Figure 9.
Competition.A, effects of increasing concentrations of competitor (unlabeled β-catenin phosphor-degron peptide) on the ubiquitination of radioactive β-catenin. The molar ratio of the competitor versus the radioactive substrate is indicated. B–D, increasing concentrations of competitor were added to preformed β-catenin–Ub1 (pane B), β-catenin–Ub2 (pane C), or β-catenin–Ub4 (pane D), followed by chase with Cdc34b–Ub. The reactions were carried out using the protocol described in the Experimental procedures section. Graphs integrate data in duplicates with indicated error bars. Ub, ubiquitin.