Scribble1/AP2 complex coordinates NMDA receptor endocytic recycling

Area of Science:

• Neuroscience
• Molecular Biology
• Cell Biology

Background:

• Glutamate receptor trafficking is essential for synaptic function and plasticity.
• NMDA receptors (NMDARs) dynamically exchange between synaptic and extrasynaptic pools, influencing synaptic plasticity.
• Scribble1, a PDZ protein, is critical for synaptogenesis and synaptic plasticity.

Purpose of the Study:

• To investigate the role of Scribble1 in regulating NMDA receptor (NMDAR) levels at synapses.
• To elucidate the molecular mechanisms by which Scribble1 controls NMDAR trafficking and synaptic plasticity.

Main Methods:

• Activity-dependent regulation of Scribble1 levels was assessed.
• The impact of Scribble1 on NMDAR surface expression was quantified.
• Mechanisms of NMDAR recycling and degradation were investigated.
• Protein-protein interactions involving Scribble1 and AP2 were analyzed.

Main Results:

• Scribble1 levels are regulated in an activity-dependent manner.
• Scribble1 controls the number of NMDARs at the plasma membrane.
• Scribble1 inhibits lysosomal trafficking and degradation of GluN2A subunits by promoting NMDAR recycling.
• A YxxR motif in Scribble1 mediates interaction with AP2, controlling these processes.

Conclusions:

• Scribble1 acts as a key regulator of synaptic NMDAR levels.
• Activity-dependent regulation of Scribble1 influences NMDAR trafficking and synaptic plasticity.
• The Scribble1-AP2 interaction defines a novel mechanism for controlling synaptic NMDAR homeostasis.