Activation of the thiazide-sensitive Na+-Cl– cotransporter by the WNK-regulated kinases SPAK and OSR1
Open Access
- 1 March 2008
- journal article
- Published by The Company of Biologists in Journal of Cell Science
- Vol. 121 (5), 675-684
- https://doi.org/10.1242/jcs.025312
Abstract
Mutations increasing WNK1 kinase expression in humans cause the pseudohypoaldosteronism type II hypertension syndrome. This condition is treated effectively by thiazide diuretics, which exert their effects by inhibiting the Na+-Cl– cotransporter (NCC), suggesting a link between WNK1 and NCC. Here, we demonstrate that the SPAK and OSR1 kinases that are activated by WNK1 phosphorylate human NCC at three conserved residues (Thr46, Thr55 and Thr60). Activation of the WNK1-SPAK/OSR1 signalling pathway by treatment of HEK293 or mpkDCT kidney distal-convoluted-tubule-derived cells with hypotonic low-chloride conditions induced phosphorylation of NCC at residues phosphorylated by SPAK/OSR1. Efficient phosphorylation of NCC was dependent upon a docking interaction between an RFXI motif in NCC and SPAK/OSR1. Mutation of Thr60 to Ala in NCC markedly inhibited phosphorylation of Thr46 and Thr55 as well as NCC activation induced by hypotonic low-chloride treatment of HEK293 cells. Our results establish that the WNK1-SPAK/OSR1 signalling pathway plays a key role in controlling the phosphorylation and activity of NCC. They also suggest a mechanism by which increased WNK1 overexpression could lead to hypertension and that inhibitors of SPAK/OSR1 might be of use in reducing blood pressure by suppressing phosphorylation and hence activity of NCC.Keywords
This publication has 31 references indexed in Scilit:
- The thiazide-sensitive Na-Cl cotransporter is regulated by a WNK kinase signaling complexJCI Insight, 2007
- Structural insights into the recognition of substrates and activators by the OSR1 kinaseEMBO Reports, 2007
- Regulation of activity and localization of the WNK1 protein kinase by hyperosmotic stressThe Journal of cell biology, 2006
- WNK1 and OSR1 regulate the Na + , K + , 2Cl − cotransporter in HeLa cellsProceedings of the National Academy of Sciences of the United States of America, 2006
- Functional interactions of the SPAK/OSR1 kinases with their upstream activator WNK1 and downstream substrate NKCC1Biochemical Journal, 2006
- Automated Identification and Quantification of Protein Phosphorylation Sites by LC/MS on a Hybrid Triple Quadrupole Linear Ion Trap Mass SpectrometerMolecular & Cellular Proteomics, 2006
- Volume sensitivity of cation-Cl−cotransporters is modulated by the interaction of two kinases: Ste20-related proline-alanine-rich kinase and WNK4American Journal of Physiology-Cell Physiology, 2006
- Cation Chloride Cotransporters Interact with the Stress-related Kinases Ste20-related Proline-Alanine-rich Kinase (SPAK) and Oxidative Stress Response 1 (OSR1)Journal of Biological Chemistry, 2002
- Human Hypertension Caused by Mutations in WNK KinasesScience, 2001
- Vasopressin‐stimulated chloride transport in transimmortalized mouse cell lines derived from the distal convoluted tubule and cortical and inner medullary collecting ductsNephrology Dialysis Transplantation, 2001