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1.
Genes Dev ; 36(7-8): 468-482, 2022 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-35450884

RESUMEN

The nucleosome remodeling and deacetylase (NuRD) complex is one of the central chromatin remodeling complexes that mediates gene repression. NuRD is essential for numerous developmental events, including heart development. Clinical and genetic studies have provided direct evidence for the role of chromodomain helicase DNA-binding protein 4 (CHD4), the catalytic component of NuRD, in congenital heart disease (CHD), including atrial and ventricular septal defects. Furthermore, it has been demonstrated that CHD4 is essential for mammalian cardiomyocyte formation and function. A key unresolved question is how CHD4/NuRD is localized to specific cardiac target genes, as neither CHD4 nor NuRD can directly bind DNA. Here, we coupled a bioinformatics-based approach with mass spectrometry analyses to demonstrate that CHD4 interacts with the core cardiac transcription factors GATA4, NKX2-5, and TBX5 during embryonic heart development. Using transcriptomics and genome-wide occupancy data, we characterized the genomic landscape of GATA4, NKX2-5, and TBX5 repression and defined the direct cardiac gene targets of the GATA4-CHD4, NKX2-5-CHD4, and TBX5-CHD4 complexes. These data were used to identify putative cis-regulatory elements controlled by these complexes. We genetically interrogated two of these silencers in vivo: Acta1 and Myh11 We show that deletion of these silencers leads to inappropriate skeletal and smooth muscle gene misexpression, respectively, in the embryonic heart. These results delineate how CHD4/NuRD is localized to specific cardiac loci and explicates how mutations in the broadly expressed CHD4 protein lead to cardiac-specific disease states.


Asunto(s)
ADN Helicasas , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Animales , ADN Helicasas/metabolismo , Genes Homeobox , Mamíferos/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Miocitos Cardíacos/metabolismo , Nucleosomas , Factores de Transcripción/genética
2.
Mol Cell ; 81(2): 239-254.e8, 2021 01 21.
Artículo en Inglés | MEDLINE | ID: mdl-33301730

RESUMEN

Metazoan transcription factors typically regulate large numbers of genes. Here we identify via a CRISPR-Cas9 genetic screen ZNF410, a pentadactyl DNA-binding protein that in human erythroid cells directly activates only a single gene, the NuRD component CHD4. Specificity is conveyed by two highly evolutionarily conserved clusters of ZNF410 binding sites near the CHD4 gene with no counterparts elsewhere in the genome. Loss of ZNF410 in adult-type human erythroid cell culture systems and xenotransplantation settings diminishes CHD4 levels and derepresses the fetal hemoglobin genes. While previously known to be silenced by CHD4, the fetal globin genes are exposed here as among the most sensitive to reduced CHD4 levels.. In vitro DNA binding assays and crystallographic studies reveal the ZNF410-DNA binding mode. ZNF410 is a remarkably selective transcriptional activator in erythroid cells, and its perturbation might offer new opportunities for treatment of hemoglobinopathies.


Asunto(s)
ADN/genética , Células Precursoras Eritroides/metabolismo , Hemoglobina Fetal/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Factores de Transcripción/genética , Animales , Sitios de Unión , Células COS , Sistemas CRISPR-Cas , Chlorocebus aethiops , ADN/metabolismo , Células Precursoras Eritroides/citología , Células Precursoras Eritroides/trasplante , Sangre Fetal/citología , Sangre Fetal/metabolismo , Hemoglobina Fetal/metabolismo , Feto , Edición Génica , Células HEK293 , Xenoinjertos , Humanos , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/química , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Ratones , Modelos Moleculares , Células Madre Embrionarias de Ratones/citología , Unión Proteica , Conformación Proteica en Hélice alfa , Conformación Proteica en Lámina beta , Dominios y Motivos de Interacción de Proteínas , Factores de Transcripción/química , Factores de Transcripción/metabolismo , Activación Transcripcional
3.
EMBO J ; 43(12): 2453-2485, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38719994

