PURPOSE: Caveolae are cholesterol and sphingolipids rich subcellular domains on 
plasma membrane. Caveolae contain a variety of signaling proteins which provide 
platforms for signaling transduction. In addition to enriched with cholesterol 
and sphingolipids, caveolae also contain a variety of fatty acids. It has been 
well-established that acylation of protein plays a pivotal role in subcellular 
location including targeting to caveolae. However, the fatty acid compositions 
of caveolae and the type of acylation of caveolar proteins remain largely 
unknown. In this study, we investigated the fatty acids in caveolae and 
caveolin-1 bound fatty acids.
METHODS: Caveolae were isolated from Chinese hamster ovary (CHO) cells. The 
caveolar fatty acids were extracted with Folch reagent, methyl esterificated 
with BF3, and analyzed by gas chromatograph-mass spectrometer (GC/MS). The 
caveolin-1 bound fatty acids were immunoprecipitated by anti-caveolin-1 IgG and 
analyzed with GC/MS.
RESULTS: In contrast to the whole CHO cell lysate which contained a variety of 
fatty acids, caveolae mainly contained three types of fatty acids, 0.48 µg 
palmitic acid, 0.61 µg stearic acid and 0.83 µg oleic acid/caveolae 
preparation/5 × 10(7) cells. Unexpectedly, GC/MS analysis indicated that 
caveolin-1 was not acylated by myristic acid; instead, it was acylated by 
palmitic acid and stearic acid.
CONCLUSION: Caveolae contained a special set of fatty acids, highly enriched 
with saturated fatty acids, and caveolin-1 was acylated by palmitic acid and 
stearic acid. The unique fatty acid compositions of caveolae and acylation of 
caveolin-1 may be important for caveolae formation and for maintaining the 
function of caveolae.