Fig. 3: O-GlcNAcylation stabilizes SIRT7 protein.

A Knockdown of OGT regulated the protein level of SIRT7 in PANC-1 and MiaPaCa-2 cells. One representative experiment of n = 3 independent experiments is shown. B Knockdown of OGT regulated the mRNA level of SIRT7 in PANC-1 and MiaPaCa-2 cells. One representative experiment of n = 3 independent experiments is shown. C OGA inhibitors PugNAc and thiamet-G (TMG) treatment regulated the protein level of SIRT7. PANC-1 and MiaPaCa-2 cells were treated with PugNAc (1 µM, 4 h) and thiamet-G (TMG) (10 µM, 4 h), and cell lysates were immunoblotted with indicated antibodies. One representative experiment of n = 3 independent experiments is shown. D Empty vector or expression vector for OGT WT or K908A mutant was transfected to PANC-1 and MiaPaCa-2 cells, and cell lysates were immunoblotted with indicated antibodies. One representative experiment of n = 3 independent experiments is shown. E Empty vector or expression vector for OGT WT or K908A mutant was transfected to PANC-1 and MiaPaCa-2 cells, and the mRNA level of SIRT7 was detected. One representative experiment of n = 3 independent experiments is shown. F, G The NC group and siOGT groups of PANC-1 and MiaPaCa-2 cells were treated with CHX (300 µg/ml), and the protein level of SIRT7 was recorded at 0, 30, 60, 90 and 120 min. Relative SIRT7 band intensities were quantified through densitometry and are presented. One representative experiment of n = 3 independent experiments is shown. H, I PANC-1 and MiaPaCa-2 cells transfected with NC, HA-OGT or HA-OGT-908A were treated with CHX (300 µg/ml), and the protein level of SIRT7 was recorded at 0, 30, 60, 90 and 120 min. Relative SIRT7 band intensities were quantified through densitometry and are presented. One representative experiment of n = 3 independent experiments is shown. The data are shown as the means ± SD. P values were calculated by two-tailed t-tests (*P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001; NS, no significance).