Activity-regulated synaptic targeting of lncRNA ADEPTR mediates structural plasticity by localizing Sptn1 and AnkB in dendrites.

Activity-dependent structural plasticity at the synapse requires specific changes in the neuronal transcriptome. While much is known about the role of coding elements in this process, the role of the long noncoding transcriptome remains elusive. Here, we report the discovery of an intronic long noncoding RNA (lncRNA)-termed ADEPTR-that is up-regulated and synaptically transported in a cAMP/PKA-dependent manner in hippocampal neurons, independently of its protein-coding host gene. Loss of ADEPTR function suppresses activity-dependent changes in synaptic transmission and structural plasticity of dendritic spines. Mechanistically, dendritic localization of ADEPTR is mediated by molecular motor protein Kif2A. ADEPTR physically binds to actin-scaffolding regulators ankyrin (AnkB) and spectrin (Sptn1) via a conserved sequence and is required for their dendritic localization. Together, this study demonstrates how activity-dependent synaptic targeting of an lncRNA mediates structural plasticity at the synapse.