Ube2l3 gene promoter analysis and binding of AhR to the Ube2l3 promoter region. (A) Mouse Ube2l3 5′ region was analyzed in silico in order to identify binding sites for known transcription factors (boxes): HNF-3b (Hepatic Nuclear Factor 3b), AP1 (Activator Protein 1), XRE (Xenobiotic Response Element), GATA-2 (Haematopoietic GATA factor response element), C/EBPβ (CAAT enhancer binding protein beta), p300, Sp1, and TATA box. The putative transcription start site is indicated by an arrow, and the translation start site codon (ATG) is indicated by a grey box. (B) ChIP analysis of AhR binding to the Ube2l3 promoter region. ChIP experiments were performed with an antibody against AhR. PCR products corresponding to the +18/-2252 Ube2l3 promoter region were generated from genomic DNA (line 2, positive control), and from immunoprecipitated material obtained from TCDD (line 3) or vehicle (line 4) treated animals.