Conversion of MyoD to a neurogenic factor: binding site specificity determines lineage [ChIP-seq]
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ABSTRACT: MyoD and NeuroD2 are master regulators of myogenesis and neurogenesis and bind to a "shared" E-box sequence (CAGCTG) and a "private" sequence (CAGGTG or CAGATG, respectively). To determine whether private-site recognition is sufficient to confer lineage-specification, we generated a MyoD-mutant with the DNA binding specificity of NeuroD2. Our results demonstrate that redirecting MyoD binding from MyoD-private sites to NeuroD2-private sites, despite preserved binding to the MyoD/NeuroD2-shared sites, is sufficient to change MyoD from a master regulator of myogenesis to a master regulator of neurogenesis.
Project description:MyoD and NeuroD2 are master regulators of myogenesis and neurogenesis and bind to a "shared" E-box sequence (CAGCTG) and a "private" sequence (CAGGTG or CAGATG, respectively). To determine whether private-site recognition is sufficient to confer lineage-specification, we generated a MyoD-mutant with the DNA binding specificity of NeuroD2. Our results demonstrate that redirecting MyoD binding from MyoD-private sites to NeuroD2-private sites, despite preserved binding to the MyoD/NeuroD2-shared sites, is sufficient to change MyoD from a master regulator of myogenesis to a master regulator of neurogenesis.
Project description:MyoD and NeuroD2 are master regulators of myogenesis and neurogenesis and bind to a "shared" E-box sequence (CAGCTG) and a "private" sequence (CAGGTG or CAGATG, respectively). To determine whether private-site recognition is sufficient to confer lineage-specification, we generated a MyoD-mutant with the DNA binding specificity of NeuroD2. Our results demonstrate that redirecting MyoD binding from MyoD-private sites to NeuroD2-private sites, despite preserved binding to the MyoD/NeuroD2-shared sites, is sufficient to change MyoD from a master regulator of myogenesis to a master regulator of neurogenesis. RNA-seq profiling of mouse P19 cells transfected with MyoD, NeuroD2 and chimera mutants. The chimeric mutants are MyoD with the bHLH domain replaced with the NeuroD2 bHLH domain.
Project description:MyoD and NeuroD2 are master regulators of myogenesis and neurogenesis and bind to a "shared" E-box sequence (CAGCTG) and a "private" sequence (CAGGTG or CAGATG, respectively). To determine whether private-site recognition is sufficient to confer lineage-specification, we generated a MyoD-mutant with the DNA binding specificity of NeuroD2. Our results demonstrate that redirecting MyoD binding from MyoD-private sites to NeuroD2-private sites, despite preserved binding to the MyoD/NeuroD2-shared sites, is sufficient to change MyoD from a master regulator of myogenesis to a master regulator of neurogenesis. ChIP-seq profiling of MyoD, NeuroD2 and chimera mutants in mouse P19 cells transfected with these genes. The chimeric mutants are MyoD with the bHLH domain replaced with the NeuroD2 bHLH domain.
Project description:The regulatory networks of differentiation programs have been partly characterized; however, the molecular mechanisms of lineage-specific gene regulation by highly similar transcription factors remain largely unknown. Here we compare the genome-wide binding and transcription profiles of NEUROD2-mediated neurogenesis with MYOD-mediated myogenesis. We demonstrate that NEUROD2 and MYOD bind a shared CAGCTG E-box motif and E-box motifs specific for each factor: CAGGTG for MYOD and CAGATG for NEUROD2. Binding at factor-specific motifs is associated with gene transcription, whereas binding at shared sites is associated with regional epigenetic modifications but not as strongly associated with gene transcription. Binding is largely constrained to E-boxes pre-set in an accessible chromatin context that determines the set of target genes activated in each cell type. These findings demonstrate that the differentiation program is genetically determined by E-box sequence whereas cell lineage epigenetically determines the availability of E-boxes for each differentiation program. Comparing NeuroD2 induced neurogenesis and MyoD induced myogenesis by examining NeuroD2/MyoD binding sites in fibroblasts and P19 cells and corresponding changes in AcH4 using Chip-Seq. Assess chromatin accessibility using PvuII assay followed by high throughput sequencing.
