The scaffolding domain of caveolin 2 is responsible for its Golgi localization in Caco-2 cells.
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.
Breuza
Lionel
L
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.
Corby
Séverine
S
Arsanto
Jean-Pierre
JP
Delgrossi
Marie-Hélène
MH
Scheiffele
Peter
P
Le Bivic
André
A
D018938:Caco-2 Cells; D021941:Caveolae / Q000378:metabolism / Q000648:ultrastructure; D051242:Caveolin 1; D051243:Caveolin 2; D022461:Caveolins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D006801:Humans; D021962:Membrane Microdomains / Q000378:metabolism; D016253:Microscopy, Immunoelectron; D017434:Protein Structure, Tertiary
C495540:CAV1 protein, human; D051242:Caveolin 1; D051243:Caveolin 2; D022461:Caveolins