Reexamination of N-terminal domains of Syntaxin-1 in vesicle fusion from central murine synapses

Abstract

Syntaxin-1 (STX1) and Munc18-1 are two requisite components of synaptic vesicular release machinery, so much so synaptic transmission cannot proceed in their absence. They form a tight complex through two major binding modes: through STX1's N-peptide and through STX's closed conformation driven by its Habc- domain. However, physiological roles of these two reportedly different binding modes in synapses are still controversial. Here we characterized the roles of STX1's N-peptide, Habc-domain, and open conformation with and without N-peptide deletion using our STX1-null mouse model system and exogenous reintroduction of STX1A mutants. We show, on the contrary to the general view, that the Habc-domain is absolutely required and N-peptide is dispensable for synaptic transmission. However, STX1A's N-peptide plays a regulatory role, particularly in the Ca2+-sensitivity and the short-term plasticity of vesicular release, whereas STX1's open-conformation governs the vesicle fusogenicity. Strikingly, we also show neurotransmitter release still proceeds when the two interaction modes between STX1A and Munc18-1 are presumably intervened, necessitating a refinement of the conceptualization of STX1A-Munc18-1 interaction.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files. We uploaded source data files which show summary tables of mean, SEM, median, number of independent cultures, number of independent measurements, real p value for each test performed, and statistical test used for each separate figure.

Article and author information

Author details

  1. Gülçin Vardar

    Institute of Neurophysiology, Charité Universitätsmedizin, Berlin, Germany
    For correspondence
    gulcinv@gmail.com
    Competing interests
    The authors declare that no competing interests exist.
  2. Andrea Salazar-Lázaro

    Institute of Neurophysiology, Charité Universitätsmedizin, Berlin, Germany
    Competing interests
    The authors declare that no competing interests exist.
  3. Marisa M Brockmann

    Institut für Neurophysiologie, Charité Universitätsmedizin Berlin, Berlin, Germany
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1386-5359
  4. Marion Weber-Boyvat

    Institute of Neurophysiology, Charité Universitätsmedizin, Berlin, Germany
    Competing interests
    The authors declare that no competing interests exist.
  5. Sina Zobel

    Institute of Neurophysiology, Charité Universitätsmedizin, Berlin, Germany
    Competing interests
    The authors declare that no competing interests exist.
  6. Victor Wumbor-Apin Kumbol

    Einstein Center for Neurosciences Berlin, Charité Universitätsmedizin, Berlin, Germany
    Competing interests
    The authors declare that no competing interests exist.
  7. Thorsten Trimbuch

    Department of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany
    Competing interests
    The authors declare that no competing interests exist.
  8. Christian Rosenmund

    Institut für Neurophysiologie, Charité Universitätsmedizin Berlin, Berlin, Germany
    For correspondence
    christian.rosenmund@charite.de
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-3905-2444

Funding

Deutsche Forschungsgemeinschaft (SFB958,TRR186)

  • Christian Rosenmund

Deutsche Forschungsgemeinschaft (Reinhart Koselleck Projects)

  • Christian Rosenmund

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

Ethics

Animal experimentation: All procedures for animal maintenance and experiments were in accordance with the regulations of and approved by the animal welfare committee of Charité-Universitätsmedizin and the Berlin state government Agency for Health and Social Services under license number T0220/09. The generation of STX1-null mouse line was described previously (Arancillo et al. 2013, Vardar et al. 2016).

Copyright

© 2021, Vardar 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

  • 1,250
    views
  • 200
    downloads
  • 20
    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. Gülçin Vardar
  2. Andrea Salazar-Lázaro
  3. Marisa M Brockmann
  4. Marion Weber-Boyvat
  5. Sina Zobel
  6. Victor Wumbor-Apin Kumbol
  7. Thorsten Trimbuch
  8. Christian Rosenmund
(2021)
Reexamination of N-terminal domains of Syntaxin-1 in vesicle fusion from central murine synapses
eLife 10:e69498.
https://doi.org/10.7554/eLife.69498

Share this article

https://doi.org/10.7554/eLife.69498

Further reading

    1. Neuroscience
    Sven Ohl, Martin Rolfs
    Research Article

    Detecting causal relations structures our perception of events in the world. Here, we determined for visual interactions whether generalized (i.e. feature-invariant) or specialized (i.e. feature-selective) visual routines underlie the perception of causality. To this end, we applied a visual adaptation protocol to assess the adaptability of specific features in classical launching events of simple geometric shapes. We asked observers to report whether they observed a launch or a pass in ambiguous test events (i.e. the overlap between two discs varied from trial to trial). After prolonged exposure to causal launch events (the adaptor) defined by a particular set of features (i.e. a particular motion direction, motion speed, or feature conjunction), observers were less likely to see causal launches in subsequent ambiguous test events than before adaptation. Crucially, adaptation was contingent on the causal impression in launches as demonstrated by a lack of adaptation in non-causal control events. We assessed whether this negative aftereffect transfers to test events with a new set of feature values that were not presented during adaptation. Processing in specialized (as opposed to generalized) visual routines predicts that the transfer of visual adaptation depends on the feature similarity of the adaptor and the test event. We show that the negative aftereffects do not transfer to unadapted launch directions but do transfer to launch events of different speeds. Finally, we used colored discs to assign distinct feature-based identities to the launching and the launched stimulus. We found that the adaptation transferred across colors if the test event had the same motion direction as the adaptor. In summary, visual adaptation allowed us to carve out a visual feature space underlying the perception of causality and revealed specialized visual routines that are tuned to a launch’s motion direction.

    1. Neuroscience
    Gergely F Turi, Sasa Teng ... Yueqing Peng
    Research Article

    Synchronous neuronal activity is organized into neuronal oscillations with various frequency and time domains across different brain areas and brain states. For example, hippocampal theta, gamma, and sharp wave oscillations are critical for memory formation and communication between hippocampal subareas and the cortex. In this study, we investigated the neuronal activity of the dentate gyrus (DG) with optical imaging tools during sleep-wake cycles in mice. We found that the activity of major glutamatergic cell populations in the DG is organized into infraslow oscillations (0.01–0.03 Hz) during NREM sleep. Although the DG is considered a sparsely active network during wakefulness, we found that 50% of granule cells and about 25% of mossy cells exhibit increased activity during NREM sleep, compared to that during wakefulness. Further experiments revealed that the infraslow oscillation in the DG was correlated with rhythmic serotonin release during sleep, which oscillates at the same frequency but in an opposite phase. Genetic manipulation of 5-HT receptors revealed that this neuromodulatory regulation is mediated by Htr1a receptors and the knockdown of these receptors leads to memory impairment. Together, our results provide novel mechanistic insights into how the 5-HT system can influence hippocampal activity patterns during sleep.