title: Rab5 regulates motility of early endosomes on microtubules.
abstract: The small GTPase Rab5 regulates membrane docking and fusion in the early endocytic pathway. Here we reveal a new role for Rab5 in the regulation of endosome interactions with the microtubule network. Using Rab5 fused to green fluorescent protein we show that Rab5-positive endosomes move on microtubules in vivo. In vitro, Rab5 stimulates both association of early endosomes with microtubules and early-endosome motility towards the minus ends of microtubules. Moreover, similarly to endosome membrane docking and fusion, Rab5-dependent endosome movement depends on the phosphatidylinositol-3-OH kinase hVPS34. Thus, Rab5 functionally links regulation of membrane transport, motility and intracellular distribution of early endosomes.
authors.affiliation: Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse, Dresden D-01307, Germany.
authors.forename: E
authors.initials: E
authors.lastname: Nielsen
authors.forename: F
authors.initials: F
authors.lastname: Severin
authors.forename: J M
authors.initials: JM
authors.lastname: Backer
authors.forename: A A
authors.initials: AA
authors.lastname: Hyman
authors.forename: M
authors.initials: M
authors.lastname: Zerial
mesh_terms: D001692:Biological Transport; D002460:Cell Line; D004705:Endocytosis / Q000502:physiology*; D011992:Endosomes / Q000502:physiology*; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000502:physiology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics; D020696:rab5 GTP-Binding Proteins / Q000235:genetics / Q000502:physiology*
chemical_list: D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D019869:Phosphatidylinositol 3-Kinases; D020696:rab5 GTP-Binding Proteins