Project description:The regulatory networks of differentiation programs have been partly characterized; however, the molecular mechanisms of lineage-specific gene regulation by highly similar transcription factors remain largely unknown. Here we compare the genome-wide binding and transcription profiles of NEUROD2-mediated neurogenesis with MYOD-mediated myogenesis. We demonstrate that NEUROD2 and MYOD bind a shared CAGCTG E-box motif and E-box motifs specific for each factor: CAGGTG for MYOD and CAGATG for NEUROD2. Binding at factor-specific motifs is associated with gene transcription, whereas binding at shared sites is associated with regional epigenetic modifications but not as strongly associated with gene transcription. Binding is largely constrained to E-boxes pre-set in an accessible chromatin context that determines the set of target genes activated in each cell type. These findings demonstrate that the differentiation program is genetically determined by E-box sequence whereas cell lineage epigenetically determines the availability of E-boxes for each differentiation program. Total RNA samples were collected in triplicate from undifferentiated and differentiated P19 cells and MEFs, and labeled cDNA was made per Affymetrix protocol
Project description:The regulatory networks of differentiation programs have been partly characterized; however, the molecular mechanisms of lineage-specific gene regulation by highly similar transcription factors remain largely unknown. Here we compare the genome-wide binding and transcription profiles of NEUROD2-mediated neurogenesis with MYOD-mediated myogenesis. We demonstrate that NEUROD2 and MYOD bind a shared CAGCTG E-box motif and E-box motifs specific for each factor: CAGGTG for MYOD and CAGATG for NEUROD2. Binding at factor-specific motifs is associated with gene transcription, whereas binding at shared sites is associated with regional epigenetic modifications but not as strongly associated with gene transcription. Binding is largely constrained to E-boxes pre-set in an accessible chromatin context that determines the set of target genes activated in each cell type. These findings demonstrate that the differentiation program is genetically determined by E-box sequence whereas cell lineage epigenetically determines the availability of E-boxes for each differentiation program.
Project description:The regulatory networks of differentiation programs have been partly characterized; however, the molecular mechanisms of lineage-specific gene regulation by highly similar transcription factors remain largely unknown. Here we compare the genome-wide binding and transcription profiles of NEUROD2-mediated neurogenesis with MYOD-mediated myogenesis. We demonstrate that NEUROD2 and MYOD bind a shared CAGCTG E-box motif and E-box motifs specific for each factor: CAGGTG for MYOD and CAGATG for NEUROD2. Binding at factor-specific motifs is associated with gene transcription, whereas binding at shared sites is associated with regional epigenetic modifications but not as strongly associated with gene transcription. Binding is largely constrained to E-boxes pre-set in an accessible chromatin context that determines the set of target genes activated in each cell type. These findings demonstrate that the differentiation program is genetically determined by E-box sequence whereas cell lineage epigenetically determines the availability of E-boxes for each differentiation program.
Project description:The transcriptional activator MyoD serves as a master controller of myogenesis. Often in partnership with Mef2, MyoD binds to the promoters of hundreds of muscle genes in proliferating myoblasts, yet activates these targets only upon receiving cues that launch differentiation. What regulates this off/on switch of MyoD function has been incompletely understood, although known to reflect the action of chromatin modifiers. Here, we identify KAP1/TRIM28 as a key regulator of MyoD function. In myoblasts, KAP1 is present with MyoD and Mef2 at many muscle genes, where it acts as a scaffold to recruit not only co-activators such as p300 and LSD1, but also co-repressors such as G9a and HDAC1, with promoter silencing as net outcome. Upon differentiation, MSK1-mediated phosphorylation of KAP1 releases the co-repressors from the scaffold, unleashing transcriptional activation by MyoD/Mef2 and their positive cofactors. Thus, our results reveal KAP1 as a previously unappreciated interpreter of cell signaling, which modulates the ability of MyoD to drive myogenesis. Kap1 and H3K9me3 ChIPseq in proliferating C2C12 cells
Project description:The transcriptional activator MyoD serves as a master controller of myogenesis. Often in partnership with Mef2, MyoD binds to the promoters of hundreds of muscle genes in proliferating myoblasts, yet activates these targets only upon receiving cues that launch differentiation. What regulates this off/on switch of MyoD function has been incompletely understood, although known to reflect the action of chromatin modifiers. Here, we identify KAP1/TRIM28 as a key regulator of MyoD function. In myoblasts, KAP1 is present with MyoD and Mef2 at many muscle genes, where it acts as a scaffold to recruit not only co-activators such as p300 and LSD1, but also co-repressors such as G9a and HDAC1, with promoter silencing as net outcome. Upon differentiation, MSK1-mediated phosphorylation of KAP1 releases the co-repressors from the scaffold, unleashing transcriptional activation by MyoD/Mef2 and their positive cofactors. Thus, our results reveal KAP1 as a previously unappreciated interpreter of cell signaling, which modulates the ability of MyoD to drive myogenesis. Transcriptome profiling of control and Kap1KD in C2C12 during proliferation or at 48hours differentiation stage