Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.933
Filtrar
1.
Proc Natl Acad Sci U S A ; 118(38)2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34479991

RESUMO

COVID-19 induces a robust, extended inflammatory "cytokine storm" that contributes to an increased morbidity and mortality, particularly in patients with type 2 diabetes (T2D). Macrophages are a key innate immune cell population responsible for the cytokine storm that has been shown, in T2D, to promote excess inflammation in response to infection. Using peripheral monocytes and sera from human patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and a murine hepatitis coronavirus (MHV-A59) (an established murine model of SARS), we identified that coronavirus induces an increased Mφ-mediated inflammatory response due to a coronavirus-induced decrease in the histone methyltransferase, SETDB2. This decrease in SETDB2 upon coronavirus infection results in a decrease of the repressive trimethylation of histone 3 lysine 9 (H3K9me3) at NFkB binding sites on inflammatory gene promoters, effectively increasing inflammation. Mφs isolated from mice with a myeloid-specific deletion of SETDB2 displayed increased pathologic inflammation following coronavirus infection. Further, IFNß directly regulates SETDB2 in Mφs via JaK1/STAT3 signaling, as blockade of this pathway altered SETDB2 and the inflammatory response to coronavirus infection. Importantly, we also found that loss of SETDB2 mediates an increased inflammatory response in diabetic Mϕs in response to coronavirus infection. Treatment of coronavirus-infected diabetic Mφs with IFNß reversed the inflammatory cytokine production via up-regulation of SETDB2/H3K9me3 on inflammatory gene promoters. Together, these results describe a potential mechanism for the increased Mφ-mediated cytokine storm in patients with T2D in response to COVID-19 and suggest that therapeutic targeting of the IFNß/SETDB2 axis in T2D patients may decrease pathologic inflammation associated with COVID-19.


Assuntos
Coronavirus/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Mediadores da Inflamação/metabolismo , Inflamação/virologia , Macrófagos/metabolismo , Animais , COVID-19/imunologia , Infecções por Coronavirus/genética , Infecções por Coronavirus/imunologia , Síndrome da Liberação de Citocina , Citocinas/metabolismo , Diabetes Mellitus Tipo 2/genética , Feminino , Histona-Lisina N-Metiltransferase/genética , Humanos , Inflamação/metabolismo , Inflamação/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , SARS-CoV-2/metabolismo , Transdução de Sinais
2.
Nat Commun ; 12(1): 5450, 2021 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-34521827

RESUMO

Multiple myeloma is a genetically heterogeneous cancer of the bone marrow plasma cells (PC). Distinct myeloma transcriptome profiles are primarily driven by myeloma initiating events (MIE) and converge into a mutually exclusive overexpression of the CCND1 and CCND2 oncogenes. Here, with reference to their normal counterparts, we find that myeloma PC enhanced chromatin accessibility combined with paired transcriptome profiling can classify MIE-defined genetic subgroups. Across and within different MM genetic subgroups, we ascribe regulation of genes and pathways critical for myeloma biology to unique or shared, developmentally activated or de novo formed candidate enhancers. Such enhancers co-opt recruitment of existing transcription factors, which although not transcriptionally deregulated per se, organise aberrant gene regulatory networks that help identify myeloma cell dependencies with prognostic impact. Finally, we identify and validate the critical super-enhancer that regulates ectopic expression of CCND2 in a subset of patients with MM and in chronic lymphocytic leukemia.


Assuntos
Carcinogênese/genética , Ciclina D1/genética , Ciclina D2/genética , Regulação Neoplásica da Expressão Gênica , Leucemia Linfocítica Crônica de Células B/genética , Mieloma Múltiplo/genética , Transcriptoma , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Carcinogênese/metabolismo , Carcinogênese/patologia , Estudos de Casos e Controles , Linhagem Celular Tumoral , Cromatina/química , Cromatina/metabolismo , Ciclina D1/metabolismo , Ciclina D2/metabolismo , Elementos Facilitadores Genéticos , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/mortalidade , Leucemia Linfocítica Crônica de Células B/patologia , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/mortalidade , Mieloma Múltiplo/patologia , Plasmócitos/metabolismo , Plasmócitos/patologia , Proteínas Proto-Oncogênicas c-maf/genética , Proteínas Proto-Oncogênicas c-maf/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Análise de Sobrevida
3.
Nat Commun ; 12(1): 4800, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34417450

