Caveolin-2 localizes to the Golgi complex but redistributes to plasma membrane, caveolae, and rafts when co-expressed with caveolin-1
Caveolin-2 localizes to the Golgi complex but redistributes to plasma membrane, caveolae, and rafts when co-expressed with caveolin-1
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DOI：
10.1074/jbc.274.36.25708
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发表时间：
1999-09-03
影响因子：
4.8
通讯作者：
Rodriguez-Boulan, E
中科院分区：
文献类型：
--
作者：
Mora, R;Bonilha, VL;Rodriguez-Boulan, E
我们的特点比较小窝蛋白-1和-2的亚细胞分布，它们之间的相互作用和它们在极化上皮细胞小窝形成中的作用。在Fischer大鼠甲状腺（FRT）细胞，表达低水平的小窝蛋白-2，没有小窝蛋白-1，小窝蛋白-2专门定位到高尔基复合体，但部分重新分配到质膜后，共表达小窝蛋白-1转染或腺病毒介导的转导。在组成型表达小窝蛋白-1和-2的Madin-Darby犬肾（MDCK）细胞中，小窝蛋白-2定位于凝胶复合物和质膜，在那里它与小窝蛋白-1共同分布在平坦的斑块和小窝中。在FRT细胞中，内源性或过表达的小窝蛋白-2并不与低密度Triton不溶性膜，漂浮在蔗糖密度梯度，但被招募到这些膜共同表达时，与小窝蛋白-1。在MDCK细胞中，小窝蛋白-1和小窝蛋白-2都与低密度的Triton不溶性膜相关。在FRT细胞中，转染小窝蛋白-1促进了质膜小窝的组装，其优先（超过99%）定位于基底外侧表面，如MDCK细胞的组成性小窝。与此相反，从其细胞内的分布，内源性或过表达的小窝蛋白-2并没有促进小窝的组装，相反，它似乎促进组装的细胞内囊泡在高尔基体周围区域。这里报道的数据表明，小窝蛋白-1和-2有不同的和互补的亚细胞定位和极化上皮细胞中的功能特性，并建议这两种蛋白质合作进行特定的高尔基复合体和细胞表面之间的未知任务。
We have characterized comparatively the subcellular distributions of caveolins-1 and -2, their interactions and their roles in caveolar formation in polarized epithelial cells. In Fischer rat thyroid (FRT) cells, which express low levels of caveolin-2 and no caveolin-1, caveolin-2 localizes exclusively to the Golgi complex but is partially redistributed to the plasma membrane upon co-expression of caveolin-1 by transfection or by adenovirus-mediated transduction. In Madin-Darby canine kidney (MDCK) cells, which constitutively express both caveolin-1 and -2, caveolin-2 localized to both the Gels complex and to the plasma membrane, where it co-distributed with caveolin-1 in flat patches and in caveolae. In FRT cells, endogenous or overexpressed caveolin-2 did not associate with low density Triton insoluble membranes that floated in sucrose density gradients but was recruited to these membranes when co-expressed together with caveolin-1. In MDCK cells, both caveolin-1 and caveolin-2 associated with low density Triton-insoluble membranes. In FRT cells, transfection of caveolin-1 promoted the assembly of plasma membrane caveolae that localized preferentially (over 99%) to the basolateral surface, like constitutive caveolae of MDCK cells. In contrast, as expected from its intracellular distribution, endogenous or overexpressed caveolin-2 did not promote the assembly of caveolae; rather, it appeared to promote the assembly of intracellular vesicles in the peri-Golgi area. The data reported here demonstrate that caveolin-1 and -2 have different and complementary subcellular localizations and functional properties in polarized epithelial cells and suggest that the two proteins co-operate to carry out specific as yet unknown tasks between the Golgi complex and the cell surface.