Related Experiment Video
Updated: Mar 18, 2026
09:25
Quantifying Subcellular Ubiquitin-proteasome Activity in the Rodent Brain
Published on: May 21, 2019
7.3K
Visualizing K48 Ubiquitination during Presynaptic Formation By Ubiquitination-Induced Fluorescence Complementation
Maria J Pinto1, Joana R Pedro2, Rui O Costa2
1Center for Neuroscience and Cell Biology (CNC), University of CoimbraCoimbra, Portugal; PhD Programme in Experimental Biology and Biomedicine (PDBEB), Center for Neuroscience and Cell Biology, University of CoimbraCoimbra, Portugal.
Frontiers in Molecular Neuroscience
|July 5, 2016
Summary
Lysine 48-linked ubiquitin chains are crucial for presynaptic assembly during brain development. This study visualizes these ubiquitin chains in neurons, revealing their role in synapse formation and axonal growth.
Area of Science:
- Neuroscience
- Cell Biology
- Molecular Biology
Background:
- Ubiquitin signaling is vital for brain development, impacting synapse formation and neuronal transmission.
- Lysine (K) 48-linked ubiquitin chains are elevated during synaptogenesis, but their specific role remains unclear.
- Previous work suggested polyubiquitinated conjugates trigger presynaptic assembly.
Purpose of the Study:
- To characterize the axonal distribution and dynamics of K48 polyubiquitin during presynaptic formation.
- To investigate the role of K48 polyubiquitin enrichment in initiating presynaptic differentiation.
Main Methods:
- Utilized ubiquitination-induced fluorescence complementation (UiFC) to visualize K48 polyubiquitin in live hippocampal neurons.
- Validated UiFC by analyzing polyubiquitin level changes and colocalization with K48-specific antibodies.
- Employed bead-induced synapse formation and microfluidic platforms to study axonal ubiquitination dynamics.
Main Results:
- UiFC signal for K48 polyubiquitin showed diffuse distribution with aggregates in neurons, colocalizing with K48 antibodies.
- Axonal K48 polyubiquitin aggregates were stable, formed during axon growth, and colocalized with synaptic vesicle clusters.
- Rapid accumulation of K48 ubiquitination occurred at newly forming presynapses, dependent on axonal E1-mediated ubiquitination.
Conclusions:
- K48 polyubiquitin is enriched at nascent presynaptic terminals, indicating its importance in synapse formation.
- This enrichment is an axon-intrinsic event essential for presynaptic differentiation.
- The findings highlight a novel role for K48 polyubiquitin in regulating neuronal development.
