Phosphorylation of MeCP2 at Serine 80 regulates its chromatin association and neurological function. Mus musculus

Mutations of MECP2 (Methyl-CpG Binding Protein 2) cause Rett Syndrome. As a chromatin associated multifunctional protein, how MeCP2 integrates external signals and regulates neuronal function remain unclear. While neuronal activity-induced phosphorylation of MeCP2 at serine 421 (S421) has been reported, the full spectrum of MeCP2 phosphorylation together with the in vivo function of such modifications are yet to be revealed. Here we report the identification of several novel MeCP2 phosphorylation sites in normal and epileptic brains from multiple species. We demonstrate that serine 80 (S80) phosphorylation of MeCP2 is critical as its mutation into alanine (S80A) in transgenic knock-in mice leads to locomotor deficits. S80A mutation attenuates MeCP2 chromatin association at several gene promoters in resting neurons and leads to transcription changes of a small number of genes. Calcium influx in neurons causes dephosphorylation at S80, potentially contributing to its dissociation from the chromatin. We postulate that phosphorylation of MeCP2 modulates its dynamic function in neurons transiting between resting and active states within neural circuits that underlie behaviors. Overall design: E 15.5 Mecp2 -/y cortical neurons were infected with lentivirus expressing wild-type and S80A mutant MeCP2 at similar protein expression level. 2 biological independent samples and dye swap were used for this set (GSM367413) and replicate 2 set (GSM367414).