RESUMEN

Double-strand breaks (DSBs) are the most lethal form of DNA damage. Transcriptional activity at DSBs, as well as transcriptional repression around DSBs, are both required for efficient DNA repair. The chromatin landscape defines and coordinates these two opposing events. However, how the open and condensed chromatin architecture is regulated remains unclear. Here, we show that the GATAD2B-NuRD complex associates with DSBs in a transcription- and DNA:RNA hybrid-dependent manner, to promote histone deacetylation and chromatin condensation. This activity establishes a spatio-temporal boundary between open and closed chromatin, which is necessary for the correct termination of DNA end resection. The lack of the GATAD2B-NuRD complex leads to chromatin hyperrelaxation and extended DNA end resection, resulting in homologous recombination (HR) repair failure. Our results suggest that the GATAD2B-NuRD complex is a key coordinator of the dynamic interplay between transcription and the chromatin landscape, underscoring its biological significance in the RNA-dependent DNA damage response.


Asunto(s)
Cromatina , Roturas del ADN de Doble Cadena , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Cromatina/metabolismo , Cromatina/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , ARN/metabolismo , ARN/genética , Daño del ADN , ADN/metabolismo , ADN/genética , Animales , Humanos , Transcripción Genética , Reparación del ADN , Ratones
4.
Genes Dev ; 34(3-4): 179-193, 2020 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-31879358

RESUMEN

The GATA-type zinc finger transcription factor TRPS1 has been implicated in breast cancer. However, its precise role remains unclear, as both amplifications and inactivating mutations in TRPS1 have been reported. Here, we used in vitro and in vivo loss-of-function approaches to dissect the role of TRPS1 in mammary gland development and invasive lobular breast carcinoma, which is hallmarked by functional loss of E-cadherin. We show that TRPS1 is essential in mammary epithelial cells, since TRPS1-mediated suppression of interferon signaling promotes in vitro proliferation and lactogenic differentiation. Similarly, TRPS1 expression is indispensable for proliferation of mammary organoids and in vivo survival of luminal epithelial cells during mammary gland development. However, the consequences of TRPS1 loss are dependent on E-cadherin status, as combined inactivation of E-cadherin and TRPS1 causes persistent proliferation of mammary organoids and accelerated mammary tumor formation in mice. Together, our results demonstrate that TRPS1 can function as a context-dependent tumor suppressor in breast cancer, while being essential for growth and differentiation of normal mammary epithelial cells.


Asunto(s)
Neoplasias de la Mama/fisiopatología , Carcinogénesis/genética , Diferenciación Celular/genética , Células Epiteliales/citología , Proteínas Represoras/metabolismo , Animales , Neoplasias de la Mama/genética , Cadherinas/genética , Supervivencia Celular/genética , Cromatina/genética , Cromatina/metabolismo , Modelos Animales de Enfermedad , Femenino , Eliminación de Gen , Regulación Neoplásica de la Expresión Génica , Humanos , Glándulas Mamarias Humanas/crecimiento & desarrollo , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Ratones , Unión Proteica/genética , Proteínas Represoras/genética , Transducción de Señal/genética
5.
Trends Biochem Sci ; 48(1): 11-25, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-35798615

RESUMEN

The nucleosome-remodeling and deacetylase (NuRD) complex is an essential transcriptional regulator in all complex animals. All seven core subunits of the complex exist as multiple paralogs, raising the question of whether the complex might utilize paralog switching to achieve cell type-specific functions. We examine the evidence for this idea, making use of published quantitative proteomic data to dissect NuRD composition in 20 different tissues, as well as a large-scale CRISPR knockout screen carried out in >1000 human cancer cell lines. These data, together with recent reports, provide strong support for the idea that distinct permutations of the NuRD complex with tailored functions might regulate tissue-specific gene expression programs.


Asunto(s)
Nucleosomas , Proteómica , Animales , Humanos , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Línea Celular
6.
EMBO J ; 42(21): e113448, 2023 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-37737560

