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1.
Physiol Plant ; 176(3): e14371, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38837414

RESUMO

The WRKY transcription factor (TF) genes form a large family in higher plants, with 72 members in Arabidopsis (Arabidopsis thaliana). The gaseous phytohormone ethylene (ET) regulates multiple physiological processes in plants. It is known that 1-aminocyclopropane-1-carboxylic acid (ACC) synthases (ACSs, EC 4.4.1.14) limit the enzymatic reaction rate of ethylene synthesis. However, whether WRKY TFs regulate the expression of ACSs and/or ACC oxidases (ACOs, EC 1.14.17.4) remains largely elusive. Here, we demonstrated that Arabidopsis WRKY22 positively regulated the expression of a few ACS and ACO genes, thus promoting ethylene production. Inducible overexpression of WRKY22 caused shorter hypocotyls without ACC treatment. A qRT-PCR screening demonstrated that overexpression of WRKY22 activates the expression of several ACS and ACO genes. The promoter regions of ACS5, ACS11, and ACO5 were also activated by WRKY22, which was revealed by a dual luciferase reporter assay. A follow-up chromatin immunoprecipitation coupled with quantitative PCR (ChIP-qPCR) and electrophoretic mobility shift assay (EMSA) showed that the promoter regions of ACS5 and ACO5 could be bound by WRKY22 directly. Moreover, wrky22 mutants had longer primary roots and more lateral roots than wild type, while WRKY22-overexpressing lines showed the opposite phenotype. In conclusion, this study revealed that WRKY22 acts as a novel TF activating, at least, the expression of ACS5 and ACO5 to increase ethylene synthesis and modulate root development.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Etilenos , Regulação da Expressão Gênica de Plantas , Liases , Raízes de Plantas , Fatores de Transcrição , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Etilenos/metabolismo , Etilenos/biossíntese , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Liases/genética , Liases/metabolismo , Aminoácido Oxirredutases/genética , Aminoácido Oxirredutases/metabolismo , Regiões Promotoras Genéticas/genética , Carbono-Carbono Liases/metabolismo , Carbono-Carbono Liases/genética , Ativação Transcricional/genética
2.
Biol Direct ; 19(1): 42, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38831379

RESUMO

Triple-negative breast cancer (TNBC) is more aggressive and has a higher metastasis rate compared with other subtypes of breast cancer. Due to the lack of drug-targetable receptors, chemotherapy is now the only available systemic treatment for TNBC. However, some patients might still develop drug resistance and have poor prognosis. Therefore, novel molecular biomarkers and new treatment targets are urgently needed for patients with TNBC. To provide molecular insights into TNBC progression, we investigated the function and the underlying mechanism of Defective in cullin neddylation 1 domain containing 5 (DCUN1D5) in the regulation of TNBC. By TCGA dataset and surgical specimens with immunohistochemical (IHC) staining method, DCUN1D5 was identified to be significantly upregulated in TNBC tumor tissues and negatively associated with prognosis. A series of in vitro and in vivo experiments were performed to confirm the oncogenic role of DCUN1D5 in TNBC. Overexpression of FN1 or PI3K/AKT activator IGF-1 could restore the proliferative and invasive ability induced by DCUN1D5 knockdown and DCUN1D5 could act as a novel transcriptional target of transcription factor Yin Yang 1 (YY1). In conclusion, YY1-enhanced DCUN1D5 expression could promote TNBC progression by FN1/PI3K/AKT pathway and DCUN1D5 might be a potential prognostic biomarker and therapeutic target for TNBC treatment.


