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1.
Mol Cell ; 81(15): 3043-3045, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34358457

RESUMO

Neguembor et al. (2021) use super-resolution microscopy to illuminate genome packaging inside the cell nucleus. They discover that transcription and topoisomerases protect chromatin from collapsing in a crumpled state refractory to DNA loop extrusion by cohesin proteins.


Assuntos
Proteínas de Ciclo Celular , Proteínas Cromossômicas não Histona , Proteínas de Ciclo Celular/genética , Cromatina/genética , Proteínas Cromossômicas não Histona/genética , DNA/genética , Humanos
2.
Nat Commun ; 12(1): 4674, 2021 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-34344879

RESUMO

In most organisms, the number and distribution of crossovers that occur during meiosis are tightly controlled. All chromosomes must receive at least one 'obligatory crossover' and crossovers are prevented from occurring near one another by 'crossover interference'. However, the mechanistic basis of this phenomenon of crossover interference has remained mostly mysterious. Using quantitative super-resolution cytogenetics and mathematical modelling, we investigate crossover positioning in the Arabidopsis thaliana wild-type, an over-expressor of the conserved E3 ligase HEI10, and a hei10 heterozygous line. We show that crossover positions can be explained by a predictive, diffusion-mediated coarsening model, in which large, approximately evenly-spaced HEI10 foci grow at the expense of smaller, closely-spaced clusters. We propose this coarsening process explains many aspects of Arabidopsis crossover positioning, including crossover interference. Consistent with this model, we also demonstrate that crossover positioning can be predictably modified in vivo simply by altering HEI10 dosage, with higher and lower dosage leading to weaker and stronger crossover interference, respectively. As HEI10 is a conserved member of the RING finger protein family that functions in the interference-sensitive pathway for crossover formation, we anticipate that similar mechanisms may regulate crossover positioning in diverse eukaryotes.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas Cromossômicas não Histona/metabolismo , Troca Genética/genética , Meiose/genética , Proteínas de Arabidopsis/genética , Proteínas Cromossômicas não Histona/genética , Cromossomos de Plantas/genética , Cromossomos de Plantas/metabolismo , Simulação por Computador , Dosagem de Genes , Estágio Paquíteno/genética , Complexo Sinaptonêmico/genética , Complexo Sinaptonêmico/metabolismo
3.
Elife ; 102021 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-34309512

RESUMO

DNA loops can be formed by a mechanism in which the cohesin complex pulls DNA strands through its ring structure using biased Brownian motion.


Assuntos
Proteínas de Ciclo Celular , Proteínas Cromossômicas não Histona , Proteínas de Ciclo Celular/genética , Proteínas Cromossômicas não Histona/genética , Cromossomos , DNA
4.
Mol Cell ; 81(15): 3082-3095.e6, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34197738

RESUMO

To understand how chromatin domains coordinate gene expression, we dissected select genetic elements organizing topology and transcription around the Prdm14 super enhancer in mouse embryonic stem cells. Taking advantage of allelic polymorphisms, we developed methods to sensitively analyze changes in chromatin topology, gene expression, and protein recruitment. We show that enhancer insulation does not rely strictly on loop formation between its flanking boundaries, that the enhancer activates the Slco5a1 gene beyond its prominent domain boundary, and that it recruits cohesin for loop extrusion. Upon boundary inversion, we find that oppositely oriented CTCF terminates extrusion trajectories but does not stall cohesin, while deleted or mutated CTCF sites allow cohesin to extend its trajectory. Enhancer-mediated gene activation occurs independent of paused loop extrusion near the gene promoter. We expand upon the loop extrusion model to propose that cohesin loading and extrusion trajectories originating at an enhancer contribute to gene activation.