RESUMEN

The nucleosome remodeling and histone deacetylase (NuRD) complex physically associates with BCL11B to regulate murine T-cell development. However, the function of NuRD complex in mature T cells remains unclear. Here, we characterize the fate and metabolism of human T cells in which key subunits of the NuRD complex or BCL11B are ablated. BCL11B and the NuRD complex bind to each other and repress natural killer (NK)-cell fate in T cells. In addition, T cells upregulate the NK cell-associated receptors and transcription factors, lyse NK-cell targets, and are reprogrammed into NK-like cells (ITNKs) upon deletion of MTA2, MBD2, CHD4, or BCL11B. ITNKs increase OPA1 expression and exhibit characteristically elongated mitochondria with augmented oxidative phosphorylation (OXPHOS) activity. OPA1-mediated elevated OXPHOS enhances cellular acetyl-CoA levels, thereby promoting the reprogramming efficiency and antitumor effects of ITNKs via regulating H3K27 acetylation at specific targets. In conclusion, our findings demonstrate that the NuRD complex and BCL11B cooperatively maintain T-cell fate directly by repressing NK cell-associated transcription and indirectly through a metabolic-epigenetic axis, providing strategies to improve the reprogramming efficiency and antitumor effects of ITNKs.


Asunto(s)
Histonas , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Animales , Humanos , Ratones , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , GTP Fosfohidrolasas/genética , GTP Fosfohidrolasas/metabolismo , Histona Desacetilasas/genética , Histona Desacetilasas/metabolismo , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Dinámicas Mitocondriales , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Linfocitos T/metabolismo , Factores de Transcripción/metabolismo , Proteínas Supresoras de Tumor/metabolismo
7.
Development ; 151(8)2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38619323

RESUMEN

Regulation of chromatin states is essential for proper temporal and spatial gene expression. Chromatin states are modulated by remodeling complexes composed of components that have enzymatic activities. CHD4 is the catalytic core of the nucleosome remodeling and deacetylase (NuRD) complex, which represses gene transcription. However, it remains to be determined how CHD4, a ubiquitous enzyme that remodels chromatin structure, functions in cardiomyocytes to maintain heart development. In particular, whether other proteins besides the NuRD components interact with CHD4 in the heart is controversial. Using quantitative proteomics, we identified that CHD4 interacts with SMYD1, a striated muscle-restricted histone methyltransferase that is essential for cardiomyocyte differentiation and cardiac morphogenesis. Comprehensive transcriptomic and chromatin accessibility studies of Smyd1 and Chd4 null embryonic mouse hearts revealed that SMYD1 and CHD4 repress a group of common genes and pathways involved in glycolysis, response to hypoxia, and angiogenesis. Our study reveals a mechanism by which CHD4 functions during heart development, and a previously uncharacterized mechanism regarding how SMYD1 represses cardiac transcription in the developing heart.


Asunto(s)
ADN Helicasas , Proteínas de Unión al ADN , Regulación del Desarrollo de la Expresión Génica , Corazón , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Miocitos Cardíacos , Factores de Transcripción , Animales , Humanos , Ratones , Diferenciación Celular/genética , Cromatina/metabolismo , Glucólisis/genética , Corazón/embriología , N-Metiltransferasa de Histona-Lisina/metabolismo , N-Metiltransferasa de Histona-Lisina/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Ratones Noqueados , Proteínas Musculares/metabolismo , Proteínas Musculares/genética , Miocitos Cardíacos/metabolismo , Proteómica , Transcripción Genética
8.
Mol Cell ; 73(5): 985-1000.e6, 2019 03 07.
Artículo en Inglés | MEDLINE | ID: mdl-30711375

RESUMEN

Hyper-phosphorylation of RB controls its interaction with E2F and inhibits its tumor suppressor properties. However, during G1 active RB can be mono-phosphorylated on any one of 14 CDK phosphorylation sites. Here, we used quantitative proteomics to profile protein complexes formed by each mono-phosphorylated RB isoform (mP-RB) and identified the associated transcriptional outputs. The results show that the 14 sites of mono-phosphorylation co-ordinate RB's interactions and confer functional specificity. All 14 mP-RBs interact with E2F/DP proteins, but they provide different shades of E2F regulation. RB mono-phosphorylation at S811, for example, alters RB transcriptional activity by promoting its association with NuRD complexes. The greatest functional differences between mP-RBs are evident beyond the cell cycle machinery. RB mono-phosphorylation at S811 or T826 stimulates the expression of oxidative phosphorylation genes, increasing cellular oxygen consumption. These results indicate that RB activation signals are integrated in a phosphorylation code that determines the diversity of RB activity.


