Figure 6. FRET measurement of altered IR structure or environment associated with insulin resistance in CHO cells.

(A) Schematic representation of the IR-CFP-YFP probe and alterations in (B) total IR tyrosine phosphorylation or (C) energy transfer in that probe under acute or chronic insulin stimulation and after re-stimulation following insulin removal. The probe was transiently expressed in CHO cells. Symbols are as described in figure 1. Gray bars (Fig. 6B) represent IR phosphorylation levels normalized to IR expression levels determined by IR-CFP-YFP fluorescence.