Ectopic expression of BtpA in HeLa cells induces filopodia. HeLa cells were transiently transfected with plasmids encoding GFP-BtpA. Sixteen hours after transfection the cells were fixed and actin was stained with Rhodamine phalloidin. Images were taken using confocal fluorescence microscopy. Large image on top, Z-Stack of 16 merged images slices (1 μm depth) of HeLa cells, showing actin distribution (red) and one cell expressing GFP-BtpA (green). The smaller images below are individual image slices. Scale bar, 25 μm. Data are representative of 3 or more independent experiments.