Abstract

Neural wiring and activity are essential for proper brain function and behavioral outputs and rely on mechanisms that guide the formation, elimination, and remodeling of synapses. During development, it is therefore vital that synaptic densities and architecture are tightly regulated to allow for appropriate neural circuit formation and function. δ-Catenin, a component of the cadherin-catenin cell adhesion complex, has been demonstrated to be a critical regulator of synaptic density and function in the developing central neurons. In this study, we identified forms of δ-catenin that include only the N-terminal (DcatNT) or the C-terminal (DcatCT) regions. We found that these δ-catenin forms are differentially expressed in different regions of the male mouse brain. Our results also indicated that in rat primary cortical culture, these forms are generated in an activity-dependent manner by Ca2+-dependent and calpain-mediated cleavage of δ-catenin or in an activity-independent but lysosome-dependent manner. Functionally, loss of the domain containing the calpain-cleavage sites allowing for generation of DcatCT and DcatNT perturbed the density of a subpopulation of dendritic protrusions in rat hippocampal neurons. This subpopulation likely included protrusions that are either in transition toward becoming mature mushroom spines or in the process of being eliminated. By influencing this subpopulation of spines, proteolytic processing of δ-catenin can likely regulate the balance between mature and immature dendritic protrusions in coordination with neural activity. We conclude that by undergoing cleavage, δ-catenin differentially regulates the densities of subpopulations of dendritic spines and contributes to proper neural circuit wiring in the developing brain.

Highlights

  • Neural wiring and activity are essential for proper brain function and behavioral outputs and rely on mechanisms that guide the formation, elimination, and remodeling of synapses

  • Loss of the domain containing the calpain-cleavage sites allowing for generation of DcatCT and DcatNT perturbed the density of a subpopulation of dendritic protrusions in rat hippocampal neurons

  • We have identified a novel proteolysis-based mechanism that allows ␦-catenin to regulate the densities of dendritic protrusion subpopulations in developing central neurons

Read more

Summary

ARTICLE cro

A role for proteolytic regulation of ␦-catenin in remodeling a subpopulation of dendritic spines in the rodent brain. Loss of the domain containing the calpain-cleavage sites allowing for generation of DcatCT and DcatNT perturbed the density of a subpopulation of dendritic protrusions in rat hippocampal neurons. This subpopulation likely included protrusions that are either in transition toward becoming mature mushroom spines or in the process of being eliminated. Proteolytic regulation is a commonly used mechanism in central neurons to allow for selective substrate cleavage leading to differential functional output, for example local or compartmentalized signaling, or allow functional roles that are different from the uncleaved forms of the protein (19 –21). Proteolytic regulation of ␦-catenin can coordinate with neural activity to influence the balance between mature and immature dendritic protrusions and regulate neural circuit formation in developing central neurons

Results
Discussion
Functional roles of DcatCT and DcatNT
Experimental procedures
Cell culture and transfection
Construct name
Pharmacological reagents
Lysate preparation and immunoblotting
In vitro cleavage assay
Calculate molecular weight
Immunocytochemistry and microscopy
Immunoblot and morphology analysis
Fraction and approximate density for each population
Above threshold fraction comparison

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.