The target of ezetimibe is Niemann-Pick C1-Like 1 (NPC1L1).
Ezetimibe is a potent inhibitor of cholesterol absorption that has been approved for the treatment of hypercholesterolemia, but its molecular target has been elusive. Using a genetic approach, we recently identified Niemann-Pick C1-Like 1 (NPC1L1) as a critical mediator of cholesterol absorption and an essential component of the ezetimibe-sensitive pathway. To determine whether NPC1L1 is the direct molecular target of ezetimibe, we have developed a binding assay and shown that labeled ezetimibe glucuronide binds specifically to a single site in brush border membranes and to human embryonic kidney 293 cells expressing NPC1L1. Moreover, the binding affinities of ezetimibe and several key analogs to recombinant NPC1L1 are virtually identical to those observed for native enterocyte membranes. KD values of ezetimibe glucuronide for mouse, rat, rhesus monkey, and human NPC1L1 are 12,000, 540, 40, and 220 nM, respectively. Last, ezetimibe no longer binds to membranes from NPC1L1 knockout mice. These results unequivocally establish NPC1L1 as the direct target of ezetimibe and should facilitate efforts to identify the molecular mechanism of cholesterol transport.
Garcia-Calvo
Margarita
M
Department of Metabolic Disorders, Merck Research Laboratories, Rahway, NJ 07065, USA. magarita-garcia-calvo@merck.com
Lisnock
JeanMarie
J
Bull
Herbert G
HG
Hawes
Brian E
BE
Burnett
Duane A
DA
Braun
Matthew P
MP
Crona
James H
JH
Davis
Harry R
HR
Dean
Dennis C
DC
Detmers
Patricia A
PA
Graziano
Michael P
MP
Hughes
Meredith
M
Macintyre
D Euan
DE
Ogawa
Anthony
A
O'neill
Kim A
KA
Iyer
Sai Prasad N
SP
Shevell
Diane E
DE
Smith
Marsha M
MM
Tang
Yui S
YS
Makarewicz
Amanda M
AM
Ujjainwalla
Feroze
F
Altmann
Scott W
SW
Chapman
Kevin T
KT
Thornberry
Nancy A
NA
D000818:Animals; D001384:Azetidines / Q000737:chemistry / Q000494:pharmacology*; D001665:Binding Sites; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D020895:Enterocytes / Q000166:cytology / Q000378:metabolism; D000069438:Ezetimibe; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000166:cytology; D008253:Macaca mulatta; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008871:Microvilli / Q000378:metabolism; D009542:Niemann-Pick Diseases; D011485:Protein Binding; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013045:Species Specificity
D001384:Azetidines; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C410800:NPC1L1 protein, human; C482444:NPC1L1 protein, rat; C482445:Npc1l1 protein, mouse; D011506:Proteins; D000069438:Ezetimibe