Oligomerization of VIP21-caveolin in vitro is stabilized by long chain fatty acylation or cholesterol

Item Type:	Article
Title:	Oligomerization of VIP21-caveolin in vitro is stabilized by long chain fatty acylation or cholesterol
Creators Name:	Monier, S. and Dietzen, D.J. and Hastings, W.R. and Lublin, D.M. and Kurzchalia, T.V.
Abstract:	VIP21-caveolin is one of the components which form the cytoplasmic surface of caveolae. In vivo, this integral membrane protein is found in homo-oligomers with molecular masses of approximately 200, 400 and 600 kDa. These oligomers are also formed by the addition of cytosol to the in vitro synthesized and membrane inserted VIP21-caveolin. Here we show that long chain fatty acyl coenzyme A esters can completely substitute for cytosol in inducing 200 kDa and 400 kDa complexes, whereas 25-hydroxy-cholesterol can produce the 200 kDa oligomer. In order to understand whether acylation of VIP21-caveolin itself is a prerequisite for oligomerization, we studied a mutant protein lacking all three cysteines. When analyzed by velocity sucrose gradient centrifugation in the presence of the non-ionic detergent octylglucoside, both palmitoylated and non-palmitoylated VIP21-caveolin formed oligomers that were indistinguishable. However, only the oligomers of the non-palmitoylated protein are disrupted when analyzed by SDS-PAGE without boiling. These data suggest that the protein domains of VIP21-caveolin are the primary determinants of oligomerization, but that palmitoylation of cysteine residues can increase the stability of the oligomers.
Keywords:	VIP21-Caveolin, Caveolae, Oligomerization, Cholesterol, Fatty Acylation, Animals, Dogs
Source:	FEBS Letters
ISSN:	0014-5793
Publisher:	Elsevier
Volume:	388
Number:	2-3
Page Range:	143-149
Date:	17 June 1996
Official Publication:	https://doi.org/10.1016/0014-5793(96)00519-4
PubMed:	View item in PubMed

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