title: Correctors Rescue CFTR Mutations in Nucleotide-Binding Domain 1 (NBD1) by Modulating Proteostasis.
abstract: We evaluated whether small molecule correctors could rescue four nucleotide-binding domain 1 (NBD1) mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene (A455E, S492F, ΔI507, and R560T). We first transfected Cos-7 cells (green monkey kidney cells) with A455E, S492F, ΔI507, or R560T and created HEK-293 (human embryonic kidney cells) cell lines stably expressing these CFTR mutations. The mutants showed lowered protein expression, instability at physiological temperature, and rapid degradation. After treatment with correctors CFFT-002, CFFT-003, C3, C4, and/or C18, the combination of C18+C4 showed the most correction and resulted in increased CFTR residing in the plasma membrane. We found a profound decrease in binding of CFTR to histone deacetylases (HDAC) 6 and 7 and heat shock proteins (Hsps) 27 and 40. Silencing Hsp27 or 40 rescued the mutants, but no additional amount of CFTR was rescued when both proteins were knocked down simultaneously. Thus, CFTR mutations in NBD1 can be rescued by a combination of correctors, and the treatment alters the interaction between mutated CFTR and the endoplasmic reticulum machinery.
authors: Departments of Medicine and Physiology, Division of Gastroenterology and Hepatology, Johns Hopkins University, School of Medicine, Baltimore, MD, 21205, USA.|Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 303 CCS/Bloco G/Sala G2-055, Rio de Janeiro, RJ, 21941-902, Brazil.
authors: Miquéias
authors: http://orcid.org/0000-0002-7444-9359
authors: M
authors: Lopes-Pacheco
authors: Departments of Medicine and Physiology, Division of Gastroenterology and Hepatology, Johns Hopkins University, School of Medicine, Baltimore, MD, 21205, USA.
authors: Inna
authors: I
authors: Sabirzhanova
authors: Departments of Medicine and Physiology, Division of Gastroenterology and Hepatology, Johns Hopkins University, School of Medicine, Baltimore, MD, 21205, USA.
authors: Daniele
authors: D
authors: Rapino
authors: Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Av. Carlos Chagas Filho, 303 CCS/Bloco G/Sala G2-055, Rio de Janeiro, RJ, 21941-902, Brazil.
authors: Marcelo M
authors: MM
authors: Morales
authors: Departments of Medicine and Physiology, Division of Gastroenterology and Hepatology, Johns Hopkins University, School of Medicine, Baltimore, MD, 21205, USA.
authors: William B
authors: http://orcid.org/0000-0002-2153-9764
authors: WB
authors: Guggino
authors: Departments of Medicine and Physiology, Division of Gastroenterology and Hepatology, Johns Hopkins University, School of Medicine, Baltimore, MD, 21205, USA. lcebotaru@jhmi.edu.
authors: Liudmila
authors: http://orcid.org/0000-0002-4362-8995
authors: L
authors: Cebotaru
mesh_terms: D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D002522:Chlorocebus aethiops; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics* / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D009154:Mutation
chemical_list: C505032:CFTR protein, human; D019005:Cystic Fibrosis Transmembrane Conductance Regulator
keywords: correctors; cystic fibrosis; mutagenesis; protein misfolding; proteostasis network