A proline-rich motif on VGLUT1 reduces synaptic vesicle super-pool and spontaneous release frequency
- CNRS - Université de Bordeaux, France
- CNRS - INSERM - Université Pierre et Marie Curie, France
- Institut Pasteur, France
- CNRS, Université Paris-Sud, Université Paris-Saclay, France
- Max-Planck-Institut fuer Experimentelle Medizin, Germany
Abstract
Glutamate secretion at excitatory synapses is tightly regulated to allow for the precise tuning of synaptic strength. Vesicular Glutamate Transporters (VGLUT) accumulate glutamate into synaptic vesicles (SV) and thereby regulate quantal size. Further, the number of release sites and the release probability of SVs maybe regulated by the organization of active zone proteins and SV clusters. In the present work, we uncover a mechanism mediating an increased SV clustering through the interaction of VGLUT1 second proline-rich domain, endophilinA1 and intersectin1. This strengthening of SV clusters results in a combined reduction of axonal SV super-pool size and miniature excitatory events frequency. Our findings support a model in which clustered vesicles are held together through multiple weak interactions between Src homology 3 and proline-rich domains of synaptic proteins. In mammals, VGLUT1 gained a proline-rich sequence that recruits endophilinA1 and turns the transporter into a regulator of SV organization and spontaneous release.
Data availability
Raw measures and intermediate data processing of images and electrophysiology traces are submited in source files appended to this submission.Source images and electrophysiology traces reported in this study are fully available upon request to the corresponding author (Etienne Herzog - https://orcid.org/0000-0002-0058-6959).
Article and author information
Author details
Fabrice P Cordelières
Funding
Agence Nationale de la Recherche (ANR-12-JSV4-0005-01 VGLUT-IQ)
- Etienne Herzog
Agence Nationale de la Recherche (ANR-10-LABX-43 BRAIN)
- Yann Humeau
- Etienne Herzog
Agence Nationale de la Recherche (ANR-10-IDEX-03-02 PEPS SV-PIT)
- Etienne Herzog
Agence Nationale de la Recherche (PSYVGLUT 09-MNPS-033)
- Salah El Mestikawy
Agence Nationale de la Recherche (ANR-10-INBS-04)
- Fabrice P Cordelières
European Commission (Erasmus-Mundus European Neuroscience Campus Program)
- Xiao Min Zhang
- Etienne Herzog
Fondation pour la Recherche Médicale (FDT20120925288)
- Kätlin Silm
Fondation pour la Recherche Médicale (ING20150532192)
- Maria Florencia Angelo
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: The experimental design and all procedures were in accordance with the European guide for the care and use of laboratory animals, approved by the ethics committee of Bordeaux Universities (CE50), and registered with the french ministry for research under the APAFIS n{degree sign}1692. Every effort was made to minimize the number of animals used and their suffering.
Copyright
© 2019, Zhang 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
-
- 2,555
- views
-
- 404
- downloads
-
- 18
- 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)
A proline-rich motif on VGLUT1 reduces synaptic vesicle super-pool and spontaneous release frequency
eLife 8:e50401.
https://doi.org/10.7554/eLife.50401
Further reading
-
- Cell Biology
- Genetics and Genomics
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.
-
- Cell Biology
- Immunology and Inflammation
Macrophages are crucial in the body’s inflammatory response, with tightly regulated functions for optimal immune system performance. Our study reveals that the RAS–p110α signalling pathway, known for its involvement in various biological processes and tumourigenesis, regulates two vital aspects of the inflammatory response in macrophages: the initial monocyte movement and later-stage lysosomal function. Disrupting this pathway, either in a mouse model or through drug intervention, hampers the inflammatory response, leading to delayed resolution and the development of more severe acute inflammatory reactions in live models. This discovery uncovers a previously unknown role of the p110α isoform in immune regulation within macrophages, offering insight into the complex mechanisms governing their function during inflammation and opening new avenues for modulating inflammatory responses.