RESUMO

Histone lysine methylations have primarily been linked to selective recruitment of reader or effector proteins that subsequently modify chromatin regions and mediate genome functions. Here, we describe a divergent role for histone H4 lysine 20 mono-methylation (H4K20me1) and demonstrate that it directly facilitates chromatin openness and accessibility by disrupting chromatin folding. Thus, accumulation of H4K20me1 demarcates highly accessible chromatin at genes, and this is maintained throughout the cell cycle. In vitro, H4K20me1-containing nucleosomal arrays with nucleosome repeat lengths (NRL) of 187 and 197 are less compact than unmethylated (H4K20me0) or trimethylated (H4K20me3) arrays. Concordantly, and in contrast to trimethylated and unmethylated tails, solid-state NMR data shows that H4K20 mono-methylation changes the H4 conformational state and leads to more dynamic histone H4-tails. Notably, the increased chromatin accessibility mediated by H4K20me1 facilitates gene expression, particularly of housekeeping genes. Altogether, we show how the methylation state of a single histone H4 residue operates as a focal point in chromatin structure control. While H4K20me1 directly promotes chromatin openness at highly transcribed genes, it also serves as a stepping-stone for H4K20me3-dependent chromatin compaction.


Assuntos
Cromatina/metabolismo , Genes Essenciais , Histonas/metabolismo , Lisina/metabolismo , Transcrição Genética , Sequência de Aminoácidos , Animais , Ciclo Celular/genética , Linhagem Celular , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/química , Humanos , Espectroscopia de Ressonância Magnética , Metilação , Camundongos , Modelos Biológicos , Nucleossomos/metabolismo , Conformação Proteica
4.
Biochim Biophys Acta Gene Regul Mech ; 1864(10): 194744, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34389510

RESUMO

The antigenic variation is an essential mechanism employed by the malaria parasite to establish a chronic infection in humans. Three major virulent proteins EMP1, RIFINs, and STEVOR have been implicated in contributing to the antigenic variation process and are encoded by multigene families in Plasmodium spp. The key virulence factor PfEMP1 is encoded by var genes, and it exhibits a mutually exclusive transcriptional switching between var genes, ensuring an individual parasite only transcribes a single var gene at a time. Expression of var genes is tightly regulated by two histone epigenetic methylation marks H3K36me3 and H3K9me3, of which the H3K36me3 mark is highly enriched on transcription start sites (TSSs) of suppressed var genes in P. falciparum. However, the mechanisms of H3K36me3 mark propagation on all the 59 var genes of P. falciparum are not known. Here, we have identified a PHD (Plant Homeodomain-like Domain) like domain present within the PfSET2 protein that specifically binds to the H3K36me2 mark, an intermediate product of the H3K36me3 mark formation on the nucleosome. Surprisingly, we have found that PHD - H3K36me2 interaction leads to stimulation of SET2 domain activity on the nucleosome substrates. The allosteric stimulation of the PfSET2 domain by PHD-like domain present within the same protein suggests a novel mechanism of H3K36me3 mark propagation on var genes of P. falciparum. This study proposes allosteric regulation of PfSET2 protein by H3K36me2 mark as an essential mechanism of var genes suppression to ensure successful antigenic variation by the malaria parasite.


Assuntos
Código das Histonas , Histona-Lisina N-Metiltransferase/química , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Plasmodium falciparum/enzimologia , Proteínas de Protozoários/química , Proteínas de Protozoários/metabolismo , Regulação Alostérica , Metilação , Nucleossomos/enzimologia , Domínios Proteicos
5.
Elife ; 102021 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-34431785

RESUMO

Leukemic oncoproteins cause uncontrolled self-renewal of hematopoietic progenitors by aberrant gene activation, eventually causing leukemia. However, the molecular mechanism underlying aberrant gene activation remains elusive. Here, we showed that leukemic MLL fusion proteins associate with the HBO1 histone acetyltransferase (HAT) complex through their trithorax homology domain 2 (THD2) in various human cell lines. MLL proteins associated with the HBO1 complex through multiple contacts mediated mainly by the ING4/5 and PHF16 subunits in a chromatin-bound context where histone H3 lysine 4 tri-methylation marks were present. Of the many MLL fusions, MLL-ELL particularly depended on the THD2-mediated association with the HBO1 complex for leukemic transformation. The C-terminal portion of ELL provided a binding platform for multiple factors including AF4, EAF1, and p53. MLL-ELL activated gene expression in murine hematopoietic progenitors by loading an AF4/ENL/P-TEFb (AEP) complex onto the target promoters wherein the HBO1 complex promoted the association with AEP complex over EAF1 and p53. Moreover, the NUP98-HBO1 fusion protein exerted its oncogenic properties via interaction with MLL but not its intrinsic HAT activity. Thus, the interaction between the HBO1 complex and MLL is an important nexus in leukemic transformation, which may serve as a therapeutic target for drug development.


