Fig. 3

XBP1 activates IL-6 expression via binding to the IL-6 promoter in melanoma cells. a Sequence alignment of the putative UPR element of the Il-6 promoter from humans, rats and mice. The ACGT core is indicated in bold. b Mel-RMu cells were transfected with plasmids expressing Flag-tagged XBP1s or control (ctrl.). Chromatin immunoprecipitation (ChIP) was performed by using control IgG or anti-Flag antibody before PCR amplification of the indicated region of the IL-6 promoter. c ChIP assays of extracts from 293T cells co-transfected with the empty vector or pCMV-XBP1s plasmid together with the IL-6 or IL-6 without the ACGT core (IL-6Δ) promoter constructs, using anti-XBP1s antibody. d Luciferase reporter assays were performed in 293T cells cotransfected with pCMV-XBP1s plasmid together with Luc constructs under the control of the wild-type (WT) human IL-6 promoter or that with the ACGT core deleted (IL-6Δ). The results are from at least three independent experiments. The data are presented as the mean ± s.e.m. *P < 0.05, **P < 0.01 by two-way ANOVA