Cathepsin B Is Secreted Apically from Xenopus 2F3 Cells and Cleaves the Epithelial Sodium Channel (ENaC) to Increase Its Activity

• Type of Material: Article
• Authors: Abdel A. Alli, Emory University; John Z. Song, Emory University; Otor Al-Khalili, Emory University; Hui-Fang Bao, Emory University; Heping Ma, Emory University; Alia A. Alli, Emory University; Douglas C Eaton, Emory University
• Language: English
• Date: 2012-08-31
• Publisher: American Society for Biochemistry and Molecular Biology
• Publication Version: Final Published Version
• Copyright Statement: © 2012 by The American Society for Biochemistry and Molecular Biology, Inc.
• Final Published Version (URL): http://www.jbc.org/content/287/36/30073
• Title of Journal or Parent Work: Journal of Biological Chemistry
• ISSN: 0021-9258
• Volume: 287
• Issue: 36
• Start Page: 30073
• End Page: 30083
• Grant/Funding Information: This work was supported, in whole or in part, by National Institutes of Health Grants F32 DK093255–01 (to Abdel A. Alli), T32 DK007771 (to C. A. Parkos), 5R01 DK067110 (to H.-P. M.), and R37 DK037963 (to D. C. E.).
• Keywords: Cathepsin B; ENaC Activation; Epithelial Cell; Sodium Transport; Cysteine Protease; Proteolytic Enzymes; ENaC
• Research Categories: Biology, Physiology; Chemistry, Biochemistry

Abstract

Background: Epithelial sodium channels (ENaC) are activated by proteolytic cleavage. Several proteases including furin and prostasin cleave ENaC. Results: Cathepsin B also cleaves and activates ENaC. Cathepsin B cleaves ENaC α but not β or γ subunits. Conclusion: Cathepsin B is a secreted protease, so it may cleave ENaC at the cell surface. Significance: Cathepsin B cleavage represents a novel ENaC regulatory mechanism.