Asunto(s)
Neoplasias de la Mama/metabolismo , Proteína de Retinoblastoma/metabolismo , Transducción de Señal , Neoplasias de la Mama/genética , Línea Celular Tumoral , Factores de Transcripción E2F/genética , Factores de Transcripción E2F/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Mutación , Fosforilación Oxidativa , Fosforilación , Unión Proteica , Proteómica/métodos , Proteína de Retinoblastoma/genética , Transducción de Señal/genética , Transcripción Genética
9.
Am J Hum Genet ; 110(3): 442-459, 2023 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-36812914

RESUMEN

Dysregulated Plastin 3 (PLS3) levels associate with a wide range of skeletal and neuromuscular disorders and the most common types of solid and hematopoietic cancer. Most importantly, PLS3 overexpression protects against spinal muscular atrophy. Despite its crucial role in F-actin dynamics in healthy cells and its involvement in many diseases, the mechanisms that regulate PLS3 expression are unknown. Interestingly, PLS3 is an X-linked gene and all asymptomatic SMN1-deleted individuals in SMA-discordant families who exhibit PLS3 upregulation are female, suggesting that PLS3 may escape X chromosome inactivation. To elucidate mechanisms contributing to PLS3 regulation, we performed a multi-omics analysis in two SMA-discordant families using lymphoblastoid cell lines and iPSC-derived spinal motor neurons originated from fibroblasts. We show that PLS3 tissue-specifically escapes X-inactivation. PLS3 is located ∼500 kb proximal to the DXZ4 macrosatellite, which is essential for X chromosome inactivation. By applying molecular combing in a total of 25 lymphoblastoid cell lines (asymptomatic individuals, individuals with SMA, control subjects) with variable PLS3 expression, we found a significant correlation between the copy number of DXZ4 monomers and PLS3 levels. Additionally, we identified chromodomain helicase DNA binding protein 4 (CHD4) as an epigenetic transcriptional regulator of PLS3 and validated co-regulation of the two genes by siRNA-mediated knock-down and overexpression of CHD4. We show that CHD4 binds the PLS3 promoter by performing chromatin immunoprecipitation and that CHD4/NuRD activates the transcription of PLS3 by dual-luciferase promoter assays. Thus, we provide evidence for a multilevel epigenetic regulation of PLS3 that may help to understand the protective or disease-associated PLS3 dysregulation.


Asunto(s)
Epigénesis Genética , Atrofia Muscular Espinal , Femenino , Humanos , Masculino , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Proteínas de Microfilamentos/genética , Neuronas Motoras/metabolismo , Atrofia Muscular Espinal/genética
10.
Mol Cell ; 71(1): 56-72.e4, 2018 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-30008319

RESUMEN

Chromatin remodeling complexes play essential roles in metazoan development through widespread control of gene expression, but the precise molecular mechanisms by which they do this in vivo remain ill defined. Using an inducible system with fine temporal resolution, we show that the nucleosome remodeling and deacetylation (NuRD) complex controls chromatin architecture and the protein binding repertoire at regulatory regions during cell state transitions. This is primarily exerted through its nucleosome remodeling activity while deacetylation at H3K27 follows changes in gene expression. Additionally, NuRD activity influences association of RNA polymerase II at transcription start sites and subsequent nascent transcript production, thereby guiding the establishment of lineage-appropriate transcriptional programs. These findings provide a detailed molecular picture of genome-wide modulation of lineage-specific transcription by an essential chromatin remodeling complex as well as insight into the orchestration of molecular events involved in transcriptional transitions in vivo. VIDEO ABSTRACT.


Asunto(s)
Regulación de la Expresión Génica , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Células Madre Embrionarias de Ratones/metabolismo , Nucleosomas/metabolismo , ARN Polimerasa II/metabolismo , Transcripción Genética , Acetilación , Animales , Línea Celular , Histonas/genética , Histonas/metabolismo , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Ratones , Células Madre Embrionarias de Ratones/citología , Nucleosomas/genética , ARN Polimerasa II/genética , Sitio de Iniciación de la Transcripción
11.
Nucleic Acids Res ; 52(7): 3607-3622, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38281186

