Immunofluorescence Staining Procedure

Coverslips (Thermo Fisher Scientific) were used for seeding the cells. Until about 80% confluency, cells were subsequently followed by the routine immunofluorescence staining procedure [43 (link)]. After being washed twice with phosphate-buffered saline (PBS), cells were subjected to fixation for 15 min with 4% paraformaldehyde and permeabilization and blocking with Triton X-100 (0.2%, Sigma-Aldrich) for 10 min and donkey serum (10%, Jackson ImmunoResearch) for 1 h at room temperature, respectively. Following incubation with primary antibodies, the coverslips were incubated with secondary antibodies. Finally, Hoechst 33342 (Thermo Fisher Scientific) was used to label the nuclei. Zeiss Confocal System LSM900 and Leica SP5 Confocal System were applied to capture images.