mRNA Trafficking in the Nervous System: A Key Mechanism of the Involvement of Activity-Regulated Cytoskeleton-Associated Protein (Arc) in Synaptic Plasticity

Figure 1

Localized expression of genes is crucial for activity-dependent synaptic modification. Synapse-activating signal (yellow star) may belong to a wide range of stimuli, including behavioral experience. Activated synapse sends a signal to the nucleus to transcribe a gene whose product is needed to modify the synapse. Pre-mRNA is exported to the cytoplasm and can be transported to the site of synaptic modification, where it is translated to produce a protein (dark blue oval) needed for synaptic modification. Alternatively or concomitantly, mRNA may be translated immediately after export to the cytoplasm and the product of translation is transported to the target site (not shown). Light green oval symbolizes all proteins that are needed for pre-mRNA maturation, export, and transport. Neurotransmitters (blue dots) are encapsulated in synaptic vesicles and released into synaptic cleft and are taken up by their receptors (yellow ovals); voltage-gated channels and neurotransmitter reuptake pumps are presented as dark grey box and light blue ovals, respectively.