Project description:Although BTB-zinc finger (BTB-ZF) transcription factors control the differentiation of multiple hematopoietic and immune lineages, how they function is poorly understood. The BTB-ZF factor Thpok controls intrathymic CD4+ T cell development and expression of most CD4+- and CD8+-lineage genes. Here, we identify the nucleosome remodeling and deacetylase (NuRD) complex as a novel Thpok cofactor. We locate three amino-acid residues within the Thpok BTB domain that are required for both NuRD binding and Thpok functions, and show that NuRD recruitment recapitulates the functions of the Thpok BTB domain. NuRD mediates Thpok repression of CD8+-lineage genes, including the transcription factor Runx3, but is dispensable for Cd4 expression. We show that these functions cannot be performed by the BTB domain of the Thpok-related factor Bcl6, which fails to bind NuRD. Thus, cofactor binding critically contributes to the functional specificity of BTB-zinc finger factors, which control the differentiation of most hematopoietic subsets.
Project description:This data represent characterization of the interactome of murine Thpok. A version of Thpok (Thpok-Bio) subject to biotinylation in vivo by the BirA biotin ligase was used; to assess Thpok interactions in primary cells, Thpok-Bio was retrovirally expressed in in vitro activated CD4+ T cells from Thpokfl/fl Ox40-Cre+ mice carrying a Rosa26BirA allele. Expression of Ox40-Cre, initiated upon T cell activation, causes the deletion of endogenous Thpokfl alleles, so that transduced cells only express Thpok-Bio. Two Thpok deletion constructs (BKK and RFK) were also analyzed. Following streptavidin pulldown, proteins were separated by SDS-PAGE, the full lane cut into 9 slices, and in-gel digested. FIles are: 1384 - empty vector; 1385 - Thpok; 1386 - Thpok + Ethidium Bromide; 1387 - Thpok BKK; 1388 - Thpok RFK.
Project description:T cell precursors develop into cytotoxic CD8 and helper CD4+ T cells in thymus. Thpok, a BTB/POZ family transcription factor, enforces commitment to the CD4 lineage and suppresses cytotoxic gene expression. However, it is still not fully understood how Thpok directs CD4 T cell development. Here, using mass-spectrometry, we identify nucleosome remodeling and deacetylase (NuRD) complex as a novel Thpok cofactor. We demonstrate that the Thpok BTB domain is essential for NuRD recruitment. Reconstituting NuRD binding to a BTB-less version of Thpok (which cannot bind NuRD) restored CD4 T cell in vivo. RNA sequencing showed that CD4 T cells expressing the reconstituted protein express a transcriptome similar to that of CD4 T cells expressing Thpok. Thus, our results demonstrate that NuRD recruitment is both necessary and sufficient for the function of the Thpok BTB domain in CD4 T cell development.
Project description:Thpok-RKF which harbors a mutation in the BTB domain and disrupts the interaction between NuRD complex could not repress CD8 and CD8 lineage genes expression in Thpokfl/flRunx3fl/dYFPCd4-Cre+ from B2m-/- host. However, Thpok-RKF upregulates CD4 expression in these mice.
Project description:The NuRD complex is generally thought to repress transcription at both hyper- and hypomethylated regions in the genome. In addition, the complex is involved in the DNA damage response. Here, we show that ZMYND8 bridges NuRD to a number of putative DNA-binding zinc finger proteins. The ZMYND8 MYND domain directly interacts with PPPL? motifs in the NuRD subunit GATAD2A. Furthermore, GATAD2A and GATAD2B exclusively form homodimers and they thus define mutually exclusive NuRD subcomplexes. ZMYND8 and MBD3 share a large number of genome-wide binding sites, mostly active promoters and enhancers. Depletion of ZMYND8 does not affect NuRD occupancy genome-wide and expression of NuRD/ZMYND8 target genes in steady-state asynchronous cells. However, ZMYND8 facilitates immediate recruitment of GATAD2A/NuRD to induced sites of DNA damage. These results thus show that a specific substoichiometric interaction with a NuRD subunit paralogue provides unique functionality to a distinct NuRD subcomplex.
