Hypotonicity stimulates potassium flux through the WNK-SPAK/OSR1 kinase cascade and the Ncc69 sodium-potassium-2-chloride cotransporter in the drosophila renal tubule

Abstract

Background: Hypotonicity stimulates transepithelial ion and water flux in the Drosophila renal tubule through unknown mechanisms. Results: The with-no-lysine (WNK) and Ste20-related proline/alanine-rich (SPAK)/oxidative stress response (OSR1) kinase cascade regulates transepithelial K+flux through the fly sodium-potassium-2-chloride cotransporter (NKCC). Conclusion: The kinase/NKCC pathway is required for the tubule's response to hypotonicity. Significance: This provides a molecular mechanism by which flies osmoregulate.