Assuntos
Carcinogênese/genética , Histona Acetiltransferases/genética , Histona-Lisina N-Metiltransferase/genética , Leucemia/genética , Proteína de Leucina Linfoide-Mieloide/genética , Animais , Transformação Celular Neoplásica , Feminino , Células HEK293 , Histona Acetiltransferases/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Proteína de Leucina Linfoide-Mieloide/metabolismo
6.
Cancer Sci ; 112(10): 3935-3944, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34251718

RESUMO

Homeostasis of the hematopoietic system is achieved in a hierarchy, with hematopoietic stem cells at the pinnacle. Because only hematopoietic stem cells (HSCs) can self-renew, the size of the hematopoietic system is strictly controlled. In hematopoietic reconstitution experiments, 1 HSC can reconstitute the entire hematopoietic system, whereas 50 multipotent progenitors cannot. This indicates that only HSCs self-renew, whereas non-HSC hematopoietic progenitors are programmed to differentiate or senesce. Oncogenic mutations of the mixed lineage leukemia gene (MLL) overcome this "programmed differentiation" by conferring the self-renewing ability to non-HSC hematopoietic progenitors. In leukemia, mutated MLL proteins constitutively activate a broad range of previously transcribed CpG-rich promoters by an MLL-mediated transcriptional activation system. This system promotes self-renewal by replicating an expression profile similar to that of the mother cell in its daughter cells. In this transcriptional activation system, MLL binds to unmethylated CpG-rich promoters and recruits RNA polymerase II. MLL recruits p300/CBP through its transcriptional activation domain, which acetylates histone H3 at lysines 9, 18, and 27. The AF4 family/ENL family/P-TEFb complex (AEP) binds to acetylated H3K9/18/27 to activate transcription. Gene rearrangements of MLL with AEP- or CBP/p300-complex components generate constitutively active transcriptional machinery of this transcriptional activation system, which causes aberrant self-renewal of leukemia stem cells. Inhibitors of the components of this system effectively decrease their leukemogenic potential.


Assuntos
Autorrenovação Celular/fisiologia , Células-Tronco Hematopoéticas/fisiologia , Histona-Lisina N-Metiltransferase/genética , Leucemia/etiologia , Proteína de Leucina Linfoide-Mieloide/genética , Ativação Transcricional/fisiologia , Acetilação , Diferenciação Celular , Autorrenovação Celular/genética , Senescência Celular , Ilhas de CpG/genética , Proteínas de Ligação a DNA/metabolismo , Proteína p300 Associada a E1A/metabolismo , Rearranjo Gênico , Hematopoese/fisiologia , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Humanos , Leucemia/prevenção & controle , Lisina/metabolismo , Células-Tronco Multipotentes/fisiologia , Mutação , Proteína de Leucina Linfoide-Mieloide/metabolismo , Fator B de Elongação Transcricional Positiva/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , RNA Polimerase II/metabolismo , Fatores de Elongação da Transcrição/metabolismo
7.
Int J Mol Sci ; 22(14)2021 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-34299035

RESUMO

SET domain bifurcated 1 (SETDB1) is a histone H3 lysine 9 (H3K9) methyltransferase that exerts important effects on epigenetic gene regulation. SETDB1 complexes (SETDB1-KRAB-KAP1, SETDB1-DNMT3A, SETDB1-PML, SETDB1-ATF7IP-MBD1) play crucial roles in the processes of histone methylation, transcriptional suppression and chromatin remodelling. Therefore, aberrant trimethylation at H3K9 due to amplification, mutation or deletion of SETDB1 may lead to transcriptional repression of various tumour-suppressing genes and other related genes in cancer cells. Lung cancer is the most common type of cancer worldwide in which SETDB1 amplification and H3K9 hypermethylation have been indicated as potential tumourigenesis markers. In contrast, frequent inactivation mutations of SETDB1 have been revealed in mesothelioma, an asbestos-associated, locally aggressive, highly lethal, and notoriously chemotherapy-resistant cancer. Above all, the different statuses of SETDB1 indicate that it may have different biological functions and be a potential diagnostic biomarker and therapeutic target in lung cancer and mesothelioma.


Assuntos
Histona-Lisina N-Metiltransferase/metabolismo , Neoplasias Pulmonares/patologia , Mesotelioma/patologia , Animais , Humanos , Neoplasias Pulmonares/metabolismo , Mesotelioma/metabolismo
8.
Nat Commun ; 12(1): 4359, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34272378

RESUMO

Histone H3 lysine 9 (H3K9) methylation is a central epigenetic modification that defines heterochromatin from unicellular to multicellular organisms. In mammalian cells, H3K9 methylation can be catalyzed by at least six distinct SET domain enzymes: Suv39h1/Suv39h2, Eset1/Eset2 and G9a/Glp. We used mouse embryonic fibroblasts (MEFs) with a conditional mutation for Eset1 and introduced progressive deletions for the other SET domain genes by CRISPR/Cas9 technology. Compound mutant MEFs for all six SET domain lysine methyltransferase (KMT) genes lack all H3K9 methylation states, derepress nearly all families of repeat elements and display genomic instabilities. Strikingly, the 6KO H3K9 KMT MEF cells no longer maintain heterochromatin organization and have lost electron-dense heterochromatin. This is a compelling analysis of H3K9 methylation-deficient mammalian chromatin and reveals a definitive function for H3K9 methylation in protecting heterochromatin organization and genome integrity.


Assuntos
Fibroblastos/metabolismo , Heterocromatina/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Lisina/metabolismo , Animais , Sistemas CRISPR-Cas , Sequenciamento de Cromatina por Imunoprecipitação , Cromatografia Líquida , Desmetilação , Epigênese Genética , Fibroblastos/enzimologia , Deleção de Genes , Heterocromatina/enzimologia , Heterocromatina/genética , Heterocromatina/ultraestrutura , Histona-Lisina N-Metiltransferase/genética , Hibridização in Situ Fluorescente , Espectrometria de Massas , Metilação , Camundongos , Microscopia Eletrônica de Transmissão , Mutação , Processamento de Proteína Pós-Traducional/genética , RNA-Seq , Sequências Repetitivas de Ácido Nucleico/genética , Retroelementos/genética , Transdução de Sinais/genética
9.
Eur J Med Chem ; 223: 113677, 2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34225179

RESUMO

MLL1-WDR5 interaction is essential for the formation of MLL core complex and its H3K4 methyltransferase activity. Disrupting MLL1-WDR5 interaction has been proposed as a potential therapeutic approach in the treatment of leukemia. A "toolkit" of well-characterized chemical probe will allow exploring animal studies. Based on a specific MLL1-WDR5 PPI inhibitor (DDO-2117), which was previously reported by our group, we conducted a bioisosterism approach by click chemistry to discover novel phenyltriazole scaffold MLL1-WDR5 interaction blockers. Here, our efforts resulted in the best inhibitor 24 (DDO-2093) with high binding affinity (Kd = 11.6 nM) and with improved drug-like properties. Both in vitro and in vivo assays revealed 24 could efficiently block the MLL1-WDR5 interaction. Furthermore, 24 significantly suppressed tumor growth in the MV4-11 xenograft mouse model and showed a favorable safety profile. We propose 24 as a chemical probe that is suitable for in vivo pharmacodynamic and biological studies of MLL1-WDR5 interaction.


Assuntos
Antineoplásicos/química , Histona-Lisina N-Metiltransferase/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteína de Leucina Linfoide-Mieloide/metabolismo , Animais , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Sítios de Ligação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Cinética , Camundongos , Camundongos Nus , Simulação de Acoplamento Molecular , Proteína de Leucina Linfoide-Mieloide/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Ligação Proteica , Mapas de Interação de Proteínas/efeitos dos fármacos , Relação Estrutura-Atividade , Transplante Heterólogo , Triazóis/química , Triazóis/metabolismo , Triazóis/farmacologia , Triazóis/uso terapêutico
10.
Nat Commun ; 12(1): 4113, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-34226540

RESUMO

Tri-methylation on lysine 40 of α-tubulin (α-TubK40me3) is a recently identified post-translational modification involved in mitosis and cytokinesis. However, knowledge about α-TubK40me3 in microtubule function and post-mitotic cells remains largely incomplete. Here, we report that α-TubK40me3 is required for neuronal polarization and migration by promoting microtubule formation. α-TubK40me3 is enriched in mouse cerebral cortex during embryonic day (E)14 to E16. Knockdown of α-tubulin methyltransferase SETD2 at E14 leads to the defects in neuronal migration, which could be restored by overexpressing either a cytoplasm-localized SETD2 truncation or α-TubK40me3-mimicking mutant. Furthermore, α-TubK40me3 is preferably distributed on polymerized microtubules and potently promotes tubulin nucleation. Downregulation of α-TubK40me3 results in reduced microtubule abundance in neurites and disrupts neuronal polarization, which could be rescued by Taxol. Additionally, α-TubK40me3 is increased after losing α-tubulin K40 acetylation (α-TubK40ac) and largely rescues α-TubK40ac function. This study reveals a critical role of α-TubK40me3 in microtubule formation and neuronal development.


Assuntos
Movimento Celular , Microtúbulos/metabolismo , Neurônios/metabolismo , Tubulina (Proteína)/metabolismo , Acetilação , Animais , Córtex Cerebral , Citocinese , Técnicas de Silenciamento de Genes , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Lisina/metabolismo , Metilação , Camundongos , Mitose , Neurogênese , Paclitaxel , Processamento de Proteína Pós-Traducional
11.
Int J Mol Sci ; 22(14)2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34299101

RESUMO

Children with the new coronavirus disease 2019 (COVID-19) have milder symptoms and a better prognosis than adult patients. Several investigations assessed type I, II, and III interferon (IFN) signatures in SARS-CoV-2 infected adults, however no data are available for pediatric patients. TRIM28 and SETDB1 regulate the transcription of multiple genes involved in the immune response as well as of human endogenous retroviruses (HERVs). Exogenous viral infections can trigger the activation of HERVs, which in turn can induce inflammatory and immune reactions. Despite the potential cross-talks between SARS-CoV-2 infection and TRIM28, SETDB1, and HERVs, information on their expressions in COVID-19 patients is lacking. We assessed, through a PCR real time Taqman amplification assay, the transcription levels of six IFN-I stimulated genes, IFN-II and three of its sensitive genes, three IFN-lIIs, as well as of TRIM28, SETDB1, pol genes of HERV-H, -K, and -W families, and of env genes of Syncytin (SYN)1, SYN2, and multiple sclerosis-associated retrovirus (MRSV) in peripheral blood from COVID-19 children and in control uninfected subjects. Higher expression levels of IFN-I and IFN-II inducible genes were observed in 36 COVID-19 children with mild or moderate disease as compared to uninfected controls, whereas their concentrations decreased in 17 children with severe disease and in 11 with multisystem inflammatory syndrome (MIS-C). Similar findings were found for the expression of TRIM-28, SETDB1, and every HERV gene. Positive correlations emerged between the transcriptional levels of type I and II IFNs, TRIM28, SETDB1, and HERVs in COVID-19 patients. IFN-III expressions were comparable in each group of subjects. This preserved induction of IFN-λs could contribute to the better control of the infection in children as compared to adults, in whom IFN-III deficiency has been reported. The upregulation of IFN-I, IFN-II, TRIM28, SETDB1, and HERVs in children with mild symptoms, their declines in severe cases or with MIS-C, and the positive correlations of their transcription in SARS-CoV-2-infected children suggest that they may play important roles in conditioning the evolution of the infection.


Assuntos
COVID-19/epidemiologia , COVID-19/metabolismo , Retrovirus Endógenos/metabolismo , SARS-CoV-2/isolamento & purificação , Índice de Gravidade de Doença , COVID-19/patologia , COVID-19/virologia , Estudos de Casos e Controles , Criança , Retrovirus Endógenos/genética , Feminino , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Interferon Tipo I/genética , Interferon Tipo I/metabolismo , Interferon gama/genética , Interferon gama/metabolismo , Interferons/genética , Interferons/metabolismo , Itália/epidemiologia , Masculino , Proteína 28 com Motivo Tripartido/genética , Proteína 28 com Motivo Tripartido/metabolismo
12.
Nat Genet ; 53(7): 1022-1035, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34155378

RESUMO

Hypoxia-inducible transcription factors (HIFs) are fundamental to cellular adaptation to low oxygen levels, but it is unclear how they interact with chromatin and activate their target genes. Here, we use genome-wide mutagenesis to identify genes involved in HIF transcriptional activity, and define a requirement for the histone H3 lysine 4 (H3K4) methyltransferase SET1B. SET1B loss leads to a selective reduction in transcriptional activation of HIF target genes, resulting in impaired cell growth, angiogenesis and tumor establishment in SET1B-deficient xenografts. Mechanistically, we show that SET1B accumulates on chromatin in hypoxia, and is recruited to HIF target genes by the HIF complex. The selective induction of H3K4 trimethylation at HIF target loci is both HIF- and SET1B-dependent and, when impaired, correlates with decreased promoter acetylation and gene expression. Together, these findings show SET1B as a determinant of site-specific histone methylation and provide insight into how HIF target genes are differentially regulated.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Regulação da Expressão Gênica , Histona-Lisina N-Metiltransferase/metabolismo , Hipóxia/genética , Acetilação , Animais , Humanos , Hipóxia/metabolismo , Metilação , Camundongos , Camundongos Knockout , Modelos Animais , Regiões Promotoras Genéticas , Ligação Proteica
13.
Cell Death Dis ; 12(7): 633, 2021 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-34148069

RESUMO

Colorectal cancer (CRC) stem cells are resistant to cancer therapy and are therefore responsible for tumour progression after conventional therapy fails. However, the molecular mechanisms underlying the maintenance of stemness are poorly understood. In this study, we identified PCGF1 as a crucial epigenetic regulator that sustains the stem cell-like phenotype of CRC. PCGF1 expression was increased in CRC and was significantly correlated with cancer progression and poor prognosis in CRC patients. PCGF1 knockdown inhibited CRC stem cell proliferation and CRC stem cell enrichment. Importantly, PCGF1 silencing impaired tumour growth in vivo. Mechanistically, PCGF1 bound to the promoters of CRC stem cell markers and activated their transcription by increasing the H3K4 histone trimethylation (H3K4me3) marks and decreasing the H3K27 histone trimethylation (H3K27me3) marks on their promoters by increasing expression of the H3K4me3 methyltransferase KMT2A and the H3K27me3 demethylase KDM6A. Our findings suggest that PCGF1 is a potential therapeutic target for CRC treatment.


Assuntos
Neoplasias Colorretais/enzimologia , Metilação de DNA , Epigênese Genética , Células-Tronco Neoplásicas/enzimologia , Complexo Repressor Polycomb 1/metabolismo , Animais , Proliferação de Células , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteína de Leucina Linfoide-Mieloide/genética , Proteína de Leucina Linfoide-Mieloide/metabolismo , Células-Tronco Neoplásicas/patologia , Fenótipo , Complexo Repressor Polycomb 1/genética , Carga Tumoral , Microambiente Tumoral
14.
PLoS Biol ; 19(6): e3001297, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34111112

RESUMO

Recent studies have shown that long noncoding RNAs (lncRNAs) are critical regulators in the central nervous system (CNS). However, their roles in the cerebellum are currently unclear. In this work, we identified the isoform 204 of lncRNA Gm2694 (designated as lncRNA-Promoting Methylation (lncRNA-PM)) is highly expressed in the cerebellum and derived from the antisense strand of the upstream region of Cerebellin-1 (Cbln1), a well-known critical cerebellar synaptic organizer. LncRNA-PM exhibits similar spatiotemporal expression pattern as Cbln1 in the postnatal mouse cerebellum and activates the transcription of Cbln1 through Pax6/Mll1-mediated H3K4me3. In mouse cerebellum, lncRNA-PM, Pax6/Mll1, and H3K4me3 are all associated with the regulatory regions of Cbln1. Knockdown of lncRNA-PM in cerebellum causes deficiencies in Cbln1 expression, cerebellar synaptic integrity, and motor function. Together, our work reveals an lncRNA-mediated transcriptional activation of Cbln1 through Pax6-Mll1-H3K4me3 and provides novel insights of the essential roles of lncRNA in the cerebellum.


Assuntos
Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Proteína de Leucina Linfoide-Mieloide/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Fator de Transcrição PAX6/metabolismo , Precursores de Proteínas/metabolismo , RNA Longo não Codificante/metabolismo , Sinapses/metabolismo , Processamento Alternativo/genética , Cerebelo/metabolismo , Regulação da Expressão Gênica , Células HEK293 , Histona-Lisina N-Metiltransferase/genética , Humanos , Atividade Motora , Proteína de Leucina Linfoide-Mieloide/genética , Neurônios/metabolismo , Terminações Pré-Sinápticas/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Longo não Codificante/genética , Ativação Transcricional/genética
15.
Development ; 148(11)2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34117888

RESUMO

Persistent loss of dietary protein usually signals a shutdown of key metabolic pathways. In Drosophila larvae that have reached a 'critical weight' and can pupariate to form viable adults, such a metabolic shutdown would needlessly lead to death. Inositol 1,4,5-trisphosphate-mediated calcium (IP3/Ca2+) release in some interneurons (vGlutVGN6341) allows Drosophila larvae to pupariate on a protein-deficient diet by partially circumventing this shutdown through upregulation of neuropeptide signaling and the expression of ecdysone synthesis genes. Here, we show that IP3/Ca2+ signals in vGlutVGN6341 neurons drive expression of Set2, a gene encoding Drosophila Histone 3 Lysine 36 methyltransferase. Furthermore, Set2 expression is required for larvae to pupariate in the absence of dietary protein. IP3/Ca2+ signal-driven Set2 expression upregulates key Ca2+-signaling genes through a novel positive-feedback loop. Transcriptomic studies, coupled with analysis of existing ChIP-seq datasets, identified genes from larval and pupal stages that normally exhibit robust H3K36 trimethyl marks on their gene bodies and concomitantly undergo stronger downregulation by knockdown of either the intracellular Ca2+ release channel IP3R or Set2. IP3/Ca2+ signals thus regulate gene expression through Set2-mediated H3K36 marks on select neuronal genes for the larval to pupal transition.


Assuntos
Sinalização do Cálcio/fisiologia , Proteínas de Drosophila/metabolismo , Drosophila/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Larva/metabolismo , Nutrientes , Pupa/metabolismo , Animais , Cálcio/metabolismo , Drosophila/embriologia , Drosophila/genética , Proteínas de Drosophila/genética , Regulação da Expressão Gênica no Desenvolvimento , Histona-Lisina N-Metiltransferase/genética , Receptores de Inositol 1,4,5-Trifosfato/genética , Interneurônios/metabolismo , Neurônios/metabolismo , Pupa/genética
16.
J Biol Chem ; 297(1): 100898, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34157286

RESUMO

Post-translational modifications to tubulin are important for many microtubule-based functions inside cells. It was recently shown that methylation of tubulin by the histone methyltransferase SETD2 occurs on mitotic spindle microtubules during cell division, with its absence resulting in mitotic defects. However, the catalytic mechanism of methyl addition to tubulin is unclear. We used a truncated version of human wild type SETD2 (tSETD2) containing the catalytic SET and C-terminal Set2-Rpb1-interacting (SRI) domains to investigate the biochemical mechanism of tubulin methylation. We found that recombinant tSETD2 had a higher activity toward tubulin dimers than polymerized microtubules. Using recombinant single-isotype tubulin, we demonstrated that methylation was restricted to lysine 40 of α-tubulin. We then introduced pathogenic mutations into tSETD2 to probe the recognition of histone and tubulin substrates. A mutation in the catalytic domain (R1625C) allowed tSETD2 to bind to tubulin but not methylate it, whereas a mutation in the SRI domain (R2510H) caused loss of both tubulin binding and methylation. Further investigation of the role of the SRI domain in substrate binding found that mutations within this region had differential effects on the ability of tSETD2 to bind to tubulin versus the binding partner RNA polymerase II for methylating histones in vivo, suggesting distinct mechanisms for tubulin and histone methylation by SETD2. Finally, we found that substrate recognition also requires the negatively charged C-terminal tail of α-tubulin. Together, this study provides a framework for understanding how SETD2 serves as a dual methyltransferase for both histone and tubulin methylation.


Assuntos
Domínio Catalítico , Histona-Lisina N-Metiltransferase/química , Tubulina (Proteína)/metabolismo , Animais , Células COS , Chlorocebus aethiops , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Humanos , Metilação , Mutação , Ligação Proteica , Processamento de Proteína Pós-Traducional
17.
J Med Chem ; 64(12): 8221-8245, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-34105966

RESUMO

WD repeat-containing protein 5 (WDR5) is essential for the stability and methyltransferase activity of the mixed lineage leukemia 1 (MLL1) complex. Dysregulation of the MLL1 gene is associated with human acute leukemias, and the direct disruption of the WDR5-MLL1 protein-protein interaction (PPI) is emerging as an alternative strategy for MLL-rearranged cancers. Here, we represent a new aniline pyrimidine scaffold for WDR5-MLL1 inhibitors. A comprehensive structure-activity analysis identified a potent inhibitor 63 (DDO-2213), with an IC50 of 29 nM in a competitive fluorescence polarization assay and a Kd value of 72.9 nM for the WDR5 protein. Compound 63 selectively inhibited MLL histone methyltransferase activity and the proliferation of MLL translocation-harboring cells. Furthermore, 63 displayed good pharmacokinetic properties and suppressed the growth of MV4-11 xenograft tumors in mice after oral administration, first verifying the in vivo efficacy of targeting the WDR5-MLL1 PPI by small molecules.


Assuntos
Antineoplásicos/uso terapêutico , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Leucemia/tratamento farmacológico , Proteína de Leucina Linfoide-Mieloide/antagonistas & inibidores , Ligação Proteica/efeitos dos fármacos , Compostos de Anilina/síntese química , Compostos de Anilina/metabolismo , Compostos de Anilina/farmacocinética , Compostos de Anilina/uso terapêutico , Animais , Antineoplásicos/síntese química , Antineoplásicos/metabolismo , Antineoplásicos/farmacocinética , Proliferação de Células/efeitos dos fármacos , Estabilidade de Medicamentos , Feminino , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Camundongos Endogâmicos BALB C , Microssomos Hepáticos/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Proteína de Leucina Linfoide-Mieloide/metabolismo , Pirimidinas/síntese química , Pirimidinas/metabolismo , Pirimidinas/farmacocinética , Pirimidinas/uso terapêutico , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Chem Commun (Camb) ; 57(55): 6788-6791, 2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34137401

RESUMO

Histone lysine methylation and acetylation are important posttranslational modifications that regulate gene expression in humans. Due to the interplay of these two modifications, new chemical methods to study lysine posttranslational modifications are highly desired. Here, we report the use of γ-difluorolysine as a lysine mimic and 19F NMR probe for examinations of histone methylation and acetylation.


Assuntos
Histona Acetiltransferases/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Lisina/química , Espectroscopia de Ressonância Magnética/métodos , Acetilação , Metilação
19.
DNA Repair (Amst) ; 105: 103159, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34174709

RESUMO

DNA replication is a highly regulated process that occurs in the context of chromatin structure and is sensitive to several histone post-translational modifications. In Saccharomyces cerevisiae, the histone methylase Set1 is responsible for the transcription-dependent deposition of H3K4 methylation (H3K4me) throughout the genome. Here we show that a combination of a hypomorphic replication mutation (orc5-1) with the absence of Set1 (set1Δ) compromises the progression through S-phase, and this is associated with a large increase in DNA damage. The ensuing DNA damage checkpoint activation, in addition to that of the spindle assembly checkpoint, restricts the growth of orc5-1 set1Δ. The opposite effects of the lack of RNase H activity and the reduction of histone levels on orc5-1 set1Δ viability are in agreement with their expected effects on replication fork progression. We propose that the role of H3K4 methylation during DNA replication becomes critical when the replication forks acceleration due to decreased origin firing in the orc5-1 background increases the risk for transcription replication conflicts. Furthermore, we show that an increase of reactive oxygen species levels, likely a consequence of the elevated DNA damage, is partly responsible for the lethality in orc5-1 set1Δ.


Assuntos
Dano ao DNA , Replicação do DNA , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Metilação , Processamento de Proteína Pós-Traducional , Fase S , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/fisiologia
20.
Trends Pharmacol Sci ; 42(8): 688-699, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34074527

RESUMO

KMT2 methyltransferases are important regulators of gene transcription through the methylation of histone H3 lysine 4 at promoter and enhancer regions. They reside in large, multisubunit protein complexes, which not only regulate their catalytic activities but also mediate their interactions with chromatin. The KMT2 family was initially associated with cancer due to the discovery of KMT2A translocations in mixed-lineage leukemia (MLL). However, emerging evidences suggest that the methyltransferase activity of KMT2 enzymes can also be important in cancer, raising the prospect of targeting the catalytic domain of KMT2 as a therapeutic strategy. In this review, we summarize recent advances in our understanding of KMT2 enzyme mechanisms and their regulation on nucleosomes, which will provide mechanistic insights into therapeutic discoveries targeting their methyltransferase activities.


Assuntos
Proteína de Leucina Linfoide-Mieloide , Neoplasias , Proteínas de Ligação a DNA/metabolismo , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo , Humanos , Metilação , Proteína de Leucina Linfoide-Mieloide/genética , Proteína de Leucina Linfoide-Mieloide/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...