Fig. 4

NOS1 inhibits the deacetylation of H4K16 by S-nitrosylation of HDAC2. a-d A375 cells were treated with or without IFNα (1000 U/ml) for 1 h. ChIP was performed using specific a anti-H4K16ac, b anti-H4K5ac, c anti-H3ac and d anti-Rbp1 antibodies. e HDAC2 siRNA or the control siRNA were transfected into A375 cells for 24 h, followed by stimulation with IFNα (1000 U/ml) for 1 h. ChIP was performed using H4K16ac antibodies. f Similar to e, but HDAC2 expression vectors were used to transfect A375 cells for 24 h before IFNα stimulation. g HDAC2 siRNA or control siRNA was used to transfect A375 cells for 24 h and then stimulated with or without IFNα (1000 U/ml) for 6 h. Western blotting was performed using the indicated antibodies. h, i Using the same protocol as in e, ChIP assays were performed using specific h anti-Rpb1 and i anti-H4K5ac antibodies. j, k Control/NOS1 (A375) cells were treated with IFNα (1000 U/ml) for 1 h. ChIP assays were performed using specific j anti-H4K16ac and k anti-Rpb1 antibodies. l Over-NOS1 (A375) cells were transfected with HDAC2-WT or HDAC2-MUT vectors for 24 h and then treated with IFNα (1000 U/ml) for 1 h. ChIP assays were performed using specific anti-H4K16ac antibodies. ns, not significant; *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001