Assuntos
Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Neoplasias de Mama Triplo Negativas , Fator de Transcrição YY1 , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/metabolismo , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Feminino , Fator de Transcrição YY1/metabolismo , Fator de Transcrição YY1/genética , Linhagem Celular Tumoral , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatidilinositol 3-Quinases/genética , Animais , Progressão da Doença , Transdução de Sinais , Camundongos , Ativação Transcricional , Regulação Neoplásica da Expressão Gênica , Camundongos Nus , Fibronectinas
3.
Nat Commun ; 15(1): 4749, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38834569

RESUMO

Gene Transfer Agents (GTAs) are phage-like particles that cannot self-multiply and be infectious. Caulobacter crescentus, a bacterium best known as a model organism to study bacterial cell biology and cell cycle regulation, has recently been demonstrated to produce bona fide GTA particles (CcGTA). Since C. crescentus ultimately die to release GTA particles, the production of GTA particles must be tightly regulated and integrated with the host physiology to prevent a collapse in cell population. Two direct activators of the CcGTA biosynthetic gene cluster, GafY and GafZ, have been identified, however, it is unknown how GafYZ controls transcription or how they coordinate gene expression of the CcGTA gene cluster with other accessory genes elsewhere on the genome for complete CcGTA production. Here, we show that the CcGTA gene cluster is transcriptionally co-activated by GafY, integration host factor (IHF), and by GafZ-mediated transcription anti-termination. We present evidence that GafZ is a transcription anti-terminator that likely forms an anti-termination complex with RNA polymerase, NusA, NusG, and NusE to bypass transcription terminators within the 14 kb CcGTA cluster. Overall, we reveal a two-tier regulation that coordinates the synthesis of GTA particles in C. crescentus.


Assuntos
Proteínas de Bactérias , Caulobacter crescentus , Regulação Bacteriana da Expressão Gênica , Família Multigênica , Ativação Transcricional , Caulobacter crescentus/genética , Caulobacter crescentus/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Bacteriófagos/genética , Transcrição Gênica , Terminação da Transcrição Genética
4.
Protein Sci ; 33(6): e5012, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38723180

RESUMO

The enormous LysR-type transcriptional regulators (LTTRs), which are diversely distributed amongst prokaryotes, play crucial roles in transcription regulation of genes involved in basic metabolic pathways, virulence and stress resistance. However, the precise transcription activation mechanism of these genes by LTTRs remains to be explored. Here, we determine the cryo-EM structure of a LTTR-dependent transcription activation complex comprising of Escherichia coli RNA polymerase (RNAP), an essential LTTR protein GcvA and its cognate promoter DNA. Structural analysis shows two N-terminal DNA binding domains of GcvA (GcvA_DBD) dimerize and engage the GcvA activation binding sites, presenting the -35 element for specific recognition with the conserved σ70R4. In particular, the versatile C-terminal domain of α subunit of RNAP directly interconnects with GcvA_DBD, σ70R4 and promoter DNA, providing more interfaces for stabilizing the complex. Moreover, molecular docking supports glycine as one potential inducer of GcvA, and single molecule photobleaching experiments kinetically visualize the occurrence of tetrameric GcvA-engaged transcription activation complex as suggested for the other LTTR homologs. Thus, a general model for tetrameric LTTR-dependent transcription activation is proposed. These findings will provide new structural and functional insights into transcription activation of the essential LTTRs.


Assuntos
RNA Polimerases Dirigidas por DNA , Escherichia coli , Ativação Transcricional , Escherichia coli/genética , Escherichia coli/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , RNA Polimerases Dirigidas por DNA/química , RNA Polimerases Dirigidas por DNA/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Regiões Promotoras Genéticas , Microscopia Crioeletrônica , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Modelos Moleculares , Simulação de Acoplamento Molecular , Regulação Bacteriana da Expressão Gênica , Multimerização Proteica , Sítios de Ligação
5.
J Gene Med ; 26(5): e3692, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38745073

