GSE68960
Histone methylation by the Kleefstra Syndrome protein EHMT1 mediates homeostatic synaptic scaling.
Homeostatic plasticity, a form of synaptic plasticity, maintains the fine balance between overall excitation and inhibition in developing and mature neuronal networks. Although the synaptic mechanisms of homeostatic plasticity are well characterized, the associated transcriptional program remains poorly understood. We show that the Kleefstra syndrome-associated protein, EHMT1, plays a critical and cell-autonomous role in synaptic scaling by responding to attenuated neuronal firing or sensory drive. Chronic activity deprivation increased the amount of neuronal dimethylated H3 at lysine 9 (H3K9me2), the catalytic product of EHMT1 and an epigenetic marker for gene repression. Genetic knockdown and pharmacological blockade of EHMT1 or EHMT2 prevented the increase of H3K9me2 and synaptic scaling up. Furthermore, BDNF repression was preceded by EHMT1/2-mediated H3K9me2 deposition at the Bdnf promoter during synaptic scaling up, both in vivo or in vivo. These findings suggest that changes in chromatin state through H3K9me2 governs a repressive program to achieve synaptic scaling. Overall design: 12 samples (4 conditions in biological triplicate), 3 wt, 3 wt tetradotoxin treated, 3 k.d., 3 k.d. tetradotoxin treated