Cholesterol transport through lysosome-peroxisome membrane contacts
Authors: Hong-Hua Miao
Ya-Cheng Liao
Bei-Bei Chu
Wei Qi
Ximing Du
Jiang Wang
Bo-Liang Li
Chang Xie
Bao-Liang Song
Hongyuan Yang
Journal: Cell (2015)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: Cholesterol; Organelles; LDL-cholesterol transport; Peroxisome genes; Membrane contacts
Affiliations: State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China; College of Life Sciences, the Institute for Advanced Studies, Wuhan University, Wuhan 430072, China; College of Animal Sciences and Veterinary Medicine, Henan Agricultural University, Zhengzhou 450002, Henan Province, China., State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China., School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia., College of Animal Sciences and Veterinary Medicine, Henan Agricultural University, Zhengzhou 450002, Henan Province, China., College of Life Sciences, the Institute for Advanced Studies, Wuhan University, Wuhan 430072, China. Electronic address: .

Abstract:  Cholesterol is dynamically transported among organelles, which is essential for multiple cellular functions. However, the mechanism underlying intracellular cholesterol transport has remained largely unknown. We established an amphotericin B-based assay enabling a genome-wide shRNA screen for delayed LDL-cholesterol transport and identified 341 hits with particular enrichment of peroxisome genes, suggesting a previously unappreciated pathway for cholesterol transport. We show dynamic membrane contacts between peroxisome and lysosome, which are mediated by lysosomal Synaptotagmin VII binding to the lipid PI(4,5)P2 on peroxisomal membrane. LDL-cholesterol enhances such contacts, and cholesterol is transported from lysosome to peroxisome. Disruption of critical peroxisome genes leads to cholesterol accumulation in lysosome. Together, these findings reveal an unexpected role of peroxisome in intracellular cholesterol transport. We further demonstrate massive cholesterol accumulation in human patient cells and mouse model of peroxisomal disorders, suggesting a contribution of abnormal cholesterol accumulation to these diseases. 

Retracted: No

PubPeer comments:
null, 
null, 
null, 
 Is it possible they were pulling down non-intact peroxisomes? I can t see another explanation. I m not aware of any evidence of a  transporting intermediate . A proteinase K assay of their prep would be useful. , 
 I am surprised that the targeted pull-down with Ni-NTA works so well and clean. When using these Ni-resins for purification of his-tagged proteins, unless the target protein is overexpressed (e.g. 30% total protein), there is always a lot of other proteins binding and eluting from them. Also, for peroxisome-targeted protein, I would expect a small but noticeable cytoplasmic fraction to be present since the protein first folds in the cytoplasm and only then is transported into peroxisomes. , 
 Figure S1D u2013 more similar than expected, could authors check it please? ![file] , 
 During supplementary figure preparation, we inadvertently omitted the cell colony image set of the CD1C knock-down cells and duplicated that of the LRP2 knock-down cells in Figure S1D. Here are the original data including the growth assay of the CD1C and LRP2 knockdown cells. Thanks for pointing out this error. We have contacted the journal to correct it. , 
 ![file] , 
 ![file] , 
 ![file] , 
 ![file] , 
 Which part of the EGFP-His6-SKL sequence would be the transmembrane domain then? SKL is a short peptide signal entirely different from the peroxisomal membrane protein PEX11a. , 
 Did the authors already know that EGFP-His6-SKL would be anchored to the peroxisomal membrane with His tag sticking out to the cytosol before they designed this pull down experiment? Or they just got lucky even though SKL was supposed to target the protein to peroxisomal lumen? ,