Fig. 6. IGFBP-5 and IGFBP-3 inhibit IGF-I and IGF-II-mediated FKHRL1 phosphorylation in primary mammary epithelial cells. Cells were serum-starved overnight before treatment with (A) 1 nM IGF-I±10 nM IGFBP-5; and (B) 5 nM IGF-II±10 nM IGFBP-5 or -3. Control cells (CON) were maintained in serum-free medium without treatment. Cell lysates were separated by 8% SDS-PAGE and analyzed by immunoblotting with an antibody that recognises both the phosphorylated (^*) and non-phosphorylated form of FKHRL1. Immunoblotting for total PKB was used to indicate equal protein levels. Results are representative of three experiments.