Supplementary Figure 6: The IQGAP1-derived peptides inhibit Akt activation.
(a) Sequences of cell permeable IG1DPs. (b) Empty vector (Mock) and HA-tagged IQ domain alone was stably expressed in Hs578T cells. Cell lysates were analyzed by IB with the indicated antibodies. (c) Hs578T cells were transfected with empty vector or p110α subunit of PI3K for 24 h. Then, cells were treated with the indicated 20 μM of IG1DPs for 24 h. Cell lysates were analyzed by IB (top) and pS473Akt immunoblots were quantified and the graph is shown as mean ± s.d. of three independent experiments (bottom). (d) Cells containing PIK3CA mutations were treated with 30 μM IG1DPs for 48 h. Cell lysates were analyzed by IB with the indicated antibodies. (e) pS473Akt blots of Fig. 7d were quantified and the graph is shown as mean ± s.d. of n = 3 independent experiments. Paired Student t-tests were used for statistical analysis (∗, P < 0.05; ∗∗, P < 0.01; n.s., not significant). (f) Hs578T cells were transfected with a constitutively active Rac1 or Cdc42 for 24. Then, cells were treated with 20 μM of the indicated IG1DPs for 48 h. Cell viability and protein expression were measured and the graph is shown as mean ± s.d. of n = 3 independent experiments. Paired Student t-tests were used for statistical analysis (∗, P < 0.05; ∗∗, P < 0.01; n.s., not significant). Source data for c,e,f can be found in Supplementary Table 1. Unprocessed original scans of blots are shown in Supplementary Fig. 7.