Assuntos
Fator de Ligação a CCCTC/metabolismo , Cromatina/genética , Elementos Facilitadores Genéticos , Animais , Fator de Ligação a CCCTC/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Expressão Gênica , Camundongos , Células-Tronco Embrionárias Murinas , Coativador 2 de Receptor Nuclear/genética , Regiões Promotoras Genéticas , Proteínas de Ligação a RNA/genética , Fatores de Transcrição/genética
5.
Mol Cell ; 81(15): 3065-3081.e12, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34297911

RESUMO

The chromatin fiber folds into loops, but the mechanisms controlling loop extrusion are still poorly understood. Using super-resolution microscopy, we visualize that loops in intact nuclei are formed by a scaffold of cohesin complexes from which the DNA protrudes. RNA polymerase II decorates the top of the loops and is physically segregated from cohesin. Augmented looping upon increased loading of cohesin on chromosomes causes disruption of Lamin at the nuclear rim and chromatin blending, a homogeneous distribution of chromatin within the nucleus. Altering supercoiling via either transcription or topoisomerase inhibition counteracts chromatin blending, increases chromatin condensation, disrupts loop formation, and leads to altered cohesin distribution and mobility on chromatin. Overall, negative supercoiling generated by transcription is an important regulator of loop formation in vivo.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Cromatina/química , Cromatina/genética , Proteínas Cromossômicas não Histona/metabolismo , Transcrição Genética/fisiologia , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/genética , Linhagem Celular , Núcleo Celular/genética , Proteoglicanas de Sulfatos de Condroitina/genética , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Cromatina/metabolismo , Proteínas Cromossômicas não Histona/química , Proteínas Cromossômicas não Histona/genética , DNA Topoisomerases Tipo I/genética , DNA Topoisomerases Tipo I/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Feminino , Humanos , Laminas/genética , Laminas/metabolismo , RNA Polimerase II/metabolismo , Imagem Individual de Molécula/métodos
6.
Int J Mol Sci ; 22(13)2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34203408

RESUMO

TENT4A (PAPD7) is a non-canonical poly(A) polymerase, of which little is known. Here, we show that TENT4A regulates multiple biological pathways and focuses on its multilayer regulation of translesion DNA synthesis (TLS), in which error-prone DNA polymerases bypass unrepaired DNA lesions. We show that TENT4A regulates mRNA stability and/or translation of DNA polymerase η and RAD18 E3 ligase, which guides the polymerase to replication stalling sites and monoubiquitinates PCNA, thereby enabling recruitment of error-prone DNA polymerases to damaged DNA sites. Remarkably, in addition to the effect on RAD18 mRNA stability via controlling its poly(A) tail, TENT4A indirectly regulates RAD18 via the tumor suppressor CYLD and via the long non-coding antisense RNA PAXIP1-AS2, which had no known function. Knocking down the expression of TENT4A or CYLD, or overexpression of PAXIP1-AS2 led each to reduced amounts of the RAD18 protein and DNA polymerase η, leading to reduced TLS, highlighting PAXIP1-AS2 as a new TLS regulator. Bioinformatics analysis revealed that TLS error-prone DNA polymerase genes and their TENT4A-related regulators are frequently mutated in endometrial cancer genomes, suggesting that TLS is dysregulated in this cancer.


Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Reparo do DNA/fisiologia , DNA Polimerase Dirigida por DNA/metabolismo , Neoplasias do Endométrio/metabolismo , Mutação/genética , Polinucleotídeo Adenililtransferase/metabolismo , RNA Mensageiro/metabolismo , Western Blotting , Linhagem Celular Tumoral , Proteínas Cromossômicas não Histona/genética , Biologia Computacional , Dano ao DNA/genética , Dano ao DNA/fisiologia , Reparo do DNA/genética , Replicação do DNA/genética , Replicação do DNA/fisiologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , DNA Polimerase Dirigida por DNA/genética , Neoplasias do Endométrio/genética , Feminino , Células HEK293 , Humanos , Imunoprecipitação , Células MCF-7 , Reação em Cadeia da Polimerase , Polinucleotídeo Adenililtransferase/genética , Estabilidade de RNA/genética , Estabilidade de RNA/fisiologia , RNA Mensageiro/genética , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação/genética , Ubiquitinação/fisiologia
8.
Science ; 373(6551)2021 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-34244384

