Coexpressed Auxiliary Subunits Exhibit Distinct Modulatory Profiles on AMPA Receptor Function

• CKAMP44 and TARP γ-8 increase surface expression of AMPA receptors
• Both proteins can be contained within the same AMPA receptor complex
• They both influence neuronal morphology
• Short- and long-term synaptic plasticity is differentially modulated by both proteins

SummaryGating properties and surface trafficking of AMPA receptors (AMPARs) are modulated by auxiliary subunits. Here we studied the function of coexpressed auxiliary subunits belonging to two different classes. We focused on TARP γ-8 and CKAMP44 in dentate gyrus (DG) granule cells, since both subunits are highly expressed in this cell type. TARP γ-8 and CKAMP44 decrease the rate of deactivation but have an opposing influence on receptor desensitization, which accounts for their differential modulation of synaptic short-term plasticity. Furthermore, long-term plasticity (LTP) requires TARP γ-8 but not CKAMP44. The coexpression of both auxiliary subunits is necessary for the efficient targeting of AMPARs to the cell surface of DG granule cells. Finally, electrophysiological and biochemical evidence support the notion that CKAMP44 and TARP γ-8 can be contained in the same AMPAR complex.Video Abstract To view the video inline, enable JavaScript on your browser. However, you can download and view the video by clicking on the icon belowHelp with MP4 filesOptionsDownload video (49808 K)