RESUMEN

Biologically precise enhancer licensing by lineage-determining transcription factors enables activation of transcripts appropriate to biological demand and prevents deleterious gene activation. This essential process is challenged by the millions of matches to most transcription factor binding motifs present in many eukaryotic genomes, leading to questions about how transcription factors achieve the exquisite specificity required. The importance of chromatin remodeling factors to enhancer activation is highlighted by their frequent mutation in developmental disorders and in cancer. Here, we determine the roles of CHD4 in enhancer licensing and maintenance in breast cancer cells and during cellular reprogramming. In unchallenged basal breast cancer cells, CHD4 modulates chromatin accessibility. Its depletion leads to redistribution of transcription factors to previously unoccupied sites. During cellular reprogramming induced by the pioneer factor GATA3, CHD4 activity is necessary to prevent inappropriate chromatin opening. Mechanistically, CHD4 promotes nucleosome positioning over GATA3 binding motifs to compete with transcription factor-DNA interaction. We propose that CHD4 acts as a chromatin proof-reading enzyme that prevents unnecessary gene expression by editing chromatin binding activities of transcription factors.


Asunto(s)
Cromatina , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Femenino , Humanos , Sitios de Unión , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Reprogramación Celular/genética , Cromatina/metabolismo , Ensamble y Desensamble de Cromatina , Elementos de Facilitación Genéticos , Factor de Transcripción GATA3/metabolismo , Factor de Transcripción GATA3/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Nucleosomas/metabolismo , Nucleosomas/genética , Unión Proteica , Factores de Transcripción/metabolismo
12.
Proc Natl Acad Sci U S A ; 120(33): e2307287120, 2023 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-37552759

RESUMEN

The nucleosome remodeling and deacetylase (NuRD) complex modifies nucleosome positioning and chromatin compaction to regulate gene expression. The methyl-CpG-binding domain proteins 2 and 3 (MBD2 and MBD3) play a critical role in complex formation; however, the molecular details of how they interact with other NuRD components have yet to be fully elucidated. We previously showed that an intrinsically disordered region (IDR) of MBD2 is necessary and sufficient to bind to the histone deacetylase core of NuRD. Building on that work, we have measured the inherent structural propensity of the MBD2-IDR using solvent and site-specific paramagnetic relaxation enhancement measurements. We then used the AlphaFold2 machine learning software to generate a model of the complex between MBD2 and the histone deacetylase core of NuRD. This model is remarkably consistent with our previous studies, including the current paramagnetic relaxation enhancement data. The latter suggests that the free MBD2-IDR samples conformations similar to the bound structure. We tested this model of the complex extensively by mutating key contact residues and measuring binding using an intracellular bioluminescent resonance energy transfer assay. Furthermore, we identified protein contacts that, when mutated, disrupted gene silencing by NuRD in a cell model of fetal hemoglobin regulation. Hence, this work provides insights into the formation of NuRD and highlights critical binding pockets that may be targeted to block gene silencing for therapy. Importantly, we show that AlphaFold2 can generate a credible model of a large complex that involves an IDR that folds upon binding.


Asunto(s)
Histona Desacetilasas , Nucleosomas , Histona Desacetilasas/metabolismo , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Silenciador del Gen , Cromatina , Histona Desacetilasa 1/genética
13.
Immunol Rev ; 305(1): 29-42, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34927255

RESUMEN

B lymphocytes develop from uncommitted precursors into immunoglobulin (antibody)-producing B cells, a major arm of adaptive immunity. Progression of early progenitors to antibody-expressing cells in the bone marrow is orchestrated by the temporal regulation of different gene programs at discrete developmental stages. A major question concerns how B cells control the accessibility of these genes to transcription factors. Research has implicated nucleosome remodeling ATPases as mediators of chromatin accessibility. Here, we describe studies of chromodomain helicase DNA-binding 4 (CHD4; also known as Mi-2ß) in early B cell development. CHD4 comprises multiple domains that function in nucleosome mobilization and histone binding. CHD4 is a key component of Nucleosome Remodeling and Deacetylase, or NuRD (Mi-2) complexes, which assemble with other proteins that mediate transcriptional repression. We review data demonstrating that CHD4 is necessary for B lineage identity: early B lineage progression, proliferation in response to interleukin-7, responses to DNA damage, and cell survival in vivo. CHD4-NuRD is also required for the Ig heavy-chain repertoire by promoting utilization of distal variable (VH ) gene segments in V(D)J recombination. In conclusion, the regulation of chromatin accessibility by CHD4 is essential for production of antibodies by B cells, which in turn mediate humoral immune responses to pathogens and disease.


