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Multiple Molecular Chaperone‐mediated Pharmacologic Rescue of Δ F508‐CFTR from ERAD
Author(s) -
Singh Om V.,
Zeitlin Pamela L.
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a420-b
Subject(s) - cystic fibrosis transmembrane conductance regulator , δf508 , endoplasmic reticulum associated protein degradation , microbiology and biotechnology , cystic fibrosis , membrane protein , chemistry , cytosol , biology , endoplasmic reticulum , unfolded protein response , biochemistry , genetics , membrane , enzyme
Cystic Fibrosis (CF) is an autosomal recessive disorder caused by dysfunction or absence of a single membrane glycoprotein chloride channel, the CF transmembrane conductance regulator (CFTR). Mutant ΔF508, retained in the ER, and degraded by the ubiquitin‐proteasome pathway. 4‐phynylbutyrate (4‐PBA) can rescue ΔF508‐CFTR. Goal of this study was to identify the proteins interacting with CFTR during CFTR‐transit from ER to the plasma membrane (PM). We hypothesize, a subset of proteins interacting to CFTR during restoration of ΔF508‐CFTR, will correlate with proteins binding to wtCFTR. Cellular lysates from IB3‐1, CF bronchial epithelial cells (ΔF508/W 1282X), non‐CF (corrected IB3‐1 by wtCFTR, S9) and rescued‐CF (4‐PBA treated IB3‐1) were collected and immunoprecipitated using anti‐CFTR 169 antisera, and resolved on 2‐DE. Differentially expressed proteins were identified by PMF using MALDI‐TOF. A subset of HSP70 family members were tracked at sub‐cellular compartments (ER, Cytosol and PM). Significant Z scores and maximum coverage included for GRP(s) 94, 78, 75, 58, HSP(s) 84, 70, 27, HSC70, Vimentin and KRT18. Connectivity map shows multiple ER‐network proteins were interacted with CFTR through either regulation or signaling pathways. Multiple ER‐chaperones (GRPs94, 78, 75, 58 and HSP84) interacted with B form of CFTR (160 kDa) in ER, but not with folded C form of CFTR (180 kDa) in the PM. 4‐PBA rescued CFTR associated with changes in the network of ER and cytosolic chaperones mimics patterns of proteins interacted with wtCFTR. This work was supported by RO1 HL 59410 and NO1 BAA HL 02‐04