Breuza Lionel, Corby Séverine, Arsanto Jean-Pierre, Delgrossi Marie-Hélène, Scheiffele Peter, Le Bivic André
Laboratoire de Neurogenèse et Morphogenèse au cours du Développement et chez l'Adulte (NMDA), UMR 6156, Institut de Biologie du Développement de Marseille, Faculté des Sciences de Luminy, case 907, Université de la Méditerranée, Marseille, France.
J Cell Sci. 2002 Dec 1;115(Pt 23):4457-67. doi: 10.1242/jcs.00130.
In this work, we showed that in Caco-2 cells, a polarized cell line derived from human colon cancer that does not express caveolin 1 (Cav-1), there was no detectable expression of caveolin 2 (Cav-2). When Cav-2 was reintroduced in these cells, it accumulated in the Golgi complex. A chimera, in which the scaffolding domain of Cav-1 was replaced by the one from Cav-2, induced a prominent Golgi staining of Cav-1, strongly indicating that this domain was responsible for the accumulation of Cav-2 in the Golgi complex. Cav-2 was able to interact with Cav-1 in the Golgi complex but this interaction was not sufficient to export it from this compartment. Several chimeras between Cav-1 and 2 were used to show that surface expression of caveolin was necessary but not sufficient to promote caveolae formation. Interestingly, levels of incorporation of the chimeras into Triton insoluble rafts correlated with their ability to trigger caveolae formation raising the possibility that a critical concentration of caveolins to discrete domains of the plasma membrane might be necessary for caveolae formation.
在本研究中，我们发现，在Caco-2细胞（一种源自人结肠癌的极化细胞系，不表达小窝蛋白1（Cav-1））中，未检测到小窝蛋白2（Cav-2）的表达。当在这些细胞中重新引入Cav-2时，它会积聚在高尔基体复合物中。一种嵌合体，其中Cav-1的支架结构域被Cav-2的支架结构域取代，诱导了Cav-1在高尔基体上的显著染色，强烈表明该结构域负责Cav-2在高尔基体复合物中的积聚。Cav-2能够在高尔基体复合物中与Cav-1相互作用，但这种相互作用不足以将其从该区室中输出。使用了几种Cav-1和2之间的嵌合体来表明小窝蛋白的表面表达对于促进小窝形成是必要的，但不是充分的。有趣的是，嵌合体掺入Triton不溶性筏的水平与其触发小窝形成的能力相关，这增加了一种可能性，即小窝形成可能需要小窝蛋白在质膜离散区域达到临界浓度。
