CPEB-mediated cytoplasmic polyadenylation and the regulation of experience-dependent translation of alpha-CaMKII mRNA at synapses

Long-term changes in synaptic efficacy may require the regulated translatio n of dendritic mRNAs. While the basis of such regulation is unknown, it see med possible that some features of translational control in development cou ld be recapitulated in neurons. Polyadenylation-induced translation of oocy te mRNAs requires the cis-acting CPE sequence and the CPE-binding protein C PEB. CPEB is also present in the dendritic layers of the hippocampus, at sy napses in cultured neurons, and in postsynaptic densities of adult brain. a lpha-CaMKII mRNA, which is localized in dendrites and is necessary for syna ptic plasticity and LTP, contains two CPEs. These CPEs are bound by CPEB an d mediate polyadenylation-induced translation in injected Xenopus oocytes. In the intact brain, visual experience induces alpha-CaMKII mRNA polyadenyl ation and translation, suggesting that this process likely occurs at synaps es.