Asunto(s)
Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Recombinación V(D)J , Linfocitos B/metabolismo , ADN , ADN Helicasas/genética , ADN Helicasas/metabolismo , Humanos , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo
14.
J Cell Sci ; 136(7)2023 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-36861403

RESUMEN

Chromatin remodeling enzymes form large multiprotein complexes that play central roles in regulating access to the genome. Here, we characterize the nuclear import of the human CHD4 protein. We show that CHD4 enters the nucleus by means of several importin-α proteins (1, 5, 6 and 7), but independently of importin ß1. Importin α1 directly interacts with a monopartite 'KRKR'-motif in the N-terminus of CHD4 (amino acids 304-307). However, alanine mutagenesis of this motif only leads to an ∼50% reduction in nuclear localization of CHD4, implying that there are additional import mechanisms. Interestingly, we could show that CHD4 was already associated with the nucleosome remodeling deacetylase (NuRD) core subunits, such as MTA2, HDAC1 and RbAp46 (also known as RBBP7), in the cytoplasm, suggesting an assembly of the NuRD core complex before nuclear import. We propose that, in addition to the importin-α-dependent nuclear localization signal, CHD4 is dragged into the nucleus by a 'piggyback' mechanism using the import signals of the associated NuRD subunits.


Asunto(s)
Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Nucleosomas , Humanos , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Nucleosomas/metabolismo , alfa Carioferinas/metabolismo , Transporte Activo de Núcleo Celular , Núcleo Celular/metabolismo , Histona Desacetilasas/metabolismo , Proteínas Represoras/metabolismo
15.
Development ; 149(11)2022 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-35695185

RESUMEN

In the developing subpallium, the fate decision between neurons and glia is driven by expression of Dlx1/2 or Olig1/2, respectively, two sets of transcription factors with a mutually repressive relationship. The mechanism by which Dlx1/2 repress progenitor and oligodendrocyte fate, while promoting transcription of genes needed for differentiation, is not fully understood. We identified a motif within DLX1 that binds RBBP4, a NuRD complex subunit. ChIP-seq studies of genomic occupancy of DLX1 and six different members of the NuRD complex show that DLX1 and NuRD colocalize to putative regulatory elements enriched near other transcription factor genes. Loss of Dlx1/2 leads to dysregulation of genome accessibility at putative regulatory elements near genes repressed by Dlx1/2, including Olig2. Consequently, heterozygosity of Dlx1/2 and Rbbp4 leads to an increase in the production of OLIG2+ cells. These findings highlight the importance of the interplay between transcription factors and chromatin remodelers in regulating cell-fate decisions.


Asunto(s)
Proteínas de Homeodominio , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Diferenciación Celular/genética , Genes Homeobox , Proteínas de Homeodominio/metabolismo , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
16.
Circ Res ; 133(1): 48-67, 2023 06 23.
Artículo en Inglés | MEDLINE | ID: mdl-37254794

RESUMEN

BACKGROUND: Left ventricular noncompaction (LVNC) is a prevalent cardiomyopathy associated with excessive trabeculation and thin compact myocardium. Patients with LVNC are vulnerable to cardiac dysfunction and at high risk of sudden death. Although sporadic and inherited mutations in cardiac genes are implicated in LVNC, understanding of the mechanisms responsible for human LVNC is limited. METHODS: We screened the complete exome sequence database of the Pediatrics Cardiac Genomics Consortium and identified a cohort with a de novo CHD4 (chromodomain helicase DNA-binding protein 4) proband, CHD4M202I, with congenital heart defects. We engineered a humanized mouse model of CHD4M202I (mouse CHD4M195I). Histological analysis, immunohistochemistry, flow cytometry, transmission electron microscopy, and echocardiography were used to analyze cardiac anatomy and function. Ex vivo culture, immunopurification coupled with mass spectrometry, transcriptional profiling, and chromatin immunoprecipitation were performed to deduce the mechanism of CHD4M195I-mediated ventricular wall defects. RESULTS: CHD4M195I/M195I mice developed biventricular hypertrabeculation and noncompaction and died at birth. Proliferation of cardiomyocytes was significantly increased in CHD4M195I hearts, and the excessive trabeculation was associated with accumulation of ECM (extracellular matrix) proteins and a reduction of ADAMTS1 (ADAM metallopeptidase with thrombospondin type 1 motif 1), an ECM protease. We rescued the hyperproliferation and hypertrabeculation defects in CHD4M195I hearts by administration of ADAMTS1. Mechanistically, the CHD4M195I protein showed augmented affinity to endocardial BRG1 (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 4). This enhanced affinity resulted in the failure of derepression of Adamts1 transcription such that ADAMTS1-mediated trabeculation termination was impaired. CONCLUSIONS: Our study reveals how a single mutation in the chromatin remodeler CHD4, in mice or humans, modulates ventricular chamber maturation and that cardiac defects associated with the missense mutation CHD4M195I can be attenuated by the administration of ADAMTS1.


