Dependence of level of β-catenin on β-catenin
degradation. Thick line with open circle: total β-catenin level. Thin line with open circle: unphosphorylated β-catenin level. Kinases such as PKA inhibit β-catenin degradation. Higher PKA activity corresponds to lower degradation rate constant kβdeg, giving higher β-catenin level. Other kinetic parameters of added reaction steps, kG/kG' and kβ/kβ', were set at 1/1 and 1/1 min-1, respectively. Thin line with solid circle: TCF/β-catenin level. Dashed line: the results when kβ = k13. Unphosphorylated β-catenin level is shown. The result for the total β-catenin level is similar, not shown here (see text for detailed description).