Caveolin-1 was the first protein identified that colocalizes with the ≈10-nm filaments found on the inside surface of caveolae membranes. We have used a combination of electron microscopy (EM), circular dichroism, and analytical ultracentrifugation to determine the structure of the oligomers that form when the first 101 aa of caveolin-1 (Cav1-101) are allowed to associate. We determined that amino acids 79-96 in this caveolin-1 fragment are arranged in an α-helix. Cav1-101 oligomers are ≈11 nm in diameter and contain seven molecules of Cav1-101. These subunits, in turn, are able to assemble into 50 nm long x 11 nm diameter filaments that closely match the morphology of the filaments in the caveolae filamentous coat. We propose that the heptameric subunit forms in part through lateral interactions between the α-helices of the seven Cav1-101 units. Caveolin-1, therefore, appears to be the structural molecule of the caveolae filamentous coat.
|Original language||English (US)|
|Number of pages||6|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|Publication status||Published - Aug 20 2002|
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