Abstract
Familial hyperkalemic hypertension (FHHt) can be mainly attributed to increased activity of the renal Na+:Cl- cotransporter (NCC), which is caused by altered expression and regulation of the with-no-lysine (K) 1 (WNK1) or WNK4 kinases. The WNK1 gene gives rise to a kidney-specific isoform that lacks the kinase domain (KS-WNK1), the expression of which occurs primarily in the distal convoluted tubule. The role played by KS-WNK1 in the modulation of the WNK/STE20-proline-alanine rich kinase (SPAK)/ NCC pathway remains elusive. In the present study, we assessed the effect of human KS-WNK1 on NCC activity and on the WNK4-SPAK pathway. Microinjection of oocytes with human KS-WNK1 cRNA induces remarkable activation and phosphorylation of SPAK and NCC. The effect of KS-WNK1 was abrogated by eliminating a WNK-WNK-interacting domain and by a specific WNK inhibitor, WNK463, indicating that the activation of SPAK/NCC by KS-WNK1 is due to interaction with another WNK kinase. Under control conditions in oocytes, the activating serine 335 of the WNK4 T loop is not phosphorylated. In contrast, this serine becomes phosphorylated when the intracellular chloride concentration ([Cl-]i) is reduced or when KS-WNK1 is coexpressed with WNK4. KS-WNK1-mediated activation of WNK4 is not due to a decrease of the [Cl-]i. Coimmunoprecipitation analysis revealed that KS-WNK1 and WNK4 interact with each other and that WNK4 becomes autophosphorylated at serine 335 when it is associated with KS-WNK1. Together, these observations suggest that WNK4 becomes active in the presence of KS-WNK1, despite a constant [Cl-]i.
| Original language | English (US) |
|---|---|
| Pages (from-to) | F734-F745 |
| Journal | American Journal of Physiology - Renal Physiology |
| Volume | 315 |
| Issue number | 3 |
| DOIs | |
| State | Published - Sep 6 2018 |
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Keywords
- Distal convoluted tubule
- Diuretics
- Na:Cl cotransporter
- Salt transport
- STE20-proline-alanine rich kinase
ASJC Scopus subject areas
- Physiology
- Urology
Cite this
Kidney-specific WNK1 isoform (KS-WNK1) is a potent activator of WNK4 and NCC. / Argaiz, Eduardo R.; Chavez-Canales, Maria; Ostrosky-Frid, Mauricio; Rodríguez-Gama, Alejandro; Vázquez, Norma; Gonzalez-Rodriguez, Xochiquetzal; Garcia-Valdes, Jesus; Hadchouel, Juliette; Ellison, David; Gamba, Gerardo.
In: American Journal of Physiology - Renal Physiology, Vol. 315, No. 3, 06.09.2018, p. F734-F745.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Kidney-specific WNK1 isoform (KS-WNK1) is a potent activator of WNK4 and NCC
AU - Argaiz, Eduardo R.
AU - Chavez-Canales, Maria
AU - Ostrosky-Frid, Mauricio
AU - Rodríguez-Gama, Alejandro
AU - Vázquez, Norma
AU - Gonzalez-Rodriguez, Xochiquetzal
AU - Garcia-Valdes, Jesus
AU - Hadchouel, Juliette
AU - Ellison, David
AU - Gamba, Gerardo
PY - 2018/9/6
Y1 - 2018/9/6
N2 - Familial hyperkalemic hypertension (FHHt) can be mainly attributed to increased activity of the renal Na+:Cl- cotransporter (NCC), which is caused by altered expression and regulation of the with-no-lysine (K) 1 (WNK1) or WNK4 kinases. The WNK1 gene gives rise to a kidney-specific isoform that lacks the kinase domain (KS-WNK1), the expression of which occurs primarily in the distal convoluted tubule. The role played by KS-WNK1 in the modulation of the WNK/STE20-proline-alanine rich kinase (SPAK)/ NCC pathway remains elusive. In the present study, we assessed the effect of human KS-WNK1 on NCC activity and on the WNK4-SPAK pathway. Microinjection of oocytes with human KS-WNK1 cRNA induces remarkable activation and phosphorylation of SPAK and NCC. The effect of KS-WNK1 was abrogated by eliminating a WNK-WNK-interacting domain and by a specific WNK inhibitor, WNK463, indicating that the activation of SPAK/NCC by KS-WNK1 is due to interaction with another WNK kinase. Under control conditions in oocytes, the activating serine 335 of the WNK4 T loop is not phosphorylated. In contrast, this serine becomes phosphorylated when the intracellular chloride concentration ([Cl-]i) is reduced or when KS-WNK1 is coexpressed with WNK4. KS-WNK1-mediated activation of WNK4 is not due to a decrease of the [Cl-]i. Coimmunoprecipitation analysis revealed that KS-WNK1 and WNK4 interact with each other and that WNK4 becomes autophosphorylated at serine 335 when it is associated with KS-WNK1. Together, these observations suggest that WNK4 becomes active in the presence of KS-WNK1, despite a constant [Cl-]i.
AB - Familial hyperkalemic hypertension (FHHt) can be mainly attributed to increased activity of the renal Na+:Cl- cotransporter (NCC), which is caused by altered expression and regulation of the with-no-lysine (K) 1 (WNK1) or WNK4 kinases. The WNK1 gene gives rise to a kidney-specific isoform that lacks the kinase domain (KS-WNK1), the expression of which occurs primarily in the distal convoluted tubule. The role played by KS-WNK1 in the modulation of the WNK/STE20-proline-alanine rich kinase (SPAK)/ NCC pathway remains elusive. In the present study, we assessed the effect of human KS-WNK1 on NCC activity and on the WNK4-SPAK pathway. Microinjection of oocytes with human KS-WNK1 cRNA induces remarkable activation and phosphorylation of SPAK and NCC. The effect of KS-WNK1 was abrogated by eliminating a WNK-WNK-interacting domain and by a specific WNK inhibitor, WNK463, indicating that the activation of SPAK/NCC by KS-WNK1 is due to interaction with another WNK kinase. Under control conditions in oocytes, the activating serine 335 of the WNK4 T loop is not phosphorylated. In contrast, this serine becomes phosphorylated when the intracellular chloride concentration ([Cl-]i) is reduced or when KS-WNK1 is coexpressed with WNK4. KS-WNK1-mediated activation of WNK4 is not due to a decrease of the [Cl-]i. Coimmunoprecipitation analysis revealed that KS-WNK1 and WNK4 interact with each other and that WNK4 becomes autophosphorylated at serine 335 when it is associated with KS-WNK1. Together, these observations suggest that WNK4 becomes active in the presence of KS-WNK1, despite a constant [Cl-]i.
KW - Distal convoluted tubule
KW - Diuretics
KW - Na:Cl cotransporter
KW - Salt transport
KW - STE20-proline-alanine rich kinase
UR - http://www.scopus.com/inward/record.url?scp=85051144127&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85051144127&partnerID=8YFLogxK
U2 - 10.1152/ajprenal.00145.2018
DO - 10.1152/ajprenal.00145.2018
M3 - Article
C2 - 29846116
AN - SCOPUS:85051144127
VL - 315
SP - F734-F745
JO - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
JF - American Journal of Physiology - Renal Fluid and Electrolyte Physiology
SN - 1931-857X
IS - 3
ER -