RESUMO

BACKGROUND: Sevoflurane (Sevo) preconditioning and postconditioning play a protective role against injury induced by hepatic ischemia/reperfusion (I/R). At the same time, the involvement of macrophage infiltration in this process and the precise mechanisms are unclear. Here, we designed this research to elucidate the protective effects of Sevo against hepatic I/R injury and the molecules involved. METHODS: The alleviating effect of Sevo on the liver injury was analyzed by liver function analysis, hematoxylin and eosin staining, Masson trichrome staining, terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end labeling, western blot analysis and an enzyme-linked immunosorbent assay. An in vitro cell model was developed using alpha mouse liver 12 (AML12) cells, and the cell model was treated with oxygen-glucose deprivation and reoxygenation and Sevo. Multiple bioinformatics databases were used to screen transcriptional regulators related to hepatic I/R injury and the targets of Krueppel-like factor 5 (KLF5). KLF5 expression was artificially upregulated alone or with integrin beta-2 (ITGB2) knockdown to substantiate their involvement in Sevo-mediated hepatoprotection. RESULTS: Sevo protected the liver against I/R injury by reducing cell apoptosis and inflammatory response. KLF5 was upregulated in liver tissues following I/R injury, whereas KLF5 overexpression aggravated macrophage infiltration and liver injury induced by I/R injury. KLF5 bound to the promoter of ITGB2 to enhance ITGB2 transcription. Knockdown of ITGB2 reversed the aggravation of injury caused by KLF5 overexpression in mice and AML12 cells. CONCLUSIONS: Sevo blocked KLF5-mediated transcriptional activation of ITGB2, thereby inhibiting macrophage infiltration in hepatic I/R injury.


Assuntos
Fatores de Transcrição Kruppel-Like , Fígado , Macrófagos , Traumatismo por Reperfusão , Sevoflurano , Animais , Fatores de Transcrição Kruppel-Like/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/genética , Camundongos , Macrófagos/metabolismo , Sevoflurano/farmacologia , Fígado/metabolismo , Fígado/patologia , Ativação Transcricional , Masculino , Modelos Animais de Doenças , Apoptose , Antígenos CD18/metabolismo , Antígenos CD18/genética , Linhagem Celular , Camundongos Endogâmicos C57BL , Regulação da Expressão Gênica
6.
Mol Cell Biol ; 44(5): 178-193, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38767243

RESUMO

Transcription factor 12 (TCF12) is a known oncogene in many cancers. However, whether TCF12 can regulate malignant phenotypes and angiogenesis in osteosarcoma is not elucidated. In this study, we demonstrated increased expression of TCF12 in osteosarcoma tissues and cell lines. High TCF12 expression was associated with metastasis and poor survival rate of osteosarcoma patients. Knockdown of TCF12 reduced the proliferation, migration, and invasion of osteosarcoma cells. TCF12 was found to bind to the promoter region of sphingosine kinase 1 (SPHK1) to induce transcriptional activation of SPHK1 expression and enhance the secretion of sphingosine-1-phosphate (S1P), which eventually resulted in the malignant phenotypes of osteosarcoma cells. In addition, S1P secreted by osteosarcoma cells promoted the angiogenesis of HUVECs by targeting S1PR4 on the cell membrane to activate the STAT3 signaling pathway. These findings suggest that TCF12 may induce transcriptional activation of SPHK1 to promote the synthesis and secretion of S1P. This process likely enhances the malignant phenotypes of osteosarcoma cells and induces angiogenesis via the S1PR4/STAT3 signaling pathway.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos , Lisofosfolipídeos , Neovascularização Patológica , Osteossarcoma , Fosfotransferases (Aceptor do Grupo Álcool) , Fator de Transcrição STAT3 , Transdução de Sinais , Esfingosina , Humanos , Osteossarcoma/genética , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT3/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Lisofosfolipídeos/metabolismo , Neovascularização Patológica/metabolismo , Neovascularização Patológica/genética , Linhagem Celular Tumoral , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Regulação Neoplásica da Expressão Gênica , Proliferação de Células/genética , Células Endoteliais da Veia Umbilical Humana/metabolismo , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Ativação Transcricional/genética , Receptores de Esfingosina-1-Fosfato/metabolismo , Receptores de Esfingosina-1-Fosfato/genética , Receptores de Lisoesfingolipídeo/metabolismo , Receptores de Lisoesfingolipídeo/genética , Movimento Celular/genética , Masculino , Animais , Feminino , Angiogênese
7.
Cell Rep ; 43(5): 114194, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38735043

