RING Finger Protein 4 (RNF4) Derepresses Gene Expression from DNA Methylation [DNA and Chromosomes]

October 29th, 2014 by Wang, Y.

RNF4 is an E3 ubiquitin ligase originally identified as a transcription co-activator. The mechanism how RNF4 promotes transcription remains unclear. In this study, I found that RNF4 antagonizes transcriptional repression mediated by DNA methylation. RNF4 does not promote DNA demethylation, but mediates the ubiquitination of MeCP2, a Methyl-CpG-binding domain (MBD) protein. Removal of MeCP2 from gene promoters activates transcription. This study thus not only uncovers how RNF4 functions as a transcription activator, but also reveals the mechanism how MeCP2 protein stability is regulated.