Abstract
Lipoprotein cholesterol is delivered to the limiting membrane of late endosomes/lysosomes (LELs) by Niemann-Pick C1 (NPC1). However, the mechanism of cholesterol transport from LELs to the endoplasmic reticulum (ER) is poorly characterized. We report that oxysterol-binding protein-related protein 1L (ORP1L) is necessary for this stage of cholesterol export. CRISPR-mediated knockout of ORP1L in HeLa and HEK293 cells reduced esterification of cholesterol to the level in NPC1 knockout cells, and it increased the expression of sterol-regulated genes and de novo cholesterol synthesis, indicative of a block in cholesterol transport to the ER. In the absence of this transport pathway, cholesterol-enriched LELs accumulated in the Golgi/perinuclear region. Cholesterol delivery to the ER required the sterol-, phosphatidylinositol 4-phosphate-, and vesicle-associated membrane protein-associated protein (VAP)-binding activities of ORP1L, as well as NPC1 expression. These results suggest that ORP1L-dependent membrane contacts between LELs and the ER coordinate cholesterol transfer with the retrograde movement of endo-lysosomal vesicles.
| Original language | English |
|---|---|
| Pages (from-to) | 1807-1818 |
| Number of pages | 12 |
| Journal | Cell Reports |
| Volume | 19 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - May 30 2017 |
Bibliographical note
Funding Information:We thank Mark Charman and Robert Douglas for technical assistance, Mary-Jane Travors for EM analysis, and Antonietta Pietrangelo for critical review of the manuscript. Dr. Thomas Lagace (Ottawa Heart Institute) provided the LDLR antibody. Funding was provided by the Canadian Institutes of Health Research MOP-15284 (to N.D.R.) and the Bernard and Winnifred Mary Lockwood Endowment.
Publisher Copyright:
© 2017 The Author(s)
ASJC Scopus Subject Areas
- General Biochemistry,Genetics and Molecular Biology
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't