FIGURE 3:

The essential regions in APC and Axin each make important but partially overlapping contributions to a fully functional destruction complex. (A) Schematic representation of APC2 and Axin. Essential regions are indicated in red. (B) The essential regions in APC2 and Axin work cooperatively to ensure efficient reduction of βcat levels. Coexpression of indicated APC2 and Axin mutants in SW480 cells, followed by quantification of βcat fluorescence intensity. Top, mutants are sorted into groups that are defined by how many essential regions remain present. Middle, βcat average intensity. Bottom, table describing which essential regions remain present. (C) For βcat reduction, up to two essential regions are largely dispensable. Columns represent the averages of the groups that were defined in B. Student’s t test was used. (D) Immunoblot analysis of expression levels of a subset of the APC2 mutants used; others are given in other figures or in Roberts et al. (2011, 2012) or Pronobis et al. (2015). (E) Expression levels of indicated Axin mutant.