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Angiotensin II signaling increases activity of the renal Na-Cl cotransporter through a WNK4-SPAK-dependent pathway

2009 , San-Cristóbal, Pedro , Pacheco Álvarez, Diana , Richardson, Ciaran , Ring, Aaron M. , Vazquez, Norma , Rafiqi, Fatema H. , Chari, Divya , Kahle, Kristopher T. , Leng, Qiang , Bobadilla, Norma A. , Hebert, Steven C. , Alessi, Dario R. , Lifton, Richard P. , Gamba, Gerardo

Mutations in the kinase WNK4 cause pseudohypoaldosteronism type II (PHAII), a syndrome featuring hypertension and high serum K(+) levels (hyperkalemia). WNK4 has distinct functional states that regulate the balance between renal salt reabsorption and K(+) secretion by modulating the activities of renal transporters and channels, including the Na-Cl cotransporter NCC and the K(+) channel ROMK. WNK4's functions could enable differential responses to intravascular volume depletion (hypovolemia) and hyperkalemia. Because hypovolemia is uniquely associated with high angiotensin II (AngII) levels, AngII signaling might modulate WNK4 activity. We show that AngII signaling in Xenopus oocytes increases NCC activity by abrogating WNK4's inhibition of NCC but does not alter WNK4's inhibition of ROMK. This effect requires AngII, its receptor AT1R, and WNK4, and is prevented by the AT1R inhibitor losartan. NCC activity is also increased by WNK4 harboring mutations found in PHAII, and this activity cannot be further augmented by AngII signaling, consistent with PHAII mutations providing constitutive activation of the signaling pathway between AT1R and NCC. AngII's effect on NCC is also dependent on the kinase SPAK because dominant-negative SPAK or elimination of the SPAK binding motif in NCC prevent activation of NCC by AngII signaling. These effects extend to mammalian cells. AngII increases phosphorylation of specific sites on SPAK and NCC that are necessary for activation of each in mpkDCT cells. These findings place WNK4 in the signaling pathway between AngII and NCC, and provide a mechanism by which hypovolemia maximizes renal salt reabsoprtion without concomitantly increasing K(+) secretion. © Proceedings of the National Academy of Sciences

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WNK3 is a Putative Chloride-sensing Kinase

2011 , Pacheco Álvarez, Diana , Gamba, Gerardo

The with-no-lysine kinase 3 (WNK3) is a serine/threonine kinase that modulates the activity of the electroneutral cation-coupled chloride cotransporters (CCC). Using the Xenopus laevis oocyte heterologous expression system, it has been shown that WNK3 activates the Na(+)-coupled chloride cotransporters NKCC1, NKCC2, and NCC and inhibits the K(+)-coupled chloride cotransporters KCC1 through KCC4. Interestingly, the effect of catalytically inactive WNK3 is opposite to that of wild type WNK3: inactive WNK3 inhibits NKCCs and activates KCCs. In doing so, wild type and catalytically inactive WNK3 bypass the tonicity requirement for activation/inhibition of the cotransporter. Thus, WNK3 modulation of the electroneutral cotransporters promotes Cl(-) influx and prevents Cl(-) efflux, thus fitting the profile for a putative "Cl(-)-sensing kinase". Other kinases that potentially have these properties are the Ste20-type kinases, SPAK/OSR1, which become phosphorylated in response to reductions in intracellular chloride concentration and regulate the activity of NKCC1. It has been demonstrated that WNKs lie upstream of SPAK/OSR1 and that the activity of these kinases is activated by phosphorylation of threonines in the T-loop by WNKs. It is possible that a protein phosphatase is also involved in the WNK3 effects on its associated cotransporters because activation of KCCs and inhibition of NKCCs by inactive WNK3 can be prevented by known inhibitors of protein phosphatases, such as calyculin A and cyclosporine, suggesting that a protein phosphatase is also involved in the protein complex. Copyright © 2011 S. Karger AG, Basel. © Cellular Physiology and Biochemistry

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The European Eel NCCβ Gene Encodes a Thiazide-resistant Na-Cl Cotransporter

2016 , Moreno, Erika , Plata, Consuelo , Rodríguez-Gama, Alejandro , Argaiz, Eduardo R. , Vázquez, Norma , Leyva Ríos, Karla , Islas, León , Cutler, Christopher , Pacheco Álvarez, Diana , Mercado, Adriana , Cariño-Cortés, Raquel , Castañeda-Bueno, María , Gamba, Gerardo

