Figure 7. The 20R2 of APCL is required to inhibit β-catenin transcriptional activity (A) and to down-regulate β-catenin (B) but is not necessary to recruit Axin (C) in the presence of SAMP repeats.

A, SW480 cells were transiently transfected on day 1 with reporter plasmids and 100(flag) or the indicated APCL constructs. yAPCL-2μ contains the mutations shown in figure 4A. TOP/FOP reporter assays were performed on day 3 to measure β-catenin transcriptional activity. The data are presented as the mean ± standard deviation of three independent values from a representative experiment. * p<0.004 compared with flag, Student's t-test. ns, not significant. In a parallel experiment, cells were transiently transfected with 1 μg of the indicated plasmids on day 1. Cell extracts were prepared on day 3 and were subjected to western blotting using the indicated antibodies. The molecular weights are presented in kDa. B, SW480 cells were transiently transfected with control vector (flag) or the indicated APCL constructs, fixed on day 3 and stained with an anti-β-catenin antibody. Bar, 10 μM. C, DLD1 cells were transiently transfected on day 1 with the indicated APCL constructs or N-terminal flag-tagged Axin, either individually or in combination. The cells were fixed on day 3 and were stained with an anti-flag antibody. Where applicable, the percentages indicate the proportion of different localisation patterns in the transfected cells. The imaging parameters were identical for each type of tag. Bar, 10 μM.