Golgi reorientation in MDA-MB-435S cells is supported by Tiam1. (a) MDA-MB-435S cells were plated on collagen I (50 μg/ml)-coated coverslips overnight, and then fixed and stained for Tiam1 (green), GM130 (red; Golgi marker), and DAPI (blue). (b) Confluent cells were transfected with either 200 nM control siRNA (si Ctrl) or Tiam1 siRNA (si Tiam1) overnight and then examined with Western blot for suppression of Tiam1 expression. (c) Cells from parallel cultures were then serum starved for 12 hours, wounded, and examined for serum-dependent Golgi reorientation, as described in Materials and Methods. Quantification is shown for three independent experiments.