Cingulin: characterization and localization.
Cingulin: characterization and localization.
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发表时间：
1989-05
影响因子：
4
通讯作者：
Sandra Citi;H. Sabanay;J. Kendrick-Jones;Benjamin Geiger
中科院分区：
文献类型：
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作者：
Sandra Citi;H. Sabanay;J. Kendrick-Jones;Benjamin Geiger
Cingulin是一种与鸡小肠上皮紧密连接相关的蛋白质成分，已通过一种新的方法纯化至均一并进行了表征。纯化的扣带蛋白是一种热稳定的细长二聚体，由两个Mr为108，000的多肽（扣带蛋白-108）组成，斯托克斯半径约为15 nm，分子长度为130 nm +/- 32 nm。用单克隆抗体测定了扣带蛋白在多种禽类组织和培养细胞中的组织分布和亚细胞定位。半薄冰冻切片的间接免疫荧光分析表明，cingulin定位于各种极化上皮细胞和内皮细胞的连接复合物中，而它基本上不存在于间充质细胞和肌源性细胞中。在透化和固定培养的鸡胚肾细胞中，抗体仅染色上皮细胞之间的接触区域。用抗扣带蛋白和抗粘着斑蛋白抗体对这些细胞进行双重免疫荧光标记表明，扣带蛋白位于与粘附连接相关的富含粘着斑蛋白的细胞骨架带附近，但在焦点接触和应力纤维中不存在。在培养的肾细胞中，肌动蛋白被检测到主要在应力纤维和在周边交界区，在那里它表现出类似于扣带蛋白的分布，表明肌动蛋白丝可能是在紧密连接水平的膜下细胞骨架的一部分。间接免疫电子显微镜标记的冷冻切片的鸡肠道表明，cingulin是本地化沿着内面表面的紧密连接（zonula occludens），显然是排除了更多的基础zonula adhaerens，从桥粒。
Cingulin, a protein component associated with the tight junctions of chicken intestinal epithelium, has been purified to homogeneity by a new procedure and characterized. Purified cingulin is a heat-stable elongated dimer, composed of two polypeptides of Mr 108,000 (cingulin-108), with a Stokes' radius of approximately 15 nm, and a molecular length of 130 nm +/- 32 nm. Monoclonal antibodies were used to determine the tissue distribution and subcellular localization of cingulin in a variety of avian tissues and cultured cells. Indirect immunofluorescence analysis of semi-thin frozen sections demonstrated that cingulin is localized in the junctional complex of various polarized epithelia and in the endothelium, whereas it is essentially absent from mesenchymal and myogenic cells. In permeabilized and fixed cultured chick embryo kidney cells, the antibodies stained solely the regions of contacts between the epithelial cells. Double immunofluorescent labeling of these cells with anti-cingulin and anti-vinculin antibodies showed that cingulin is localized close to the vinculin-rich cytoskeletal belt associated with adherens junctions, but is absent from focal contacts and stress fibers. In cultured kidney cells, actin was detected mainly in stress fibers and in the peripheral junctional regions, where it showed a distribution similar to that of cingulin, suggesting that actin filaments may be part of the submembrane cytoskeleton at the level of the tight junction. Indirect immunoelectron microscopic labeling of ultrathin frozen sections of chicken intestine showed that cingulin is localized along the endofacial surfaces of the tight junction (zonula occludens), and is apparently excluded from the more basal zonula adhaerens, and from the desmosomes.