TY - JOUR
T1 - Interaction of Human OATP1B1 with PDZK1 Is Required for Its Trafficking to the Hepatocyte Plasma Membrane
AU - Wang, Pijun
AU - Murray, John W.
AU - Wolkoff, Allan W.
N1 - Publisher Copyright:
© 2023 by The American Society for Pharmacology and Experimental Therapeutics.
PY - 2023/10/1
Y1 - 2023/10/1
N2 - Uptake of xenobiotics by hepatocytes is mediated by specific proteins, including organic anion transporting polypeptides (OATPs), residing on the basolateral (sinusoidal) plasma membrane. Many of the OATPs have PDZ consensus binding sites, determined by their C-terminal 4 amino acids, while others do not. Mouse and rat OATP1A1 are associated with PDZK1, which is necessary for their trafficking to the plasma membrane. humanOATP1B1 (hOATP1B1) is a major drug transporter in human liver. Although localized to the plasma membrane, it was thought to lack a PDZ consensus motif, suggesting that the trafficking paradigm for murine OATPs is not applicable to human liver. The aimof the present study was to determine whether hOATP1B1 is a ligand for hPDZK1. hOATP1B1 immunoprecipitates with hPDZK1 following co-expression in 293T cells as well as in normal human liver. Co-expression with each of the 4 PDZ domains revealed interaction with domain 1 only. A truncated version of hOATP1B1 that lacks its terminal 4 amino acid PDZ binding motif as well as hOATP1B3, which does not contain a PDZ binding consensus motif, failed to interactwith hPDZK1. Immunofluorescencemicroscopy of hOATP1B1 in stably transfected HeLa cells that endogenously express hPDZK1 showed that it distributes predominantly along the plasma membrane whereas hOATP1B1 lacking its terminal 4 amino acids distributes primarily intracellularly with little plasma membrane localization. Similar to findings in rats and mice, human OATP1B1 is a ligand for PDZK1 and requires interaction with PDZK1 for optimal trafficking to the hepatocyte plasmamembrane.
AB - Uptake of xenobiotics by hepatocytes is mediated by specific proteins, including organic anion transporting polypeptides (OATPs), residing on the basolateral (sinusoidal) plasma membrane. Many of the OATPs have PDZ consensus binding sites, determined by their C-terminal 4 amino acids, while others do not. Mouse and rat OATP1A1 are associated with PDZK1, which is necessary for their trafficking to the plasma membrane. humanOATP1B1 (hOATP1B1) is a major drug transporter in human liver. Although localized to the plasma membrane, it was thought to lack a PDZ consensus motif, suggesting that the trafficking paradigm for murine OATPs is not applicable to human liver. The aimof the present study was to determine whether hOATP1B1 is a ligand for hPDZK1. hOATP1B1 immunoprecipitates with hPDZK1 following co-expression in 293T cells as well as in normal human liver. Co-expression with each of the 4 PDZ domains revealed interaction with domain 1 only. A truncated version of hOATP1B1 that lacks its terminal 4 amino acid PDZ binding motif as well as hOATP1B3, which does not contain a PDZ binding consensus motif, failed to interactwith hPDZK1. Immunofluorescencemicroscopy of hOATP1B1 in stably transfected HeLa cells that endogenously express hPDZK1 showed that it distributes predominantly along the plasma membrane whereas hOATP1B1 lacking its terminal 4 amino acids distributes primarily intracellularly with little plasma membrane localization. Similar to findings in rats and mice, human OATP1B1 is a ligand for PDZK1 and requires interaction with PDZK1 for optimal trafficking to the hepatocyte plasmamembrane.
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U2 - 10.1124/dmd.123.001248
DO - 10.1124/dmd.123.001248
M3 - Article
C2 - 37442606
AN - SCOPUS:85171393406
SN - 0090-9556
VL - 51
SP - 1342
EP - 1349
JO - Drug Metabolism and Disposition
JF - Drug Metabolism and Disposition
IS - 10
ER -