Fig. 4

PLK1 promotes RhoA activation by association with RhoGDI1. a HeLa cells were transfected with mock or HA-PLK1. A pull-down assay was performed using Rhotekin-agarose beads to detect active RhoA and PAK1-agarose beads to detect active Rac1/Cdc42 as described in Materials and Methods b HeLa cells were transfected with control siRNA or two PLK1 siRNAs. Cell lysates were subjected to pull-down assay. c Cells were treated with 200 nM of BI 6727 for 4 h. Cell lysates were subjected to pull-down assay. d HeLa cells were co-transfected with HA-PLK1 along with GFP or GFP-RhoGDI1 aa 90-111. Cell lysates were subjected to pull-down assay (left panel). Relative intensity graphs show mean ± S.D. (n = 3) for GTP-RhoA/total RhoA or GTP-Rac1/total Rac1 (right panel). **P < 0.01