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Cytotechnology

, Volume 34, Issue 1–2, pp 1–9 | Cite as

Stable expression and functional characterization of a Na+-taurocholate cotransporting green fluorescent protein in human hepatoblastoma HepG2 cells

  • Gerd A. Kullak-UblickEmail author
  • Manfred G. Ismair
  • Ralf Kubitz
  • Marcus Schmitt
  • Dieter Häussinger
  • Bruno Stieger
  • Bruno Hagenbuch
  • Peter J. Meier
  • Ulrich Beuers
  • Gustav Paumgartner
Article

Abstract

Sodium-dependent uptake of bile acids from blood is aliver-specific function which is mediated by theNa+-taurocholate cotransporting polypeptide(Ntcp). We report the stable expression of aNa+-taurocholate cotransporting green fluorescentfusion protein in the human hepatoblastoma cell lineHepG2, normally lacking Ntcp expression. Ntcp-EGFPassociated green fluorescence colocalized with Ntcpimmunofluorescence in the plasma membrane. Intransfected HepG2 cells, the fusion protein mediatedthe sodium-dependent uptake of the bile acidtaurocholate (Km: 24.6 μmol/l) and of the anionicsteroids estrone-3-sulfate and dehydroepiandrosteronesulfate. We conclude that the Ntcp-EGFP fusion proteinfollows the sorting route of Ntcp, is functionallyidentical to Ntcp and could be used to monitor proteintrafficking in living HepG2 cells.

bile acids and salts bile formation cholestasis luminescent proteins organic anion transport 

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Copyright information

© Kluwer Academic Publishers 2000

Authors and Affiliations

  • Gerd A. Kullak-Ublick
    • 1
    • 2
    Email author
  • Manfred G. Ismair
    • 3
  • Ralf Kubitz
    • 4
  • Marcus Schmitt
    • 4
  • Dieter Häussinger
    • 4
  • Bruno Stieger
    • 3
  • Bruno Hagenbuch
    • 3
  • Peter J. Meier
    • 3
  • Ulrich Beuers
    • 5
  • Gustav Paumgartner
    • 5
  1. 1.Divisions of Clinical Pharmacology/Toxicology, Department of MedicineUniversity HospitalZürichSwitzerland
  2. 2.Gastroenterology/Hepatology, Department of MedicineUniversity HospitalZürichSwitzerland
  3. 3.Divisions of Clinical Pharmacology/Toxicology, Department of MedicineUniversity HospitalZürichSwitzerland
  4. 4.Department of MedicineUniversity of DüsseldorfDüsseldorfGermany
  5. 5.Department of Medicine II, Klinikum GrosshadernUniversity of MunichMunichGermany

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