Depolarization induces acetylation of histone H2B in the hippocampus

Phosphorylation is critically involved in synaptic plasticity and memory. Recent studies have shown that another posttranslational modification, acetylation, particularly of histone H3, also plays important roles in long-term potentiation and memory. However, activity-dependent modification of different histones of the nucleosome is not clearly understood. Here we show that depolarization enhances acetylation of histone H2B in the CA1 region of the hippocampus. Depolarization-induced H2B acetylation is dependent on calcium/calmodulin-dependent kinase and extracellular signal-regulated kinase activity. In addition, inhibition of DNA methyltransferase activity also abolishes depolarization-induced increase in H2B acetylation. These results show that acetylation of histone H2B is regulated in an activity-dependent manner by the molecular events important for synaptic plasticity and memory.