Distinct synaptic pools of DAPK1 differentially regulate activity-dependent synaptic CaMKII accumulation

Area of Science:

• Neuroscience
• Molecular Biology
• Cell Biology

Background:

• Synaptic plasticity, including long-term potentiation (LTP) and long-term depression (LTD), underlies learning and memory.
• Ca2+/calmodulin-dependent protein kinase II (CaMKII) accumulation at synapses is crucial for LTP.
• Suppression of CaMKII synaptic accumulation is required for LTD.

Purpose of the Study:

• To investigate the mechanisms of DAPK1 localization to synapses.
• To elucidate how DAPK1 regulates CaMKII synaptic movement during LTD.
• To understand the role of DAPK1 binding modes in synaptic plasticity.

Main Methods:

• Immunofluorescence and live-cell imaging to visualize protein localization.
• Biochemical assays to study protein-protein interactions.
• Genetic manipulation to assess the function of DAPK1 binding domains.

Main Results:

• DAPK1 basal synaptic localization depends on F-actin.
• LTD-specific retention of DAPK1 at synapses requires an additional binding mode, likely to GluN2B.
• F-actin binding is necessary but not sufficient for suppressing CaMKII movement; it enables LTD-specific binding for CaMKII suppression.

Conclusions:

• DAPK1 employs dual localization mechanisms for synaptic regulation.
• F-actin and GluN2B binding cooperate to control synaptic CaMKII localization.
• These DAPK1-mediated mechanisms are critical for regulating synaptic plasticity during LTD.