Trichomonas vaginalis Cysteine Proteinases: Iron Response in Gene Expression and Proteolytic Activity

Figure 8

Genomic structure of different CP genes regulated by iron at the transcriptional or posttranscriptional level. (a) Transcriptional level. Comparison between the previously described iron inducible ap65-1 gene promoter [85–87] and other two genes regulated by iron: the tvcp1 gene promoter that responds to low-iron concentration. The tvlegu-1 gene that responds to high-iron condition has a Motif 3 (M3, green box) element in the 5′-region, where the transcription start site (TSS) is also found (Figure 9). CPS: iron responsive core promoter sequence, MRE (blue boxes), Myb recognition element; Inr (pink boxes), initiator element; arrow: TSS. (b) Posttranscriptional level: comparison between two different genes with IRE hairpin loop elements located in the 5′-UTR, tvcp4 mRNA, or in the 3′ UTR, tvcp12 mRNA where the RNA-binding protein will bind under low-iron concentrations.

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