POLARIZED APICAL DISTRIBUTION OF GLYCOSYL-PHOSPHATIDYLINOSITOL-ANCHORED PROTEINS IN A RENAL EPITHELIAL-CELL LINE
POLARIZED APICAL DISTRIBUTION OF GLYCOSYL-PHOSPHATIDYLINOSITOL-ANCHORED PROTEINS IN A RENAL EPITHELIAL-CELL LINE
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DOI：
10.1073/pnas.85.24.9557
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发表时间：
1988-12-01
影响因子：
11.1
通讯作者：
RODRIGUEZBOULAN, E
中科院分区：
文献类型：
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作者：
LISANTI, MP;SARGIACOMO, M;RODRIGUEZBOULAN, E
极化上皮细胞单层包含两个不同的质膜结构域，由紧密连接的存在所描绘。一个面向外部环境的顶端表面和一个具有细胞接触和细胞底物附着功能的底外侧表面。理解上皮细胞极性的核心是如何产生这种细胞表面特化的问题。最近出现了另一类膜糖蛋白，可能对这种极性的生物发生机制产生新的见解。这类成员含有一个大的细胞外蛋白结构域，通过糖基磷脂酰肌醇连接到膜上。利用极化肾上皮细胞系（Madin.sbd.）Darby犬肾)，我们通过磷脂酰肌醇特异性磷脂酶c的释放鉴定了内源性糖基磷脂酰肌醇锚定蛋白。鉴定了6种糖基磷脂酰肌醇锚定蛋白，分别为110、85、70、55、38和35 kDa，似乎局限于根尖表面。我们的数据与糖基磷脂酰肌醇膜锚点可能包含“靶向”到根尖表面的必要信息的观点是一致的。
Polarized epithelial cell monolayers contain two distinct plasma membrane domains as delineated by the presence of tight junctions.sbd.i.e., an apical surface that faces the external environment and a basolateral surface that functions both in cell.sbd.cell contact and cell.sbd.substrate attachment. Central to the understanding of epithelial cell polarity is the question of how such cell-surface specializations are generated. A different class of membrane glycoproteins has recently emerged that may yield new insight into the mechanism underlying the biogenesis of this polarity. Members of this class contain a large extracellular protein domain linked to the membrane via glycosyl-phosphatidylinositol. Using a polarized renal epithelial cell line (Madin.sbd.Darby canine kidney), we identified endogenous glycosyl-phosphatidylinositol-anchored proteins through release by a phosphatidylinositol-specific phospholipase C. Six glycosyl-phosphatidylinositol-anchored proteins of 110, 85, 70, 55, 38, and 35 kDa were identified and appeared to be restricted to the apical surface. Our data are consistent with the notion that the glycosyl-phosphatidylinositol membrane anchor may contain the necessary information for "targeting" to the apical surface.