IRES mediated translation initiation requires a different repertoire of factors than canonical cap-dependent translation. Treatments that inhibit the canonical translation factor EIF4G1 have little or no effect on the ability of the Insr and Igf1r cellular IRESes to promote translation. Transcripts for two cellular receptors contain RNA elements that facilitate translation initiation without intact EIF4G1.
View Article and Find Full Text PDFBacterial infection often leads to suppression of mRNA translation, but hosts are nonetheless able to express immune response genes through as yet unknown mechanisms. Here, we use a Drosophila model to demonstrate that antimicrobial peptide (AMP) production during infection is paradoxically stimulated by the inhibitor of cap-dependent translation, 4E-BP (eIF4E-binding protein; encoded by the Thor gene). We found that 4E-BP is induced upon infection with pathogenic bacteria by the stress-response transcription factor ATF4 and its upstream kinase, GCN2.
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