Intracellular cholesterol trafficking is dependent upon NPC2 interaction with Lysobisphosphatidic Acid
- Rutgers University, United States
Abstract
Unesterified cholesterol accumulation in the late endosomal/lysosomal (LE/LY) compartment is the cellular hallmark of Niemann-Pick C (NPC) disease, caused by defects in the genes encoding NPC1 or NPC2. We previously reported the dramatic stimulation of NPC2 cholesterol transport rates to and from model membranes by the LE/LY phospholipid lysobisphosphatidic acid (LBPA). It had been previously shown that enrichment of NPC1-deficient cells with LBPA results in cholesterol clearance. Here we demonstrate that LBPA enrichment in human NPC2-deficient cells, either directly or via its biosynthetic precursor phosphtidylglycerol (PG), is entirely ineffective, indicating an obligate functional interaction between NPC2 and LBPA in cholesterol trafficking. We further demonstrate that NPC2 interacts directly with LBPA and identify the NPC2 hydrophobic knob domain as the site of interaction. Together these studies reveal a heretofore unknown step of intracellular cholesterol trafficking which is critically dependent upon the interaction of LBPA with functional NPC2 protein.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files
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1nep, Epididymal secretory protein E1Orientation of Proteins in Membranes (OPM) Database.
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NPC intracellular cholesterol transporter 2 isoform 2 precursor [Homo sapiens]NCBI Protein Database, NP_006423.1.
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NPC intracellular cholesterol transporter 2 precursor [Mus musculus]NCBI Protein Database, NP_075898.1.
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NPC intracellular cholesterol transporter 2 precursor [Bos taurus]NCBI Protein Database, NP_776343.1.
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epididymal secretory protein E1 [Felis catus]NCBI Protein Database, XP_003987882.1.
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NPC intracellular cholesterol transporter 2 precursor [Pan troglodytes]NCBI Protein Database, NP_001009075.1.
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NPC2 [Saccharomyces cerevisiae]NCBI Protein Database, KZV12184.1.
Article and author information
Author details
Funding
Ara Parseghian Medical Research Foundation
- Olga Ilnytska
- Judith Storch
American Heart Association (11PRE7330012)
- Leslie A McCauliff
American Heart Association (18CDA34110230)
- Olga Ilnytska
American Heart Association (14GRNT19990014)
- Judith Storch
National Institutes of Health (GM 1125866)
- Judith Storch
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2019, McCauliff et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Intracellular cholesterol trafficking is dependent upon NPC2 interaction with Lysobisphosphatidic Acid
eLife 8:e50832.
https://doi.org/10.7554/eLife.50832
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