title: Na+/K+-ATPase β1-subunit is recruited in Na-K-2Cl co-transporter isoform 2 multiprotein complexes in rat kidneys: possible role in blood pressure regulation.
abstract: OBJECTIVE
  The progression from prehypertensive to hypertensive state in spontaneous hypertensive rats (SHRs) is accompanied by a significant increase in membrane expression of Na-K-2Cl co-transporter isoform 2 (NKCC2), suggesting that the altered NKCC2 trafficking and activity are directly related with the development of hypertension in this strain. The aim of this work is to gain insights on the molecular mechanism that underlies this phenomenon.
  
  
  METHODS
  We performed a comparative analysis of NKCC2 multiprotein complexes (MPCs) in the kidney of SHRs versus Wistar Kyoto rats by Blue Native difference gel electrophoresis combined with mass spectrometry.
  
  
  RESULTS
  We found that the recruitment of the β-subunit isoform 1 of the Na(+)-K(+)-ATPase (β1NK) in NKCC2 MPCs was significantly increased in the kidneys of SHR compared with Wistar Kyoto rat control strain. Co-immunoprecipitation experiments showed that β1NK actually interacts with NKCC2 in the native tissue. The analysis of the physiological role of β1NK-NKCC2 interaction in human embryonic kidney cells showed that β1NK increased the steady-state membrane expression and activity of NKCC2 enhancing NKCC2 trafficking toward the plasma membrane.
  
  
  CONCLUSIONS
  We identify a new NKCC2-interacting partner involved in the modulation of NKCC2 intracellular trafficking and possibly involved in the regulation of blood pressure.
authors.affiliation: aDepartment of Sciences, University of Basilicata, Potenza bDepartment of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari cDepartment of Environmental Sciences, Tuscia University, Viterbo dConsiglio Nazionale delle Ricerche, Bari, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Carmosino
authors.forename: Silvia
authors.initials: S
authors.lastname: Torretta
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Procino
authors.forename: Annamaria
authors.initials: A
authors.lastname: Timperio
authors.forename: Lello
authors.initials: L
authors.lastname: Zolla
authors.forename: Maria
authors.initials: M
authors.lastname: Svelto
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D018450:Disease Progression; D006801:Humans; D006973:Hypertension / Q000209:etiology* / Q000378:metabolism; D047468:Immunoprecipitation; D007668:Kidney / Q000378:metabolism*; D008297:Male; D046912:Multiprotein Complexes / Q000378:metabolism; D058246:Prehypertension / Q000378:metabolism; D020033:Protein Isoforms / Q000378:metabolism; D021381:Protein Transport; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012964:Sodium / Q000378:metabolism; D028021:Sodium-Potassium-Chloride Symporters / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D027981:Symporters
chemical_list: D046912:Multiprotein Complexes; D020033:Protein Isoforms; D028021:Sodium-Potassium-Chloride Symporters; D027981:Symporters; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase