C. hTERT-RPE-1 cells treated with PCM1 siRNA were transfected by an empty vector (EV) or plasmids producing PCM1-WT*, -S327A* or -S372E*, and immunofluorescence microscopy performed. Enlarged images of the regions around the basal body are shown in insets. Scale bars, 5 μm and 1 μm (inset). 