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bioRxiv · 10.1101/2021.09.24.461707

γ-TuRCs are required for asymmetric microtubule nucleation from the somatic Golgi of Drosophila neurons

Conduit, P. T.·Mukherjee, A.
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Abstract

Microtubules are polarised polymers nucleated by multi-protein {gamma}-tubulin ring complexes ({gamma}-TuRCs). Within neurons, microtubule polarity is plus-end-out in axons and mixed or minus-end-out in dendrites. Previously we showed that within the soma of Drosophila sensory neurons {gamma}-tubulin localises asymmetrically to Golgi stacks, Golgi-derived microtubules grow asymmetrically towards the axon, and growing microtubule plus-ends are guided towards the axon and restricted from entering dendrite in a Kinesin-2-dependent manner (Mukerjee et al., 2020). Here we show that depleting {gamma}-TuRCs perturbs the direction of microtubule growth from the Golgi stacks, consistent with a model for asymmetric microtubule nucleation involving {gamma}-TuRCs and other nucleation-promoting factors. We also directly observe microtubule turning along microtubule bundles and show that depleting APC, proposed to link Kinesin-2 to plus ends, reduces microtubule turning and increases plus end growth into dendrites. These results support a model of asymmetric nucleation and guidance within the neuronal soma that helps establish and maintain overall microtubule polarity.

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Conduit, P. T., Mukherjee, A.. 2021-09-24. γ-TuRCs are required for asymmetric microtubule nucleation from the somatic Golgi of Drosophila neurons. https://doi.org/10.1101/2021.09.24.461707

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