XRN2 Autoregulation and Control of Polycistronic Gene Expresssion in Caenorhabditis elegans

摘要: XRN2 is a conserved 5’→3’ exoribonuclease that complexes with proteins contain XRN2-binding domains (XTBDs). In Caenorhabditis elegans (C. elegans), the XTBD-protein PAXT-1 stabilizes to retain its activity. activity also promoted by 3'(2'),5'-bisphosphate nucleotidase 1 (BPNT1) through hydrolysis of an endogenous XRN inhibitor 3’-phosphoadenosine-5'-phosphate (PAP). Here, we find unbiased screening loss bpnt-1 function suppresses lethality caused paxt-1 deletion. This unexpected finding explained autoregulation, which occurs repression cryptic promoter and destabilization xrn-2 transcript. De-repression appears be triggered such more robust perturbation, elimination both BPNT1, less detrimental worm viability than absence alone. Indeed, two distinct mechanisms are alleviated at different thresholds inactivation. Like 15% C. genes, in operon, identify additional operons under control, consistent broader polycistronic gene regulation. Regulation intercistronic regions link genes but part may allow operate on monocistronic organisms lacking operons.