Two cis-acting elements in the 3′ untranslated region of α-CaMKII regulate its dendritic targeting

Dendritic localization of the or subunit of Ca2+/calmodulin-dependent protein kinase II (alpha CaMKII) mRNA in CNS neurons requires its 3' untranslated region (3'UTR). We investigated this targeting mechanism by identifying two cis-acting elements in the 3'UTR. One is a 30-nucleotide element that mediated dendritic translocation. A homologous sequence in the 3'UTR of neurogranin, transcripts of which also reside in dendrites, also funtioned in cis to promote its dendritic transport. Other putative elements in the alpha CaMKII mRNA inhibit its transport in a resting state. This inhibition was removed in depolarized neurons, and such activity-dependent derepression was a primary requirement for their dendritic targeting.