Targeting Disabled‐2 to Stabilize ΔF508‐CFTR

Abstract

The fatal genetic disease Cystic Fibrosis (CF) is caused by mutations in the CF Transmembrane Conductance Regulator (CFTR) gene. The most common mutation, ΔF508‐CFTR, negatively impacts the processing, gating, and stability of CFTR. Existing combination therapies elicit only modest benefit in ΔF508‐CFTR patients. Potentiators and correctors address the gating and processing defects of ΔF508‐CFTR, respectively, but do not specifically target its stability. Thus, by targeting additional aspects of the mutant CFTR life cycle we may significantly improve CF patient prognosis.
 Here, we present evidence for a new class of stabilizers that target CFTR half‐life. The adaptor protein Disabled‐2 (Dab2), is an essential mediator of CFTR endocytosis. The Dab2 Dab homology (DH) domain is required for Dab2 to co‐assemble in complex with CFTR, and our lab has shown that DH peptide inhibitors enhance ΔF508‐CFTR function alone and even more so when combined with correctors and potentiators. We have now used an engineered peptide with high‐affinity for the DH domain as a reporter in a fluorescence anisotropy based high‐throughput screen to identify candidate small‐molecule inhibitors. FRET and NMR are used to further characterize the intermolecular binding between the DH domain and potential stabilizers.