title: The BET Protein BRD2 Cooperates with CTCF to Enforce Transcriptional and Architectural Boundaries.
abstract: Bromodomain and extraterminal motif (BET) proteins are pharmacologic targets for the treatment of diverse diseases, yet the roles of individual BET family members remain unclear. We find that BRD2, but not BRD4, co-localizes with the architectural/insulator protein CCCTC-binding factor (CTCF) genome-wide. CTCF recruits BRD2 to co-bound sites whereas BRD2 is dispensable for CTCF occupancy. Disruption of a CTCF/BRD2-occupied element positioned between two unrelated genes enables regulatory influence to spread from one gene to another, suggesting that CTCF and BRD2 form a transcriptional boundary. Accordingly, single-molecule mRNA fluorescence in situ hybridization (FISH) reveals that, upon site-specific CTCF disruption or BRD2 depletion, expression of the two genes becomes increasingly correlated. HiC shows that BRD2 depletion weakens boundaries co-occupied by CTCF and BRD2, but not those that lack BRD2. These findings indicate that BRD2 supports boundary activity, and they raise the possibility that pharmacologic BET inhibitors can influence gene expression in part by perturbing domain boundary function.
authors.affiliation: Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Hsu
authors.affiliation: Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Gilgenast
authors.affiliation: Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Caroline R
authors.initials: CR
authors.lastname: Bartman
authors.affiliation: Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Edwards
authors.affiliation: Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Stonestrom
authors.affiliation: Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
authors.forename: Peng
authors.initials: P
authors.lastname: Huang
authors.affiliation: Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Emerson
authors.affiliation: Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
authors.forename: Perry
authors.initials: P
authors.lastname: Evans
authors.affiliation: Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Werner
authors.affiliation: Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Cheryl A
authors.initials: CA
authors.lastname: Keller
authors.affiliation: Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Belinda
authors.initials: B
authors.lastname: Giardine
authors.affiliation: Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Ross C
authors.initials: RC
authors.lastname: Hardison
authors.affiliation: Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Arjun
authors.initials: A
authors.lastname: Raj
authors.affiliation: Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA. Electronic address: jcremins@seas.upenn.edu.
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Phillips-Cremins
authors.affiliation: Division of Hematology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA. Electronic address: blobel@email.chop.edu.
authors.forename: Gerd A
authors.initials: GA
authors.lastname: Blobel
mesh_terms: D000818:Animals; D001665:Binding Sites; D000076246:CCCTC-Binding Factor; D064113:CRISPR-Cas Systems; D002460:Cell Line; D002843:Chromatin / Q000235:genetics / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D053595:Embryonic Stem Cells / Q000378:metabolism*; D004742:Enhancer Elements, Genetic; D050982:GATA1 Transcription Factor / Q000235:genetics / Q000378:metabolism; D000072669:Gene Editing / Q000379:methods; D017404:In Situ Hybridization, Fluorescence; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D000072760:Single Molecule Imaging / Q000379:methods; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D000092468:Bromodomain Containing Proteins
chemical_list: D000076246:CCCTC-Binding Factor; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D050982:GATA1 Transcription Factor; D026901:Membrane Transport Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C490844:Brd2 protein, mouse; D000092468:Bromodomain Containing Proteins; C518476:Brd3 protein, mouse; C486694:Brd4 protein, mouse; C000619698:Ctcf protein, mouse; C509051:mitoferrin protein, mouse
keywords: BET proteins; BRD2; CTCF; chromatin architecture; transcription