FIG. 8.
Effect of pp125FAK regulatory loop peptide on PIG-induced tyrosine phosphorylation of pp125FAK and associated IRS-1. Isolated rat adipocytes were electroporated with regulatory loop peptide Y576/577 or control peptide F576/577 (50 μg/ml) and then incubated in the absence or presence of increasing concentrations of PIG 41. pp125FAK was immunoprecipitated (IP) with anti-pp125FAK antibody from defatted cell lysates and then either immunoblotted (IB) with antiphosphotyrosine or anti-pp125FAK antibodies or reimmunoprecipitated with anti-IRS-1 antibody as indicated. Immunoprecipitated IRS-1 was immunoblotted with antiphosphotyrosine or anti-IRS-1 antibodies. Phosphorimages of a typical experiment are shown (left section) repeated three times with similar results. Quantitative evaluation is given as fold stimulation (mean ± standard deviation [right section]). Basal tyrosine phosphorylation is set at 1 in each case.