# Revealing acute consequences of rapid degradation of synaptic fusion proteins at individual synapses using Auxin-Inducible Degron 2 technology

## TL;DR

This study uses a new method to rapidly degrade synaptic proteins and observe their immediate effects on synapses in real time.

## Contribution

The study introduces the use of AID2 technology to acutely degrade synaptic proteins and observe real-time consequences at individual synapses.

## Key findings

- Acute degradation of PSD-95 or gephyrin leads to loss of AMPA or GABAA receptors at the same synapses.
- Acute GKAP degradation, but not PSD-95 degradation, reduces scaffold size at synapses.
- AID2 technology enables rapid degradation of postsynaptic scaffold proteins in cultured neurons and in vivo.

## Abstract

Roles of particular proteins in synaptic organization and function are commonly studied by knock-out, knock-down or overexpression strategies. Such approaches are typically protracted, associated with adaptive changes and challenge the ability to observe acute consequences at individual synapses. Here we describe the use of Auxin-Inducible Degron 2 (AID2) technology and coexpressed reporters to study real-time effects of rapidly degrading postsynaptic density proteins at individual synapses. We establish the capacity of AID2 technology to rapidly degrade postsynaptic scaffold fusion proteins in cultured neurons and in vivo. We show that acute PSD-95 or gephyrin degradation leads to concomitant loss of AMPA or GABAA receptors from the same synapses. Unexpectedly, we find that acute GKAP, but not PSD-95 degradation, is associated with scaffold size reductions at the same synapses. Our findings demonstrate the utility of approaches based on acute degradation and live imaging for studying the roles of select proteins in synaptic organization.

Roles of specific synaptic proteins in postsynaptic organization revealed by acute, Auxin-Inducible Degron 2 Technology-mediated degradation of synaptic fusion proteins, combined with real time measurements of consequences at individual synapses.