
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DOI：
10.1006/jsbi.2000.4244
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发表时间：
2000-12-01
影响因子：
3
通讯作者：
Miyaguchi, K
中科院分区：
文献类型：
--
作者：
Miyaguchi, K
用冷冻电镜方法观察了成年鸡视网膜色素上皮的粘附小带（ZA）。交叉断裂ZA的深蚀刻显示细胞间隙中的小球。这些球状体显然对应于在薄片中看到的电子致密结构。斜向断裂ZA的深蚀刻进一步揭示了从细胞外表面延伸到细胞间隙的杆状结构。这些杆状体（平均约9 nm厚，约20 nm长）直，有时分为两段或三段。杆状体通常相对于质膜倾斜约60度，并且它们通常在其远端连接到细胞间小球。当杆与分离的钙粘蛋白相比，以前报道的，这表明，杆和小球的组合可能代表钙粘蛋白的细胞外部分。在ZA质膜的P面上观察到膜颗粒，它们的分布密度约为杆的7倍。冷冻蚀刻还揭示了ZA细胞质表面上的特征性颗粒复合物，其可能代表将钙粘蛋白连接到肌动蛋白束的细胞溶质蛋白，（C）2000学术出版社。
The zonula adherens (ZA) in adult chicken retinal pigment epithelium was examined with cryo-electron microscopic methods. Deep-etching of the cross-fractured ZA showed globules in the intercellular space. These globules apparently correspond to the electron-dense structure seen in thin sections. Deep-etching of obliquely fractured ZA further revealed rod-like structures extending from the extracellular surface into the intercellular space. These rods (mean similar to9 nm thick, similar to 20 nm long) were straight and sometimes divided into two or three segments. The rods typically canted at similar to 60 degrees with respect to the plasma membrane, and they were often connected to the intercellular globules at their distal ends. When the rods are compared with the isolated cadherins reported previously, it is suggested that a combination of a rod and a globule may represent an extracellular part of cadherin. Membrane particles were observed on the P-face of the ZA plasma membrane, and their distribution density was approximately seven times that of the rods. The freeze-etching also revealed a characteristic particle complex on the ZA cytoplasmic surface, which may represent the cytosolic proteins linking cadherins to actin bundles, (C) 2000 Academic Press.