Activity-regulated N-cadherin endocytosis

Area of Science:

• Neuroscience
• Cell Biology
• Synaptic Plasticity

Background:

• Enduring synaptic plasticity requires regulation of synaptic adhesion molecules like N-cadherin.
• Activity-regulated trafficking of these adhesion molecules remains poorly understood.

Purpose of the Study:

• To investigate the regulation of N-cadherin trafficking at synapses.
• To elucidate the role of NMDA receptor (NMDAR) activity in N-cadherin endocytosis.
• To establish a mechanistic link between NMDAR signaling, N-cadherin dynamics, and synaptic plasticity.

Main Methods:

• Studied N-cadherin internalization rates at synapses.
• Investigated the impact of NMDA receptor activation on N-cadherin trafficking.
• Examined the role of beta-catenin in N-cadherin endocytosis.
• Utilized a mutant beta-catenin (Y654F) to disrupt NMDAR-dependent regulation.
• Assessed the effects of N-cadherin stabilization on synaptic plasticity.

Main Results:

• Surface N-cadherin exhibits high basal internalization rates.
• NMDA receptor activation significantly reduces N-cadherin endocytosis, increasing surface levels.
• Beta-catenin regulates N-cadherin endocytosis and accumulates in spines upon NMDAR stimulation.
• Overexpression of beta-catenin Y654F mutant blocks NMDAR-dependent N-cadherin internalization.
• Stabilization of surface N-cadherin inhibits NMDAR-dependent synaptic plasticity.

Conclusions:

• NMDA receptor activity directly regulates N-cadherin endocytosis.
• Beta-catenin acts as a key mediator in this process.
• N-cadherin stabilization by NMDAR signaling is crucial for synaptic plasticity.