Following transcription, Arc mRNA is transported out of the nucleus and localized to neuronal dendrites and activated synapses, a process dependent on the 3 UTR, polymerization of actin, and ERK phosphorylation. The mRNA (and aggregate protein) is carried along microtubules radiating out from the nucleus by kinesin (specifically KIF5) and likely translocated into dendritic spines by the actin-based motor protein myosin-Va. Arc has been shown to be associated with polyribosomes at synaptic sites, and is translated in isolated synaptoneurosomal fractions in vitro indicating that the protein is likely locally translated in vivo'.