title: Characterization of the cellular localization, expression level, and function of SNP variants of MRP2/ABCC2.
abstract: OBJECTIVE
  The presence of single nucleotide polymorphisms (SNPs) has been reported for multidrug resistance-associated protein 2 (MRP2/ABCC2). The purpose of the current study was to characterize the localization, expression level, and function of MRP2 variants.
  
  
  METHODS
  The expression and cellular localization of the wild-type and three kinds of reported SNP variants of MRP2 molecules were analyzed in LLC-PK1 cells after infection with the recombinant Tet-off adenoviruses. Their function was determined by using the isolated membrane vesicles from the infected LLC-PK1 cells.
  
  
  RESULTS
  The transport activity for E217betaG, LTC4, and DNP-SG, normalized by the expression level of MRP2, was similar between the wild-type, V417I, and A1450T MRP2s. The transport activity of S789F MRP2 was slightly higher than that of wild-type MRP2. However, the expression level of S789F and A1450T MRP2 proteins was significantly lower compared with the wild-type and V417I MRP2. In addition, although the wild-type and V417I MRP2 were exclusively localized in the apical membrane, S789F and A1450T MRP2 were located in the apical membrane and also in the intracellular compartment.
  
  
  CONCLUSIONS
  These results suggest that the most frequently observed V417I substitution may not affect the in vivo function of MRP2, whereas the much less frequently observed S789F and A1450T may be associated with the reduced in vivo function.
authors.affiliation: School of Pharmaceutical Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Hirouchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suzuki
authors.forename: Masaya
authors.initials: M
authors.lastname: Itoda
authors.forename: Shogo
authors.initials: S
authors.lastname: Ozawa
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Sawada
authors.forename: Ichiro
authors.initials: I
authors.lastname: Ieiri
authors.forename: Kenji
authors.initials: K
authors.lastname: Ohtsubo
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sugiyama
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D015153:Blotting, Western; D022162:Cytoplasmic Vesicles / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology; D007150:Immunohistochemistry; D018374:LLC-PK1 Cells; D017997:Leukotriene C4 / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D013552:Swine
chemical_list: D017997:Leukotriene C4; D004958:Estradiol