Figure 7: An illustration showing the relationship among MeCP2 SUMOylation, its association with CREB and other proteins in the repressor complex, CREB DNA binding to the Bdnf gene promoter and Bdnf gene expression.

(a) Under physiological condition, MeCP2 binds to the methylated DNA and is associated with Sin3a, HDAC1 and CREB to form a repressor complex that suppresses CREB binding to the CRE element and inhibits Bdnf gene expression. (b) On stimulation, MeCP2 phosphorylation (at Thr-308 and Ser-421)-dependent MeCP2 SUMOylation takes place that enhances MeCP2 binding to methylated DNA, dissociates CREB from the repressor complex, which allows more CREB, in association with CBP, to bind to the CRE element on DNA promoter and increases Bdnf gene expression.