Premium
Roscovitine is a proteostasis regulator that corrects the trafficking defect of F 508del‐ CFTR by a CDK ‐independent mechanism
Author(s) -
Norez C,
Vandebrouck C,
Bertrand J,
Noel S,
Durieu E,
Oumata N,
Galons H,
Antigny F,
Chatelier A,
Bois P,
Meijer L,
Becq F
Publication year - 2014
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/bph.12859
Subject(s) - calnexin , cystic fibrosis transmembrane conductance regulator , microbiology and biotechnology , endoplasmic reticulum , cyclin dependent kinase , chemistry , proteostasis , regulator , endocytosis , biology , proteasome , calreticulin , cell cycle , biochemistry , cell , gene
Background and Purpose The most common mutation in cystic fibrosis ( CF ), F 508del, causes defects in trafficking, channel gating and endocytosis of the CF transmembrane conductance regulator ( CFTR ) protein. Because CF is an orphan disease, therapeutic strategies aimed at improving mutant CFTR functions are needed to target the root cause of CF . Experimental Approach Human CF airway epithelial cells were treated with roscovitine 100 μ M for 2 h before CFTR maturation, expression and activity were examined. The mechanism of action of roscovitine was explored by recording the effect of depleting endoplasmic reticulum ( ER ) Ca 2+ on the F 508del‐ CFTR /calnexin interaction and by measuring proteasome activity. Key Results Of the cyclin‐dependent kinase ( CDK ) inhibitors investigated, roscovitine was found to restore the cell surface expression and defective channel function of F 508del‐ CFTR in human CF airway epithelial cells. Neither olomoucine nor ( S )‐ CR 8, two very efficient CDK inhibitors, corrected F 508del‐ CFTR trafficking demonstrating that the correcting effect of roscovitine was independent of CDK inhibition. Competition studies with inhibitors of the ER quality control ( ERQC ) indicated that roscovitine acts on the calnexin pathway and on the degradation machinery. Roscovitine was shown (i) to partially inhibit the interaction between F 508del‐ CFTR and calnexin by depleting ER Ca 2+ and (ii) to directly inhibit the proteasome activity in a Ca 2+ ‐independent manner. Conclusions and Implications Roscovitine is able to correct the defective function of F 508del‐ CFTR by preventing the ability of the ERQC to interact with and degrade F 508del‐ CFTR via two synergistic but CDK ‐independent mechanisms. Roscovitine has potential as a pharmacological therapy for CF.