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Ehret E, Stroh S, Auberson M, Ino F, Jäger Y, Maillard M, Szabo R, Bugge TH, Frateschi S, Hummler E. Kidney-Specific Membrane-Bound Serine Proteases CAP1/Prss8 and CAP3/St14 Affect ENaC Subunit Abundances but Not Its Activity. Cells 2023; 12:2342. [PMID: 37830556 PMCID: PMC10572026 DOI: 10.3390/cells12192342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/06/2023] [Accepted: 09/12/2023] [Indexed: 10/14/2023] Open
Abstract
The serine proteases CAP1/Prss8 and CAP3/St14 are identified as ENaC channel-activating proteases in vitro, highly suggesting that they are required for proteolytic activation of ENaC in vivo. The present study tested whether CAP3/St14 is relevant for renal proteolytic ENaC activation and affects ENaC-mediated Na+ absorption following Na+ deprivation conditions. CAP3/St14 knockout mice exhibit a significant decrease in CAP1/Prss8 protein expression with altered ENaC subunit and decreased pNCC protein abundances but overall maintain sodium balance. RNAscope-based analyses reveal co-expression of CAP3/St14 and CAP1/Prss8 with alpha ENaC in distal tubules of the cortex from wild-type mice. Double CAP1/Prss8; CAP3/St14-deficiency maintained Na+ and K+ balance on a Na+-deprived diet, restored ENaC subunit protein abundances but showed reduced NCC activity under Na+ deprivation. Overall, our data clearly show that CAP3/St14 is not required for direct proteolytic activation of ENaC but for its protein abundance. Our study reveals a complex regulation of ENaC by these serine proteases on the expression level rather than on its proteolytic activation.
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Affiliation(s)
- Elodie Ehret
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, 1011 Lausanne, Switzerland; (E.E.)
- National Center of Competence in Research “Kidney.CH”, 1011 Lausanne, Switzerland
| | - Sévan Stroh
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, 1011 Lausanne, Switzerland; (E.E.)
| | - Muriel Auberson
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, 1011 Lausanne, Switzerland; (E.E.)
| | - Frédérique Ino
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, 1011 Lausanne, Switzerland; (E.E.)
- Department of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Yannick Jäger
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, 1011 Lausanne, Switzerland; (E.E.)
- Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Marc Maillard
- Service of Nephrology, Department of Medicine, Lausanne University Hospital (CHUV), 1005 Lausanne, Switzerland
| | - Roman Szabo
- National Institutes of Health/NIDCR, Bethesda, MD 20892, USA
| | - Thomas H. Bugge
- National Institutes of Health/NIDCR, Bethesda, MD 20892, USA
| | - Simona Frateschi
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, 1011 Lausanne, Switzerland; (E.E.)
| | - Edith Hummler
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, 1011 Lausanne, Switzerland; (E.E.)
- National Center of Competence in Research “Kidney.CH”, 1011 Lausanne, Switzerland
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