Rab5 regulates motility of early endosomes on microtubules.
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.
Nielsen
E
E
Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse, Dresden D-01307, Germany.
Severin
F
F
Backer
J M
JM
Hyman
A A
AA
Zerial
M
M
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*
D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D019869:Phosphatidylinositol 3-Kinases; D020696:rab5 GTP-Binding Proteins