title: Building lipid 'PIPelines' throughout the cell by ORP/Osh proteins.
abstract: In eukaryotic cells, a sterol gradient exists between the early and late regions of the secretory pathway. This gradient seems to rely on non-vesicular transport mechanisms mediated by specialized carriers. The oxysterol-binding protein-related protein (ORP)/oxysterol-binding homology (Osh) family has been assumed initially to exclusively include proteins acting as sterol sensors/transporters and many efforts have been made to determine their mode of action. Our recent studies have demonstrated that some ORP/Osh proteins are not mere sterol transporters, but sterol/phosphatidylinositol 4-phosphate [PI(4)P] exchangers. They exploit the PI(4)P gradient at the endoplasmic reticulum (ER)/Golgi interface, or at membrane-contact sites between these compartments, to actively create a sterol gradient. Other recent reports have suggested that all ORP/Osh proteins bind PI(4)P and recognize a second lipid that is not necessary sterol. We have thus proposed that ORP/Osh proteins use PI(4)P gradients between organelles to convey various lipid species.
authors.affiliation: *Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice Sophia-Antipolis and CNRS, 660 route des lucioles, 06560 Valbonne, France.
authors.forename: Joachim
authors.initials: J
authors.lastname: Moser von Filseck
authors.affiliation: *Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice Sophia-Antipolis and CNRS, 660 route des lucioles, 06560 Valbonne, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Mesmin
authors.affiliation: *Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice Sophia-Antipolis and CNRS, 660 route des lucioles, 06560 Valbonne, France.
authors.forename: Joëlle
authors.initials: J
authors.lastname: Bigay
authors.affiliation: *Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice Sophia-Antipolis and CNRS, 660 route des lucioles, 06560 Valbonne, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Antonny
authors.affiliation: *Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice Sophia-Antipolis and CNRS, 660 route des lucioles, 06560 Valbonne, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Drin
mesh_terms: D000818:Animals; D001692:Biological Transport; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D050356:Lipid Metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008954:Models, Biological; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism; D011987:Receptors, Steroid / Q000737:chemistry / Q000378:metabolism*; D000098825:Oxysterol Binding Proteins
chemical_list: D008024:Ligands; D008565:Membrane Proteins; D018129:Phosphatidylinositol Phosphates; D020033:Protein Isoforms; D011987:Receptors, Steroid; D000098825:Oxysterol Binding Proteins; C037178:phosphatidylinositol 4-phosphate