BEAF Regulates Cell-Cycle Genes through the Controlled Deposition of H3K9 Methylation Marks into Its Conserved Dual-Core Binding Sites
Figure 9
Regulated Gene Expression Requires Cooperative Binding of BEAF to Dual-Cores and Is Impaired by BID
(A) Schematic representation of BEAF. Its N-terminus is the DNA binding domain (AA 1–80) which targets one CGATA motif [17,23–25]. Its C-terminus, required for assembly of BEAF complexes, is called the BEAF self-interaction domain (BID; AA 80–280). As a result, expression of BID under the control of the GAL4-daugtherlesss (da) activator in transgenic flies dominantly competes with the cooperative binding of BEAF [25], as represented in (B).
(B) Schematic representation showing how the cooperative binding of BEAF complexes to clustered CGATAs of dual-cores is compromised by expression of BID upon its assembly with BEAF subunits.
(C) Quantitative RT-PCR analysis in 4–8-hour embryos expressing a GAL4-driven BID transgene. The results are expressed as copy number of amplification products measured for each gene in embryos expressing BID or in embryos expressing the da-GAL4 driver alone. The y-axis shows the number of copies of amplification products per μg of RNA normalized for each gene in control cells, where N =1 corresponds to 9,900 copies of actin, 11,200 copies of CG9745, 77,300 copies of snf, 59,400 copies of mei-S332, and 116,200 copies of cdk7. Experimental error is denoted by the differentially colored (gray) portion at the top of each bar. Note that BID expression leads to lethality at later stages of development [25].