Functional characterization of endocytic signals in the SynDIG/PRRT family members SynDIG1 and SynDIG4 in heterologous cells and neurons.

The transmembrane protein Synapse Differentiation Induced Gene 4 (SynDIG4), also known as Proline-rich transmembrane protein 1 (PRRT1), is an AMPA-type glutamate receptor (AMPAR) auxiliary factor that is necessary for maintaining extra-synaptic pools of GluA1. Loss of SynDIG4, and the subsequent decrease in extra-synaptic GluA1, has been found to significantly impact synaptic plasticity in the hippocampus. However, how SynDIG4 establishes and maintains these pools is unclear.