Fig. 2. USP13 expression is regulated by c-Jun/AP-1 activity in cervical cancer cells.

A Schematic of potential AP-1 binding sites in the USP13 promoter region. B Representative western blot of HeLa and SiHa cells after treatment with JNK-IN-8 (3 µM) or DMSO control for 48 h. Lysates were analysed for the expression of USP13, phosphorylated c-Jun (S73) and c-Jun. GAPDH was used as a loading control. C RT-qPCR analysis of USP13 mRNA expression in HeLa and SiHa cells after treatment with JNK-IN-8 (3 µM) or DMSO control for 48 h. mRNA expression was normalized against U6 mRNA levels. D Representative western blot of HeLa and SiHa cells after transfection of a pool of four specific c-Jun siRNA for 72 h. Lysates were analysed for the expression of USP13 and c-Jun. GAPDH was used as a loading control. E RT-qPCR analysis of USP13 and cJUN mRNA expression of HeLa and SiHa after transfection of a pool of four specific c-Jun siRNA for 72 h. mRNA expression was normalized against U6 mRNA levels. F Cells were treated as in B and chromatin was prepared from HeLa cells and c-Jun was immunoprecipitated using an anti-c-Jun antibody, followed by RT-qPCR using primers specific to the two putative AP-1 binding sites in the USP13 promoter. c-Jun binding is presented as percentage of input chromatin. Bars are the means ± standard deviation from at least three biological repeats. *p < 0.05; **p < 0.01; ***p < 0.001 (Student’s t-test).