Table 1.

Localization of the IR in caveolae microdomains is essential for the metabolic signaling of insulin

Function	Evidence
Direct binding of IR and Cav1	IR has caveolin binding domain (6)
	Coimmunoprecipitation of IR and Cav1 (18)
Colocalization of IR and Cav1	IR and Cav1 are recovered in light-density fractions in a sucrose density flotation assay (12, 39)
	Fluorescence microscopy (5)
	Electron microscopy (40, 41)
Insulin signaling via caveolae	Stimulation of Cav1 tyrosine phosphorylation by insulin (9, 42)
	Cav1-deficient mice exhibit insulin resistance due to accelerated degradation of IR in adipose tissue (7, 43)
	Cholesterol depletion disrupts caveolae and metabolic signaling of insulin (44, 45)
	Accumulated GM3 eliminates IR from DRM and inhibits IR–IRS-1 signaling (12)