The thiazide-sensitive Na-Cl cotransporter (NCC) is the major pathway for salt reabsorption in the mammalian distal convoluted tubule. NCC plays a key role in the regulation of blood pressure. Its inhibition with thiazides constitutes the primary baseline therapy for arterial hypertension. However, the thiazide-binding site in NCC is unknown. Mammals have only one gene encoding for NCC. The eel, however, contains a duplicate gene. NCCα is an ortholog of mammalian NCC and is expressed in the kidney. NCCβ is present in the apical membrane of the rectum. Here we cloned and functionally characterized NCCβ from the European eel. The cRNA encodes a 1043-amino acid membrane protein that, when expressed in Xenopus oocytes, functions as an Na-Cl cotransporter with two major characteristics, making it different from other known NCCs. First, eel NCCβ is resistant to thiazides. Single-point mutagenesis supports that the absence of thiazide inhibition is, at least in part, due to the substitution of a conserved serine for a cysteine at position 379. Second, NCCβ is not activated by low-chloride hypotonic stress, although the unique Ste20-related proline alanine-rich kinase (SPAK) binding site in the amino-terminal domain is conserved. Thus, NCCβ exhibits significant functional differences from NCCs that could be helpful in defining several aspects of the structure-function relationship of this important cotransporter. © 2016 ASBMB. Currently published by Elsevier Inc; originally published by American Society for Biochemistry and Molecular Biology.

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Aspectos estructurales, funcionales y patológicos del cotransportador de NaCl sensible a tiazidas

2014-11 , Moreno, Erika , Pacheco Álvarez, Diana , Ríos Argaiz, Eduardo

El cotransportador de Na-Cl sensible a tiazidas (NCC o CST) es la principal vía de reabsorción de sal en el túbulo distal de la nefrona y es el sitio de acción de los diuréticos de tipo tiazida que, por su utilidad en el manejo de la hipertensión arterial, se encuentran dentro de los medicamentos más recetados en el mundo. El NCC es una proteína de suma importancia para la fisiología renal, ya que permite mantener la homeostasis de sal y agua en el organismo. Cuando suceden mutaciones inactivantes en el gen que codifica para este cotransportador se produce una enfermedad conocida como síndrome de Gitelman, el cual es un trastorno autosómico recesivo caracterizado clínicamente por hipotensión arterial, alcalosis metabólica, hipocalemia e hipocalciuria, lo que resalta la importancia de este gen en la regulación de la presión arterial y el equilibrio hidroelectrolítico. En este trabajo hacemos una breve revisión de los conocimientos que se tienen acerca de este cotransportador, con especial énfasis en la biología molecular, propiedades fisiológicas y aspectos patológicos del NCC. ©Revista de Investigación Clínica

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WNK3 and WNK4 exhibit opposite sensitivity with respect to cell volume and intracellular chloride concentration

2020 , Pacheco Álvarez, Diana , Carrillo-Pérez, Diego Luis , Mercado, Adriana , Leyva Ríos, Karla , Moreno, Erika , Castañeda-Bueno, María , Elisa Hernández-Mercado , Vázquez, Norma , Gamba, Gerardo

Cation-coupled chloride cotransporters (CCC) play a role in modulating intracellular chloride concentration ([Cl-]i) and cell volume. Cell shrinkage and cell swelling are accompanied by an increase or decrease in [Cl-]i, respectively. Cell shrinkage and a decrease in [Cl-]i increase the activity of NKCCs (Na-K-Cl cotransporters: NKCC1, NKCC2, and Na-Cl) and inhibit the activity of KCCs (K-Cl cotransporters: KCC1 to KCC4), wheras cell swelling and an increase in [Cl-]i activate KCCs and inhibit NKCCs; thus, it is unlikely that the same kinase is responsible for both effects. WNK1 and WNK4 are chloride-sensitive kinases that modulate the activity of CCC in response to changes in [Cl-]i. Here, we showed that WNK3, another member of the serine-threonine kinase WNK family with known effects on CCC, is not sensitive to [Cl-]i but can be regulated by changes in extracellular tonicity. In contrast, WNK4 is highly sensitive to [Cl-]i but is not regulated by changes in cell volume. The activity of WNK3 toward NaCl cotransporter is not affected by eliminating the chloride-binding site of WNK3, further confirming that the kinase is not sensitive to chloride. Chimeric WNK3/WNK4 proteins were produced, and analysis of the chimeras suggests that sequences within the WNK’s carboxy-terminal end may modulate the chloride affinity. We propose that WNK3 is a cell volume-sensitive kinase that translates changes in cell volume into phosphorylation of CCC. Copyright © 2020 the American Physiological Society

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WNK3-SPAK Interaction is Required for the Modulation of NCC and other Members of the SLC12 Family