RESUMO

Children with Down syndrome have a 150-fold increased risk of developing myeloid leukemia, but the mechanism of predisposition is unclear. Because Down syndrome leukemogenesis initiates during fetal development, we characterized the cellular and developmental context of preleukemic initiation and leukemic progression using gene editing in human disomic and trisomic fetal hematopoietic cells and xenotransplantation. GATA binding protein 1 (GATA1) mutations caused transient preleukemia when introduced into trisomy 21 long-term hematopoietic stem cells, where a subset of chromosome 21 microRNAs affected predisposition to preleukemia. By contrast, progression to leukemia was independent of trisomy 21 and originated in various stem and progenitor cells through additional mutations in cohesin genes. CD117+/KIT proto-oncogene (KIT) cells mediated the propagation of preleukemia and leukemia, and KIT inhibition targeted preleukemic stem cells.


Assuntos
Proteínas de Ciclo Celular/genética , Síndrome de Down/genética , Fator de Transcrição GATA1/genética , Células-Tronco Hematopoéticas/fisiologia , Leucemia Mieloide/genética , Pré-Leucemia/genética , Animais , Antígenos CD34/análise , Proteínas de Ciclo Celular/metabolismo , Linhagem da Célula , Proliferação de Células , Transformação Celular Neoplásica , Proteínas Cromossômicas não Histona/genética , Cromossomos Humanos Par 21/genética , Cromossomos Humanos Par 21/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Síndrome de Down/complicações , Feminino , Fator de Transcrição GATA1/metabolismo , Hematopoese , Transplante de Células-Tronco Hematopoéticas , Xenoenxertos , Humanos , Leucemia Mieloide/metabolismo , Leucemia Mieloide/patologia , Fígado/embriologia , Masculino , Megacariócitos/fisiologia , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Mutação , Pré-Leucemia/metabolismo , Pré-Leucemia/patologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-kit/análise , Proteínas Proto-Oncogênicas c-kit/antagonistas & inibidores
9.
Nucleic Acids Res ; 49(13): 7406-7423, 2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-34214177

RESUMO

Heterochromatin binding protein HP1ß plays an important role in chromatin organization and cell differentiation, however the underlying mechanisms remain unclear. Here, we generated HP1ß-/- embryonic stem cells and observed reduced heterochromatin clustering and impaired differentiation. We found that during stem cell differentiation, HP1ß is phosphorylated at serine 89 by CK2, which creates a binding site for the pluripotency regulator KAP1. This phosphorylation dependent sequestration of KAP1 in heterochromatin compartments causes a downregulation of pluripotency factors and triggers pluripotency exit. Accordingly, HP1ß-/- and phospho-mutant cells exhibited impaired differentiation, while ubiquitination-deficient KAP1-/- cells had the opposite phenotype with enhanced differentiation. These results suggest that KAP1 regulates pluripotency via its ubiquitination activity. We propose that the formation of subnuclear membraneless heterochromatin compartments may serve as a dynamic reservoir to trap or release cellular factors. The sequestration of essential regulators defines a novel and active role of heterochromatin in gene regulation and represents a dynamic mode of remote control to regulate cellular processes like cell fate decisions.


Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Células-Tronco Embrionárias/metabolismo , Heterocromatina/metabolismo , Proteína 28 com Motivo Tripartido/metabolismo , Animais , Caseína Quinase II/metabolismo , Diferenciação Celular , Linhagem Celular , Células Cultivadas , Proteínas Cromossômicas não Histona/química , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/fisiologia , Cricetinae , Células-Tronco Embrionárias/citologia , Técnicas de Inativação de Genes , Humanos , Camundongos , Fosforilação , Serina/metabolismo , Proteína 28 com Motivo Tripartido/genética , Proteína 28 com Motivo Tripartido/fisiologia
10.
Nat Commun ; 12(1): 4360, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34272384

