Abstract

Proper neurological function in humans requires precise control of levels of the epigenetic regulator methyl CpGbinding protein 2. MeCP2 protein levels are low in fetal brains, where the predominant MECP2 transcripts have an unusually long 39 untranslated region. Here, we show that miR-483-5p, an intragenic microRNA of the imprinted IGF2, regulates MeCP2 levels through a human-specific binding site in the MECP2 long 39 UTR. We demonstrate the inverse correlation of miR-483-5p and MeCP2 levels in developing human brains and fibroblasts from Beckwith-Wiedemann syndrome patients. Importantly, expression of miR-483-5p rescues abnormal dendritic spine phenotype of neurons overexpressing human MeCP2. In addition, miR-483-5p modulates the levels of proteins of the MeCP2-interacting corepressor complexes, including HDAC4 and TBL1X. These data provide insight into the role of miR-483-5p in regulating the levels of MeCP2 and interacting proteins during human fetal development. © 2013 by Cold Spring Harbor Laboratory Press.