Sorting nexin 27 interacts with multidrug resistance-associated protein 4 (MRP4) and mediates internalization of MRP4.
J Biol Chem
; 287(18): 15054-65, 2012 Apr 27.
Article
en En
| MEDLINE
| ID: mdl-22411990
ABSTRACT
Multidrug resistance-associated protein 4 (MRP4/ABCC4) makes a vital contribution to the bodily distribution of drugs and endogenous compounds because of its cellular efflux abilities. However, little is known about the mechanism regulating its cell surface expression. MRP4 has a PDZ-binding motif, which is a potential sequence that modulates the membrane expression of MRP4 via interaction with PDZ adaptor proteins. To investigate this possible relationship, we performed GST pull-down assays and subsequent analysis with matrix-assisted laser desorption/ionization-time of flight mass spectrometry. This method identified sorting nexin 27 (SNX27) as the interacting PDZ adaptor protein with a PDZ-binding motif of MRP4. Its interaction was confirmed by a coimmunoprecipitation study using HEK293 cells. Knockdown of SNX27 by siRNA in HEK293 cells raised MRP4 expression on the plasma membrane, increased the extrusion of 6-[(14)C]mercaptopurine, an MRP4 substrate, and conferred resistance against 6-[(14)C]mercaptopurine. Cell surface biotinylation studies indicated that the inhibition of MRP4 internalization was responsible for these results. Immunocytochemistry and cell surface biotinylation studies using COS-1 cells showed that SNX27 localized to both the early endosome and the plasma membrane. These data suggest that SNX27 interacts with MRP4 near the plasma membrane and promotes endocytosis of MRP4 and thereby negatively regulates its cell surface expression and transport function.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Endosomas
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Membrana Celular
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Regulación de la Expresión Génica
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Proteínas Asociadas a Resistencia a Múltiples Medicamentos
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Nexinas de Clasificación
Tipo de estudio:
Risk_factors_studies
Límite:
Animals
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Humans
Idioma:
En
Año:
2012
Tipo del documento:
Article