1. Cell Biology
  2. Neuroscience

Munc13 supports fusogenicity of non-docked vesicles at synapses with disrupted active zones

  1. Chao Tan
  2. Giovanni de Nola
  3. Claire Qiao
  4. Cordelia Imig
  5. Richard T Born
  6. Nils Brose
  7. Pascal S Kaeser  Is a corresponding author
  1. Harvard Mecical School, United States
  2. Harvard Medical School, United States
  3. University of Copenhagen, Denmark
  4. Max Planck Institute for Multidisciplinary Sciences, Germany
https://doi.org/10.7554/eLife.79077
Share this article
Cite this article
  1. Chao Tan
  2. Giovanni de Nola
  3. Claire Qiao
  4. Cordelia Imig
  5. Richard T Born
  6. Nils Brose
  7. Pascal S Kaeser
(2022)
Munc13 supports fusogenicity of non-docked vesicles at synapses with disrupted active zones
eLife 11:e79077.
https://doi.org/10.7554/eLife.79077
  2. Download BibTeX
  3. Download .RIS

Abstract

Active zones consist of protein scaffolds that are tightly attached to the presynaptic plasma membrane. They dock and prime synaptic vesicles, couple them to voltage-gated Ca2+ channels, and direct neurotransmitter release towards postsynaptic receptor domains. Simultaneous RIM+ELKS ablation disrupts these scaffolds, abolishes vesicle docking and removes active zone-targeted Munc13, but some vesicles remain releasable. To assess whether this enduring vesicular fusogenicity is mediated by non-active zone-anchored Munc13 or is Munc13-independent, we ablated Munc13-1 and Munc13-2 in addition to RIM+ELKS in mouse hippocampal neurons. The hextuple knockout synapses lacked docked vesicles, but other ultrastructural features were near-normal despite the strong genetic manipulation. Removing Munc13 in addition to RIM+ELKS impaired action potential-evoked vesicle fusion more strongly than RIM+ELKS knockout by further decreasing the releasable vesicle pool. Hence, Munc13 can support some fusogenicity without RIM and ELKS, and presynaptic recruitment of Munc13, even without active zone-anchoring, suffices to generate some fusion-competent vesicles.

Data availability

All data generated or analyzed in this study, including individual data points, are included in the figures. Source data files for Fig. 1 - figure supplement 3, Fig. 2 - figure supplement 1 and Fig. 2 - figure supplement 2 are provided, and a source data table that contains all means, errors, statistical tests and p-values is also included.

Article and author information

Author details

  1. Chao Tan

    Department of Neurobiology, Harvard Mecical School, Boston, United States
    Competing interests
    No competing interests declared.

  2. Giovanni de Nola

    Department of Neurobiology, Harvard Medical School, Boston, United States
    Competing interests
    No competing interests declared.

  3. Claire Qiao

    Department of Neurobiology, Harvard Medical School, Boston, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-2084-2478

  4. Cordelia Imig

    Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7351-8706

  5. Richard T Born

    Department of Neurobiology, Harvard Mecical School, Boston, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4360-427X

  6. Nils Brose

    Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Goettingen, Germany
    Competing interests
    Nils Brose, Reviewing editor, eLife.

  7. Pascal S Kaeser

    Department of Neurobiology, Harvard Medical School, Boston, United States
    For correspondence
    kaeser@hms.harvard.edu
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1558-1958

Funding

National Institute of Mental Health (MH113349)

  • Pascal S Kaeser

National Institute of Neurological Disorders and Stroke (NS083898)

  • Pascal S Kaeser

Harvard Medical School (NA)

  • Pascal S Kaeser

Max Planck Institute for Multidisciplinary Sciences (open access funding)

  • Cordelia Imig
  • Nils Brose

German Research Foundation (EXC 2067/1-390729940)

  • Nils Brose

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

Ethics

Animal experimentation: This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All animal experiments were approved by the Harvard University Animal Care and Use Committee (protocol number IS00000049).

Copyright

© 2022, Tan 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

  • 2,001
    views
  • 354
    downloads
  • 11
    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. Chao Tan
  2. Giovanni de Nola
  3. Claire Qiao
  4. Cordelia Imig
  5. Richard T Born
  6. Nils Brose
  7. Pascal S Kaeser
(2022)
Munc13 supports fusogenicity of non-docked vesicles at synapses with disrupted active zones
eLife 11:e79077.
https://doi.org/10.7554/eLife.79077

Share this article

https://doi.org/10.7554/eLife.79077

Categories and tags

Research organism

Further reading

    1. Cell Biology

    Stratification of enterochromaffin cells by single-cell expression analysis

    Yan Song, Linda J Fothergill ... Gene W Yeo
    Research Article

    Dynamic interactions between gut mucosal cells and the external environment are essential to maintain gut homeostasis. Enterochromaffin (EC) cells transduce both chemical and mechanical signals and produce 5-hydroxytryptamine to mediate disparate physiological responses. However, the molecular and cellular basis for functional diversity of ECs remains to be adequately defined. Here, we integrated single-cell transcriptomics with spatial image analysis to identify 14 EC clusters that are topographically organized along the gut. Subtypes predicted to be sensitive to the chemical environment and mechanical forces were identified that express distinct transcription factors and hormones. A Piezo2+ population in the distal colon was endowed with a distinctive neuronal signature. Using a combination of genetic, chemogenetic, and pharmacological approaches, we demonstrated Piezo2+ ECs are required for normal colon motility. Our study constructs a molecular map for ECs and offers a framework for deconvoluting EC cells with pleiotropic functions.

    1. Cell Biology

    Small-molecule activation of TFEB alleviates Niemann–Pick disease type C via promoting lysosomal exocytosis and biogenesis

    Kaili Du, Hongyu Chen ... Dan Li
    Research Article

    Niemann–Pick disease type C (NPC) is a devastating lysosomal storage disease characterized by abnormal cholesterol accumulation in lysosomes. Currently, there is no treatment for NPC. Transcription factor EB (TFEB), a member of the microphthalmia transcription factors (MiTF), has emerged as a master regulator of lysosomal function and promoted the clearance of substrates stored in cells. However, it is not known whether TFEB plays a role in cholesterol clearance in NPC disease. Here, we show that transgenic overexpression of TFEB, but not TFE3 (another member of MiTF family) facilitates cholesterol clearance in various NPC1 cell models. Pharmacological activation of TFEB by sulforaphane (SFN), a previously identified natural small-molecule TFEB agonist by us, can dramatically ameliorate cholesterol accumulation in human and mouse NPC1 cell models. In NPC1 cells, SFN induces TFEB nuclear translocation via a ROS-Ca2+-calcineurin-dependent but MTOR-independent pathway and upregulates the expression of TFEB-downstream genes, promoting lysosomal exocytosis and biogenesis. While genetic inhibition of TFEB abolishes the cholesterol clearance and exocytosis effect by SFN. In the NPC1 mouse model, SFN dephosphorylates/activates TFEB in the brain and exhibits potent efficacy of rescuing the loss of Purkinje cells and body weight. Hence, pharmacological upregulating lysosome machinery via targeting TFEB represents a promising approach to treat NPC and related lysosomal storage diseases, and provides the possibility of TFEB agonists, that is, SFN as potential NPC therapeutic candidates.

    1. Cell Biology
    2. Developmental Biology

    Lens Development: Bringing signaling complexity into focus

    Sarah Y Coomson, Salil A Lachke
    Insight

    A study in mice reveals key interactions between proteins involved in fibroblast growth factor signaling and how they contribute to distinct stages of eye lens development.