PKA phosphorylation of AMPA receptor subunits controls synaptic trafficking underlying plasticity

The regulated incorporation of AMPA receptors into synapses is important for synaptic plasticity. Here we examine the role of protein kinase A (PKA) in this process. We found that PKA phosphorylation of the AMPA receptor subunits GluR4 and GluR1 directly controlled the synaptic incorporation of AMPA receptors in organotypic slices from rat hippocampus. Activity-driven PKA phosphorylation of GluR4 was necessary and sufficient to relieve a retention interaction and drive receptors into synapses. In contrast, PKA phosphorylation of GluR1 and the activity of calcium/calmodulin-dependent kinase II (CaMKII) were both necessary for receptor incorporation. Thus, PKA phosphorylation of AMPA receptor subunits contributes to diverse mechanisms underlying synaptic plasticity.