Project description:The NuRD complex is generally thought to repress transcription at both hyper- and hypomethylated regions in the genome. In addition, the complex is involved in the DNA damage response. Here, we show that ZMYND8 bridges NuRD to a number of putative DNA-binding zinc finger proteins. The ZMYND8 MYND domain directly interacts with PPPL? motifs in the NuRD subunit GATAD2A. Furthermore, GATAD2A and GATAD2B exclusively form homodimers and they thus define mutually exclusive NuRD subcomplexes. ZMYND8 and MBD3 share a large number of genome-wide binding sites, mostly active promoters and enhancers. Depletion of ZMYND8 does not affect NuRD occupancy genome-wide and expression of NuRD/ZMYND8 target genes in steady-state asynchronous cells. However, ZMYND8 facilitates immediate recruitment of GATAD2A/NuRD to induced sites of DNA damage. These results thus show that a specific substoichiometric interaction with a NuRD subunit paralogue provides unique functionality to a distinct NuRD subcomplex.
Project description:The Nucleosome Remodeling and Deacetylase (NURD) complex is a key regulator of cell differentiation that has also been implicated in tumorigenesis. Loss of the NURD subunit DOC1 is associated with human oral squamous cell carcinomas (OSCC). Here, we show that restoration of DOC1 expression in OSCC cells leads to a reversal of epithelial-mesenchymal transition (EMT). This is caused by the DOC1-dependent recruitment of NURD to repress the Twist master regulators of EMT. NURD recruitment drives extensive epigenetic reprogramming, including eviction of the SWI/SNF remodeler, formation of inaccessible chromatin, H3K27 deacetylation, recruitment of PRC2 and KDM1A, followed by H3K27 methylation and H3K4 demethylation. Strikingly, depletion of SWI/SNF mimics the effects of DOC1 re-expression. Our results suggest that SWI/SNF and NURD function antagonistically to control chromatin state. We propose that disturbance of this dynamic equilibrium may lead to defects in gene expression that drive human cancer.
Project description:The transcription factor Thpok is essential for CD4 T cell development in the thymus and remains expressed in post-thymic CD4 T cells. We post-thymically inactivated Thpok and compared microarray gene expression in Thpok-deficient CD4 T cells to that in their wildtype CD4 or CD8 counterparts We show that Thpok constrains the transcriptional circuitry to maintain CD4+-lineage integrity in naM-CM-/ve cells and to couple effector differentiation to environmental cues after antigenic stimulation. Redundantly with the related factor LRF, Thpok is continuously needed to prevent the trans-differentiation of mature CD4+ into -CD8+ T cells. We activated naM-CM-/ve CD4 T cells (either wild-type or Thpok-deficient) and CD8 T cells (wild-type) in vitro under Th1 conditions. Differentiated effectors were sorted 4 days after activation into CD4+CD8- and CD4-CD8+ (wild-type) and CD4+CD8- and CD4+CD8+ (Thpok-deficient) subsets. Total RNA was extracted from sorted subsets and processed for microarray analyses (Affymetrix Mouse Exon 1.0 ST array) at the NCI microarray facility, following the manufacturerM-bM-^@M-^Ys recommendation. Data is from 3 replicates (except wild-type CD4-CD8+ cells, for which two samples only were processed), generated from two distinct cell preparations.
Project description:The NuRD complex is generally thought to repress transcription at both hyper- and hypomethylated regions in the genome. In addition, the complex is involved in the DNA damage response. Here, we show that ZMYND8 bridges NuRD to a number of putative DNA-binding zinc finger proteins. The ZMYND8 MYND domain directly interacts with PPPLΦ motifs in the NuRD subunit GATAD2A. Furthermore, GATAD2A and GATAD2B exclusively form homodimers and they thus define mutually exclusive NuRD subcomplexes. ZMYND8 and MBD3 share a large number of genome-wide binding sites, mostly active promoters and enhancers. Depletion of ZMYND8 does not affect NuRD occupancy genome-wide and expression of NuRD/ZMYND8 target genes in steady-state asynchronous cells. However, ZMYND8 facilitates immediate recruitment of GATAD2A/NuRD to induced sites of DNA damage in a PAR-dependent manner. These results thus show that a specific substoichiometric interaction with a NuRD subunit paralogue provides unique functionality to a distinct NuRD subcomplex.