title: p66Alpha-MBD2 coiled-coil interaction and recruitment of Mi-2 are critical for globin gene silencing by the MBD2-NuRD complex.
abstract: Nucleosome remodeling complexes comprise several large families of chromatin modifiers that integrate multiple epigenetic control signals to play key roles in cell type-specific transcription regulation. We previously isolated a methyl-binding domain protein 2 (MBD2)-containing nucleosome remodeling and deacetylation (NuRD) complex from primary erythroid cells and showed that MBD2 contributes to DNA methylation-dependent embryonic and fetal β-type globin gene silencing during development in vivo. Here we present structural and biophysical details of the coiled-coil interaction between MBD2 and p66α, a critical component of the MBD2-NuRD complex. We show that enforced expression of the isolated p66α coiled-coil domain relieves MBD2-mediated globin gene silencing and that the expressed peptide interacts only with a subset of components of the MBD2-NuRD complex that does not include native p66α or Mi-2. These results demonstrate the central importance of the coiled-coil interaction and suggest that MBD2-dependent DNA methylation-driven gene silencing can be disrupted by selectively targeting this coiled-coil complex.
authors.affiliation: Department of Human and Molecular Genetics, Institute of Structural Biology and Drug Design, Center for the Study of Biological Complexity, and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA.
authors.forename: Merlin Nithya
authors.initials: MN
authors.lastname: Gnanapragasam
authors.forename: J Neel
authors.initials: JN
authors.lastname: Scarsdale
authors.forename: Maria L
authors.initials: ML
authors.lastname: Amaya
authors.forename: Heather D
authors.initials: HD
authors.lastname: Webb
authors.forename: Megha A
authors.initials: MA
authors.lastname: Desai
authors.forename: Ninad M
authors.initials: NM
authors.lastname: Walavalkar
authors.forename: Shou Zhen
authors.initials: SZ
authors.lastname: Wang
authors.forename: Sheng
authors.initials: S
authors.lastname: Zu Zhu
authors.forename: Gordon D
authors.initials: GD
authors.lastname: Ginder
authors.forename: David C
authors.initials: DC
authors.lastname: Williams
mesh_terms: D015153:Blotting, Western; D019175:DNA Methylation / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism*; D044127:Epigenesis, Genetic / Q000235:genetics*; D020868:Gene Silencing; D006801:Humans; D047468:Immunoprecipitation; D056245:Mi-2 Nucleosome Remodeling and Deacetylase Complex / Q000378:metabolism*; D008958:Models, Molecular; D034622:RNA Interference; D012097:Repressor Proteins / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D004268:DNA-Binding Proteins; C468769:GATAD2A protein, human; C489325:MBD2 protein, human; D012097:Repressor Proteins; D056245:Mi-2 Nucleosome Remodeling and Deacetylase Complex