Activity-dependent changes of spine proteomes

It is well established that synapses undergo activity-dependent changes in their synaptic strength. The weakening or strengthening of synapses is driven by translational and/or post-translational changes in their proteins composition, the so-called “synaptic proteome”. Its composition is highly dynamic both in basal condition and as a result of synaptic activity. Therefore, acquisition of data on the proteomic changes underlying synaptic plasticity is crucial to properly understand the molecular mechanisms by which these organelles modify their weight according to activity. Although it is possible to obtain the proteomic profile of synaptic proteins from a bunch of different preparations (Sharma et al., 2015; Biesmann et al., 2013; Distler et al., 2014; Loh 2016) these methods do not allow to specifically detecting proteomic changes in activated synapses. Hence, with this study we aim at providing a pilot proteome dataset from hippocampal activated synapses by taking advantages of a recently developed activity-dependent synaptic expression vector . The method is based on the new expression vector pSYNACTIVE (Gobbo et al., 2017) that allows to achieve the activity dependent translation of reporter proteins at activated dendritic spines. This is possible as the pSYNACTIVE vector exploits the 5’UTR and 3’UTR RNA sequences of Arc/Arg3.1 mRNA and a PSD-targeting protein sequence fused to the report (Gobbo et al., 2017). The experimental approach we propose has several advantages over the existing methods as it allows to: i) correlating protein abundance in activated synapses with the strengthening of excitatory synapses; ii) obtaining the functional mapping of activated synapses. By doing so it is possible to establish how different pattern of activity may activate different subset of excitatory synapses.