Identification of Caveolin-1 as a Fatty Acid Binding Protein

• Published in: Biochemical and biophysical research communications Vol. 255; no. 1; pp. 34 - 39
• Main Authors: Trigatti, Bernardo L., Anderson, Richard G.W., Gerber, Gerhard E.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 05.02.1999
• Subjects: Adipocytes; Animals; Binding Sites; Biological Transport; Caveolin 1; Caveolins; Cell Line; Cell Membrane - chemistry; Cell Membrane - metabolism; Fatty Acids - chemistry; Fatty Acids - metabolism; Membrane Proteins - chemistry; Membrane Proteins - metabolism; Mice; Protein Binding
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.1998.0123

In an attempt to identify high affinity, fatty acid binding proteins present in 3T3-L1 adipocytes plasma membranes, we labeled proteins in purified plasma membranes with the photoreactive fatty acid analogue, 11-m-diazirinophenoxy[11-3H]undecanoate. A single membrane protein of 22 kDa was covalently labeled after photolysis. This protein fractionated with caveolin-1 containing caveolae and was immunoprecipitated by an anti-caveolin-1 monoclonal antibody. Furthermore, 2D-PAGE analysis revealed that both the α and β isoforms of caveolin-1 could be labeled by the photoreactive fatty acid upon photolysis, indicating that both bind fatty acids. The saturable binding of the photoreactive fatty acid suggests caveolin-1 has a lipid binding site that may either operate during intracellular lipid traffic or regulate caveolin-1 function.