TY - JOUR
T1 - Cholesterol-regulated translocation of NPC1L1 to the cell surface facilitates free cholesterol uptake
AU - Yu, Liqing
AU - Bharadwaj, Shantaram
AU - Brown, J. Mark
AU - Ma, Yinyan
AU - Du, Wei
AU - Davis, Matthew A.
AU - Michaely, Peter
AU - Liu, Pingsheng
AU - Willingham, Mark C.
AU - Rudel, Lawrence L.
PY - 2006/3/10
Y1 - 2006/3/10
N2 - Although NPC1L1 is required for intestinal cholesterol absorption, data demonstrating mechanisms by which this protein facilitates the process are few. In this study, a hepatoma cell line stably expressing human NPC1L1 was established, and cholesterol uptake was studied. A relationship between NPC1L1 intracellular trafficking and cholesterol uptake was apparent. At steady state, NPC1L1 proteins localized predominantly to the transferrin-positive endocytic recycling compartment, where free cholesterol also accumulated as revealed by filipin staining. Interestingly, acute cholesterol depletion induced with methyl-β-cyclodextrin stimulated relocation of NPC1L1 to the plasma membrane, preferentially to a newly formed "apical-like" subdomain. This translocation was associated with a remarkable increase in cellular cholesterol uptake, which in turn was dose-dependently inhibited by ezetimibe, a novel cholesterol absorption inhibitor that specifically binds to NPC1L1. These findings define a cholesterol-regulated endocytic recycling of NPC1L1 as a novel mechanism regulating cellular cholesterol uptake.
AB - Although NPC1L1 is required for intestinal cholesterol absorption, data demonstrating mechanisms by which this protein facilitates the process are few. In this study, a hepatoma cell line stably expressing human NPC1L1 was established, and cholesterol uptake was studied. A relationship between NPC1L1 intracellular trafficking and cholesterol uptake was apparent. At steady state, NPC1L1 proteins localized predominantly to the transferrin-positive endocytic recycling compartment, where free cholesterol also accumulated as revealed by filipin staining. Interestingly, acute cholesterol depletion induced with methyl-β-cyclodextrin stimulated relocation of NPC1L1 to the plasma membrane, preferentially to a newly formed "apical-like" subdomain. This translocation was associated with a remarkable increase in cellular cholesterol uptake, which in turn was dose-dependently inhibited by ezetimibe, a novel cholesterol absorption inhibitor that specifically binds to NPC1L1. These findings define a cholesterol-regulated endocytic recycling of NPC1L1 as a novel mechanism regulating cellular cholesterol uptake.
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U2 - 10.1074/jbc.M511123200
DO - 10.1074/jbc.M511123200
M3 - Article
C2 - 16407187
AN - SCOPUS:33646564118
SN - 0021-9258
VL - 281
SP - 6616
EP - 6624
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 10
ER -