Abstract
Members of the bromodomain and extra-terminal domain (BET) family of proteins (bromodomain-containing (BRD) 2, 3, 4, and T) are widely expressed and highly conserved regulators of gene expression in eukaryotes. These proteins have been intimately linked to human disease, and more than a dozen clinical trials are currently underway to test BET-protein inhibitors as modulators of cancer. However, although it is clear that these proteins use their bromodomains to bind both histones and transcription factors bearing acetylated lysine residues, the molecular mechanisms by which BET family proteins regulate gene expression are not well defined. In particular, the functions of the other domains such as the ET domain have been less extensively studied. Here, we examine the properties of the ET domain of BRD3 as a protein/protein interaction module. Using a combination of pulldown and biophysical assays, we demonstrate that BRD3 binds to a range of chromatin-remodeling complexes, including the NuRD, BAF, and INO80 complexes, via a short linear "KIKL" motif in one of the complex subunits. NMR-based structural analysis revealed that, surprisingly, this mode of interaction is shared by the AF9 and ENL transcriptional coregulators that contain an acetyl-lysine-binding YEATS domain and regulate transcriptional elongation. This observation establishes a functional commonality between these two families of cancer-related transcriptional regulators. In summary, our data provide insight into the mechanisms by which BET family proteins might link chromatin acetylation to transcriptional outcomes and uncover an unexpected functional similarity between BET and YEATS family proteins.
Highlights
Members of the bromodomain and extra-terminal domain (BET) family of proteins (bromodomain-containing (BRD) 2, 3, 4, and T) are widely expressed and highly conserved regulators of gene expression in eukaryotes
BET bromodomains recognize ⑀-acetylated lysines, with targets including histone H3 acetylated at Lys-14 and histone H4 bearing either single or multiple acetylation modifications at Lys-5/Lys-8/Lys-12/Lys-15 [2,3,4]
Two of the proteins detected with the largest number of peptides were the chromatin-remodeling enzymes CHD4 and BRG1
Summary
Members of the bromodomain and extra-terminal domain (BET) family of proteins (bromodomain-containing (BRD) 2, 3, 4, and T) are widely expressed and highly conserved regulators of gene expression in eukaryotes. NMR-based structural analysis revealed that, surprisingly, this mode of interaction is shared by the AF9 and ENL transcriptional coregulators that contain an acetyl-lysinebinding YEATS domain and regulate transcriptional elongation This observation establishes a functional commonality between these two families of cancer-related transcriptional. BET bromodomains recognize ⑀-acetylated lysines, with targets including histone H3 acetylated at Lys-14 and histone H4 bearing either single or multiple acetylation modifications at Lys-5/Lys-8/Lys-12/Lys-15 [2,3,4] Transcription factors such as GATA-1, TWIST, RelA, and STAT3 are established targets [5,6,7,8]. Fusions of BRD3/4 with the protein Nuclear in Testis give rise to NUT midline carcinoma, an aggressive malignancy, and BRD4 has
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
