Transcriptional regulation of Rc3h1. (A) A web-based search for transcriptional factors that bind to the Rc3h1 promoter identified binding sites for STATs, GATA, IKZF and c-Rel. Luciferase reporter assays were used to evaluate the activational effects of eight transcription factors on the Rc3h1 promoter regions. Using a (B) -2.1 kb Rc3h1 promoter region, STAT1, STAT3, GATA2, and c-Rel resulted in a significant increase in luciferase activity; IKZF2 resulted in a significant decrease. STAT1, STAT3, GATA2, and c-Rel also resulted in increased luciferase activity using the (C) -1.3 kb and (D) -0.2 kb Rc3h1 promoter regions. Values are fold induction of luciferase activity of transcription factor-transfected cells relative to non-transcription factor transfected cells. Data are mean values ± SEM of 3-4 independent experiments.