title: Dictyostelium EHD associates with Dynamin and participates in phagosome maturation.
abstract: Proteins that contain Eps15 homology domains (EHDs) in their C-terminus are newly identified key regulators of endosomal membrane trafficking. Here, we show that D. discoideum contains a single EHD protein (referred to as EHD) that localizes to endosomal compartments and newly formed phagosomes. We provide the first evidence that EHD regulates phagosome maturation. Deletion of EHD results in defects in intraphagosomal proteolysis and acidification. These defects are linked to early delivery of lysosomal enzymes and fast retrieval of the vacuolar H(+)-ATPase in maturing phagosomes. We also demonstrate that EHD physically interacts with DymA. Our results indicate that EHD and DymA can associate independently with endomembranes, and yet they share identical kinetics in recruitment to phagosomes and release during phagosome maturation. Functional analysis of ehd(-), dymA(-) and double dymA(-)ehd(-) knockout strains indicate that DymA and EHD play non-redundant and independent functions in phagosome maturation. Finally, we show that the absence of EHD leads to increased tubulation of endosomes, indicating that EHD participates in the scission of endosomal tubules, as reported for DymA.
authors.affiliation: Department of Biochemistry, University of Geneva, Geneva CH-1211, Switzerland.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Gueho
authors.affiliation: Department of Biochemistry, University of Geneva, Geneva CH-1211, Switzerland.
authors.forename: Cristina
authors.initials: C
authors.lastname: Bosmani
authors.affiliation: Department of Biochemistry, University of Lausanne, Epalinges CH-1066, Switzerland.
authors.forename: Navin
authors.initials: N
authors.lastname: Gopaldass
authors.affiliation: Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier, CNRS, UMR 5235, Place Eugène Bataillon, Montpellier Cedex 05 34095, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Molle
authors.affiliation: Department of Biochemistry, University of Geneva, Geneva CH-1211, Switzerland.
authors.forename: Thierry
authors.initials: T
authors.lastname: Soldati
authors.affiliation: Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier, CNRS, UMR 5235, Place Eugène Bataillon, Montpellier Cedex 05 34095, France francois.letourneur@univ-montp2.fr.
authors.forename: François
authors.identifier: 0000-0003-2232-6127
authors.initials: F
authors.lastname: Letourneur
mesh_terms: D000595:Amino Acid Sequence; D004023:Dictyostelium / Q000378:metabolism*; D034281:Dynamins / Q000378:metabolism*; D011992:Endosomes / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D009154:Mutation / Q000235:genetics; D010588:Phagosomes / Q000378:metabolism*; D011485:Protein Binding; D059748:Proteolysis; D015800:Protozoan Proteins / Q000737:chemistry / Q000378:metabolism*; D059008:Time-Lapse Imaging
chemical_list: D015800:Protozoan Proteins; D034281:Dynamins
keywords: D. discoideum; Dynamin; EHD; Endosome; Membrane trafficking; Phagocytosis