RESUMO

The glucocorticoid receptor (GR) regulates gene expression, governing aspects of homeostasis, but is also involved in cancer. Pharmacological GR activation is frequently used to alleviate therapy-related side-effects. While prior studies have shown GR activation might also have anti-proliferative action on tumours, the underpinnings of glucocorticoid action and its direct effectors in non-lymphoid solid cancers remain elusive. Here, we study the mechanisms of glucocorticoid response, focusing on lung cancer. We show that GR activation induces reversible cancer cell dormancy characterised by anticancer drug tolerance, and activation of growth factor survival signalling accompanied by vulnerability to inhibitors. GR-induced dormancy is dependent on a single GR-target gene, CDKN1C, regulated through chromatin looping of a GR-occupied upstream distal enhancer in a SWI/SNF-dependent fashion. These insights illustrate the importance of GR signalling in non-lymphoid solid cancer biology, particularly in lung cancer, and warrant caution for use of glucocorticoids in treatment of anticancer therapy related side-effects.


Assuntos
Antineoplásicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Cromatina/metabolismo , Inibidor de Quinase Dependente de Ciclina p57/metabolismo , Glucocorticoides/farmacologia , Neoplasias Pulmonares/metabolismo , Receptores de Glucocorticoides/metabolismo , Animais , Ciclo Celular/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Sobrevivência Celular/efeitos dos fármacos , Cromatina/genética , Sequenciamento de Cromatina por Imunoprecipitação , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Inibidor de Quinase Dependente de Ciclina p57/genética , Elementos Facilitadores Genéticos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Imidazóis/farmacologia , Imuno-Histoquímica , Neoplasias Pulmonares/genética , Camundongos , Proteômica , Pirazinas/farmacologia , RNA Interferente Pequeno , RNA-Seq , Receptor IGF Tipo 1/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Int J Mol Sci ; 22(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202641

RESUMO

The cohesin complex is crucial for mediating sister chromatid cohesion and for hierarchal three-dimensional organization of the genome. Mutations in cohesin genes are present in a range of cancers. Extensive research over the last few years has shown that cohesin mutations are key events that contribute to neoplastic transformation. Cohesin is involved in a range of cellular processes; therefore, the impact of cohesin mutations in cancer is complex and can be cell context dependent. Candidate targets with therapeutic potential in cohesin mutant cells are emerging from functional studies. Here, we review emerging targets and pharmacological agents that have therapeutic potential in cohesin mutant cells.


Assuntos
Proteínas de Ciclo Celular/genética , Proteínas Cromossômicas não Histona/genética , Predisposição Genética para Doença , Mutação , Neoplasias/genética , Biomarcadores Tumorais , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/metabolismo , Proteínas Cromossômicas não Histona/química , Proteínas Cromossômicas não Histona/metabolismo , Reparo do DNA , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Gerenciamento Clínico , Regulação da Expressão Gênica , Humanos , Terapia de Alvo Molecular/métodos , Neoplasias/diagnóstico , Neoplasias/metabolismo , Neoplasias/terapia , Especificidade de Órgãos , Ligação Proteica , Relação Estrutura-Atividade
12.
Cancer Sci ; 112(9): 3711-3721, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34107118

