Expression data from HeLa cells after MBD2 and MBD3 knock down. Homo sapiens

The heterogeneous collection of NuRD complexes can be grouped into the MBD2 or MBD3 containing complexes MBD2-NuRD and MBD3-NuRD. MBD2 is known to bind to methylated CpG sequences in vitro in contrast to MBD3. Although functional differences have been described, a direct comparison of MBD2 and MBD3 in respect to genome-wide binding and function has been lacking. Here we show when depleting cells for MBD2, the MBD2 bound genes increase their activity, whereas MBD2 plus MBD3 bound genes reduce their activity. Most strikingly, MBD3 is enriched at active promoters, whereas MBD2 is bound at methylated promoters and enriched at exon sequences of active genes. This suggests a functional connection between MBD2 binding to chromatin and splicing. Overall design: 9 Total samples were analysed. Three individual replicates for HeLa cells treated with siRNA against MBD2, MBD3 or scrambled siRNA were performed. We calculated the fold change of gene expression of cells treated with MBD2- or MBD3-siRNA over cells treated with scrambled siRNA.