Microtubules provide directional cues for polarized axonal transport through interaction with kinesin motor head.
Post-Golgi carriers of various newly synthesized axonal membrane proteins, which possess kinesin (KIF5)-driven highly processive motility, were transported from the TGN directly to axons. We found that KIF5 has a preference to the microtubules in the initial segment of axon. Low dose paclitaxel treatment caused missorting of KIF5, as well as axonal membrane proteins to the tips of dendrites. Microtubules in the initial segment of axons showed a remarkably high affinity to EB1-YFP, which was known to bind the tips of growing microtubules. These findings revealed unique features of the microtubule cytoskeletons in the initial segment, and suggested that they provide directional information for polarized axonal transport.
Nakata
Takao
T
Department of Cell Biology and Anatomy, Graduate School of Medicine, University of Tokyo, 7-3-1, Hongo, Tokyo, Japan 113-0033.
Hirokawa
Nobutaka
N
D000818:Animals; D001370:Axonal Transport / Q000502:physiology*; D001369:Axons / Q000378:metabolism / Q000648:ultrastructure; D002352:Carrier Proteins / Q000187:drug effects / Q000378:metabolism; D016764:Cell Polarity / Q000502:physiology*; D002478:Cells, Cultured; D003712:Dendrites / Q000378:metabolism / Q000648:ultrastructure; D005333:Fetus; D016547:Kinesins / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D008869:Microtubule-Associated Proteins; D008870:Microtubules / Q000378:metabolism* / Q000648:ultrastructure; D020409:Molecular Motor Proteins / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D017239:Paclitaxel / Q000494:pharmacology; D017434:Protein Structure, Tertiary / Q000502:physiology; D011993:Recombinant Fusion Proteins
D002352:Carrier Proteins; C405804:EB1 microtubule binding proteins; D008869:Microtubule-Associated Proteins; D020409:Molecular Motor Proteins; D011993:Recombinant Fusion Proteins; C475469:Kif5b protein, mouse; D016547:Kinesins; D017239:Paclitaxel