RESUMO

Antimitotic drugs such as vinca alkaloids and taxanes cause mitotic cell death after prolonged mitotic arrest. However, a fraction of cells escape from mitotic arrest by undergoing mitotic slippage, which is related to resistance to antimitotic drugs. Tipping the balance to mitotic cell death thus can be a way to overcome the drug resistance. Here we found that depletion of a mitotic regulator, CHAMP1 (chromosome alignment-maintaining phosphoprotein, CAMP), accelerates the timing of mitotic cell death after mitotic arrest. Live cell imaging revealed that CHAMP1-depleted cells died earlier than mock-treated cells in the presence of antimitotic drugs that resulted in the reduction of cells undergoing mitotic slippage. Depletion CHAMP1 reduces the expression of antiapoptotic Bcl-2 family proteins, especially Mcl-1. We found that CHAMP1 maintains Mcl-1 expression both at protein and mRNA levels independently of the cell cycle. At the protein level, CHAMP1 maintains Mcl-1 stability by suppressing proteasome-dependent degradation. Depletion of CHAMP1 reduces cell viability, and exhibits synergistic effects with antimitotic drugs. Our data suggest that CHAMP1 plays a role in the maintenance of Mcl-1 expression, implying that CHAMP1 can be a target to overcome the resistance to antimitotic drugs.


Assuntos
Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Neoplasias/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Transdução de Sinais/genética , Células A549 , Animais , Antimitóticos/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Resistencia a Medicamentos Antineoplásicos/genética , Células HEK293 , Células HeLa , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Mitose/efeitos dos fármacos , Mitose/genética , Neoplasias/genética , Neoplasias/patologia , Interferência de RNA , Transdução de Sinais/efeitos dos fármacos , Transfecção , Carga Tumoral/genética , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Development ; 148(13)2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-34104941

RESUMO

Zygotic genomic activation (ZGA) is a landmark event in the maternal-to-zygotic transition (MZT), and the regulation of ZGA by maternal factors remains to be elucidated. In this study, the depletion of maternal ring finger protein 114 (RNF114), a ubiquitin E3 ligase, led to developmental arrest of two-cell mouse embryos. Using immunofluorescence and transcriptome analysis, RNF114 was proven to play a crucial role in major ZGA. To study the underlying mechanism, we performed protein profiling in mature oocytes and found a potential substrate for RNF114, chromobox 5 (CBX5), ubiquitylation and degradation of which was regulated by RNF114. The overexpression of CBX5 prevented embryonic development and impeded major ZGA. Furthermore, TAB1 was abnormally accumulated in mutant two-cell embryos, which was consistent with the result of in vitro knockdown of Rnf114. Knockdown of Cbx5 or Tab1 in maternal RNF114-depleted embryos partially rescued developmental arrest and the defect of major ZGA. In summary, our study reveals that maternal RNF114 plays a precise role in degrading some important substrates during the MZT, the misregulation of which may impede the appropriate activation of major ZGA in mouse embryos.


Assuntos
Desenvolvimento Embrionário/fisiologia , Genoma , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Zigoto/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Animais , Proteínas Cromossômicas não Histona/genética , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Fatores de Transcrição/metabolismo , Transcriptoma
14.
Biophys J ; 120(13): 2631-2643, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34087208

RESUMO

Within the nucleus of the eukaryotic cell, DNA is partitioned into domains of highly condensed, transcriptionally silent heterochromatin and less condensed, transcriptionally active euchromatin. Heterochromatin protein 1α (HP1α) is an architectural protein that establishes and maintains heterochromatin, ensuring genome fidelity and nuclear integrity. Although the mechanical effects of changes in the relative amount of euchromatin and heterochromatin brought about by inhibiting chromatin-modifying enzymes have been studied previously, here we measure how the material properties of the nuclei are modified after the knockdown of HP1α. These studies were inspired by the observation that poorly invasive MCF7 breast cancer cells become more invasive after knockdown of HP1α expression and that, indeed, in many solid tumors the loss of HP1α correlates with the onset of tumor cell invasion. Atomic force microscopy (AFM), optical tweezers (OT), and techniques based on micropipette aspiration (MA) were each used to characterize the mechanical properties of nuclei extracted from HP1α knockdown or matched control MCF7 cells. Using AFM or OT to locally indent nuclei, those extracted from MCF7 HP1α knockdown cells were found to have apparent Young's moduli that were significantly lower than nuclei from MCF7 control cells, consistent with previous studies that assert heterochromatin plays a major role in governing the mechanical response in such experiments. In contrast, results from pipette-based techniques in the spirit of MA, in which the whole nuclei were deformed and aspirated into a conical pipette, showed considerably less variation between HP1α knockdown and control, consistent with previous studies reporting that it is predominantly the lamins in the nuclear envelope that determine the mechanical response to large whole-cell deformations. The differences in chromatin organization observed by various microscopy techniques between the MCF7 control and HP1α knockdown nuclei correlate well with the results of our measured mechanical responses and our hypotheses regarding their origin.


