title: Chemical rescue of deltaF508-CFTR mimics genetic repair in cystic fibrosis bronchial epithelial cells.
abstract: In a previous study of sodium 4-phenylbutyrate (4-PBA)-responsive proteins in cystic fibrosis (CF) IB3-1 bronchial epithelial cells, we identified 85 differentially expressed high abundance proteins from whole cellular lysate (Singh, O. V., Vij, N., Mogayzel, P. J., Jr., Jozwik, C., Pollard, H. B., and Zeitlin, P. L. (2006) Pharmacoproteomics of 4-phenylbutyrate-treated IB3-1 cystic fibrosis bronchial epithelial cells. J. Proteome Res. 5, 562-571). In the present work we hypothesize that a subset of heat shock proteins that interact with cystic fibrosis transmembrane conductance regulator (CFTR) in common during chemical rescue and genetic repair will identify therapeutic networks for targeted intervention. Immunocomplexes were generated from total cellular lysates, and three subcellular fractions (endoplasmic reticulum (ER), cytosol, and plasma membrane) with anti-CFTR polyclonal antibody from CF (IB3-1), chemically rescued CF (4-PBA-treated IB3-1), and genetically repaired CF (IB3-1/S9 daughter cells repaired by gene transfer with adeno-associated virus-(wild type) CFTR). CFTR-interacting proteins were analyzed on two-dimensional gels and identified by mass spectrometry. A set of 16 proteins known to act in ER-associated degradation were regulated in common and functionally connected to the protein processing, protein folding, and inflammatory response. Some of these proteins were modulated exclusively in ER, cytosol, or plasma membrane. A subset of 4-PBA-modulated ER-associated degradation chaperones (GRP94, HSP84, GRP78, GRP75, and GRP58) was observed to associate with the immature B form of CFTR in ER. HSP70 and HSC70 interacted with the C band (mature form) of CFTR at the cell surface. We conclude that chemically rescued CFTR associates with a specific set of HSP70 family proteins that mark therapeutic interactions and can be useful to correct both ion transport and inflammatory phenotypes in CF subjects.
authors.affiliation: Department of Pediatrics, The Johns Hopkins School of Medicine, Baltimore, Maryland 21287, USA.
authors.forename: Om V
authors.initials: OV
authors.lastname: Singh
authors.forename: Harvey B
authors.initials: HB
authors.lastname: Pollard
authors.forename: Pamela L
authors.initials: PL
authors.lastname: Zeitlin
mesh_terms: D001692:Biological Transport; D001980:Bronchi / Q000166:cytology*; D002462:Cell Membrane / Q000378:metabolism; D019295:Computational Biology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000737:chemistry* / Q000235:genetics*; D003600:Cytosol / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D000091342:Endoplasmic Reticulum Chaperone BiP; D004847:Epithelial Cells / Q000378:metabolism*; D005786:Gene Expression Regulation; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D007249:Inflammation; D018832:Molecular Chaperones / Q000378:metabolism; D009154:Mutation; D013347:Subcellular Fractions
chemical_list: C505032:CFTR protein, human; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D018832:Molecular Chaperones; D019005:Cystic Fibrosis Transmembrane Conductance Regulator