caa a22 4500 606176136 CHVBK 20210128100746.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00018-014-1786-x doi (NATIONALLICENCE)springer-10.1007/s00018-014-1786-x Ligand-dependent localization and function of ORP-VAP complexes at membrane contact sites [Elektronische Daten] [Marion Weber-Boyvat, Henriikka Kentala, Johan Peränen, Vesa Olkkonen] Oxysterol-binding protein/OSBP-related proteins (ORPs) constitute a conserved family of sterol/phospholipid-binding proteins with lipid transporter or sensor functions. We investigated the spatial occurrence and regulation of the interactions of human OSBP/ORPs or the S. cerevisiae orthologs, the Osh (OSBP homolog) proteins, with their endoplasmic reticulum (ER) anchors, the VAMP-associated proteins (VAPs), by employing bimolecular fluorescence complementation and pull-down set-ups. The ORP-VAP interactions localize frequently at distinct subcellular sites, shown in several cases to represent membrane contact sites (MCSs). Using established ORP ligand-binding domain mutants and pull-down assays with recombinant proteins, we show that ORP liganding regulates the ORP-VAP association, alters the subcellular targeting of ORP-VAP complexes, or modifies organelle morphology. There is distinct protein specificity in the effects of the mutants on subcellular targeting of ORP-VAP complexes. We provide evidence that complexes of human ORP2 and VAPs at ER-lipid droplet interfaces regulate the hydrolysis of triglycerides and lipid droplet turnover. The data suggest evolutionarily conserved, complex ligand-dependent functions of ORP-VAP complexes at MCSs, with implications for cellular lipid homeostasis and signaling. Springer Basel, 2014 BiFC nationallicence Membrane contact site nationallicence OSBP nationallicence Oxysterol nationallicence VAMP-associated protein nationallicence BiFC : Bimolecular fluorescence complementation nationallicence EM : Electron microscopy nationallicence ER : Endoplasmic reticulum nationallicence FFAT : Two phenylalanines in an acidic tract nationallicence GST : Glutathione-S-transferase nationallicence LD : Lipid droplet nationallicence MCS : Membrane contact site nationallicence OHC : Hydroxycholesterol nationallicence ORD : OSBP-related ligand-binding domain nationallicence ORP : OSBP-related protein nationallicence OSBP : Oxysterol-binding protein nationallicence Osh : OSBP homolog (in yeast) nationallicence PI4P : Phosphatidylinositol-4-phosphate nationallicence PIP : Phosphoinositide nationallicence PM : Plasma membrane nationallicence TG : Triglyceride nationallicence VAMP : Vesicle-associated membrane protein nationallicence VAP : VAMP-associated protein nationallicence Weber-Boyvat Marion Minerva Foundation Institute for Medical Research, Biomedicum 2U, Tukholmankatu 8, 00290, Helsinki, Finland aut Kentala Henriikka Minerva Foundation Institute for Medical Research, Biomedicum 2U, Tukholmankatu 8, 00290, Helsinki, Finland aut Peränen Johan Cell and Molecular Biology Program, Institute of Biotechnology, University of Helsinki, 00014, Helsinki, Finland aut Olkkonen Vesa Minerva Foundation Institute for Medical Research, Biomedicum 2U, Tukholmankatu 8, 00290, Helsinki, Finland aut Cellular and Molecular Life Sciences Springer Basel 72/10(2015-05-01), 1967-1987 1420-682X 72:10<1967 2015 72 18 https://doi.org/10.1007/s00018-014-1786-x text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00018-014-1786-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Weber-Boyvat Marion Minerva Foundation Institute for Medical Research, Biomedicum 2U, Tukholmankatu 8, 00290, Helsinki, Finland aut NATIONALLICENCE 700 1- Kentala Henriikka Minerva Foundation Institute for Medical Research, Biomedicum 2U, Tukholmankatu 8, 00290, Helsinki, Finland aut NATIONALLICENCE 700 1- Peränen Johan Cell and Molecular Biology Program, Institute of Biotechnology, University of Helsinki, 00014, Helsinki, Finland aut NATIONALLICENCE 700 1- Olkkonen Vesa Minerva Foundation Institute for Medical Research, Biomedicum 2U, Tukholmankatu 8, 00290, Helsinki, Finland aut NATIONALLICENCE 773 0- Cellular and Molecular Life Sciences Springer Basel 72/10(2015-05-01), 1967-1987 1420-682X 72:10<1967 2015 72 18