HK-2 human renal proximal tubule cells as a model for G protein-coupled receptor kinase type 4-mediated dopamine 1 receptor uncoupling

John J. Gildea, Ishan Shah, Ryan Weiss, Nicholas D. Casscells, Helen E. McGrath, Jin Zhang, Robin A. Felder

Research output: Contribution to journalArticle


HK-2 human renal proximal tubule cells (RPTC) are commonly used in the in vitro study of "normal" RPTCs. We discovered recently that HK-2 cells are uncoupled from dopamine 1 receptor (D1R) adenylyl cyclase (AC) stimulation. We hypothesized that G protein-coupled receptor kinase type 4 (GRK4) single nucleotide polymorphisms may be responsible for the D1R/AC uncoupling in HK-2. This hypothesis was tested by genotyping GRK4 single nucleotide polymorphisms, measuring D1-like receptor agonist (fenoldopam)-stimulated cAMP accumulation, quantifying D1R inhibition of sodium transport, and testing the ability of GRK4 small interfering RNA to reverse the D1R/AC uncoupling. We compared HK-2 with 2 normally coupled human RPTC cell lines and 2 uncoupled RPTC cell lines. The HK-2 cell line was found to have 4 of 6 potential GRK4 single nucleotide polymorphisms known to uncouple the D1R from AC (namely, R65L, A142V, and A486V). AC response to fenoldopam stimulation was increased in the 2 normally coupled human RPTC cell lines (FEN: 2.02±0.05-fold and 2.33±0.19-fold over control; P

Original languageEnglish (US)
Pages (from-to)505-511
Number of pages7
Issue number3
Publication statusPublished - Sep 2010



  • dopamine receptors
  • FRET
  • GRK4
  • HK-2
  • NaKATPase
  • NHE3
  • renal proximal tubule

ASJC Scopus subject areas

  • Internal Medicine

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