Mechanism of regulation of renal ion transport by WNK kinases

作者：Huang Chou Long^*; Yang Sung Sen; Lin Shih Hua

来源：Current Opinion in Nephrology and Hypertension, 2008, 17(5): 519-525.

DOI：10.1097/MNH.0b013e32830dd580

• aldosterone
• Gordon's syndrome
• PHA2
• pseudohypoaldosteronism type 2
• WNK1
• WNK3
• WNK4

Purpose of review
This review summarizes recent advances in the understanding of the mechanism of regulation of renal ion transport by WNK kinases.
Recent findings
There are four mammalian WNK [with-no-lysine (K)] kinases: WNK1--WNK4. Mutations of WNK1 and INNK4 in humans cause hypertension and hyperkalemia at least partly by altering renal sodium and potassium transport. WNK1 and WNK4 stimulate endocytosis of ROMK1 by recruiting an endocytic scaffold protein, intersectin. The recruitment is independent of the kinase activity and occurs between the PXXP motif of WNKs and the SH3 domain of intersectin. Regulation of cation-chloride-cou pled cotransporters, Na+-K+-2Cl(-) cotransporter (NKCC) 1 and NKCC2 [and the Na-Cl cotransporter (NCC), undersome conditions] by WNKs requires kinase activity. WNK1 and WNK4 bind with and phosphorylate two Ste20-related protein kinases, OSR1 and SPAK, which in turn bind with and phosphorylate NKCCs and NCC to increase their activity. Binding of OSR1/SPAK to upstream activators (WNKs) and downstream substrates (NKCCs and NCC) are both mediated by a docking site ill the C-terminus of OSR1/SPAK and RFX[V/1] motifs present in WNKs or in NKCCs and NCC.
Summary
WNKs regulate ion transport via both catalytic and noncatalytic mechanisms. We discuss hypotheses that WNKs, contrasting with aldosterone, play important roles in dissociating sodium reabsorption from potassium secretion.

• 出版日期2008-9