Cell Signaling Technology

Product Pathways - Chromatin Regulation / Epigenetics

BRD4 Antibody #12183

Applications Reactivity Sensitivity MW (kDa) Source
W IP H (B) (Dg) (Pg) Endogenous 200 Rabbit

Applications Key:  W=Western Blotting  IP=Immunoprecipitation
Reactivity Key:  H=Human  B=Bovine  Dg=Dog  Pg=Pig
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

BRD4 Antibody recognizes endogenous levels of total BRD4 protein. This antibody specifically recognizes the BRD4 long isoform (UniProt #O60885-1) and does not recognize other isoforms.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to residues surrounding Leu1129 of human BRD4 protein. Antibodies are purified by protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts from various cell lines using BRD4 Antibody.

IP

IP

Immunoprecipitation of BRD4 from 293T cell extracts using Normal Rabbit IgG #2729 (lane 2) or BRD4 Antibody (lane 3). Lane 1 is 10% input. Western blot analysis was performed using BRD4 Antibody.

Background

Bromodomain-containing protein 4 (BRD4) is a member of the bromodomains and extraterminal (BET) family of proteins, which also includes BRD2, BRD3, and BRDT (1-3). BET family proteins contain two tandem bromodomains and an extra terminal (ET) domain, and bind acetyl lysine residues (3). BRD4 is a chromatin-binding protein with a preference for Lys14 on histone H3 as well as Lys5 and Lys12 on histone H4 (4). BRD4 chromatin binding occurs throughout the cell cycle, including condensed mitotic chromosomes, when the majority of genes are silenced (5). BRD4 association with chromatin during mitosis is thought to be an important part of the bookmarking mechanism to accelerate re-activation of the silenced genes upon exit from mitosis (2,6). BRD4 has been shown to facilitate transcription by recruiting the positive transcription elongation factor b (pTEFb) complex that phosphorylates Ser2 of the heptapeptide repeat of the C-terminal domain of RNA polymerase II, promoting transcription elongation (3,7,8). In addition, BRD4 has been found to be part of the super elongation complex and the polymerase associated factor complex (PAFc) in MLL-fusion derived leukemia cell lines, demonstrating a role for BRD4 in the regulation of transcription elongation (9). Research studies have shown that BRD4 (and BET family proteins) may be promising theraeupic targets for various Myc-driven cancers, such as Burkitt’s lymphoma and certain acute myeloid leukemias (1,10,11). Investigators have found molecular inhibition of BET proteins to be effective in inducing apoptosis in various MLL-fusion driven leukemic cell lines by competing BRD3 and BRD4 from chromatin, leading to reduced expression of Bcl-2, Myc, and CDK6 (9). BET inhibition has also been shown to have antitumor activities against nuclear protein in testis (NUT) midline carcinoma cell lines and xenografts in mice where BRD4 is found to be a frequent translocation partner of the NUT protein (12). In addition, BRD4 regulates the expression of some inflammatory genes, and inhibition of BRD4 (and BET family proteins) chromatin binding causes reduced expression of a subset of inflammatory genes in macrophages, leading to protection against endotoxic shock and sepsis (13).

  1. Belkina, A.C. and Denis, G.V. (2012) Nat Rev Cancer 12, 465-77.
  2. Voigt, P. and Reinberg, D. (2011) Genome Biol 12, 133.
  3. Wu, S.Y. and Chiang, C.M. (2007) J Biol Chem 282, 13141-5.
  4. Dey, A. et al. (2003) Proc Natl Acad Sci U S A 100, 8758-63.
  5. Dey, A. et al. (2009) Mol Biol Cell 20, 4899-909.
  6. Zhao, R. et al. (2011) Nat Cell Biol 13, 1295-304.
  7. Jang, M.K. et al. (2005) Mol Cell 19, 523-34.
  8. Yang, Z. et al. (2005) Mol Cell 19, 535-45.
  9. Dawson, M.A. et al. (2011) Nature 478, 529-33.
  10. Muller, S. et al. (2011) Expert Rev Mol Med 13, e29.
  11. Mertz, J.A. et al. (2011) Proc Natl Acad Sci U S A 108, 16669-74.
  12. Filippakopoulos, P. et al. (2010) Nature 468, 1067-73.
  13. Nicodeme, E. et al. (2010) Nature 468, 1119-23.

Application References

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Companion Products

For Research Use Only. Not For Use In Diagnostic Procedures.

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