Asunto(s)
No Compactación Aislada del Miocardio Ventricular , Mutación Missense , Humanos , Animales , Niño , Ratones , Ventrículos Cardíacos , Causalidad , Mutación , Miocitos Cardíacos , Cromatina , No Compactación Aislada del Miocardio Ventricular/genética , Proteína ADAMTS1/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética
17.
EMBO Rep ; 24(4): e55362, 2023 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-36722816

RESUMEN

During neuronal development, extensive changes to chromatin states occur to regulate lineage-specific gene expression. The molecular factors underlying the repression of non-neuronal genes in differentiated neurons are poorly characterised. The Mi2/NuRD complex is a multiprotein complex with nucleosome remodelling and histone deacetylase activity. Whilst NuRD has previously been implicated in the development of nervous system tissues, the precise nature of the gene expression programmes that it coordinates is ill-defined. Furthermore, evidence from several species suggests that Mi-2 may be incorporated into multiple complexes that may not possess histone deacetylase activity. We show that Mi-2 activity is required for suppressing ectopic expression of germline genes in neurons independently of HDAC1/NuRD, whilst components of NuRD, including Mi-2, regulate neural gene expression to ensure proper development of the larval nervous system. We find that Mi-2 binding in the genome is dynamic during neuronal maturation, and Mi-2-mediated repression of ectopic gene expression is restricted to the early stages of neuronal development, indicating that Mi-2/NuRD is required for establishing stable neuronal transcriptomes during the early stages of neuronal differentiation.


Asunto(s)
Expresión Génica Ectópica , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2 , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Histona Desacetilasas/metabolismo , Cromatina/genética , Nucleosomas
18.
Proc Natl Acad Sci U S A ; 119(6)2022 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-35105803

RESUMEN

BRD4 is well known for its role in super-enhancer organization and transcription activation of several prominent oncogenes including c-MYC and BCL2 As such, BRD4 inhibitors are being pursued as promising therapeutics for cancer treatment. However, drug resistance also occurs for BRD4-targeted therapies. Here, we report that BRD4 unexpectedly interacts with the LSD1/NuRD complex and colocalizes with this repressive complex on super-enhancers. Integrative genomic and epigenomic analyses indicate that the BRD4/LSD1/NuRD complex restricts the hyperactivation of a cluster of genes that are functionally linked to drug resistance. Intriguingly, treatment of breast cancer cells with a small-molecule inhibitor of BRD4, JQ1, results in no immediate activation of the drug-resistant genes, but long-time treatment or destabilization of LSD1 by PELI1 decommissions the BRD4/LSD1/NuRD complex, leading to resistance to JQ1 as well as to a broad spectrum of therapeutic compounds. Consistently, PELI1 is up-regulated in breast carcinomas, its level is negatively correlated with that of LSD1, and the expression level of the BRD4/LSD1/NuRD complex-restricted genes is strongly correlated with a worse overall survival of breast cancer patients. Together, our study uncovers a functional duality of BRD4 in super-enhancer organization of transcription activation and repression linking to oncogenesis and chemoresistance, respectively, supporting the pursuit of a combined targeting of BRD4 and PELI1 in effective treatment of breast cancer.


