Xing Liang, Marcela Kokes, Richard D Fetter, Maria Danielle Sallee, Adrian W Moore, Jessica L Feldman, Kang Shen
eLife 2020 Jul 13A polarized arrangement of neuronal microtubule arrays is the foundation of membrane trafficking and subcellular compartmentalization. Conserved among both invertebrates and vertebrates, axons contain exclusively 'plus-end-out' microtubules while dendrites contain a high percentage of 'minus-end-out' microtubules, the origins of which have been a mystery. Here we show that in Caenorhabditis elegans the dendritic growth cone contains a non-centrosomal microtubule organizing center (MTOC), which generates minus-end-out microtubules along outgrowing dendrites and plus-end-out microtubules in the growth cone. RAB-11-positive endosomes accumulate in this region and co-migrate with the microtubule nucleation complex γ-TuRC. The MTOC tracks the extending growth cone by kinesin-1/UNC-116-mediated endosome movements on distal plus-end-out microtubules and dynein clusters this advancing MTOC. Critically, perturbation of the function or localization of the MTOC causes reversed microtubule polarity in dendrites. These findings unveil the endosome-localized dendritic MTOC as a critical organelle for establishing axon-dendrite polarity. © 2020, Liang et al.
Xing Liang, Marcela Kokes, Richard D Fetter, Maria Danielle Sallee, Adrian W Moore, Jessica L Feldman, Kang Shen. Growth cone-localized microtubule organizing center establishes microtubule orientation in dendrites. eLife. 2020 Jul 13;9
PMID: 32657271
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