Growth Cone-Localized Microtubule Organizing Center Establishes Microtubule Orientation in Dendrites

A 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 the dendritic growth cone contains a non-centrosomal microtubule organizing center, 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 are responsible for localizing 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 dendritic MTOC as a critical organelle for establishing axon-dendrite polarity.

Keywords: neuronal cell polarity, Dendrite development, Microtubule organization, γ-TuRC, non-centrosomal microtubule organizing center

Suggested Citation: Suggested Citation

Liang, Xing and Kokes, Marcela and Fetter, Richard and Sallee, Maria D. and Moore, Adrian W. and Feldman, Jessica and Shen, Kang, Growth Cone-Localized Microtubule Organizing Center Establishes Microtubule Orientation in Dendrites. Available at SSRN: https://ssrn.com/abstract=3519576 or http://dx.doi.org/10.2139/ssrn.3519576

This version of the paper has not been formally peer reviewed.