RESUMO

Class switch recombination (CSR) diversifies the effector functions of antibodies and involves complex regulation of transcription and DNA damage repair. Here, we show that the deubiquitinase USP7 promotes CSR to immunoglobulin A (IgA) and suppresses unscheduled IgG switching in mature B cells independent of its role in DNA damage repair, but through modulating switch region germline transcription. USP7 depletion impairs Sα transcription, leading to abnormal activation of Sγ germline transcription and increased interaction with the CSR center via loop extrusion for unscheduled IgG switching. Rescue of Sα transcription by transforming growth factor ß (TGF-ß) in USP7-deleted cells suppresses Sγ germline transcription and prevents loop extrusion toward IgG CSR. Mechanistically, USP7 protects transcription factor RUNX3 from ubiquitination-mediated degradation to promote Sα germline transcription. Our study provides evidence for active transcription serving as an anchor to impede loop extrusion and reveals a functional interplay between USP7 and TGF-ß signaling in promoting RUNX3 expression for efficient IgA CSR.


Assuntos
Subunidade alfa 3 de Fator de Ligação ao Core , Imunoglobulina A , Switching de Imunoglobulina , Ativação Transcricional , Peptidase 7 Específica de Ubiquitina , Subunidade alfa 3 de Fator de Ligação ao Core/metabolismo , Subunidade alfa 3 de Fator de Ligação ao Core/genética , Animais , Imunoglobulina A/metabolismo , Peptidase 7 Específica de Ubiquitina/metabolismo , Peptidase 7 Específica de Ubiquitina/genética , Camundongos , Fator de Crescimento Transformador beta/metabolismo , Camundongos Endogâmicos C57BL , Humanos , Ubiquitinação , Linfócitos B/metabolismo , Linfócitos B/imunologia , Imunoglobulina G/metabolismo , Imunoglobulina G/imunologia , Estabilidade Proteica
8.
Clin Transl Med ; 14(5): e1680, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38769668

RESUMO

BACKGROUND: A series of studies have demonstrated the emerging involvement of transfer RNA (tRNA) processing during the progression of tumours. Nevertheless, the roles and regulating mechanisms of tRNA processing genes in neuroblastoma (NB), the prevalent malignant tumour outside the brain in children, are yet unknown. METHODS: Analysis of multi-omics results was conducted to identify crucial regulators of downstream tRNA processing genes. Co-immunoprecipitation and mass spectrometry methods were utilised to measure interaction between proteins. The impact of transcriptional regulators on expression of downstream genes was measured by dual-luciferase reporter, chromatin immunoprecipitation, western blotting and real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) methods. Studies have been conducted to reveal impact and mechanisms of transcriptional regulators on biological processes of NB. Survival differences were analysed using the log-rank test. RESULTS: c-Myc was identified as a transcription factor driving tRNA processing gene expression and subsequent malate-aspartate shuttle (MAS) in NB cells. Mechanistically, c-Myc directly promoted the expression of glutamyl-prolyl-tRNA synthetase (EPRS) and leucyl-tRNA synthetase (LARS), resulting in translational up-regulation of glutamic-oxaloacetic transaminase 1 (GOT1) as well as malate dehydrogenase 1 (MDH1) via inhibiting general control nonrepressed 2 or activating mechanistic target of rapamycin signalling. Meanwhile, lamin A (LMNA) inhibited c-Myc transactivation via physical interaction, leading to suppression of MAS, aerobic glycolysis, tumourigenesis and aggressiveness. Pre-clinically, lobeline was discovered as a LMNA-binding compound to facilitate its interaction with c-Myc, which inhibited aminoacyl-tRNA synthetase expression, MAS and tumour progression of NB, as well as growth of organoid derived from c-Myc knock-in mice. Low levels of LMNA or elevated expression of c-Myc, EPRS, LARS, GOT1 or MDH1 were linked to a worse outcome and a shorter survival time of clinical NB patients. CONCLUSIONS: These results suggest that targeting c-Myc transactivation by LMNA inhibits tRNA processing essential for MAS and tumour progression.


