| First Author | Jang MK | Year | 2005 |
| Journal | Mol Cell | Volume | 19 |
| Issue | 4 | Pages | 523-34 |
| PubMed ID | 16109376 | Mgi Jnum | J:101015 |
| Mgi Id | MGI:3590381 | Doi | 10.1016/j.molcel.2005.06.027 |
| Citation | Jang MK, et al. (2005) The bromodomain protein Brd4 is a positive regulatory component of P-TEFb and stimulates RNA polymerase II-dependent transcription. Mol Cell 19(4):523-34 |
| abstractText | Brd4 is a mammalian bromodomain protein that binds to acetylated chromatin. Proteomic analysis revealed that Brd4 interacts with cyclinT1 and Cdk9 that constitutes core positive transcription elongation factor b (P-TEFb). Brd4 interacted with P-TEFb in the living nucleus through its bromodomain. About half of P-TEFb was bound to the inhibitory subunit and functionally inactive. Brd4 interacted with P-TEFb that was free of the inhibitory subunit. An increase in Brd4 expression led to increased P-TEFb-dependent phosphorylation of RNA polymerase II (RNAPII) CTD and stimulation of transcription from promoters in vivo. Conversely, a reduction in Brd4 expression by siRNA reduced CTD phosphorylation and transcription, revealing that Brd4 is a positive regulatory component of P-TEFb. In chromatin immunoprecipitation (ChIP) assays, the recruitment of P-TEFb to a promoter was dependent on Brd4 and was enhanced by an increase in chromatin acetylation. Together, P-TEFb alternately interacts with Brd4 and the inhibitory subunit to maintain functional equilibrium in the cell. |
