A dominant-negative Cav-1 mutant has been described which functionally inactivates caveolin-1 upon binding [21] . The mutant carries a F92A/V94A double mutation in the scaffolding domain (SD) of canine caveolin-1. Expression in rat adipose and COS-1 cells has been shown to interfere with the interaction of Cav-1 with the insulin receptor and impairs receptor function.