Assuntos
Núcleo Celular , Proteínas Cromossômicas não Histona , Proteínas Cromossômicas não Histona/genética , Heterocromatina , Humanos , Células MCF-7 , Fatores de Transcrição
15.
Rinsho Ketsueki ; 62(5): 352-359, 2021.
Artigo em Japonês | MEDLINE | ID: mdl-34108313

RESUMO

STAG2 and other cohesin complex components are mutated in ∼10-15% of myeloid neoplasms, particularly in myelodysplastic syndrome (MDS) and secondary acute myeloid leukemia. STAG2 mutations often coincide with other driver mutations, such as RUNX1, SRSF2, and ASXL1, suggesting a strong functional interaction among these mutations in myeloid neoplasms. To elucidate the mechanism of cohesin-induced leukemogenesis, we generated Stag2 conditional knockout (KO) mice but they only exhibited relatively mild hematopoietic abnormalities and did not develop lethal myeloid neoplasms. In contrast, Stag2/Runx1 double KO mice exhibited marked differentiation abnormalities, expanded hematopoietic stem/progenitor cell pools, and pancytopenia, which led to the development of lethal MDS. Abnormalities in gene expression and transcription factor activities were also more extensive in double KO mice than in single KO mice. Additionally, in situ Hi-C revealed a marked reduction in chromosomal three-dimensional loop formation between enhancer and promoter elements. This was associated with the downregulation of genes with high basal transcriptional pausing that are important for HSPC regulation. Thus, cohesin cooperates with the transcription factor RUNX1 to regulate chromosomal three-dimensional structure and gene expression, and mutational dysfunction of these proteins, along with consequent loss of regulation, is thought to result in the formation of myeloid neoplasms.


Assuntos
Leucemia Mieloide Aguda , Síndromes Mielodisplásicas , Animais , Proteínas de Ciclo Celular/genética , Proteínas Cromossômicas não Histona/genética , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Camundongos , Mutação , Síndromes Mielodisplásicas/genética
16.
Nat Commun ; 12(1): 3184, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34075040

RESUMO

During spermatogenesis, meiosis is accompanied by a robust alteration in gene expression and chromatin status. However, it remains elusive how the meiotic transcriptional program is established to ensure completion of meiotic prophase. Here, we identify a protein complex that consists of germ-cell-specific zinc-finger protein ZFP541 and its interactor KCTD19 as the key transcriptional regulators in mouse meiotic prophase progression. Our genetic study shows that ZFP541 and KCTD19 are co-expressed from pachytene onward and play an essential role in the completion of the meiotic prophase program in the testis. Furthermore, our ChIP-seq and transcriptome analyses identify that ZFP541 binds to and suppresses a broad range of genes whose function is associated with biological processes of transcriptional regulation and covalent chromatin modification. The present study demonstrates that a germ-cell specific complex that contains ZFP541 and KCTD19 promotes the progression of meiotic prophase towards completion in male mice, and triggers the reconstruction of the transcriptional network and chromatin organization leading to post-meiotic development.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Proteínas Nucleares/metabolismo , Estágio Paquíteno/genética , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Espermátides/citologia , Espermatogênese/genética , Fatores de Transcrição/metabolismo , Animais , Proteínas de Ciclo Celular/genética , Sequenciamento de Cromatina por Imunoprecipitação , Proteínas Cromossômicas não Histona/genética , Modelos Animais de Doenças , Feminino , Histona Desacetilase 1/metabolismo , Histona Desacetilase 2/metabolismo , Humanos , Infertilidade Masculina/genética , Masculino , Camundongos , Camundongos Knockout , Proteínas Nucleares/genética , Oócitos/citologia , Oócitos/metabolismo , Canais de Potássio de Abertura Dependente da Tensão da Membrana/genética , RNA-Seq , Espermátides/metabolismo , Fatores de Transcrição/genética , Transcrição Genética
17.
Mol Cell Biol ; 41(7): e0004421, 2021 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-33941618