2012 , Pacheco Álvarez, Diana , Vázquez, Norma , Castañeda-Bueno, María , De los Heros, Paola , Cortes-González, César , Moreno, Erika , Meade, Patricia , Bobadilla, Norma A. , Gamba, Gerardo

The serine/threonine with no lysine kinase 3 (WNK3) modulates the activity of the electroneutral cation-coupled chloride cotransporters (CCC) to promote Cl(-) influx and prevent Cl(-) efflux, thus fitting the profile for a putative "Cl(-)-sensing kinase". The Ste20-type kinases, SPAK/OSR1, become phosphorylated in response to reduction in intracellular chloride concentration and regulate the activity of NKCC1. Several studies have now shown that WNKs function upstream of SPAK/OSR1. This study was designed to analyze the role of WNK3-SPAK interaction in the regulation of CCCs with particular emphasis on NCC. In this study we used the functional expression system of Xenopus laevis oocytes to show that different SPAK binding sites in WNK3 ((241, 872, 1336)RFxV) are required for the kinase to have effects on CCCs. WNK3-F1337A no longer activated NKCC2, but the effects on NCC, NKCC1, and KCC4 were preserved. In contrast, the effects of WNK3 on these cotransporters were prevented in WNK3-F242A. The elimination of F873 had no consequence on WNK3 effects. WNK3 promoted NCC phosphorylation at threonine 58, even in the absence of the unique SPAK binding site of NCC, but this effect was abolished in the mutant WNK3-F242A. Thus, our data support the hypothesis that the effects of WNK3 upon NCC and other CCCs require the interaction and activation of the SPAK kinase. The effect is dependent on one of the three binding sites for SPAK that are present in WNK3, but not on the SPAK binding sites on the CCCs, which suggests that WNK3 is capable of binding both SPAK and CCCs to promote their phosphorylation.

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WNK-SPAK-NCC cascade revisited: WNK1 stimulates the activity of the Na-Cl cotransporter via SPAK, an effect antagonized by WNK4

2014 , Chávez-Canales, María , Zhang, Chong , Soukaseum, Christelle , Moreno, Erika , Pacheco Álvarez, Diana , Vidal-Petiot, Emmanuelle , Castañeda-Bueno, María , Vázquez, Norma , Rojas-Vega, Lorena , Meermeier, Nicholas P. , Rogers, ,Shaunessy , Jeunemaitre, Xavier , Yang, Chao-Ling , Ellison, David H. , Gamba, Gerardo , Hadchouel, Juliette

The with-no-lysine (K) kinases, WNK1 and WNK4, are key regulators of blood pressure. Their mutations lead to familial hyperkalemic hypertension (FHHt), associated with an activation of the Na-Cl cotransporter (NCC). Although it is clear that WNK4 mutants activate NCC via Ste20 proline-alanine-rich kinase, the mechanisms responsible for WNK1-related FHHt and alterations in NCC activity are not as clear. We tested whether WNK1 modulates NCC through WNK4, as predicted by some models, by crossing our recently developed WNK1-FHHt mice (WNK1(+/FHHt)) with WNK4(-/-) mice. Surprisingly, the activated NCC, hypertension, and hyperkalemia of WNK1(+/FHHt) mice remain in the absence of WNK4. We demonstrate that WNK1 powerfully stimulates NCC in a WNK4-independent and Ste20 proline-alanine-rich kinase-dependent manner. Moreover, WNK4 decreases the WNK1 and WNK3-mediated activation of NCC. Finally, the formation of oligomers of WNK kinases through their C-terminal coiled-coil domain is essential for their activity toward NCC. In conclusion, WNK kinases form a network in which WNK4 associates with WNK1 and WNK3 to regulate NCC. © 2014 American Heart Association, Inc.

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Structure-function relationships in the sodium chloride cotransporter

2023 , Moreno, Erika , Pacheco Álvarez, Diana , Chávez-Canales, María , Elizalde, Stephanie , Leyva Ríos, Karla , Gamba, Gerardo

