title: Insights into the mechanisms of sterol transport between organelles.
abstract: In cells, the levels of sterol vary greatly among organelles. This uneven distribution depends largely on non-vesicular routes of transfer, which are mediated by soluble carriers called lipid-transfer proteins (LTPs). These proteins have a domain with a hydrophobic cavity that accommodates one sterol molecule. However, a demonstration of their role in sterol transport in cells remains difficult. Numerous LTPs also contain membrane-binding elements, but it is not clear how these LTPs couple their ability to target organelles with lipid transport activity. This issue appears critical, since many sterol transporters are thought to act at contact sites between two membrane-bound compartments. Here, we emphasize that biochemical and structural studies provide precious insights into the mode of action of sterol-binding proteins. Recent studies on START, Osh/ORP and NPC proteins suggest models on how these proteins could transport sterol between organelles and, thereby, influence cellular functions.
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.forename: Bruno
authors.initials: B
authors.lastname: Antonny
authors.forename: Guillaume
authors.initials: G
authors.lastname: Drin
mesh_terms: D000818:Animals; D001665:Binding Sites; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism; D005089:Exocytosis; D006801:Humans; D008247:Lysosomes / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D008958:Models, Molecular; D015388:Organelles / Q000378:metabolism*; D011487:Protein Conformation; D011987:Receptors, Steroid / Q000378:metabolism; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D013261:Sterols / Q000378:metabolism*; D000098825:Oxysterol Binding Proteins
chemical_list: D002352:Carrier Proteins; D002784:Cholesterol; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D011987:Receptors, Steroid; D029701:Saccharomyces cerevisiae Proteins; D013261:Sterols; C087901:KES1 protein, S cerevisiae; D000098825:Oxysterol Binding Proteins; C030363:lipid transfer protein