MBD2 and multiple domains of CHD4 are required for transcriptional repression by Mi-2/NuRD complexes.
Mi-2/nucleosome remodeling and deacetylase (NuRD) chromatin remodeling complexes are important regulators of chromatin structure and DNA accessibility. We examined requirements for individual domains of chromodomain helicase DNA-binding protein 4 (CHD4), a core catalytic component of NuRD complexes, as well as the NuRD subunit methyl-binding domain protein 2 (MBD2) and methylated DNA, for NuRD function in the context of tissue-specific transcription. By itself, loss of NuRD activity is not sufficient for transcriptional activation. However, NuRD complexes greatly reduce activation of the B cell-specific mb-1 (Cd79a) gene by the transcription factors EBF1 and Pax5. Using our B cell model system, we determined that the two chromodomains and ATPase/helicase and C-terminal domains (CTD) of CHD4 are all necessary for repression of mb-1 promoters by NuRD. All of these domains except the CTD are required for efficient association of CHD4 with mb-1 promoter chromatin. Loss of MBD2 expression or of DNA methylation impaired association of CHD4 with mb-1 promoter chromatin and enhanced its transcription. We conclude that repressive functions of MBD2-containing NuRD complexes are dependent on cooperative interactions between the major domains of CHD4 with histones and DNA and on binding of methylated DNA by MBD2.
Integrated Department of Immunology, National Jewish Health, Denver, Colorado, USA.
Julita
J
Ramírez
Carissa
C
Dege
Tatiana G
TG
Kutateladze
James
J
Hagman
D000595:Amino Acid Sequence; D001324:Autoantigens / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001402:B-Lymphocytes / Q000378:metabolism; D001483:Base Sequence; D051925:CD79 Antigens / Q000235:genetics; D002460:Cell Line; D019175:DNA Methylation; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D056245:Mi-2 Nucleosome Remodeling and Deacetylase Complex / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D051757:PAX5 Transcription Factor / Q000378:metabolism; D011401:Promoter Regions, Genetic; D054730:Protein Interaction Domains and Motifs; D034741:RNA, Small Interfering / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000378:metabolism; D014158:Transcription, Genetic
D001324:Autoantigens; D051925:CD79 Antigens; C497881:CD79A protein, human; C115323:CHD4 protein, human; D004268:DNA-Binding Proteins; C081976:EBF1 protein, human; C489325:MBD2 protein, human; D051757:PAX5 Transcription Factor; C497281:PAX5 protein, human; D034741:RNA, Small Interfering; D015534:Trans-Activators; D056245:Mi-2 Nucleosome Remodeling and Deacetylase Complex