Preferred apical distribution of glycosyl-phosphatidylinositol (GPI) anchored proteins: a highly conserved feature of the polarized epithelial cell phenotype.
Preferred apical distribution of glycosyl-phosphatidylinositol (GPI) anchored proteins: a highly conserved feature of the polarized epithelial cell phenotype.
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DOI：
10.1007/bf01872889
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发表时间：
1990-03
期刊：
影响因子：
--
通讯作者：
Rodriguez-Boulan E
中科院分区：
文献类型：
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作者：
Lisanti MP;Le Bivic A;Saltiel AR;Rodriguez-Boulan E
我们使用敏感的生物素极性测定来调查来自不同物种（狗、猪、人）和组织（即肾（MDCK I、MDCK II、LLC-PK1）和肠（Caco-2 和 SK-CO15））的五种模型上皮细胞系中糖基磷脂酰肌醇（GPI）锚定蛋白的表面分布。对聚碳酸酯过滤器上生长的汇合单层的顶端或基底外侧表面进行生物素化后，在磷脂酰肌醇特异性磷脂酶 C 存在的情况下，GPI 锚定蛋白通过从 Triton X-114 富含去污剂相到缺乏去污剂相的转变来识别。所有检测到的 GPI 锚定蛋白（每种细胞类型 3-9 个，至少 13 种不同的蛋白）均被发现是顶端极化的；没有观察到 GPI 锚定蛋白优先定位于基底表面。 GPI 锚定蛋白之一被鉴定为癌胚抗原 (CEA)。 MDCK II-RCAr 是一种糖蛋白和糖脂半乳糖基化存在多效性缺陷（可能影响 GPI 锚）的突变细胞系，对 MDCK II-RCAr 的调查也揭示了所有 GPI 锚定蛋白的顶端极化。相比之下，MDCK II-ConA'（一种具有未知糖基化缺陷的突变细胞系）的分析揭示了五种 GPI 锚定蛋白，其中两种似乎相对未极化。我们的结果表明，GPI 锚定蛋白的极化顶端分布在物种和组织类型之间高度保守，并且可能取决于糖基化。
We use a sensitive biotin polarity assay to survey the surface distribution of glycosyl-phosphatidylinositol (GPI) anchored proteins in five model epithelial cell lines derived from different species (dog, pig, man) and tissues, i.e., kidney (MDCK I, MDCK II, LLC-PK1) and intestine (Caco-2 and SK-CO15). After biotinylation of apical or basolateral surfaces of confluent monolayers grown on polycarbonate filters, GPI-anchored proteins are identified by their shift from a Triton X-114 detergent-rich phase to a detergent-poor phase in the presence of phosphatidylinositol-specific phospholipase C. All GPI-anchored proteins detected (3–9 per cell type, at least 13 different proteins) are found to be apically polarized; no GPI-anchored protein is observed preferentially localized to the basal surface. One of the GPI-anchored proteins is identified as carcinoembryonic antigen (CEA). Survey of MDCK II-RCAr, a mutant cell line with a pleiotropic defect in galactosylation of glycoproteins and glycolipids (that presumably affects GPI anchors) also reveals an apical polarization of all GPI-anchored proteins. In contrast, analysis of MDCK II-ConA′ (a mutant cell line with an unknown defect in glycosylation) revealed five GPI-anchored proteins, two of which appeared relatively unpolarized. Our results indicate that the polarized apical distribution of GPI-anchored proteins is highly conserved across species and tissue-type and may depend on glycosylation.