RNA-protein interactions play a key role in the aberrant splicing of CFTR exon 9. Exon 9 skipping leads to the production of a nonfunctional chloride channel associated with severe forms of cystic fibrosis. The missplicing depends on TDP-43 binding to an extended UG-rich binding site upstream of CFTR exon 9 3' splicing site (3'ss) and is associated with concomitant hnRNP A1 recruitment. Although TDP-43 is the dominant inhibitor of exon 9 inclusion, the role of hnRNP A1, a protein with two RNA recognition motifs, remained unclear. In this work, we have studied the interaction between hnRNP A1 and the CFTR pre-mRNA using NMR spectroscopy and Isothermal Titration Calorimetry. The affinities are submicromolar, and Isothermal Titration Calorimetry data suggest complexes with a 1:1 stoichiometry. NMR titrations reveal that hnRNP A1 interacts with model CTFR 3'ss sequences in a fast exchange regime at the NMR timescale. Splicing assays finally show that this hnRNP A1 binding site represents a previously unknown exonic splicing silencer element. Together, our results shed light on the mechanism of aberrant CFTR exon 9 splicing.

• MeSH
• alternativní sestřih genetika   MeSH
• cystická fibróza genetika   MeSH
• exony genetika   MeSH
• heterogenní jaderný ribonukleoprotein A1 * metabolismus   genetika   MeSH
• lidé MeSH
• místa sestřihu RNA genetika   MeSH
• prekurzory RNA genetika   metabolismus   MeSH
• protein CFTR * genetika   metabolismus   MeSH
• sestřih RNA * genetika   MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• CFTR protein, human MeSH Prohlížeč
• heterogenní jaderný ribonukleoprotein A1 * MeSH
• hnRNPA1 protein, human MeSH Prohlížeč
• místa sestřihu RNA MeSH
• prekurzory RNA MeSH
• protein CFTR * MeSH

Staufen1 (STAU1) is a dsRNA binding protein mediating mRNA transport and localization, translational control and STAU1-mediated mRNA decay (SMD). The STAU1 binding site (SBS) within human ADP-ribosylation factor1 (ARF1) 3'UTR binds STAU1 and this downregulates ARF1 cytoplasmic mRNA levels by SMD. However, how STAU1 recognizes specific mRNA targets is still under debate. Our structure of the ARF1 SBS-STAU1 complex uncovers target recognition by STAU1. STAU1 dsRNA binding domain (dsRBD) 4 interacts with two pyrimidines and one purine from the minor groove side via helix α1, the β1-β2 loop anchors the dsRBD at the end of the dsRNA and lysines in helix α2 bind to the phosphodiester backbone from the major groove side. STAU1 dsRBD3 displays the same binding mode with specific recognition of one guanine base. Mutants disrupting minor groove recognition of ARF1 SBS affect in vitro binding and reduce SMD in vivo. Our data thus reveal how STAU1 recognizes minor groove features in dsRNA relevant for target selection.

• MeSH
• ADP-ribosylační faktor 1 chemie   genetika   MeSH
• cytoplazma chemie   genetika   MeSH
• cytoskeletální proteiny chemie   genetika   MeSH
• dvouvláknová RNA chemie   genetika   MeSH
• konformace proteinů MeSH
• lidé MeSH
• proteiny vázající RNA chemie   genetika   MeSH
• stabilita RNA genetika   MeSH
• vazebná místa genetika   MeSH
• vazebný motiv pro dvoušroubovici RNA genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ADP-ribosylační faktor 1 MeSH
• cytoskeletální proteiny MeSH
• dvouvláknová RNA MeSH
• proteiny vázající RNA MeSH
• STAU1 protein, human MeSH Prohlížeč