title: An endosomal beta COP is involved in the pH-dependent formation of transport vesicles destined for late endosomes.
abstract: In this paper, we show that beta COP is present on endosomes and is required for the formation of vesicles which mediate transport from early to late endosomes. Both the association of beta COP to endosomal membranes as well as transport vesicle formation depend on the lumenal pH. We find that epsilon COP, but not gamma COP, is also associated to endosomes, and that this association is also lumenal pH dependent. Our data, thus, indicate that a subset of COPs is part of the mechanism regulating endosomal membrane transport, and that membrane association of these COPs is controlled by the acidic properties of early endosomes, presumably via a trans-membrane pH sensor.
authors.affiliation: Department of Biochemistry, Sciences II, Geneva, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Aniento
authors.forename: F
authors.initials: F
authors.lastname: Gu
authors.forename: R G
authors.initials: RG
authors.lastname: Parton
authors.forename: J
authors.initials: J
authors.lastname: Gruenberg
mesh_terms: D000818:Animals; D001692:Biological Transport; D002458:Cell Fractionation; D002460:Cell Line; D020756:Coatomer Protein; D006224:Cricetinae; D011992:Endosomes / Q000737:chemistry / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007425:Intracellular Membranes / Q000378:metabolism; D008565:Membrane Proteins / Q000032:analysis* / Q000378:metabolism / Q000502:physiology; D008869:Microtubule-Associated Proteins / Q000032:analysis* / Q000378:metabolism / Q000502:physiology; D014617:Vacuoles / Q000737:chemistry
chemical_list: D020756:Coatomer Protein; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins