FIGURE 4.

Nucleocytoplasmic shuttling of SAE2. A, nucleocytoplasmic trafficking of the SAE2 Cterm-5K/R mutant, which almost completely localized to the cytoplasm. The construct was expressed in HEK239T for 25 h, followed by serum starvation for 20 h to synchronize cell cycle stage, then addition of 10 ng/ml of the LMB nuclear export inhibitor. Live cells were examined by confocal microscopy beginning 20 min after adding LMB and images were captured at the indicated time points. As time increased, the nuclear accumulation of the Cterm5K/R SAE2 mutant protein was observed. B, statistical analysis of cells with exclusive cytoplasmic localization of the Cterm-5K/R mutant after treatment for 2 h and 4 h. At 2 and 4 h after the treatment, the disappearance of cytoplasmic SAE2 and accumulation of nuclear SAE2 was significant. * indicates p < 0.01, and ***, p < 0.0001.