Journal: Cell reports
Article Title: The Bromodomain Protein 4 Contributes to the Regulation of Alternative Splicing
doi: 10.1016/j.celrep.2019.10.066
Figure Lengend Snippet: (A) Immunoblot of BRD4 immunoprecipitates from thymocyte nuclear extracts (with and without benzonase treatment) with indicated antibodies to splicing factors FUS, HnRNPL, and U1–70. The immunoprecipitates from a single extract were run on either a 6% gel to visualize BRD4 and Fus or on a 10% gel to visualize HnRNPL and U1–70. The values under the IP lanes indicate the enrichment of anti-BRD4 co-IP, relative to the IgG control. (B, left) Immunoblot of BRD4 immunoprecipitates from HeLa nuclear extracts with indicated antibodies to splicing factors FUS, HnRNPM, U1–70, and U1-A. (B, right) Immunoblot of FUS immunoprecipitates from HeLa nuclear extracts with indicated antibodies to BRD4 and splicing factors HnRNPM, U1–70, and U1-A. (C) Schematic representation of BRD4 and BRD4-deletion mutants. The coordinates of the mouse BRD4 mutations are as follows. WT BRD4, 1402 aa; DN, 722–1402 aa; ΔC, 1–699aa; ΔBD1, 146–1402 aa; ΔBD2+B, 1–349/599–1402 aa; ΔB, 1–502/549–1402 aa; ΔET, 1–600/684–1402 aa; ΔHAT, 1–1156/1198–1402 aa. (D) Immunoblots showing pull-down analysis of recombinant BRD4 with recombinant HnRNPM. rHnRNPM (0.25 μg) was pulled down with rflag-BRD4 (0.5 μg) immobilized on Flag beads. Immunoblots were with anti-HnRNPM (upper) and anti-BRD4 (lower). (E) Immunoblots showing pull-down analysis of recombinant BRD4 with recombinant FUS. rFUS (0.25 μg) was pulled down with rflag-BRD4 (0.5 μg) WT or equimolar amounts of N-terminal or C-terminal BRD4 truncation mutants immobilized on Flag beads. Immunoblots were with anti-FUS (upper) and anti-BRD4 (lower). (F) Binding of HnRNPM (left panel) and FUS (right panel) to BRD4 mutants was assessed in pull-down assays with rBRD4 immobilized on Flag beads and immunoblotting with appropriate antibodies. The results represent the average of two experiments. (G) Retention of FUS and HnRNPM to BRD4 mutants, relative to the WT, was quantified as the fraction of input and normalized to the extent of binding to BRD4 WT. All results are representative of at least two independent experiments. See also Figure S5.
Article Snippet: Human Flag-tagged BRD4 ΔET in pCMV2 mammalian vector , ADDgene ( Bisgrove et al., 2007 ) , #21938; RRID: Addgene_21938.
Techniques: Western Blot, Co-Immunoprecipitation Assay, Control, Recombinant, Binding Assay