title: ER-endosome contact sites in endosome positioning and protrusion outgrowth.
abstract: The endoplasmic reticulum (ER) makes abundant contacts with endosomes, and the numbers of contact sites increase as endosomes mature. It is already clear that such contact sites have diverse compositions and functions, but in this mini-review we will focus on two particular types of ER-endosome contact sites that regulate endosome positioning. Formation of ER-endosome contact sites that contain the cholesterol-binding protein oxysterol-binding protein-related protein 1L (ORP1L) is coordinated with loss of the minus-end-directed microtubule motor Dynein from endosomes. Conversely, formation of ER-endosome contact sites that contain the Kinesin-1-binding protein Protrudin results in transfer of the plus-end-directed microtubule motor Kinesin-1 from ER to endosomes. We discuss the possibility that formation of these two types of contact sites is coordinated as a 'gear-shift' mechanism for endosome motility, and we review evidence that Kinesin-1-mediated motility of late endosomes (LEs) to the cell periphery promotes outgrowth of neurites and other protrusions.
authors.affiliation: Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, N-0379 Oslo, Norway Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, N-0379 Oslo, Norway.
authors.forename: Camilla
authors.initials: C
authors.lastname: Raiborg
authors.affiliation: Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, N-0379 Oslo, Norway Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, N-0379 Oslo, Norway.
authors.forename: Eva M
authors.initials: EM
authors.lastname: Wenzel
authors.affiliation: Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, N-0379 Oslo, Norway Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, N-0379 Oslo, Norway.
authors.forename: Nina M
authors.initials: NM
authors.lastname: Pedersen
authors.affiliation: Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, N-0379 Oslo, Norway Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, N-0379 Oslo, Norway Centre of Molecular Inflammation Research, Faculty of Medicine, Norwegian University of Science and Technology, N-7491 Trondheim, Norway stenmark@ulrik.uio.no.
authors.forename: Harald
authors.initials: H
authors.lastname: Stenmark
mesh_terms: D000818:Animals; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D011992:Endosomes / Q000378:metabolism*; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D010716:Phosphatidylinositols / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D010716:Phosphatidylinositols
keywords: ER; FYCO1; kinesin-1; late endosomes; protrudin