FIGURE 7.

Overexpression of wild-type but not mutant forms of ARL6/BBS3 alters responsiveness to Wnt3a ligand. In hTERT-RPE TOPflash reporter cells, overexpression of ARL6/BBS3 leads to increased β-catenin activity in response to Wnt3a ligand but no global dysregulation of β-catenin signaling. In contrast, overexpression of ARL6(T31R) and ARL6(Q73L) has no marked effect on β-catenin transcriptional activity. Cells are consistently 70–80% confluent and ciliated as observed by staining with an anti-acetylated tubulin antibody (data not shown). Error bars represent standard deviation; only the BBS3 wild type (WT) samples are statistically different from the empty vector control (p < 0.05).