Fig 2: Interaction of SIRT1–RanGap1 and SIRT1–G3BP1 occurs in 2 epithelial cell lines. (A,C) SIRT1 interacts with RanGap1 and G3BP1 in HEK 293T cells. (B,D) SIRT1 interacts with RanGap1 and G3BP1 in MCF-7 cells. The independent experiments were repeated at least three times. IgG was used as a negative control.

Fig 3: RanGap1 affects antioxidant capacity and mitochondrial functions. (A) The ROS level was decreased in SIRT1-KD cells and increased in SIRT1-OE cells. (B) The ROS level was increased in RanGap1-OE cells and did not have obvious changes in RanGap1-KD cells. (C) PGC1-α, Drp1, PINK1 and TFAM were decreased, and Mfn1 and Parkin were increased in RanGap1-KD cells. (D) PGC1-α, Drp1, Mfn1, PINK1 and TFAM were increased in RanGap1-OE cells. (E) The cell viability was significantly decreased in RanGap1-OE cells under treating with 30 to 50 μM resveratrol compared to control cells. DMSO was used as negative control. The GAPDH was used as a loading control. The pooled data were shown here as the mean ± SEM, and the significant differences from control cells were shown in p < 0.05 (*), p < 0.01 (**), and p < 0.001 (***). The independent experiments were repeated at least three times.

Fig 4: SIRT1 regulates RanGap1 expression. After treating with 20 μM resveratrol for 24 h, or having SIRT1 over-expressed or knocked down in HEK 293T cells, the relative mRNA levels were determined by RT-PCR and the protein levels were detected by Western blot. (A) SUMO1-RanGap1 was increased after activation of SIRT1. (B) SUMO1-RanGap1 was increased in SIRT1-OE cells. (C) RanGap1 was decreased in SIRT1-KD cells. (D–F) The mRNA levels of SIRT1, RanGap1, G3BP1, FASN, UBE2M, Ran, LDHB, TCP1, LMNB1, HIST1H4A and PARP1 from cells as above. The GAPDH was used as a loading control. The pooled data were shown here as the mean ± SEM, and the significant differences from control cells were shown in p < 0.05 (*), p < 0.01 (**), and p < 0.001 (***). The independent experiments were repeated at least three times.