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

FEBS Letters

Lublin, Douglas M.¹  Monier, Solange¹  Hastings, W.Randall²  Dietzen, Dennis J.²  Kurzchalia, Teymuras V.¹ 

[1] Department of Cell Biology, Max-Delbrück Centre for Molecular Medicine, Robert-Rössle-Str.10, 13 122 Berlin-Buch, Germany;Department of Pathology, Washington University School of Medicine, St. Louis, MO 63110, USA

关键词: VIP21-caveolin;    Caveolae;    Oligomerization;    Cholesterol;    Fatty acylation;   

DOI  :  10.1016/0014-5793(96)00519-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown