Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Mol Cell ; 81(17): 3526-3541.e8, 2021 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-34186021

RESUMO

BAP1 is mutated or deleted in many cancer types, including mesothelioma, uveal melanoma, and cholangiocarcinoma. It is the catalytic subunit of the PR-DUB complex, which removes PRC1-mediated H2AK119ub1, essential for maintaining transcriptional repression. However, the precise relationship between BAP1 and Polycombs remains elusive. Using embryonic stem cells, we show that BAP1 restricts H2AK119ub1 deposition to Polycomb target sites. This increases the stability of Polycomb with their targets and prevents diffuse accumulation of H2AK119ub1 and H3K27me3. Loss of BAP1 results in a broad increase in H2AK119ub1 levels that is primarily dependent on PCGF3/5-PRC1 complexes. This titrates PRC2 away from its targets and stimulates H3K27me3 accumulation across the genome, leading to a general chromatin compaction. This provides evidence for a unifying model that resolves the apparent contradiction between BAP1 catalytic activity and its role in vivo, uncovering molecular vulnerabilities that could be useful for BAP1-related pathologies.


Assuntos
Cromatina/metabolismo , Proteínas do Grupo Polycomb/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina Tiolesterase/metabolismo , Animais , Linhagem Celular/metabolismo , Cromatina/genética , Cromatina/fisiologia , Células-Tronco Embrionárias/metabolismo , Heterocromatina , Histonas/metabolismo , Humanos , Camundongos , Células-Tronco Embrionárias Murinas/metabolismo , Complexo Repressor Polycomb 1/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Proteínas do Grupo Polycomb/genética , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/fisiologia , Ubiquitina Tiolesterase/genética , Ubiquitina Tiolesterase/fisiologia , Ubiquitinação
2.
Mol Cell ; 74(5): 1020-1036.e8, 2019 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-31029541

RESUMO

The Polycomb system modifies chromatin and plays an essential role in repressing gene expression to control normal mammalian development. However, the components and mechanisms that define how Polycomb protein complexes achieve this remain enigmatic. Here, we use combinatorial genetic perturbation coupled with quantitative genomics to discover the central determinants of Polycomb-mediated gene repression in mouse embryonic stem cells. We demonstrate that canonical Polycomb repressive complex 1 (PRC1), which mediates higher-order chromatin structures, contributes little to gene repression. Instead, we uncover an unexpectedly high degree of synergy between variant PRC1 complexes, which is fundamental to gene repression. We further demonstrate that variant PRC1 complexes are responsible for distinct pools of H2A monoubiquitylation that are associated with repression of Polycomb target genes and silencing during X chromosome inactivation. Together, these discoveries reveal a new variant PRC1-dependent logic for Polycomb-mediated gene repression.


Assuntos
Cromatina/genética , Genômica , Complexo Repressor Polycomb 1/genética , Inativação do Cromossomo X/genética , Animais , Histonas/genética , Camundongos , Células-Tronco Embrionárias Murinas/metabolismo , Interferência de RNA , Ubiquitinação/genética
3.
Mol Cell ; 74(5): 1037-1052.e7, 2019 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-31029542

RESUMO

Polycomb repressive complexes 1 and 2 (PRC1 and PRC2) control cell identity by establishing facultative heterochromatin repressive domains at common sets of target genes. PRC1, which deposits H2Aub1 through the E3 ligases RING1A/B, forms six biochemically distinct subcomplexes depending on the assembled PCGF protein (PCGF1-PCGF6); however, it is yet unclear whether these subcomplexes have also specific activities. Here we show that PCGF1 and PCGF2 largely compensate for each other, while other PCGF proteins have high levels of specificity for distinct target genes. PCGF2 associates with transcription repression, whereas PCGF3 and PCGF6 associate with actively transcribed genes. Notably, PCGF3 and PCGF6 complexes can assemble and be recruited to several active sites independently of RING1A/B activity (therefore, of PRC1). For chromatin recruitment, the PCGF6 complex requires the combinatorial activities of its MGA-MAX and E2F6-DP1 subunits, while PCGF3 requires an interaction with the USF1 DNA binding transcription factor.


Assuntos
Complexo Repressor Polycomb 1/genética , Transcrição Gênica , Ubiquitina-Proteína Ligases/genética , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Cromatina/genética , Proteínas de Ligação a DNA/genética , Fator de Transcrição E2F6/genética , Heterocromatina/genética , Camundongos , Células-Tronco Embrionárias Murinas/metabolismo , Complexo Repressor Polycomb 2/genética , Proteínas do Grupo Polycomb/genética , Proteínas Repressoras/genética , Fator de Transcrição DP1/genética , Fatores de Transcrição/genética , Fatores Estimuladores Upstream/genética
4.
Dev Growth Differ ; 65(8): 461-469, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37452641

RESUMO

The enteric nervous system (ENS) regulates gut functions independently from the central nervous system (CNS) by its highly autonomic neural circuit that integrates diverse neuronal subtypes. Although several transcription factors are shown to be necessary for the generation of some enteric neuron subtypes, the mechanisms underlying neuronal subtype specification in the ENS remain elusive. In this study, we examined the biological function of Polycomb group RING finger protein 1 (PCGF1), one of the epigenetic modifiers, in the development and differentiation of the ENS by disrupting the Pcgf1 gene selectively in the autonomic-lineage cells. Although ENS precursor migration and enteric neurogenesis were largely unaffected, neuronal differentiation was impaired in the Pcgf1-deficient mice, with the numbers of neurons expressing somatostatin (Sst+ ) decreased in multiple gut regions. Notably, the decrease in Sst+ neurons was associated with the corresponding increase in calbindin+ neurons in the proximal colon. These findings suggest that neuronal subtype conversion may occur in the absence of PCGF1, and that epigenetic mechanism is primarily involved in specification of some enteric neuron subtypes.


Assuntos
Sistema Nervoso Entérico , Neurônios , Animais , Camundongos , Diferenciação Celular/genética , Fatores de Transcrição/metabolismo , Sistema Nervoso Entérico/metabolismo , Epigênese Genética , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo
5.
Proc Natl Acad Sci U S A ; 117(37): 22880-22889, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32868440

RESUMO

Polycomb group proteins are essential regulators of developmental processes across animals. Despite their importance, studies on Polycomb are often restricted to classical model systems and, as such, little is known about the evolution of these important chromatin regulators. Here we focus on Polycomb Repressive Complex 1 (PRC1) and trace the evolution of core components of canonical and non-canonical PRC1 complexes in animals. Previous work suggested that a major expansion in the number of PRC1 complexes occurred in the vertebrate lineage. We show that the expansion of the Polycomb Group RING Finger (PCGF) protein family, an essential step for the establishment of the large diversity of PRC1 complexes found in vertebrates, predates the bilaterian-cnidarian ancestor. This means that the genetic repertoire necessary to form all major vertebrate PRC1 complexes emerged early in animal evolution, over 550 million years ago. We further show that PCGF5, a gene conserved in cnidarians and vertebrates but lost in all other studied groups, is expressed in the nervous system in the sea anemone Nematostella vectensis, similar to its mammalian counterpart. Together this work provides a framework for understanding the evolution of PRC1 complex diversity and it establishes Nematostella as a promising model system in which the functional ramifications of this diversification can be further explored.


Assuntos
Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Animais , Antozoários/genética , Núcleo Celular/metabolismo , Cromatina/genética , Bases de Dados Genéticas , Evolução Molecular , Inativação Gênica/fisiologia , Variação Genética/genética , Humanos , Proteínas do Grupo Polycomb/genética , Vertebrados/genética
6.
Exp Dermatol ; 31(8): 1220-1233, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35427425

RESUMO

Melanoma belongs to cutaneous malignancy. Long non-coding RNAs (lncRNAs) have been suggested as crucial effectors in modulating progression of different malignancies, including melanoma. However, novel lncRNA solute carrier organic anion transporter family member 4A1 antisense RNA 1 (SLCO4A1-AS1) was not reported in melanoma. Herein, SLCO4A1-AS1 was detected to be up-regulated in melanoma cell lines compared with human normal melanocytes (HEM-a). Additionally, proliferation, migration and invasion of melanoma cells were weakened but apoptosis was facilitated due to SLCO4A1-AS1 down-regulation. Subsequently, miR-1306-5p was revealed to be sequestered by SLCO4A1-AS1 and down-regulated in melanoma cells. Functional assays further sustained that overexpressed miR-1306-5p had inhibitory influence on proliferation, migration and invasion and promoting influence on apoptosis of melanoma cells. Polycomb group ring finger 2 (PCGF2) was predicted as the downstream of miR-1306-5p, displaying aberrantly high expression in melanoma cell lines. Furthermore, PCGF2 expression was negatively modulated by miR-1306-5p and positively regulated by SLCO4A1-AS1. Finally, rescue assays demonstrated melanoma cell malignant behaviours suppressed by SLCO4A1-AS1 knockdown could be reversed by overexpressed PCGF2. Our study suggested that SLCO4A1-AS1 promoted the melanoma cell malignant behaviours via targeting miR-1306-5p/PCGF2, which might facilitate the discovery of novel biomarkers for melanoma treatment.


Assuntos
Melanoma , MicroRNAs , RNA Longo não Codificante , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Melanoma/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Complexo Repressor Polycomb 1 , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo
7.
Am J Med Genet A ; 188(2): 688-691, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34750959

RESUMO

Turnpenny-Fry syndrome is a very rare genetic disorder characterized by intellectual disability, developmental delay, facial dysmorphism, and skeletal abnormalities. Mutations of the PCGF2 gene are responsible for Turnpenny-Fry syndrome. This gene encodes the polycomb group ring finger 2 protein that is broadly expressed in various human tissues. To date, only 13 patients with Turnpenny-Fry syndrome have been reported. Our patient was referred to our clinic for neuromotor retardation and dysmorphic features. Whole exome sequencing (WES) was performed from the peripheral blood sample of the patient. WES revealed a heterozygous mutation in the PCGF2 gene. To the best of our knowledge, we reported the 14th patient with Turnpenny-Fry syndrome and the first from Turkey, who had new findings.


Assuntos
Deficiência Intelectual , Anormalidades Musculoesqueléticas , Humanos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Mutação , Turquia , Sequenciamento do Exoma
8.
Exp Cell Res ; 400(2): 112496, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33485844

RESUMO

The Polycomb Group Ring Finger 3 (PCGF3) protein has been reported to be significantly upregulated in pancreatic islet tumors and related to signal transduction; however, its detailed mechanisms and biological roles in other tumors, including non-small cell lung cancer (NSCLC), remain unclear. This study investigated the function of PCGF3 in NSCLC and further elucidated its mechanism of action. The immunohistochemical analysis of 86 selected lung cancer tissues revealed that PCGF3 was highly expressed in NSCLC tissues and positively correlated with lymph node metastasis and p-TNM staging. Additionally, PCGF3 promoted cell proliferation in lung cancer by regulating CyclinB1, CyclinD1, and CDK4 expression, and also promoting their migration by regulating RhoA, RhoC, and CDC42. Furthermore, PCGF3 affected both the proliferation and migration of lung cancer cells by regulating the PI3K/AKT pathway, as verified by inhibiting this pathway using LY294002. The findings of this study suggested that PCGF3 is associated with poor prognosis in patients with NSCLC and could therefore be an important biomarker for treating and preventing NSCLC.


Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas do Grupo Polycomb/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Apoptose , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Movimento Celular , Proliferação de Células , Feminino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Masculino , Pessoa de Meia-Idade , Fosfatidilinositol 3-Quinases/genética , Proteínas do Grupo Polycomb/genética , Prognóstico , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais , Taxa de Sobrevida , Células Tumorais Cultivadas
9.
J Biol Chem ; 295(28): 9712-9724, 2020 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-32482889

RESUMO

Polycomb group (PcG) proteins are essential for maintenance of lineage fidelity by coordinating developmental gene expression programs. Polycomb group ring finger 6 (PCGF6) has been previously reported to repress expression of lineage-specific genes, especially germ cell-related genes in mouse embryonic stem cells (ESCs) via the noncanonical polycomb repressive complex PRC1.6. However, the molecular mechanism of this repression remains largely unknown. Here, using RNA-Seq, real-time RT-PCR, immunohistochemistry, immunoprecipitation, and ChIP analyses, we demonstrate that PCGF6 plays an essential role in embryonic development, indicated by the partially penetrant embryonic lethality in homozygous PCGF6 (Pcgf6-/-)-deficient mice. We also found that surviving Pcgf6-deficient mice exhibit reduced fertility. Using the Pcgf6-deficient mice, we observed that ablation of Pcgf6 in somatic tissues robustly derepresses germ cell-related genes. We further provide evidence that these genes are direct targets of PCGF6 in ESCs and that endogenous PCGF6 co-localizes with the histone-modifying proteins G9A histone methyltransferase (G9A)/G9a-like protein (GLP) and histone deacetylase 1/2 (HDAC1/2) on the promoters of the germ cell-related genes. Moreover, the binding of these proteins to their target genes correlated with methylation of Lys-9 of histone 3 and with the status of histone acetylation at these genes. Moreover, the recruitment of G9A/GLP and HDAC1/2 to target promoters depended on the binding of PCGF6. Our findings indicate that PCGF6 has a critical role in safeguarding lineage decisions and in preventing aberrant expression of germ cell-related genes.


Assuntos
Inativação Gênica , Histona Desacetilase 1/metabolismo , Histona Desacetilase 2/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Células-Tronco Embrionárias Murinas/metabolismo , Complexo Repressor Polycomb 1/metabolismo , Animais , Linhagem Celular , Histona Desacetilase 1/genética , Histona Desacetilase 2/genética , Histona-Lisina N-Metiltransferase/genética , Histonas , Camundongos , Camundongos Knockout , Complexo Repressor Polycomb 1/genética , RNA-Seq
10.
Am J Hum Genet ; 103(5): 786-793, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30343942

RESUMO

PCGF2 encodes the polycomb group ring finger 2 protein, a transcriptional repressor involved in cell proliferation, differentiation, and embryogenesis. PCGF2 is a component of the polycomb repressive complex 1 (PRC1), a multiprotein complex which controls gene silencing through histone modification and chromatin remodelling. We report the phenotypic characterization of 13 patients (11 unrelated individuals and a pair of monozygotic twins) with missense mutations in PCGF2. All the mutations affected the same highly conserved proline in PCGF2 and were de novo, excepting maternal mosaicism in one. The patients demonstrated a recognizable facial gestalt, intellectual disability, feeding problems, impaired growth, and a range of brain, cardiovascular, and skeletal abnormalities. Computer structural modeling suggests the substitutions alter an N-terminal loop of PCGF2 critical for histone biding. Mutant PCGF2 may have dominant-negative effects, sequestering PRC1 components into complexes that lack the ability to interact efficiently with histones. These findings demonstrate the important role of PCGF2 in human development and confirm that heterozygous substitutions of the Pro65 residue of PCGF2 cause a recognizable syndrome characterized by distinctive craniofacial, neurological, cardiovascular, and skeletal features.

11.
Dev Growth Differ ; 62(4): 232-242, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32130724

RESUMO

Polycomb group (PcG) RING finger protein 5 (PCGF5) is a core component of the so-called Polycomb repressive complex 1.5 (PRC1.5), which is involved in epigenetic transcriptional repression. To explore the developmental function of Pcgf5, we generated Pcgf5 knockout (Pcgf5-/- ) mouse embryonic stem cell (mESC) lines with the help of CRISPR/Cas9 technology. We subjected the Pcgf5-/- and wild-type (WT) mESCs to a differentiation protocol toward mesodermal-cardiac cell types as aggregated embryoid bodies (EBs) and we found that knockout of Pcgf5 delayed the generation of the three germ layers, especially the ectoderm. Further, disruption of Pcgf5 impacted the epithelial-mesenchymal transition during EB morphogenesis and differentially affected the gene expression of essential developmental signaling pathways such as Nodal and Wnt. Finally, we also unveiled that loss of Pcgf5 induced the repression of genes involved in the Notch pathway, which may explain the enhancement of cardiomyocyte maturation and the dampening of ectodermal-neural differentiation observed in the Pcgf5-/- EBs.


Assuntos
Diferenciação Celular , Células-Tronco Embrionárias Murinas/citologia , Células-Tronco Embrionárias Murinas/metabolismo , Proteínas do Grupo Polycomb/metabolismo , Transdução de Sinais , Animais , Sistemas CRISPR-Cas/genética , Linhagem Celular , Camundongos , Camundongos Knockout , Proteínas do Grupo Polycomb/deficiência , Proteínas do Grupo Polycomb/genética , Transdução de Sinais/genética
12.
J Biol Chem ; 292(52): 21527-21537, 2017 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-29054931

RESUMO

Polycomb group (PcG) proteins are epigenetic transcriptional repressors that orchestrate numerous developmental processes and have been implicated in the maintenance of embryonic stem (ES) cell state. More recent evidence suggests that a subset of PcG proteins engages in transcriptional activation in some cellular contexts, but how this property is exerted remains largely unknown. Here, we generated ES cells with single or combined disruption of polycomb group RING finger protein 3 (Pcgf3) and Pcgf5 with the CRISPR-Cas9 technique. We report that although these mutant cells maintained their self-renewal and colony-forming capacity, they displayed severe defects in mesoderm differentiation in vitro and in vivo Using RNA-seq to analyze transcriptional profiles of ES cells with single or combined Pcgf3/5 deficiencies, we found that in contrast to the canonical role of the related polycomb repressive complex 1 (PRC1) in gene repression, Pcgf3/5 mainly function as transcriptional activators driving expression of many genes involved in mesoderm differentiation. Proteomic approaches and promoter occupancy analyses helped to establish an extended Pcgf3/5 interactome and identified several novel Pcgf3/5 interactors. These included testis-expressed 10 (Tex10), which may directly contribute to transcriptional activation via the transcriptional co-activator p300. Furthermore, Pcgf3/5 deletion in ES cells substantially reduced the occupancy of Tex10 and p300 at target genes. Finally, we demonstrated that Pcgf3/5 are essential for regulating global levels of the histone modifier H2AK119ub1 in ES cells. Our findings establish Pcgf3/5 as transcriptional activators that interact with Tex10 and p300 in ES cells and point to redundant activity of Pcgf3/5 in pluripotency maintenance.


Assuntos
Proteínas do Grupo Polycomb/metabolismo , Animais , Diferenciação Celular/genética , Linhagem Celular , Histonas/metabolismo , Camundongos , Células-Tronco Embrionárias Murinas/citologia , Proteínas Nucleares/metabolismo , Complexo Repressor Polycomb 1/metabolismo , Proteínas do Grupo Polycomb/genética , Proteínas do Grupo Polycomb/fisiologia , Regiões Promotoras Genéticas/genética , Ativação Transcricional/fisiologia
13.
Infect Immun ; 86(4)2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29358333

RESUMO

Ehrlichia chaffeensis has a group of well-characterized type I secreted tandem repeat protein (TRP) effectors that have moonlighting capabilities. TRPs modulate various cellular processes, reprogram host gene transcription as nucleomodulins, function as ubiquitin ligases, and directly activate conserved host cell signaling pathways to promote E. chaffeensis infection. One TRP-interacting host target is polycomb group ring finger protein 5 (PCGF5), a member of the polycomb group (PcG) protein family and a component of the polycomb repressive complex 1 (PRC1). The current study demonstrates that during early infection, PCGF5 strongly colocalizes with TRP120 in the nucleus and later dramatically redistributes to the ehrlichial vacuole along with other PCGF isoforms. Ectopic expression and immunoprecipitation of TRP120 confirmed the interaction of TRP120 with multiple different PCGF isoforms. At 48 h postinfection, a dramatic redistribution of PCGF isoforms from the nucleus to the ehrlichial vacuole was observed, which also temporally coincided with proteasomal degradation of PCGF isoforms and TRP120 expression on the vacuole. A decrease in PRC1-mediated repressive chromatin mark and an altered transcriptional activity in PRC1-associated Hox genes primarily from HOXB and HOXC clusters were observed along with the degradation of PCGF isoforms, suggesting disruption of the PRC1 in E. chaffeensis-infected cells. Notably, small interfering RNA (siRNA)-mediated knockdown of PCGF isoforms resulted in significantly increased E. chaffeensis infection. This study demonstrates a novel strategy in which E. chaffeensis manipulates PRC complexes through interactions between TRP120 and PCGF isoforms to promote infection.


Assuntos
Ehrlichia chaffeensis/fisiologia , Ehrlichiose/metabolismo , Ehrlichiose/microbiologia , Interações Hospedeiro-Patógeno , Proteínas do Grupo Polycomb/metabolismo , Proteínas de Ciclo Celular/metabolismo , Núcleo Celular/metabolismo , Rastreamento de Células , Ehrlichiose/genética , Genes Homeobox , Histonas/metabolismo , Interações Hospedeiro-Patógeno/genética , Humanos , Macrófagos/metabolismo , Macrófagos/microbiologia , Proteínas do Grupo Polycomb/genética , Isoformas de Proteínas , Proteólise
14.
Biochim Biophys Acta ; 1863(7 Pt A): 1499-509, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27030546

RESUMO

Arsenic trioxide (ATO) is a therapeutic agent for acute promyelocytic leukemia (APL) which induces PML-RARA protein degradation via enhanced UBE2I-mediated sumoylation. PCGF2, a Polycomb group protein, has been suggested as an anti-SUMO E3 protein by inhibiting the sumoylation of UBE2I substrates, HSF2 and RANGAP1, via direct interaction. Thus, we hypothesized that PCGF2 might play a role in ATO-induced PML-RARA degradation by interacting with UBE2I. PCGF2 protein was down-regulated upon ATO treatment in human APL cell line, NB4. Knockdown of PCGF2 in NB4 cells, in the absence of ATO treatment, was sufficient to induce sumoylation-, ubiquitylation- and PML nuclear body-mediated degradation of PML-RARA protein. Moreover, overexpression of PCGF2 protected ATO-mediated degradation of ectopic and endogenous PML-RARA in 293T and NB4 cells, respectively. In 293T cells, UBE2I-mediated PML-RARA degradation was reduced upon PCGF2 co-expression. In addition, UBE2I-mediated sumoylation of PML-RARA was reduced upon PCGF2 co-expression and PCGF2-UBE2I interaction was confirmed by co-immunoprecipitation. Likewise, endogenous PCGF2-UBE2I interaction was detected by co-immunoprecipitation and immunofluorescence assays in NB4 cells. Intriguingly, upon ATO-treatment, such interaction was disrupted and UBE2I was co-immunoprecipitated or co-localized with its SUMO substrate, PML-RARA. Taken together, our results suggested a novel role of PCGF2 in ATO-mediated degradation of PML-RARA that PCGF2 might act as a negative regulator of UBE2I via direct interaction.


Assuntos
Antineoplásicos/farmacologia , Arsenicais/farmacologia , Leucemia Promielocítica Aguda/tratamento farmacológico , Proteínas de Fusão Oncogênica/metabolismo , Óxidos/farmacologia , Complexo Repressor Polycomb 1/metabolismo , Enzimas de Conjugação de Ubiquitina/metabolismo , Trióxido de Arsênio , Linhagem Celular Tumoral , Imunofluorescência , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Humanos , Imunoprecipitação , Leucemia Promielocítica Aguda/enzimologia , Leucemia Promielocítica Aguda/genética , Leucemia Promielocítica Aguda/patologia , Proteínas de Fusão Oncogênica/genética , Complexo Repressor Polycomb 1/genética , Ligação Proteica , Proteólise , Interferência de RNA , Transdução de Sinais/efeitos dos fármacos , Sumoilação , Fatores de Tempo , Transfecção , Enzimas de Conjugação de Ubiquitina/genética , Ubiquitinação
15.
Stem Cells ; 32(12): 3112-25, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25187489

RESUMO

Polycomb group (PcG) proteins comprise evolutionary conserved factors with essential functions for embryonic development and adult stem cells. PcG proteins constitute two main multiprotein polycomb repressive complexes (PRC1 and PRC2) that operate in a hierarchical manner to silence gene transcription. Functionally distinct PRC1 complexes are defined by Polycomb group RING finger protein (Pcgf) paralogs. So far, six Pcgf paralogs (Pcgf1-6) have been identified as defining components of different PCR1-type complexes. Paralog-specific functions are not well understood. Here, we show that Pcgf6 is the only Pcgf paralog with high expression in undifferentiated embryonic stem cells (ESCs). Upon differentiation Pcgf6 expression declines. Following Pcgf6 kockdown (KD) in ESCs, the expression of pluripotency genes decreased, while mesodermal- and spermatogenesis-specific genes were derepressed. Concomitantly with the elevated expression of mesodermal lineage markers, Pcgf6 KD ESCs showed increased hemangioblastic and hematopoietic activities upon differentiation suggesting a function of Pcgf6 in repressing mesodermal-specific lineage genes. Consistant with a role in pluripotency, Pcgf6 replaced Sox2 in the generation of germline-competent induced pluripotent stem (iPS) cells. Furthermore, Pcgf6 KD in mouse embryonic fibroblasts reduced the formation of ESC-like colonies in OSKM-driven reprogramming. Together, these analyses indicate that Pcgf6 is nonredundantly involved in maintaining the pluripotent nature of ESCs and it functions in iPS reprogramming.


Assuntos
Diferenciação Celular/fisiologia , Reprogramação Celular , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Embrionárias Murinas/metabolismo , Complexo Repressor Polycomb 1/metabolismo , Animais , Linhagem Celular , Linhagem da Célula , Camundongos , Camundongos Endogâmicos C57BL , Complexos Multiproteicos/metabolismo
16.
Heliyon ; 10(6): e27634, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38533065

RESUMO

Polycomb group RING finger (PCGF) proteins, a crucial subunits of the Polycomb complex, plays an important role in regulating gene expression, embryonic development, and cell fate determination. In our research, we investigated Pcgf5, one of the six PCGF homologs, and its impact on the differentiation of P19 cells into neural stem cells. Our findings revealed that knockdown of Pcgf5 resulted in a significant decrease in the expression levels of the neuronal markers Sox2, Zfp521, and Pax6, while the expression levels of the pluripotent markers Oct4 and Nanog increased. Conversely, Pcgf5 overexpression upregulated the expression of Sox2 and Pax6, while downregulating the expression of Oct4 and Nanog. Additionally, our analysis revealed that Pcgf5 suppresses Wnt3 expression via the activation of Notch1/Hes1, and ultimately governs the differentiation fate of neural stem cells. To further validate our findings, we conducted in vivo experiments in zebrafish. We found that knockdown of pcgf5a using morpholino resulted in the downregulated expression of neurodevelopmental genes such as sox2, sox3, and foxg1 in zebrafish embryos. Consequently, these changes led to neurodevelopmental defects. In conclusion, our study highlights the important role of Pcgf5 in neural induction and the determination of neural cell fate.

17.
Cureus ; 16(1): e53099, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38283775

RESUMO

Turnpenny-Fry Syndrome (TPFS) is a rare genetic disorder characterized by a severe developmental delay and a distinctive facial gestalt. It is caused by mutations in the Polycomb Group Ring Finger Protein 2 (PCGF2) gene, which is also known to play a role in numerous tumor types. Up to date, there have been no published case reports of patients with TPFS and concomitant malignancies. The present case describes the clinical evaluation and follow-up of a male infant with severe global developmental delay (GDD) and a distinctive phenotype. At 4 years of age, clinical exome sequencing confirmed the diagnosis of TPFS. Posteriorly, at 5 years of age, the patient was also diagnosed with T-cell acute lymphoblastic leukemia (ALL). Given the scarce literature regarding this syndrome, the authors expect that this case report will provide valuable information that could improve the follow-up of patients with TPFS. Furthermore, this case highlights the necessity for the appropriate diagnosis of developmental disorders, to ensure adequate care, surveillance of comorbidities and proper genetic counselling.

18.
Dev Cell ; 59(3): 368-383.e7, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38228142

RESUMO

Cell fate is determined by specific transcription programs that are essential for tissue homeostasis and regeneration. The E3-ligases RING1A and B represent the core activity of the Polycomb repressive complex 1 (PRC1) that deposits repressive histone H2AK119 mono-ubiquitination (H2AK119ub1), which is essential for mouse intestinal homeostasis by preserving stem cell functions. However, the specific role of different PRC1 forms, which are defined by the six distinct PCGF1-6 paralogs, remains largely unexplored in vivo. We report that PCGF6 regulates mouse intestinal Tuft cell differentiation independently of H2AK119ub1 deposition. We show that PCGF6 chromatin occupancy expands outside Polycomb repressive domains, associating with unique promoter and distal regulatory elements. This occurs in the absence of RING1A/B and involves MGA-mediated E-BOX recognition and specific H3K9me2 promoter deposition. PCGF6 inactivation induces an epithelial autonomous accumulation of Tuft cells that was not phenocopied by RING1A/B loss. This involves direct PCGF6 association with a Tuft cell differentiation program that identified Polycomb-independent properties of PCGF6 in adult tissues homeostasis.


Assuntos
Complexo Repressor Polycomb 1 , Células em Tufo , Animais , Camundongos , Diferenciação Celular/fisiologia , Proteínas do Grupo Polycomb , Ubiquitina-Proteína Ligases
19.
Epigenetics Chromatin ; 16(1): 9, 2023 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-36890610

RESUMO

Polycomb group RING finger protein 6 (PCGF6) plays an important role as a regulator of transcription in a variety of cellular processes, including tumorigenesis. However, the function and expression of PCGF6 in papillary RCC (pRCC) remain unclear. In the present study, we found that PCGF6 expression was significantly elevated in pRCC tissues, and high expression of PCGF6 was associated with poor survival of patients with pRCC. The overexpression of PCGF6 promoted while depletion of PCGF6 depressed the proliferation of pRCC cells in vitro. Interestingly, myc-related zinc finger protein (MAZ), a downstream molecular of PCGF6, was upregulated in pRCC with hypomethylation promoter. Mechanically, PCGF6 promoted MAZ expression by interacting with MAX and KDM5D to form a complex, and MAX recruited PCGF6 and KDM5D to the CpG island of the MAZ promoter and facilitated H3K4 histone demethylation. Furthermore, CDK4 was a downstream molecule of MAZ that participated in PCGF6/MAZ-regulated progression of pRCC. These results indicated that the upregulation of PCGF6 facilitated MAZ/CDK4 axis expression and pRCC progression by hypomethylation of the MAZ promoter. The PCGF6/MAZ/CDK4 regulatory axis may be a potential target for the treatment of ccRCC.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Fatores de Transcrição/metabolismo , Proteínas de Ligação a DNA/metabolismo , DNA , Complexo Repressor Polycomb 1/metabolismo , Antígenos de Histocompatibilidade Menor , Histona Desmetilases , Quinase 4 Dependente de Ciclina/genética
20.
Ann Transl Med ; 10(4): 227, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35280367

RESUMO

Background: Polycomb group factor 1 (PCGF1) plays a vital role in the self-renewal of cancer stem cells (CSCs). However, the prognostic value and potential function of PCGF1 in glioma progression, especially in tumor immunity, remain unclear. Methods: This study investigated PCGF1 expression in pan-cancers and glioma using The Cancer Genome Atlas Project data, and conducted a logistic regression analysis to analyze the association between PCGF1 expression and the clinicopathological features of glioma patients. Kaplan-Meier and Cox regression analyses were used to assess the prognostic roles of PCGF1. The functional analysis using gene ontology and Kyoto Encyclopedia of Genes and Genomes databases and a gene set enrichment analysis (GSEA) were conducted to examine the PCGF1-related biological processes and signaling pathways. Finally, the roles of PCGF1 in immune infiltration were analyzed by a single sample GSEA (ssGSEA). Results: PCGF1 expression was upregulated in glioma tissues. The high expression of PCGF1 was significantly associated with an age >60 years (P<0.001), an increased World Health Organization grade (P<0.001), and wildtype isocitrate dehydrogenase (IDH) status (P<0.001), and predicted poor overall survival (OS) [hazards ratio (HR) =2.90, 95% confidence interval (CI): 2.25-3.74; P<0.001], the progression-free interval (PFI) (HR =1.99, 95% CI: 1.60-2.46; P<0.001), and disease specific survival (DSS) (HR =2.84, 95% CI: 2.18-3.71; P<0.001). The multivariate regression analysis confirmed that PCGF1 expression was an independent prognostic factor of OS (HR =1.581, 95% CI: 1.161-2.153; P=0.004). Based on the functional enrichment analysis, we identified the PCGF1-related differentially expressed genes (DEGs), and found that PCGF1 was involved in regulating many oncogenic signaling pathways, such as the phosphatidylinositol 3-kinase and protein kinase B pathway, the Janus kinase/signal transducers and activators of transcription (JKT-STAT) signaling pathway, notch signaling and integrin signaling pathway. In addition, we found that PCGF1 expression was positively associated with the abundance of Th2, but negatively associated with T follicular helper, T central memory, and T gamma delta cells. Additionally, PCGF1 participated in the regulation of numerous immune-related processes in glioma. Conclusions: PCGF1 is a promising prognostic biomarker, and as it governs cancer-related pathways and tumor immunity, it plays an important role in glioma development.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA