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

Figure 2

mRNA-protein and protein-protein interactions in localized mRNA expression in neurons. An mRNA resulting from the transcription of a gene in DNA is represented by its 3-UTR (untranslated region) containing a segment of the specific sequence (filled box) and a higher order structure, represented by two stem loops. These elements handle localized mRNA expression and are recognized and bound by specific proteins (represented by a light-blue object) and exported into the cytoplasm. Then, other RNA-binding proteins, represented by red and green objects, bind to the mRNA 3-UTR to form a localizing ribonucleoprotein (L-RNP), which is assisted by other proteins (not presented here) and supports the trafficking of mRNA to specific locations in the dendritic spine where it is translated. Before that, mRNA can be remodeled (symbolized by changes in its secondary configuration and protein (grey oval) binding), docked in the dendrite spine, preceded by phosphorylation (the P letter in a yellow circle) and disassociation of the L-RNP proteins, and translated to produce the Arc protein (dark blue oval).