FIGURE 6.

CHOP binds to the Srebf1c and Cebpa promoter/enhancer regions. A, a scaled schematic of the Srebf1c promoter/enhancer region shows the TSS (arrow) along with the putative CHOP-binding region, which overlaps exon 1 (Ex 1) and contains the indicated C/EBPα-CHOP-like binding site. Non-matching bases are in boldface. The site overlaps the SREBF1c start codon, which is underlined. B, binding of CHOP to the Srebf1c 1-kb proximal promoter was analyzed by ChIP as described in the legend to Fig. 5A. ts43-ts157 denotes a region 43–157 bp downstream of the TSS and encompassing the putative C/EBPα-CHOP site. Binding is given relative to Chop^−/− animals using a non-immune antibody. For comparison, CHOP binding to the Gadd34 promoter from the same experiment is shown (n = 4). **, p < 0.01; ***, p < 0.001. KO, knock-out. C, CHOP binding to a region ∼700 bp upstream of the Cebpa TSS is shown, along with a more distal region 4 kb upstream and an irrelevant genomic sequence (irrel) as negative controls and the Gadd34 promoter as a positive control (n = 4). NT, non-treated. D, wild-type animals were injected with Ad-Gfp or Ad-Chop as described in the legend to Fig. 4, and one group of Ad-Gfp-injected animals was treated with TM for 8 h to induce endogenous CHOP expression. Expression of CHOP and efficacy of TM treatment as determined by immunoblotting are shown. TRAPα^CHO, glycosylated TRAPα. E, binding of CHOP to an irrelevant genomic region or to the ts43-ts157 region of the Srebf1 promoter was tested by ChIP in four animals per group from the experiment shown in D. *, p < 0.05.