RESUMO

Prions are self-perpetuating, alternative protein conformations associated with neurological diseases and normal cellular functions. Saccharomyces cerevisiae contains many endogenous prions, providing a powerful system to study prionization. Previously, we demonstrated that Swi1, a component of the SWI/SNF chromatin-remodeling complex, can form the prion [SWI+]. A small region, Swi11-38, with a unique amino acid composition of low complexity, acts as a prion domain and supports [SWI+] propagation. Here, we further examine Swi11-38 through site-directed mutagenesis. We found that mutations of the two phenylalanine residues or the threonine tract inhibit Swi11-38 aggregation. In addition, mutating both phenylalanines can abolish de novo prion formation by Swi11-38, whereas mutating only one phenylalanine does not. Replacement of half of or the entire eight-threonine tract with alanines has the same effect, possibly disrupting a core region of Swi11-38 aggregates. We also show that Swi11-38 and its prion-fold-maintaining mutants form high-molecular-weight, SDS-resistant aggregates, whereas the double-phenylalanine mutants eliminate these protein species. These results indicate the necessity of the large hydrophobic residues and threonine tract in Swi11-38 in prionogenesis, possibly acting as important aggregable regions. Our findings thus highlight the importance of specific amino acid residues in the Swi1 prion domain in prion formation and maintenance.


Assuntos
Proteínas Cromossômicas não Histona/genética , Regulação Fúngica da Expressão Gênica/genética , Mutação/genética , Príons/genética , Proteínas de Saccharomyces cerevisiae/genética , Fatores de Transcrição/genética , Montagem e Desmontagem da Cromatina , Proteínas Cromossômicas não Histona/metabolismo , Cromossomos/metabolismo , Príons/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/metabolismo
18.
Nat Commun ; 12(1): 2919, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34006846

RESUMO

Cornelia de Lange Syndrome (CdLS) is a human developmental disorder caused by mutations that compromise the function of cohesin, a major regulator of 3D genome organization. Cognitive impairment is a universal and as yet unexplained feature of CdLS. We characterize the transcriptional profile of cortical neurons from CdLS patients and find deregulation of hundreds of genes enriched for neuronal functions related to synaptic transmission, signalling processes, learning and behaviour. Inducible proteolytic cleavage of cohesin disrupts 3D genome organization and transcriptional control in post-mitotic cortical mouse neurons, demonstrating that cohesin is continuously required for neuronal gene expression. The genes affected by acute depletion of cohesin belong to similar gene ontology classes and show significant numerical overlap with genes deregulated in CdLS. Interestingly, reconstitution of cohesin function largely rescues altered gene expression, including the expression of genes deregulated in CdLS.


Assuntos
Proteínas de Ciclo Celular/genética , Proteínas Cromossômicas não Histona/genética , Síndrome de Cornélia de Lange/genética , Regulação da Expressão Gênica , Mutação , Neurônios/metabolismo , Adulto , Animais , Proteínas de Ciclo Celular/metabolismo , Células Cultivadas , Proteínas Cromossômicas não Histona/metabolismo , Síndrome de Cornélia de Lange/metabolismo , Perfilação da Expressão Gênica/métodos , Humanos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Adulto Jovem
19.
Nat Commun ; 12(1): 2576, 2021 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-33958593

