The role of nuclear PKMζ in memory maintenance

Recently, protein kinase M zeta (PKM zeta) has emerged as an important player for maintaining memory. It has been reported that PKM zeta regulates the trafficking of GluA2 in postsynaptic membranes to maintain memory. However, there has been no study on PKM zeta outside the synaptic region regarding memory maintenance. Here, we found that PKM zeta is transported to the nucleus in a neural activity-dependent manner. Moreover, we found that PKM zeta phosphorylates CREB-binding protein (CBP) at serine residues and that PKM zeta inhibition reduces the acetylation of histone H2B and H3. Finally, we showed that the amnesic effect of PKM zeta inhibition can be rescued by enhancing histone acetylation level. These results suggest the possibility that nuclear PKM zeta has a crucial role in memory maintenance. (C) 2016 Elsevier Inc. All rights reserved.