title: No Evidence for Spontaneous Lipid Transfer at ER-PM Membrane Contact Sites.
abstract: Non-vesicular lipid transport steps play a crucial role in lipid trafficking and potentially include spontaneous exchange. Since membrane contact facilitates this lipid transfer, it is most likely to occur at membrane contact sites (MCS). However, to date it is unknown whether closely attached biological membranes exchange lipids spontaneously. We have set up a system for studying the exchange of lipids at MCS formed between the endoplasmic reticulum (ER) and the plasma membrane. Contact sites were stably anchored and the lipids cholesterol and phosphatidylcholine (PC) were not capable of transferring spontaneously into the opposed bilayer. We conclude that physical contact between two associated biological membranes is not sufficient for transfer of the lipids PC and cholesterol.
authors.affiliation: Department of Membrane Biochemistry, LIMES Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany. elisa.merklinger@uni-bonn.de.
authors.forename: Elisa
authors.initials: E
authors.lastname: Merklinger
authors.affiliation: Department of Membrane Biochemistry, LIMES Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany.
authors.forename: Jan-Gero
authors.initials: JG
authors.lastname: Schloetel
authors.affiliation: Department of Membrane Biochemistry, LIMES Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany.|Institute of Aerospace Medicine, German Aerospace Center (DLR), Linder Höhe, 51147, Cologne, Germany.
authors.forename: Luis
authors.initials: L
authors.lastname: Spitta
authors.affiliation: Department of Cell Biology of Lipids, LIMES Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Thiele
authors.affiliation: Department of Membrane Biochemistry, LIMES Institute, University of Bonn, Carl-Troll-Str. 31, 53115, Bonn, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Lang
mesh_terms: D000818:Animals; D001692:Biological Transport; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006801:Humans; D050356:Lipid Metabolism; D008856:Microscopy, Fluorescence; D010713:Phosphatidylcholines / Q000378:metabolism
chemical_list: D010713:Phosphatidylcholines; D002784:Cholesterol
keywords: Cholesterol; Lipid homeostasis; Lipid transport; Non-vesicular transport; Phosphatidylcholine