Fig. 2. Knockdown of ARHGEF6 using a siRNA transfection approach. (A) Western blot illustrating the level of expression of HA-ARHGEF6 in non-transfected fibroblasts, in fibroblasts transfected with HA-ARHGEF6, and fibroblasts co-transfected with HA-ARHGEF6 and either a non-silencing siRNA or the silencing siR1 and siR2 constructs. (B) Western blot illustrating the absence of interference of the siR1 and siR2 silencing constructs with the closely related ßPix protein (weak band corresponds to a less expressed ßPix isoform). (C) Punctate HA staining (red, left, HA-GEF) of a dendritic segment of a cell co-transfected with EGFP and HAARHGEF6, which contrasts with the HA staining (red, middle, HA-GEF + siR1) obtained from a cell co-transfected with HAARHGEF6, siR1 oligos and EGFP (green, right, GFP). Bar, 2 µm. (D) Quantitative analysis of HA-ARHGEF6 staining showed 89±5% reduction in siR1 co-transfected pyramidal neurons as compared to control cells. Data are mean ± s.e.m., n=4-7; P<0.05.