RT Journal Article
SR Electronic
T1 Molecular and cellular dissection of the OSBP cycle through a fluorescent inhibitor
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 844548
DO 10.1101/844548
A1 Péresse, Tiphaine
A1 Kovacs, David
A1 Subra, Mélody
A1 Bigay, Joëlle
A1 Tsai, Meng-Chen
A1 Polidori, Joël
A1 Gautier, Romain
A1 Desrat, Sandy
A1 Fleuriot, Lucile
A1 Debayle, Delphine
A1 Litaudon, Marc
A1 Pham, Van-Cuong
A1 Bignon, Jérôme
A1 Antonny, Bruno
A1 Roussi, Fanny
A1 Mesmin, Bruno
YR 2019
UL http://biorxiv.org/content/early/2019/11/20/844548.abstract
AB ORPphilins, natural molecules that strongly and selectively inhibit the growth of some cancer cell lines, are proposed to target intracellular lipid-transfer proteins of the Oxysterol-binding protein (OSBP) family. These conserved proteins exchange key lipids, such as cholesterol and phopsphatidylinositol-4-phosphate (PI(4)P), between organelle membranes. Among ORPphilins, molecules of the schweinfurthin family interfere with intracellular lipid distribution and metabolism, but their functioning at the molecular level is poorly understood. We report here that cell line sensitivity to schweinfurthin G (SWG) is inversely proportional to cellular level of OSBP. By taking advantage of the intrinsic fluorescence of SWG, we follow its fate in cell cultures and show that its incorporation at the TGN depends on OSBP cellular abundance. We report that SWG inhibits specifically the lipid exchange cycle of OSBP. As a consequence, post-Golgi trafficking, membrane cholesterol levels and PI(4)P turnover are affected. Finally, we demonstrate the direct binding of SWG into OSBP lipid-binding cavity by intermolecular FRET. Collectively these data describe for the first time a specific and intrinsically fluorescent pharmacological tool to dissect OSBP properties at the cellular and molecular levels.