Fig. 5

GCN5 regulates AIB1 expression by enhancing de novo transcription of the AIB1 gene. a GCN5 enhanced AIB1 promoter activity. 293T cells were transfected with AIB1 promoter reporters with or without PCMV-Myc-GCN5 expression plasmids. Renilla luciferase was transfected as internal control. Luciferase activities were measured and normalized to renilla luciferase value. All data are mean of independent experiments with three replicates per experiments. **p < 0.01. b Knockdown of GCN5 significantly decreased AIB1 promoter activity induced by E2F1 transfection. 293T cells were transfected with AIB1 promoter reporters with pGIPZ-shGCN5 plasmids and/or E2F1 expression plasmids. Luciferase activities were measured 48 h after transfection. **p < 0.01. c GCN5 was recruited to AIB1 promoter, as measured by ChIP assay. HepG2 cells were lysed for ChIP assays using control IgG and anti-GCN5 antibody for immunoprecipitation. d Two E2F1 binding sites were mutated in AIB1 promoter. e Mutation of E2F1 binding site 1 (+154 ~ +164 bp) significantly decreased the AIB1 promoter activity induced by GCN5 transfection. Luciferase activities were assayed and normalized to Renilla luciferase activities. **p < 0.01. f E2F1 knockdown reduced GCN5 enrichment on AIB1 promoter. siE2F1 was used to knock down E2F1 in HepG2 cells. Cells were lysed for ChIP assays using control IgG and anti-GCN5 antibody for immunoprecipitation. *p < 0.05. g GCN5 knockdown reduced H3K9 acetylation of E2F1 binding site on AIB1 promoter as measured by ChIP assay using anti-histone H3 (acetyl K9) antibody for immunoprecipitation. **p < 0.01