title: Nogo-B receptor stabilizes Niemann-Pick type C2 protein and regulates intracellular cholesterol trafficking.
abstract: The Nogo-B receptor (NgBR) is a recently identified receptor for the N terminus of reticulon 4B/Nogo-B. Other than its role in binding Nogo-B, little is known about the biology of NgBR. To elucidate a basic cellular role for NgBR, we performed a yeast two-hybrid screen for interacting proteins, using the C-terminal domain as bait, and identified Niemann-Pick type C2 protein (NPC2) as an NgBR-interacting protein. NPC2 protein levels are increased in the presence of NgBR, and NgBR enhances NPC2 protein stability. NgBR localizes primarily to the endoplasmic reticulum (ER) and regulates the stability of nascent NPC2. RNAi-mediated disruption of NgBR or genetic deficiency in NgBR lead to a decrease in NPC2 levels, increased intracellular cholesterol accumulation, and a loss of sterol sensing, all hallmarks of an NPC2 mutation. These data identify NgBR as an NPC2-interacting protein and provide evidence of a role for NgBR in intracellular cholesterol trafficking.
authors.affiliation: Department of Pharmacology and Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, CT 06520, USA.
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Harrison
authors.forename: Robert Qing
authors.initials: RQ
authors.lastname: Miao
authors.forename: Carlos
authors.initials: C
authors.lastname: Fernandez-Hernándo
authors.forename: Yajaira
authors.initials: Y
authors.lastname: Suárez
authors.forename: Alberto
authors.initials: A
authors.lastname: Dávalos
authors.forename: William C
authors.initials: WC
authors.lastname: Sessa
mesh_terms: D000818:Animals; D016466:CHO Cells; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D002784:Cholesterol / Q000378:metabolism*; D008078:Cholesterol, LDL / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D004721:Endoplasmic Reticulum / Q000378:metabolism; D055785:Gene Knockdown Techniques; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D034741:RNA, Small Interfering / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D020798:Two-Hybrid System Techniques; D033921:Vesicular Transport Proteins
chemical_list: D002352:Carrier Proteins; D008078:Cholesterol, LDL; D006023:Glycoproteins; C104585:NPC2 protein, human; C512614:NUS1 protein, human; D034741:RNA, Small Interfering; D011956:Receptors, Cell Surface; D033921:Vesicular Transport Proteins; D002784:Cholesterol