title: Endosome-ER Contacts Control Actin Nucleation and Retromer Function through VAP-Dependent Regulation of PI4P.
abstract: VAP (VAPA and VAPB) is an evolutionarily conserved endoplasmic reticulum (ER)-anchored protein that helps generate tethers between the ER and other membranes through which lipids are exchanged across adjacent bilayers. Here, we report that by regulating PI4P levels on endosomes, VAP affects WASH-dependent actin nucleation on these organelles and the function of the retromer, a protein coat responsible for endosome-to-Golgi traffic. VAP is recruited to retromer budding sites on endosomes via an interaction with the retromer SNX2 subunit. Cells lacking VAP accumulate high levels of PI4P, actin comets, and trans-Golgi proteins on endosomes. Such defects are mimicked by downregulation of OSBP, a VAP interactor and PI4P transporter that participates in VAP-dependent ER-endosomes tethers. These results reveal a role of PI4P in retromer-/WASH-dependent budding from endosomes. Collectively, our data show how the ER can control budding dynamics and association with the cytoskeleton of another membrane by direct contacts leading to bilayer lipid modifications.
authors.affiliation: Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06510, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510, USA.
authors.forename: Rui
authors.initials: R
authors.lastname: Dong
authors.affiliation: Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06510, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510, USA.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Saheki
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Sharan
authors.initials: S
authors.lastname: Swarup
authors.affiliation: Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06510, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510, USA.
authors.forename: Louise
authors.initials: L
authors.lastname: Lucast
authors.affiliation: Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: J Wade
authors.initials: JW
authors.lastname: Harper
authors.affiliation: Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA; Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06510, USA; Kavli Institute for Neurosciences, Yale University School of Medicine, New Haven, CT 06510, USA; Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510, USA. Electronic address: pietro.decamilli@yale.edu.
authors.forename: Pietro
authors.initials: P
authors.lastname: De Camilli
mesh_terms: D000199:Actins / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism*; D055786:Gene Knockout Techniques; D006367:HeLa Cells; D006801:Humans; D008840:Microfilament Proteins / Q000378:metabolism; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism*; D011987:Receptors, Steroid / Q000378:metabolism; D000069896:Transcription Activator-Like Effector Nucleases; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*; D000098825:Oxysterol Binding Proteins
chemical_list: D000199:Actins; D008840:Microfilament Proteins; D018129:Phosphatidylinositol Phosphates; D011987:Receptors, Steroid; C114051:VAPA protein, human; C496748:VAPB protein, human; D033921:Vesicular Transport Proteins; C549919:WASH protein, human; D000098825:Oxysterol Binding Proteins; C037178:phosphatidylinositol 4-phosphate; D000069896:Transcription Activator-Like Effector Nucleases