FPN1 gene structure and transcripts. Top: genomic organization and exon distribution of FPN1 (SLC40A1) locus, with (below) reported mRNA (GeneBank accession XM_047592). Middle: enlarged genomic region with exons 1-2 of FPN1 mRNA and upstream regions. Non-coding sequences are reported as open (white or coloured) boxes, coding sequences are indicated as black boxes and IRE element is indicated as a dashed box. Bent arrows below line indicate transcription start sites. P1, P2 and P3 indicate alternative promoter regions. Bottom: structure of clones obtained from -RACE analysis. Alternative regions are indicated in different colours; sequences shared by all transcripts are in yellow. On the right is reported size (aa) of putative proteins coded by the respective transcripts.
