title: Dopamine regulation of Na+-K+-ATPase requires the PDZ-2 domain of sodium hydrogen regulatory factor-1 (NHERF-1) in opossum kidney cells.
abstract: Na(+)-K(+)-ATPase activity in renal proximal tubule is regulated by several hormones including parathyroid hormone (PTH) and dopamine. The current experiments explore the role of Na(+)/H(+) exchanger regulatory factor 1 (NHERF-1) in dopamine-mediated regulation of Na(+)-K(+)-ATPase. We measured dopamine regulation of ouabain-sensitive (86)Rb uptake and Na(+)-K(+)-ATPase α1 subunit phosphorylation in wild-type opossum kidney (OK) (OK-WT) cells, OKH cells (NHERF-1-deficient), and OKH cells stably transfected with full-length human NHERF-1 (NF) or NHERF-1 constructs with mutated PDZ-1 (Z1) or PDZ-2 (Z2) domains. Treatment with 1 μM dopamine decreased ouabain-sensitive (86)Rb uptake, increased phosphorylation of Na(+)-K(+)-ATPase α1-subunit, and enhanced association of NHERF-1 with D1 receptor in OK-WT cells but not in OKH cells. Transfection with wild-type, full-length, or PDZ-1 domain-mutated NHERF-1 into OKH cells restored dopamine-mediated regulation of Na(+)-K(+)-ATPase and D1-like receptor association with NHERF-1. Dopamine did not regulate Na(+)-K(+)-ATPase or increase D1-like receptor association with NHERF-1 in OKH cells transfected with mutated PDZ-2 domain. Dopamine stimulated association of PKC-ζ with NHERF-1 in OK-WT and OKH cells transfected with full-length or PDZ-1 domain-mutated NHERF-1 but not in PDZ-2 domain-mutated NHERF-1-transfected OKH cells. These results suggest that NHERF-1 mediates Na(+)-K(+)-ATPase regulation by dopamine through its PDZ-2 domain.
authors.affiliation: Department of Medicine/Kidney Disease Program, University of Louisville, Louisville, Kentucky, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Salyer
authors.forename: Nina
authors.initials: N
authors.lastname: Lesousky
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Weinman
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Clark
authors.forename: Eleanor D
authors.initials: ED
authors.lastname: Lederer
authors.forename: Syed J
authors.initials: SJ
authors.lastname: Khundmiri
mesh_terms: D000818:Animals; D002461:Cell Line, Transformed; D048293:Didelphis; D004298:Dopamine / Q000494:pharmacology / Q000502:physiology*; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D007687:Kidney Tubules, Proximal / Q000166:cytology / Q000378:metabolism*; D009154:Mutation; D054731:PDZ Domains / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D011493:Protein Kinase C / Q000378:metabolism; D021122:Protein Subunits / Q000378:metabolism; D017447:Receptors, Dopamine D1 / Q000819:agonists / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000378:metabolism; D017923:Sodium-Hydrogen Exchangers / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D000099221:Protein Kinase C zeta
chemical_list: D004298:Dopamine; D010750:Phosphoproteins; D011493:Protein Kinase C; D021122:Protein Subunits; D017447:Receptors, Dopamine D1; D016160:Retinoblastoma Protein; D017923:Sodium-Hydrogen Exchangers; D000254:Sodium-Potassium-Exchanging ATPase; D000099221:Protein Kinase C zeta; C093376:sodium-hydrogen exchanger regulatory factor