A phosphatidylinositol-4-phosphate powered exchange mechanism to create a lipid gradient between membranes

• DOI: 10.1038/ncomms7671
• Publication Date: 2015-04-07T13:25:00Z
• Authors: Joachim Moser von...; Stefano Vanni; Bruno Mesmin; Bruno Antonny; Guillaume Drin
• Keywords: Organelle

Lipids are unevenly distributed within eukaryotic cells, thus defining organelle identity. How non-vesicular transport mechanisms generate these lipid gradients between membranes remains a central question. Here using quantitative, real-time assays, we demonstrate that Osh4p, sterol/phosphatidylinositol-4-phosphate (PI(4)P) exchanger of the ORP/Osh family, transports sterol against its gradient two by dissipating energy PI(4)P gradient. Sterol is sustained through maintenance this PI(4)P-phosphatase Sac1p. Differences in packing can stabilize generated Osh4p and modulate exchange capacity. The ability to recognize via distinct modalities dynamics N-terminal lid govern activity. We an intracellular transfer protein actively functions create membranes. able sterol, made at endoplasmic reticulum, for Golgi-synthesized PI(4)P. authors provide direct evidence concentration membranes, powered dissipation