Skip to main content
. Author manuscript; available in PMC: 2014 Jan 1.
Published in final edited form as: Trends Biochem Sci. 2012 Dec 4;38(1):47–55. doi: 10.1016/j.tibs.2012.11.001

Figure 3. RNA transport in dendrites.

Figure 3

The hnRNP (heterogeneous nuclear ribonucleoprotein) A2 and ZBP1 (zipcode binding protein 1) pathways represent two of the major RNA targeting mechanisms in neurons. hnRNP A2 (blue spheres) interacts with GA-type noncanonical motifs, as exemplified by those in the 5′ domain of BC1 and BC200 RNAs, and in the 3′ UTR of PKMζ mRNA [62]. At the synapse, BC RNAs repress translation (red T-shaped bar) by preventing 48S complex formation [42, 44], thus providing a counterbalance to translational stimulation through group I mGluR activation (dark green arrow; center, right) [53]. hnRNP A2 also interacts with expanded CGG repeat stem-loop structures in the 5′ UTR of premutation FMR1 mRNA (FMR1 mRNA*) [69, 73]. Premutation FMR1 mRNA can compete with GA motif RNAs for access to hnRNP A2, which could lead to impairments in their dendritic delivery [62]. ZBP1 (orange spheres) interacts with the β-actin mRNA zipcode, promoting dendritic delivery of the mRNA while at the same time inhibiting its translation [3]. It is possible that at the synapse, phosphorylation of ZBP1 by Src kinase (bottom, right) causes it to release β-actin mRNA, permitting translation [3]. Black arrows indicate movement and association, dark green arrow indicates stimulation, red T-shaped bars indicate inhibition.