BEAF regulates cell-cycle genes through the controlled deposition of H3K9 methylation marks into its conserved dual-core binding sites

• Published in: PLoS biology Vol. 6; no. 12; pp. 2896 - e327
• Main Authors: Emberly, Eldon, Blattes, Roxane, Schuettengruber, Bernd, Hennion, Magali, Jiang, Nan, Hart, Craig M, Käs, Emmanuel, Cuvier, Olivier
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.12.2008; Public Library of Science (PLoS)
• Subjects: Animals; Binding Sites; Biochemistry, Molecular Biology; Cell Biology; Cell Cycle Proteins - genetics; Cell Cycle Proteins - metabolism; Chromatin Immunoprecipitation; Chromosomes; Computational Biology; Computational Biology - methods; Cores; Cyclin-dependent kinases; DNA Methylation; DNA-Binding Proteins - metabolism; Drosophila; Drosophila - genetics; Drosophila - metabolism; Drosophila Proteins - metabolism; Epigenetics; Experiments; Eye Proteins - metabolism; Gene Expression Regulation; Genetics; Genomes; Genomics; Histones - metabolism; Insects; Kinases; Life Sciences; Molecular Biology; Oligonucleotide Array Sequence Analysis; Ontology; Studies; Drosophila Proteins; Oligonucleotide Array Sequence Analysis; Drosophila; Computational Biology; Gene Expression Regulation; DNA Methylation; Animals; Chromatin Immunoprecipitation; Histones; Binding Sites; Eye Proteins; Cell Cycle Proteins; DNA-Binding Proteins
• ISSN: 1545-7885; 1544-9173; 1545-7885
• DOI: 10.1371/journal.pbio.0060327

Chromatin insulators/boundary elements share the ability to insulate a transgene from its chromosomal context by blocking promiscuous enhancer-promoter interactions and heterochromatin spreading. Several insulating factors target different DNA consensus sequences, defining distinct subfamilies of insulators. Whether each of these families and factors might possess unique cellular functions is of particular interest. Here, we combined chromatin immunoprecipitations and computational approaches to break down the binding signature of the Drosophila boundary element-associated factor (BEAF) subfamily. We identify a dual-core BEAF binding signature at 1,720 sites genome-wide, defined by five to six BEAF binding motifs bracketing 200 bp AT-rich nuclease-resistant spacers. Dual-cores are tightly linked to hundreds of genes highly enriched in cell-cycle and chromosome organization/segregation annotations. siRNA depletion of BEAF from cells leads to cell-cycle and chromosome segregation defects. Quantitative RT-PCR analyses in BEAF-depleted cells show that BEAF controls the expression of dual core-associated genes, including key cell-cycle and chromosome segregation regulators. beaf mutants that impair its insulating function by preventing proper interactions of BEAF complexes with the dual-cores produce similar effects in embryos. Chromatin immunoprecipitations show that BEAF regulates transcriptional activity by restricting the deposition of methylated histone H3K9 marks in dual-cores. Our results reveal a novel role for BEAF chromatin dual-cores in regulating a distinct set of genes involved in chromosome organization/segregation and the cell cycle.