New insights into interactions between the nucleotide-binding domain of CFTR and keratin 8

Aiswarya Premchandar (1) , Anna Kupniewska (2) , Arkadiusz Bonna (1, 3) , Grazyna Faure (4) , Tomasz Fraczyk (1) , Ariel Roldan (5) , Brice Hoffmann (6) , Mélanie Faria da Cunha (2) , Harald Herrmann (7, 8) , Gergely L Lukacs (5) , Aleksander Edelman (2) , Michał Dadlez (1)

1 IBB - Institute of Biochemistry and Biophysics [Warsaw]
2 Canalopathies épithéliales: la mucoviscidose et autres maladies
3 Department of Biochemistry [Cambridge]
4 Récepteurs Canaux - Channel Receptors
5 Department of Physiology [Montréal]
6 IMPMC - Institut de minéralogie, de physique des matériaux et de cosmochimie
7 DKFZ - German Cancer Research Center - Deutsches Krebsforschungszentrum [Heidelberg]
8 University Hospital Erlangen = Uniklinikum Erlangen

The intermediate filament protein keratin 8 (K8) interacts with the nucleotide-binding domain 1 (NBD1) of the cystic fibrosis (CF) transmembrane regulator (CFTR) with phenylalanine 508 deletion (DF508), and this interaction hampers the biogenesis of functional DF508-CFTR and its insertion into the plasma membrane. Interruption of this interaction may constitute a new thera- peutic target for CF patients bearing the DF508 mutation. Here, we aimed to determine the binding surface between these two proteins, to facilitate the design of the interaction inhibitors. To identify the NBD1 fragments perturbed by the DF508 mutation, we used hydrogen–deuterium exchange coupled with mass spectrometry (HDX-MS) on recombinant wild-type (wt) NBD1 and DF508-NBD1 of CFTR. We then performed the same analysis in the presence of a peptide from the K8 head domain, and extended this investigation using bioinformatics procedures and surface plasmon res- onance, which revealed regions affected by the peptide binding in both wt-NBD1 and DF508-NBD1. Finally, we performed HDX-MS analysis of the NBD1 molecules and full-length K8, revealing hydrogen-bonding network changes accompanying complex formation. In conclusion, we have localized a region in the head segment of K8 that participates in its binding to NBD1. Our data also confirm the stronger binding of K8 to DF508-NBD1, which is supported by an additional binding site located in the vicinity of the DF508 mutation in NBD1.

Mots clés: CFTR; cystic fibrosis transmembrane conductance regulator HDX; hydrogen-deuterium exchange IF; intermediate filaments K8; keratin 8 LC; liquid chromatography MS; mass spectrometry NBD; nucleotide-binding domain SPR; surface plasmon resonance cystic fibrosis CFTR keratin 8 NBD1 hydrogen-deuterium exchange mass spectrometry protein structure; cystic fibrosis transmembrane conductance regulator; HDX; hydrogen-deuterium exchange; IF; intermediate filaments; K8; keratin 8; LC; liquid chromatography; MS; mass spectrometry; NBD; nucleotide-binding domain; SPR; surface plasmon resonance cystic fibrosis; NBD1; hydrogen-deuterium exchange mass spectrometry; protein structure

Domaines: Sciences du Vivant [q-bio]; Chimie

Aiswarya Premchandar, Anna Kupniewska, Arkadiusz Bonna, Grazyna Faure, Tomasz Fraczyk, et al.. New insights into interactions between the nucleotide-binding domain of CFTR and keratin 8. Protein Science, 2017, 26 (2), pp.343-354. ⟨10.1002/pro.3086⟩. ⟨pasteur-04102780⟩