Waheed Shabbir, Keun-Hang Susan Yang, Afzal M Dogar, Dmytro Isaev, Murat Oz
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引用次数: 0
Abstract
Background: The activity of the amiloride-sensitive epithelial sodium channel (ENaC) in the tight epithelia of the lung is regulated by proteolytic activation and ubiquitination. Pathophysiology of lung diseases is directly related to changes in one or both of these mechanisms.
Methods: In this study, we investigated the impact of ubiquitination and cathepsin-mediated proteolytic activation mechanisms on the functional regulation of ENaC in lung cancer A549 cells using the patch-clamp technique.
Results: Our findings suggest that inhibiting the proteasome (polyubiquitination) with MG132 improves ENaC activity, whereas altering the pH of the lysosome (monoubiquitination inhibition) with NH4Cl has no effect on ENaC activity. In A549 cells, inhibition of cathepsin B (CSTB) decreased the ENaC current, open probabilities (NPo and Po), and the number of active channels.
Conclusion: These findings delineate novel modes of ENaC degradation and proteolytic activation of functional channels in A549 cells. Our findings indicate that both proteolytic activation and ubiquitination of ENaC significantly affect channel function and add new insights into the endogenous ENaC processing which might help to further understand the pathophysiology of the lung disease.
期刊介绍:
Current Molecular Pharmacology aims to publish the latest developments in cellular and molecular pharmacology with a major emphasis on the mechanism of action of novel drugs under development, innovative pharmacological technologies, cell signaling, transduction pathway analysis, genomics, proteomics, and metabonomics applications to drug action. An additional focus will be the way in which normal biological function is illuminated by knowledge of the action of drugs at the cellular and molecular level. The journal publishes full-length/mini reviews, original research articles and thematic issues on molecular pharmacology.
Current Molecular Pharmacology is an essential journal for every scientist who is involved in drug design and discovery, target identification, target validation, preclinical and clinical development of drugs therapeutically useful in human disease.