RESUMO

Nitric oxide (NO) is a diffusible signaling molecule that modulates animal and plant immune responses. In addition, reactive nitrogen species derived from NO can display antimicrobial activities by reacting with microbial cellular components, leading to nitrosative stress (NS) in pathogens. Here, we identify FgAreB as a regulator of the NS response in Fusarium graminearum, a fungal pathogen of cereal crops. FgAreB serves as a pioneer transcription factor for recruitment of the chromatin-remodeling complex SWI/SNF at the promoters of genes involved in the NS response, thus promoting their transcription. FgAreB plays important roles in fungal infection and growth. Furthermore, we show that a transcription repressor (FgIxr1) competes with the SWI/SNF complex for FgAreB binding, and negatively regulates the NS response. NS, in turn, promotes the degradation of FgIxr1, thus enhancing the recruitment of the SWI/SNF complex by FgAreB.


Assuntos
Montagem e Desmontagem da Cromatina/genética , Proteínas Cromossômicas não Histona/metabolismo , Fusarium/metabolismo , Fatores de Transcrição GATA/metabolismo , Regulação Fúngica da Expressão Gênica/genética , Doenças das Plantas/microbiologia , Proteína SMARCB1/metabolismo , Fatores de Transcrição/metabolismo , Imunoprecipitação da Cromatina , Proteínas Cromossômicas não Histona/genética , Fusarium/genética , Fusarium/patogenicidade , Fatores de Transcrição GATA/genética , Proteínas de Grupo de Alta Mobilidade/genética , Proteínas de Grupo de Alta Mobilidade/metabolismo , Óxido Nítrico/metabolismo , Estresse Nitrosativo , Proteína SMARCB1/genética , Fatores de Transcrição/genética , Triticum/microbiologia , Zea mays/microbiologia
20.
Nat Commun ; 12(1): 2551, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33953173

RESUMO

Endogenous cardiac pacemaker function regulates the rate and rhythm of cardiac contraction. The mutation p.Lys23Glu in the cohesin protein Shugoshin-1 causes severe heart arrhythmias due to sinoatrial node dysfunction and a debilitating gastrointestinal motility disorder, collectively termed the Chronic Atrial and Intestinal Dysrhythmia Syndrome, linking Shugoshin-1 and pacemaker activity. Hyperpolarization-activated, cyclic nucleotide-gated cation channel 4 (HCN4) is the predominant pacemaker ion-channel in the adult heart and carries the majority of the "funny" current, which strongly contributes to diastolic depolarization in pacemaker cells. Here, we study the mechanism by which Shugoshin-1 affects cardiac pacing activity with two cell models: neonatal rat ventricular myocytes and Chronic Atrial and Intestinal Dysrhythmia Syndrome patient-specific human induced pluripotent stem cell derived cardiomyocytes. We find that Shugoshin-1 interacts directly with HCN4 to promote and stabilize cardiac pacing. This interaction enhances funny-current by optimizing HCN4 cell-surface expression and function. The clinical p.Lys23Glu mutation leads to an impairment in the interaction between Shugoshin-1 and HCN4, along with depressed funny-current and dysrhythmic activity in induced pluripotent stem cell derived cardiomyocytes derived from Chronic Atrial and Intestinal Dysrhythmia Syndrome patients. Our work reveals a critical non-canonical, cohesin-independent role for Shugoshin-1 in maintaining cardiac automaticity and identifies potential therapeutic avenues for cardiac pacemaking disorders, in particular Chronic Atrial and Intestinal Dysrhythmia Syndrome.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/metabolismo , Proteínas Musculares/metabolismo , Canais de Potássio/metabolismo , Animais , Arritmias Cardíacas , Proteínas de Ciclo Celular/genética , Linhagem Celular , Sobrevivência Celular , Proteínas Cromossômicas não Histona/genética , Técnicas de Silenciamento de Genes , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/genética , Células-Tronco Pluripotentes Induzidas/metabolismo , Transporte de Íons/fisiologia , Proteínas Musculares/genética , Contração Miocárdica , Miócitos Cardíacos/metabolismo , Marca-Passo Artificial , Canais de Potássio/genética , Ratos
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