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WNK4 regulates the balance between renal NaCl reabsorption and K+ secretion

Abstract

A key question in systems biology is how diverse physiologic processes are integrated to produce global homeostasis1. Genetic analysis can contribute by identifying genes that perturb this integration. One system orchestrates renal NaCl and K+ flux to achieve homeostasis of blood pressure and serum K+ concentration (refs. 2,3). Positional cloning implicated the serine-threonine kinase WNK4 in this process4; clustered mutations in PRKWNK4, encoding WNK4, cause hypertension and hyperkalemia (pseudohypoaldosteronism type II, PHAII5) by altering renal NaCl and K+ handling. Wild-type WNK4 inhibits the renal Na-Cl cotransporter (NCCT); mutations that cause PHAII relieve this inhibition6. This explains the hypertension of PHAII but does not account for the hyperkalemia. By expression in Xenopus laevis oocytes, we show that WNK4 also inhibits the renal K+ channel ROMK. This inhibition is independent of WNK4 kinase activity and is mediated by clathrin-dependent endocytosis of ROMK, mechanisms distinct from those that characterize WNK4 inhibition of NCCT. Most notably, the same mutations in PRKWNK4 that relieve NCCT inhibition markedly increase inhibition of ROMK. These findings establish WNK4 as a multifunctional regulator of diverse ion transporters; moreover, they explain the pathophysiology of PHAII. They also identify WNK4 as a molecular switch that can vary the balance between NaCl reabsorption and K+ secretion to maintain integrated homeostasis.

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Figure 1: WNK4 inhibits ROMK-mediated K+ currents.
Figure 2: WNK4 reduces surface expression of ROMK.
Figure 3: WNK4 inhibits ROMK through clathrin-dependent endocytosis and interacts with the C terminus of ROMK.
Figure 4: Mutant forms of WNK4 that cause PHAII increase inhibition of ROMK.
Figure 5: Role of WNK4 in regulating the balance between renal NaCl reabsorption and K+ secretion.

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References

  1. Ideker, T. et al. Integrated genomic and proteomic analyses of a systematically perturbed metabolic network. Science 292, 929–934 (2001).

    Article  CAS  Google Scholar 

  2. Lifton, R.P., Gharavi, A.G. & Geller, D.S. Molecular mechanisms of human hypertension. Cell 104, 545–556 (2001).

    Article  CAS  Google Scholar 

  3. Giebisch, G. Renal potassium transport: mechanisms and regulation. Am. J. Physiol. 274, F817–F833 (1998).

    CAS  PubMed  Google Scholar 

  4. Wilson, F.H. et al. Human hypertension caused by mutations in WNK kinases. Science 293, 1107–1112 (2001).

    Article  CAS  Google Scholar 

  5. Gordon, R.D. Syndrome of hypertension and hyperkalemia with normal glomerular filtration rate. Hypertension 8, 93–102 (1986).

    Article  CAS  Google Scholar 

  6. Wilson, F.H. et al. Molecular pathogenesis of inherited hypertension with hyperkalemia: the Na-Cl cotransporter is inhibited by wild-type but not mutant WNK4. Proc. Natl. Acad. Sci. USA 100, 680–684 (2003).

    Article  CAS  Google Scholar 

  7. Reeves, W.B. & Andreoli, T.E. Sodium chloride transport in the loop of Henle, distal convoluted tubule, and collecting duct. in The Kidney: Physiology and Pathophysiology. 3rd. edn. (eds. Seldin, D.W. & Giebisch, G.) 1333–1369 (Lippincott Williams and Wilkins, Philadelphia, Pennsylvania, 2000).

    Google Scholar 

  8. Verrey, F., Hummler, E., Schild, L. & Rossier, B.C. Control of Na+ transport by aldosterone. in The Kidney: Physiology and Pathophysiology. 3rd. edn. (eds. Seldin, D.W. & Giebisch, G.) 1441–1471 (Lippincott Williams and Wilkins, Philadelphia, Pennsylvania, 2000).

    Google Scholar 

  9. Xu, B. et al. WNK1, a novel mammalian serine/threonine protein kinase lacking the catalytic lysine in subdomain II. J. Biol. Chem. 275, 16795–16801 (2000).

    Article  CAS  Google Scholar 

  10. Zeng, W. et al. Evidence for endocytosis of ROMK potassium channel via clathrin-coated vesicles. Am. J. Physiol. Renal Physiol. 283, F630–F639 (2002).

    Article  Google Scholar 

  11. Mellman, I. Endocytosis and molecular sorting. Annu. Rev. Cell Dev. Biol. 12, 575–625 (1996).

    Article  CAS  Google Scholar 

  12. van der Bliek, A.M. et al. Mutations in human dynamin block an intermediate stage in coated vesicle formation. J. Cell Biol. 122, 553–563 (1993).

    Article  CAS  Google Scholar 

  13. Slepnev, V.I., Ochoa, G., Butler, M.H. & de Camilli, P. Tandem arrangement of the clathrin and AP-2 binding domains in amphiphysin 1 and disruption of clathrin coat function by amphiphysin fragments comprising these sites. J. Biol. Chem. 275, 17583–17589 (2000).

    Article  CAS  Google Scholar 

  14. Chen, J., Fujii, K., Zhang, L., Roberts, T. & Fu, H. Raf-1 promotes cell survival by antagonizing apoptosis signal-regulating kinase 1 through a MEK-ERK independent mechanism. Proc. Natl. Acad. Sci. USA 98, 7783–7788 (2001).

    Article  CAS  Google Scholar 

  15. Charette, S.J., Lambert, H. & Landry, J. A kinase-independent function of Ask1 in caspase-independent cell death. J. Biol. Chem. 276, 36071–36074 (2001).

    Article  CAS  Google Scholar 

  16. Choate, K.A., Kahle, K.T., Wilson, F.H., Nelson-Williams, C. & Lifton, R.P. WNK1, a kinase mutated in inherited hypertension with hyperkalemia, localizes to diverse Cl—transporting epithelia. Proc. Natl. Acad. Sci. USA 100, 663–668 (2003).

    Article  CAS  Google Scholar 

  17. Boim, M.A. et al. ROMK inwardly rectifying ATP-sensitive K+ channel. II. Cloning and distribution of alternative forms. Am. J. Physiol. 268, F1132–F1140 (1995).

    CAS  PubMed  Google Scholar 

  18. Ho, K. et al. Cloning and expression of an inwardly rectifying ATP-regulated potassium channel. Nature 362, 31–38 (1993).

    Article  CAS  Google Scholar 

  19. Gamba, G. et al. Primary structure and functional expression of a cDNA encoding the thiazide-sensitive, electroneutral sodium-chloride cotransporter. Proc. Natl. Acad. Sci. USA 90, 2749–2753 (1993).

    Article  CAS  Google Scholar 

  20. Leipziger, J. et al. PKA site mutations of ROMK2 channels shift the pH dependence to more alkaline values. Am. J. Physiol. Renal Physiol. 279, F919–F926 (2000).

    Article  CAS  Google Scholar 

  21. Ortega, B., Millar, I.D., Beesley, A.H., Robson, L. & White, S.J. Stable, polarised, functional expression of Kir1.1b channel protein in Madin-Darby canine kidney cell line. J. Physiol. 528, 5–13 (2000).

    Article  CAS  Google Scholar 

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Acknowledgements

We thank I. Giménez, P. Zhang and members of the laboratory of W. Boron for harvest of X. laevis oocytes, and P.Z. Svigals for technical assistance. This work was supported by a Specialized Center of Research Grant in Hypertension (R.P.L.) and an Interactive Program Grant (S.C.H.) from the US National Institutes of Health. K.T.K. is recipient of a Howard Hughes Medical Institute Medical Student Research Fellowship. M.D.L. is a recipient of a Human Frontiers Long Term Fellowship. R.P.L. is an Investigator of the Howard Hughes Medical Institute.

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Correspondence to Richard P Lifton.

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Kahle, K., Wilson, F., Leng, Q. et al. WNK4 regulates the balance between renal NaCl reabsorption and K+ secretion. Nat Genet 35, 372–376 (2003). https://doi.org/10.1038/ng1271

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