Fig. 1.

IQGAP1 regulates cytokinesis. (A) Schematics of V5-IQGAP1 or HA-IQGAP1 stably expressed in HeLa or in NIH3T3 cells, respectively. F, IQGAP1-F; N, IQGAP1-N; C, IQGAP1-C; IR-WW, IQGAP1-IR-WW. (B) Immunoblot demonstrating similar stable expression levels of IQGAP1 constructs in HeLa cells. Equal amounts of the cell lysate from each cell line was loaded on 10-20% gradient gels and blotted with V5 antibody. One-tenth of the lysate loaded for the constructs was resolved on the same gel and blotted with antibody against IQGAP1 to detect the endogenous protein as a control. (C) Quantification of stable HeLa cells containing three or more nuclei was scored for n=50 cells each from three independent experiments and shown as the means ± s.e.m. and average significance value of P<0.005. Cells expressing the vector (V) were included as a negative control. (D) Differential effects of IQGAP1 on cytokinesis. Cells were seeded at low density, grown for 6 days, and double stained with V5 antibodies to visualize the IQGAP1 constructs and DAPI for nuclei. Scale bar: 10 μm.