The thiazide sensitive Na+:Cl− cotransporter (NCC) is the principal via for salt reabsorption in the apical membrane of the distal convoluted tubule (DCT) in mammals and plays a fundamental role in managing blood pressure. The cotransporter is targeted by thiazide diuretics, a highly prescribed medication that is effective in treating arterial hypertension and edema. NCC was the first member of the electroneutral cation-coupled chloride cotransporter family to be identified at a molecular level. It was cloned from the urinary bladder of the Pseudopleuronectes americanus (winter flounder) 30 years ago. The structural topology, kinetic and pharmacology properties of NCC have been extensively studied, determining that the transmembrane domain (TM) coordinates ion and thiazide binding. Functional and mutational studies have discovered residues involved in the phosphorylation and glycosylation of NCC, particularly on the N-terminal domain, as well as the extracellular loop connected to TM7-8 (EL7-8). In the last decade, single-particle cryogenic electron microscopy (cryo-EM) has permitted the visualization of structures at high atomic resolution for six members of the SLC12 family (NCC, NKCC1, KCC1-KCC4). Cryo-EM insights of NCC confirm an inverted conformation of the TM1-5 and TM6-10 regions, a characteristic also found in the amino acid-polyamine-organocation (APC) superfamily, in which TM1 and TM6 clearly coordinate ion binding. The high-resolution structure also displays two glycosylation sites (N-406 and N-426) in EL7-8 that are essential for NCC expression and function. In this review, we briefly describe the studies related to the structure-function relationship of NCC, beginning with the first biochemical/functional studies up to the recent cryo-EM structure obtained, to acquire an overall view enriched with the structural and functional aspects of the cotransporter. Copyright © 2023 Moreno, Pacheco-Alvarez, Chávez-Canales, Elizalde, Leyva-Ríos and Gamba.

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Regulation of NKCC2 by a chloride-sensing mechanism involving the WNK3 and SPAK kinases

2008 , Ponce-Coria, José , San-Cristóbal, Pedro , Kahle, Kristopher T. , Vázquez, Norma , Pacheco Álvarez, Diana , De los Heros, Paola , Juárez, Patricia , Muñoz, Eva María , Michel, Gabriela , Bobadilla, Norma A. , Gimenez, Ignacio , Lifton, Richard P. , Hebert, Steven C. , Gamba, Gerardo

The Na+:K+:2Cl− cotransporter (NKCC2) is the target of loop diuretics and is mutated in Bartter's syndrome, a heterogeneous autosomal recessive disease that impairs salt reabsorption in the kidney's thick ascending limb (TAL). Despite the importance of this cation/chloride cotransporter (CCC), the mechanisms that underlie its regulation are largely unknown. Here, we show that intracellular chloride depletion in Xenopus laevis oocytes, achieved by either coexpression of the K-Cl cotransporter KCC2 or low-chloride hypotonic stress, activates NKCC2 by promoting the phosphorylation of three highly conserved threonines (96, 101, and 111) in the amino terminus. Elimination of these residues renders NKCC2 unresponsive to reductions of [Cl−]i. The chloride-sensitive activation of NKCC2 requires the interaction of two serine-threonine kinases, WNK3 (related to WNK1 and WNK4, genes mutated in a Mendelian form of hypertension) and SPAK (a Ste20-type kinase known to interact with and phosphorylate other CCCs). WNK3 is positioned upstream of SPAK and appears to be the chloride-sensitive kinase. Elimination of WNK3's unique SPAK-binding motif prevents its activation of NKCC2, as does the mutation of threonines 96, 101, and 111. A catalytically inactive WNK3 mutant also completely prevents NKCC2 activation by intracellular chloride depletion. Together these data reveal a chloride-sensing mechanism that regulates NKCC2 and provide insight into how increases in the level of intracellular chloride in TAL cells, as seen in certain pathological states, could drastically impair renal salt reabsorption.

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Rare mutations in SLC12A1 and SLC12A3 protect against hypertension by reducing the activity of renal salt cotransporters

2011 , Acuña, Rocío , Martínez-de-la-Maza, Lilia , Ponce-Coria, José , Vázquez, Norma , Ortal-Vite, Penélope , Pacheco Álvarez, Diana , Bobadilla, Norma A. , Gamba, Gerardo

Objectives: Screening for variants in SLC12A1 and SLC12A3 genes, encoding the renal Na:Cl (NCC) and Na:K:2Cl (NKCC2) cotransporters, respectively, in 3125 members of the Framingham Heart Study (FHS) revealed that carrying a rare mutation in one of these genes was associated with a significant reduction in blood pressure, in the risk of arterial hypertension, and of death due to cardiovascular disease. Because near 60% of the rare mutations identified have not been related to Bartter's or Gitelman's disease, the consequence of such mutations on cotransporter activity is unknown. Methods: We used the heterologous expression system of Xenopus laevis oocytes, microinjected with wild-type or mutant NCC or NKCC2 cRNAs, to examine the effect of these inferred NCC and NKCC2 mutations on the cotransporters' functional properties. Cotransporter activity was defined as the diuretic-sensitive radioactive tracer uptake and response to known modulators was assessed. © Journal of Hypertension