Growth cone-localized microtubule organizing center establishes microtubule orientation in dendrites

  1. Xing Liang
  2. Marcela Kokes
  3. Richard D Fetter
  4. Maria Danielle Sallee
  5. Adrian W Moore
  6. Jessica L Feldman  Is a corresponding author
  7. Kang Shen  Is a corresponding author
  1. Stanford University, United States
  2. Howard Hughes Medical Institute, United States
  3. Riken Brain Science Institute, Japan
  4. Howard Hughes Medical Institute, Stanford University, United States

Abstract

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 in Caenorhabditis elegans 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 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.

Data availability

All data generated or analyzed during this study are included in the manuscript and supporting files.

Article and author information

Author details

  1. Xing Liang

    Biology, Stanford University, Stanford, United States
    Competing interests
    No competing interests declared.
  2. Marcela Kokes

    Biology, Stanford University, Stanford, United States
    Competing interests
    No competing interests declared.
  3. Richard D Fetter

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1558-100X
  4. Maria Danielle Sallee

    Biology, Stanford University, Stanford, United States
    Competing interests
    No competing interests declared.
  5. Adrian W Moore

    Riken Brain Science Institute, Wako, Japan
    Competing interests
    No competing interests declared.
  6. Jessica L Feldman

    Biology, Stanford University, Stanford, United States
    For correspondence
    feldmanj@stanford.edu
    Competing interests
    No competing interests declared.
  7. Kang Shen

    Department of Biology, Howard Hughes Medical Institute, Stanford University, Stanford, United States
    For correspondence
    kangshen@stanford.edu
    Competing interests
    Kang Shen, Reviewing editor, eLife.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4059-8249

Funding

Howard Hughes Medical Institute

  • Kang Shen

National Institutes of Health (research project,NS082208)

  • Kang Shen

National Institutes of Health (NIH New Innovator Award,DP2GM119136-01)

  • Jessica L Feldman

National Institutes of Health (NIGMS NIH award F32GM120913-01)

  • Maria Danielle Sallee

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Copyright

© 2020, Liang et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 4,467
    views
  • 590
    downloads
  • 48
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Xing Liang
  2. Marcela Kokes
  3. Richard D Fetter
  4. Maria Danielle Sallee
  5. Adrian W Moore
  6. Jessica L Feldman
  7. Kang Shen
(2020)
Growth cone-localized microtubule organizing center establishes microtubule orientation in dendrites
eLife 9:e56547.
https://doi.org/10.7554/eLife.56547

Share this article

https://doi.org/10.7554/eLife.56547

Further reading

    1. Cell Biology
    Affiong Ika Oqua, Kin Chao ... Alejandra Tomas
    Research Article

    G protein-coupled receptors (GPCRs) are integral membrane proteins which closely interact with their plasma membrane lipid microenvironment. Cholesterol is a lipid enriched at the plasma membrane with pivotal roles in the control of membrane fluidity and maintenance of membrane microarchitecture, directly impacting on GPCR stability, dynamics, and function. Cholesterol extraction from pancreatic beta cells has previously been shown to disrupt the internalisation, clustering, and cAMP responses of the glucagon-like peptide-1 receptor (GLP-1R), a class B1 GPCR with key roles in the control of blood glucose levels via the potentiation of insulin secretion in beta cells and weight reduction via the modulation of brain appetite control centres. Here, we unveil the detrimental effect of a high cholesterol diet on GLP-1R-dependent glucoregulation in vivo, and the improvement in GLP-1R function that a reduction in cholesterol synthesis using simvastatin exerts in pancreatic islets. We next identify and map sites of cholesterol high occupancy and residence time on active vs inactive GLP-1Rs using coarse-grained molecular dynamics (cgMD) simulations, followed by a screen of key residues selected from these sites and detailed analyses of the effects of mutating one of these, Val229, to alanine on GLP-1R-cholesterol interactions, plasma membrane behaviours, clustering, trafficking and signalling in INS-1 832/3 rat pancreatic beta cells and primary mouse islets, unveiling an improved insulin secretion profile for the V229A mutant receptor. This study (1) highlights the role of cholesterol in regulating GLP-1R responses in vivo; (2) provides a detailed map of GLP-1R - cholesterol binding sites in model membranes; (3) validates their functional relevance in beta cells; and (4) highlights their potential as locations for the rational design of novel allosteric modulators with the capacity to fine-tune GLP-1R responses.

    1. Cell Biology
    2. Genetics and Genomics
    Keva Li, Nicholas Tolman ... UK Biobank Eye and Vision Consortium
    Research Article

    A glaucoma polygenic risk score (PRS) can effectively identify disease risk, but some individuals with high PRS do not develop glaucoma. Factors contributing to this resilience remain unclear. Using 4,658 glaucoma cases and 113,040 controls in a cross-sectional study of the UK Biobank, we investigated whether plasma metabolites enhanced glaucoma prediction and if a metabolomic signature of resilience in high-genetic-risk individuals existed. Logistic regression models incorporating 168 NMR-based metabolites into PRS-based glaucoma assessments were developed, with multiple comparison corrections applied. While metabolites weakly predicted glaucoma (Area Under the Curve = 0.579), they offered marginal prediction improvement in PRS-only-based models (p=0.004). We identified a metabolomic signature associated with resilience in the top glaucoma PRS decile, with elevated glycolysis-related metabolites—lactate (p=8.8E-12), pyruvate (p=1.9E-10), and citrate (p=0.02)—linked to reduced glaucoma prevalence. These metabolites combined significantly modified the PRS-glaucoma relationship (Pinteraction = 0.011). Higher total resilience metabolite levels within the highest PRS quartile corresponded to lower glaucoma prevalence (Odds Ratiohighest vs. lowest total resilience metabolite quartile=0.71, 95% Confidence Interval = 0.64–0.80). As pyruvate is a foundational metabolite linking glycolysis to tricarboxylic acid cycle metabolism and ATP generation, we pursued experimental validation for this putative resilience biomarker in a human-relevant Mus musculus glaucoma model. Dietary pyruvate mitigated elevated intraocular pressure (p=0.002) and optic nerve damage (p<0.0003) in Lmx1bV265D mice. These findings highlight the protective role of pyruvate-related metabolism against glaucoma and suggest potential avenues for therapeutic intervention.