Luciferase reporter vectors containing the human hepcidin promoter. (A) Nucleotide sequence of the 5′-flanking region of human hepcidin. The sequence of the 300 bp of the transcription start site of the human hepcidin promoter is indicated in small letters. The 5′ UTR of the hepcidin gene is indicated in capital letters starting at position +1. Underlined sequences indicate transcription factor binding motifs. The AP1 and STAT binding motifs are phylogenetically conserved (100% identity of the core sequences) in the human, mouse, and rat. The transcription factor binding motifs were identified by MatInspector²⁴  and TFsearch version 1.3. (B) Luciferase (firefly) reporter vectors. The –942 construct contains the longest promoter region analyzed in this study; the –385 construct contains the AP1, C/EBPα, and STAT binding motifs; in the –385 ΔAP1 construct the AP1 binding motif is deleted; the –165 construct contains the STAT binding motif whereas the AP1 and C/EBPα binding motifs are deleted; in the –165 ΔSTAT construct the STAT binding motif is deleted; in the –942 ΔSTAT construct the STAT binding motif is deleted, while the AP1 and C/EBPα binding motifs are preserved; SV40-driven pGL3 vector expressing luciferase (Renilla) was used as a control. Asterisks indicate the deletion of transcription factor binding motifs; ▪, the 5′ end of the promoter region.