Figure 3.

IQ motifs are required to localize IQGAP1 to the basolateral membrane.

1. Scheme showing the IQGAP1 constructs used, each of which was designed as a GFP fusion protein.
2. MDCK cells stably expressing each construct were grown in 3D cultures to form cysts, which were fixed and stained for actin (red). The basolateral (arrows) and apical (arrowheads) localization of the mutant constructs is indicated.
3. MDCK clones for each construct transfected together with the IQGAP1 siRNA were grown in 3D cultures, and the cysts were fixed and stained for Pdxl (red) and actin (blue). The basolateral (arrows) and apical (arrowheads) localization of the mutant constructs is indicated.
4. The ability of each construct to allow single lumen cysts to form in the absence of endogenous IQGAP1 was quantified and represented as a percentage of the total number of cells (n = 3, >50 cysts per experiment; values represent the mean ± s.d.).
5. The ability of each clone to allow single lumen cysts to form was quantified and represented as a percentage of the total number of cells (n = 3, >50 cysts per experiment; values represent the mean ± s.d.).
6. The angle formed between the mitotic spindle and the apicobasal axis was measured and the mean angles were: IQGAP1 GFP = 71.56 ± 2.91°; IQGAP1:N = 48.45 ± 3.67°; IQGAP1:C = 48.01 ± 3.41° (n = 3, >35 cells per experiment; values represent the mean ± s.e.m.).

Data information: Error bars represent the s.e.m. or s.d.: *P < 0.05; **P < 0.01. Scale bars, 5 μm.