Project description:The heterogeneous collection of NuRD complexes can be grouped into the MBD2 or MBD3 containing complexes MBD2-NuRD and MBD3-NuRD. 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 a strong enrichment for MBD2 at methylated CpG sequences, whereas CpGs bound by MBD3 are devoid of methylation. Gene activity of MBD2 bound genes is four fold lower as compared to genes bound by MBD3. 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. V5 ChIP followed by high throughput sequencing in HeLa cells transiently transfected with either V5-MBD2b, V5-MBD3 or V5.
Project description: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.
Project description:The heterogeneous collection of NuRD complexes can be grouped into the MBD2 or MBD3 containing complexes MBD2-NuRD and MBD3-NuRD. 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 a strong enrichment for MBD2 at methylated CpG sequences, whereas CpGs bound by MBD3 are devoid of methylation. Gene activity of MBD2 bound genes is four fold lower as compared to genes bound by MBD3. 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.
Project description: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. 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.
Project description:The Nucleosome Remodeling and Deacetylation (NuRD) complex is a crucial regulator of cellular differentiation. Two members of the Methyl-CpG-binding domain (MBD) protein family, MBD2 and MBD3, are known to be integral, but mutually exclusive subunits of the NuRD complex. Several MBD2 and MBD3 isoforms are present in mammalian cells, resulting in distinct MBD-NuRD complexes. Whether these different complexes serve distinct functional activities during differentiation is not fully explored. Based on the essential role of MBD3 in lineage commitment, we systematically investigated a diverse set of MBD2 and MBD3 variants for their potential to rescue the differentiation block observed for mouse embryonic stem cells (ESCs) lacking MBD3. While MBD3 is indeed crucial for ESC differentiation to neuronal cells, it functions independently of its MBD domain. We further identify that MBD2 isoforms can replace MBD3 during lineage commitment, however with different potential. Full-length MBD2a only partially rescues the differentiation block, while MBD2b, an isoform lacking an N-terminal GR-rich repeat, fully rescues the Mbd3 KO phenotype. In case of MBD2a, we further show that removing the methylated DNA binding capacity or the GR-rich repeat enables full redundancy to MBD3, highlighting the synergistic requirements for these domains in diversifying NuRD complex function.
Project description:Cytosine methylation on DNA is an important epigenetic and regulatory mark. Chromatin remodeling complexes containing methyl-CpG binding domain (MBD) proteins modulate chromatin structure and transcription at methylated loci. Two MBD proteins, Mbd2 and Mbd3, are mutually exclusive members of the NuRD chromatin remodeling complex, and have been shown to bind methylated or hydroxymethylated DNA, respectively. However, a recent study called both results into question, showing that chromatin binding by these proteins is partially (Mbd2) or completely (Mbd3) independent of DNA methylation/hydroxymethylation. Here we re-analyze these data and observe discrepancies with both conclusions. Furthermore, we describe multiple new datasets that demonstrate the dependence of endogenous Mbd2 and Mbd3 on DNA methylation. Interestingly, we find that Mbd2 and Mbd3 are also dependent on one another for binding, likely due to the fact that both are required for normal levels of DNA methylation/hydroxymethylation. These findings describe a regulatory loop controlling the DNA methylation machinery and its readers.
Project description:Cytosine methylation on DNA is an important epigenetic and regulatory mark. Chromatin remodeling complexes containing methyl-CpG binding domain (MBD) proteins modulate chromatin structure and transcription at methylated loci. Two MBD proteins, Mbd2 and Mbd3, are mutually exclusive members of the NuRD chromatin remodeling complex, and have been shown to bind methylated or hydroxymethylated DNA, respectively. However, a recent study called both results into question, showing that chromatin binding by these proteins is partially (Mbd2) or completely (Mbd3) independent of DNA methylation/hydroxymethylation. Here we re-analyze these data and observe discrepancies with both conclusions. Furthermore, we describe multiple new datasets that demonstrate the dependence of endogenous Mbd2 and Mbd3 on DNA methylation. Interestingly, we find that Mbd2 and Mbd3 are also dependent on one another for binding, likely due to the fact that both are required for normal levels of DNA methylation/hydroxymethylation. These findings describe a regulatory loop controlling the DNA methylation machinery and its readers.
Project description:Cytosine methylation on DNA is an important epigenetic and regulatory mark. Chromatin remodeling complexes containing methyl-CpG binding domain (MBD) proteins modulate chromatin structure and transcription at methylated loci. Two MBD proteins, Mbd2 and Mbd3, are mutually exclusive members of the NuRD chromatin remodeling complex, and have been shown to bind methylated or hydroxymethylated DNA, respectively. However, a recent study called both results into question, showing that chromatin binding by these proteins is partially (Mbd2) or completely (Mbd3) independent of DNA methylation/hydroxymethylation. Here we re-analyze these data and observe discrepancies with both conclusions. Furthermore, we describe multiple new datasets that demonstrate the dependence of endogenous Mbd2 and Mbd3 on DNA methylation. Interestingly, we find that Mbd2 and Mbd3 are also dependent on one another for binding, likely due to the fact that both are required for normal levels of DNA methylation/hydroxymethylation. These findings describe a regulatory loop controlling the DNA methylation machinery and its readers.