Asunto(s)
Neoplasias de la Mama/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Neoplasias/metabolismo , Factores de Transcripción/metabolismo , Transcripción Genética , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Proteínas de Ciclo Celular/genética , Femenino , Histona Demetilasas/genética , Histona Demetilasas/metabolismo , Humanos , Células MCF-7 , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo , Proteínas de Neoplasias/genética , Factores de Transcripción/genética
19.
J Biol Chem ; 299(1): 102812, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36539038

RESUMEN

CXXC5, a member of the CXXC family of zinc-finger proteins, is associated with numerous pathological processes. However, the pathophysiological function of CXXC5 has not been clearly established. Herein, we found that CXXC5 interacts with the CRL4B and NuRD complexes. Screening of transcriptional targets downstream of the CXXC5-CRL4B-NuRD complex by next-generation sequencing (chromatin immunoprecipitation sequencing) revealed that the complex regulates the transcriptional repression process of a cohort of genes, including TSC1 (tuberous sclerosis complex subunit 1), which play important roles in cell growth and mammalian target of rapamycin signaling pathway regulation, and whose abnormal regulation results in the activation of programmed cell death-ligand protein 1 (PD-L1). Intriguingly, CXXC5 expression increased after stimulation with vitamin B2 but decreased after vitamin D treatment. We also found that the CXXC5-CRL4B-NuRD complex promotes the proliferation of tumor cells in vitro and accelerates the growth of breast cancer in vivo. The expression of CXXC5, CUL4B, and MTA1 increased during the occurrence and development of breast cancer, and correspondingly, TSC1 expression decreased. Meanwhile, a high expression of CXXC5 was positively correlated with the histological grade of high malignancy and poor survival of patients. In conclusion, our study revealed that CXXC5-mediated TSC1 suppression activates the mammalian target of rapamycin pathway, reduces autophagic cell death, induces PD-L1-mediated immune suppression, and results in tumor development, shedding light on the mechanism of the pathophysiological function of CXXC5.


Asunto(s)
Neoplasias de la Mama , Carcinogénesis , Serina-Treonina Quinasas TOR , Dedos de Zinc , Femenino , Humanos , Antígeno B7-H1 , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Proteínas Cullin , Proteínas de Unión al ADN/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Transducción de Señal , Serina-Treonina Quinasas TOR/genética , Transactivadores
20.
Biochem Biophys Res Commun ; 701: 149555, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38325179

RESUMEN

Fetal-to-adult hemoglobin switching is controlled by programmed silencing of γ-globin while the re-activation of fetal hemoglobin (HbF) is an effective strategy for ameliorating the clinical severity of ß-thalassemia and sickle cell disease. The identification of enhancer RNAs (eRNAs) related to the fetal (α2γ2) to adult hemoglobin (α2ß2) switching remains incomplete. In this study, the transcriptomes of GYPA+ cells from six ß-thalassemia patients with extreme HbF levels were sequenced to identify differences in patterns of noncoding RNA expression. It is interesting that an enhancer upstream of CHD4, an HbF-related core subunit of the NuRD complex, was differentially transcribed. We found a significantly positive correlation of eRNA-CHD4 enhancer-gene interaction using the public database of FANTOM5. Specifically, the eRNA-CHD4 expression was found to be significantly higher in both CD34+ HSPCs and HUDEP-2 than those in K562 cells which commonly expressed high level of HbF, suggesting a correlation between eRNA and HbF expression. Furthermore, prediction of transcription binding sites of cis-eQTLs and the CHD4 genomic region revealed a putative interaction site between rs73264846 and ZNF410, a known transcription factor regulating HbF expression. Moreover, in-vitro validation showed that the inhibition of eRNA could reduce the expression of HBG expression in HUDEP-2 cells. Taken together, the findings of this study demonstrate that a distal enhancer contributes to stage-specific silencing of γ-globin genes through direct modulation of CHD4 expression and provide insights into the epigenetic mechanisms of NuRD-mediated hemoglobin switching.


Asunto(s)
Anemia de Células Falciformes , Talasemia beta , Adulto , Humanos , Hemoglobina Fetal/genética , Hemoglobina Fetal/metabolismo , gamma-Globinas/genética , gamma-Globinas/metabolismo , Talasemia beta/genética , Regulación de la Expresión Génica , Anemia de Células Falciformes/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/genética , Complejo Desacetilasa y Remodelación del Nucleosoma Mi-2/metabolismo
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