Fig. 1. OGT is arginine methylated and the modification is glucose dependent.

A H1299 cells were cultured for 18 h with different concentrations of glucose as indicated. O-GlcNAcylation and arginine methylation levels were analyzed by western blotting. B Endogenous arginine methylation of OGT after Co-IP assay with anti-OGT antibody was detected by western blotting. C HEK-293T cells overexpressing Flag-tagged OGT were treated with different concentrations of glucose for 18 h. Co-IP was then performed using anti-Flag antibody. Arginine methylation of immunopurified OGT was detected with antibodies as indicated. D HEK-293T cells overexpressing Flag-tagged OGT were treated with glucose starvation for the indicated times. Co-IP was then performed using anti-Flag antibody. Arginine methylation of immunopurified OGT was detected with antibodies as indicated. E H1299 cells were cultured with different concentrations of glucose for 18 h. The levels of PRMTs and OGT were analyzed by western blotting. F Purified GST-tagged OGT was pulled down with the Flag-PRMTs purified from HEK-293T cells. The amounts of GST-tagged OGT were visualized by Coomassie Blue staining. G The interaction between OGT and CARM1 was detected by Co-IP with anti-Flag antibody in HEK-293T cells transfected with Flag-OGT. H CARM1 and vector were transformed into HEK-293T cells re-expressing Flag-OGT. Co-IP was then performed using anti-Flag antibody. Arginine methylation of immunopurified OGT was detected with antibodies as indicated. I H1299 cells overexpressing Flag-OGT were treated with increasing concentrations of the CARM1 inhibitor TP064 for 24 h as indicated. Cell lysates were immunoprecipitated by anti-Flag antibody and the arginine methylation of OGT was analyzed with antibodies as indicated. J Increasing amounts of GST-CARM1 were incubated with GST-OGT in the presence of SAM at 30 °C for 1 h, and arginine methylation of OGT was analyzed by western blotting.