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Updated: Sep 1, 2025
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A Time-Efficient Fluorescence Spectroscopy-Based Assay for Evaluating Actin Polymerization Status in Rodent and Human Brain Tissues
Published on: June 3, 2021
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Vav independently regulates synaptic growth and plasticity through distinct actin-based processes
Hyun Gwan Park1,2, Yeongjin David Kim1,2, Eunsang Cho1,2
1Department of Brain and Cognitive Sciences, Seoul National University, Seoul, Korea.
The Journal of Cell Biology
|August 17, 2022
Summary
The Vav-Rac1-SCAR pathway regulates synaptic growth and plasticity by controlling actin dynamics. This pathway is crucial for macropinocytosis and reserve pool vesicle mobilization at the Drosophila NMJ.
Area of Science:
- Neuroscience
- Cell Biology
- Molecular Biology
Background:
- Presynaptic actin dynamics are key to synaptic growth and plasticity.
- The Rac1-SCAR pathway in Drosophila NMJs mediates BMP-induced macropinocytosis, inhibiting BMP growth signaling.
Purpose of the Study:
- To investigate the role of the Rho-type GEF Vav upstream of Rac1 in synaptic growth and plasticity.
- To elucidate the mechanisms by which Vav-Rac1-SCAR signaling regulates structural and functional presynaptic plasticity.
Main Methods:
- Utilized Drosophila NMJs as a model system.
- Investigated the function of Vav, Rac1, and SCAR in synaptic plasticity and macropinocytosis.
- Assessed post-tetanic potentiation (PTP) and synaptic depression.
- Examined reserve pool (RP) vesicle mobilization.
- Used F-actin-stabilizing drugs to rescue defects in Vav mutants.
Main Results:
- Vav acts upstream of Rac1 to inhibit synaptic growth via macropinocytosis.
- Vav-Rac1-SCAR signaling is essential for tetanus-induced synaptic plasticity, affecting PTP and synaptic depression.
- Impairment of this pathway disrupts reserve pool (RP) vesicle mobilization.
- F-actin stabilization rescues RP mobilization and plasticity defects in Vav mutants.
Conclusions:
- The actin-regulatory Vav-Rac1-SCAR signaling pathway independently controls structural and functional presynaptic plasticity.
- This pathway regulates macropinocytosis for structural plasticity and RP mobilization for functional plasticity.
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