Role of STARD4 in sterol transport between the endocytic recycling compartment and the plasma membrane Journal Article


Authors: Iaea, D. B.; Mao, S.; Lund, F. W.; Maxfield, F. R.
Article Title: Role of STARD4 in sterol transport between the endocytic recycling compartment and the plasma membrane
Abstract: Cholesterol is an essential constituent of membranes in mammalian cells. The plasma membrane and the endocytic recycling compartment (ERC) are both highly enriched in cholesterol. The abundance and distribution of cholesterol among organelles are tightly controlled by a combination of mechanisms involving vesicular and nonvesicular sterol transport processes. Using the fluorescent cholesterol analogue dehydroergosterol, we examined sterol transport between the plasma membrane and the ERC using fluorescence recovery after photobleaching and a novel sterol efflux assay. We found that sterol transport between these organelles in a U2OS cell line has a t1/2 =12-15 min. Approximately 70% of sterol transport is ATP independent and therefore is nonvesicular. Increasing cellular cholesterol levels dramatically increases bidirectional transport rate constants, but decreases in cholesterol levels have only a modest effect. A soluble sterol transport protein, STARD4, accounts for ∼25% of total sterol transport and ∼33% of nonvesicular sterol transport between the plasma membrane and ERC. This study shows that nonvesicular sterol transport mechanisms and STARD4 in particular account for a large fraction of sterol transport between the plasma membrane and the ERC. © 2017 Taskin et al.
Keywords: controlled study; unclassified drug; human cell; nonhuman; protein function; protein localization; animal cell; bleaching; intracellular transport; cell membrane; cell organelle; transferrin; endosome; intracellular space; transport kinetics; lipid transfer protein; lipid transport; fluorescence recovery after photobleaching; cholesterol transport; human; priority journal; article; endocytic recycling compartment; sterol; stard4 protein
Journal Title: Molecular Biology of the Cell
Volume: 28
Issue: 8
ISSN: 1059-1524
Publisher: The American Society for Cell Biology  
Date Published: 2017-04-15
Start Page: 1111
End Page: 1122
Language: English
DOI: 10.1091/mbc.E16-07-0499
PROVIDER: scopus
PMCID: PMC5391187
PUBMED: 28209730
DOI/URL:
Notes: Article -- Export Date: 2 June 2017 -- Source: Scopus
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