Dataset Information

Mutation-specific dual potentiators maximize rescue of CFTR gating mutants.

ABSTRACT:

Background

The potentiator ivacaftor (VX-770) has been approved for therapy of 38 cystic fibrosis (CF) mutations (?10% of the patient population) associated with a gating defect of the CF transmembrane conductance regulator (CFTR). Despite the success of VX-770 treatment of patients carrying at least one allele of the most common gating mutation G551D-CFTR, some lung function decline and P. aeruginosa colonization persist. This study aims at identifying potentiator combinations that can considerably enhance the limited channel activity of a panel of CFTR gating mutants over monotherapy.

Methods

The functional response of 13 CFTR mutants to single potentiators or systematic potentiator combinations was determined in the human bronchial epithelial cell line CFBE41o- and a subset of them was confirmed in primary human nasal epithelia (HNE).

Results

In six out of thirteen CFTR missense mutants the fractional plasma membrane (PM) activity, a surrogate measure of CFTR channel gating, reached only ?10-50% of WT channel activity upon VX-770 treatment, indicating incomplete gating correction. Combinatorial potentiator profiling and cluster analysis of mutant responses to 24 diverse investigational potentiators identified several compound pairs that improved the gating activity of R352Q-, S549R-, S549N-, G551D-, and G1244E-CFTR to ?70-120% of the WT. Similarly, the potentiator combinations were able to confer WT-like function to G551D-CFTR in patient-derived human nasal epithelia.

Conclusion

This study suggests that half of CF patients with missense mutations approved for VX-770 administration, could benefit from the development of dual potentiator therapy.

SUBMITTER: Veit G

PROVIDER: S-EPMC7190413 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature

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Publications

Mutation-specific dual potentiators maximize rescue of CFTR gating mutants.

Veit Guido G Da Fonte Dillon F DF Avramescu Radu G RG Premchandar Aiswarya A Bagdany Miklos M Xu Haijin H Bensinger Dennis D Stubba Daniel D Schmidt Boris B Matouk Elias E Lukacs Gergely L GL

Journal of cystic fibrosis : official journal of the European Cystic Fibrosis Society 20191031 2

<h4>Background</h4>The potentiator ivacaftor (VX-770) has been approved for therapy of 38 cystic fibrosis (CF) mutations (∼10% of the patient population) associated with a gating defect of the CF transmembrane conductance regulator (CFTR). Despite the success of VX-770 treatment of patients carrying at least one allele of the most common gating mutation G551D-CFTR, some lung function decline and P. aeruginosa colonization persist. This study aims at identifying potentiator combinations that can ...[more]

PMID: 31678009

Similar Datasets

Project description:Cystic fibrosis transmembrane conductance regulator (CFTR) is a unique member of the ATP-binding cassette (ABC) protein superfamily. Unlike most other ABC proteins that function as active transporters, CFTR is an ATP-gated chloride channel. The opening of CFTR's gate is associated with ATP-induced dimerization of its two nucleotide-binding domains (NBD1 and NBD2), whereas gate closure is facilitated by ATP hydrolysis-triggered partial separation of the NBDs. This generally held theme of CFTR gating-a strict coupling between the ATP hydrolysis cycle and the gating cycle-is put to the test by our recent finding of a short-lived, post-hydrolytic state that can bind ATP and reenter the ATP-induced original open state. We accidentally found a mutant CFTR channel that exhibits two distinct open conductance states, the smaller O1 state and the larger O2 state. In the presence of ATP, the transition between the two states follows a preferred O1?O2 order, a telltale sign of a violation of microscopic reversibility, hence demanding an external energy input likely from ATP hydrolysis, as such preferred gating transition was abolished in a hydrolysis-deficient mutant. Interestingly, we also observed a considerable amount of opening events that contain more than one O1?O2 transition, indicating that more than one ATP molecule may be hydrolyzed within an opening burst. We thus conclude a nonintegral stoichiometry between the gating cycle and ATP consumption. Our results lead to a six-state gating model conforming to the classical allosteric mechanism: both NBDs and transmembrane domains hold a certain degree of autonomy, whereas the conformational change in one domain will facilitate the conformational change in the other domain.

Dataset Information

Mutation-specific dual potentiators maximize rescue of CFTR gating mutants.

Background

Methods

Results

Conclusion

Publications

Mutation-specific dual potentiators maximize rescue of CFTR gating mutants.

Similar Datasets

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