Talpid3 and Cep290 control Rab8 localization at early phase of ciliogenesis. (A) RPE1 cells transiently transfected with control (siNS), Talpid3, or Cep290 siRNA were induced to quiescence for 6 h and processed for immunofluorescence with anti-glutamylated tubulin (GT335, green) and anti-Rab8a (red) antibodies. DNA was stained with DAPI (blue). Bar, 5 µm. (B) RPE1 cells transiently transfected with control, Talpid3, or Cep290 siRNAs were induced to quiescence and processed for immunofluorescence with anti-glutamylated tubulin and anti-Rab8a antibodies at indicated times after serum starvation. The percentages of RPE1 cells that stain for Rab8a in the vicinity of centrosomes were determined. Average of two to four independent experiments is shown. *, P < 0.01; **, P < 0.05 compared with NS at 6 h after serum starvation. (C and D) GFP-Rab8a RPE1 cells transiently transfected with a plasmid expressing tagRFP-Centrin2 and control, Talpid3, or Cep290 siRNAs were induced to quiescence and processed for live-cell imaging. (C) Images were taken at indicated time points. Bar, 2.5 µm. (D) The average intensity of GFP-Rab8a signals at the vicinity of centrosomes was quantified. Dots and lines show average values and trend lines, respectively.