Assuntos
Proteínas Proto-Oncogênicas c-myc , Humanos , Camundongos , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Animais , Ácido Aspártico/metabolismo , Malatos/metabolismo , RNA de Transferência/genética , RNA de Transferência/metabolismo , Neuroblastoma/metabolismo , Neuroblastoma/genética , Progressão da Doença , Ativação Transcricional/genética , Linhagem Celular Tumoral , Modelos Animais de Doenças
9.
Anticancer Res ; 44(6): 2349-2358, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38821628

RESUMO

BACKGROUND/AIM: Approximately 50% of melanomas harbor the BRAF V600E mutation and targeted therapies using BRAF inhibitors improve patient outcomes. Nonetheless, resistance to BRAF inhibitors develops rapidly and remains a challenge in melanoma treatment. In this study, we attempted to isolate long noncoding RNAs (lncRNAs) involved in BRAF inhibitor resistance using a comprehensive screening method. MATERIALS AND METHODS: We used a CRISPR-Cas9 synergistic activation mediator (SAM) protein complex in a genome-scale transcriptional activation assay to screen for candidate lncRNA genes related to BRAF inhibitor resistance. Correlation analysis was performed between expression levels of isolated lncRNA genes and IC50 of dabrafenib in a BRAF-mutated melanoma cell line. Next, online databases were used to construct the lncRNA-miRNA-mRNA regulatory network. Finally, we evaluated the significance of the expression levels of these lncRNAs and mRNAs as biomarkers using clinical specimens. RESULTS: We isolated three BRAF inhibitor resistance-associated lncRNA genes, namely SNHG16, NDUFV2-AS1, and LINC01502. We constructed a lncRNA-miRNA-mRNA network of 13 nodes consisting of three lncRNAs, six miRNAs, and four mRNAs. The lncRNAs and target mRNAs from each regulatory axis significantly and positively correlated with each other. Finally, Kaplan-Meier analysis showed that higher expression levels of MITF, which was up-regulated by LINC01502, were significantly associated with worse prognosis in BRAF V600E-mutated melanoma. CONCLUSION: The identification of these BRAF inhibitor resistance-associated lncRNA genes at the genomic scale and the establishment of the lncRNA-miRNA-mRNA regulatory network provides new insights into the underlying mechanisms of BRAF inhibitor resistance in melanoma.


Assuntos
Sistemas CRISPR-Cas , Resistencia a Medicamentos Antineoplásicos , Melanoma , Inibidores de Proteínas Quinases , Proteínas Proto-Oncogênicas B-raf , RNA Longo não Codificante , Ativação Transcricional , Humanos , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , RNA Longo não Codificante/genética , Resistencia a Medicamentos Antineoplásicos/genética , Melanoma/genética , Melanoma/tratamento farmacológico , Melanoma/patologia , Linhagem Celular Tumoral , Inibidores de Proteínas Quinases/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Imidazóis/farmacologia , Mutação , Oximas/farmacologia , RNA Mensageiro/genética , Redes Reguladoras de Genes
10.
Proc Natl Acad Sci U S A ; 121(21): e2318591121, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38739802

RESUMO

The transcription factor p73, a member of the p53 tumor-suppressor family, regulates cell death and also supports tumorigenesis, although the mechanistic basis for the dichotomous functions is poorly understood. We report here the identification of an alternate transactivation domain (TAD) located at the extreme carboxyl (C) terminus of TAp73ß, a commonly expressed p73 isoform. Mutational disruption of this TAD significantly reduced TAp73ß's transactivation activity, to a level observed when the amino (N)-TAD that is similar to p53's TAD, is mutated. Mutation of both TADs almost completely abolished TAp73ß's transactivation activity. Expression profiling highlighted a unique set of targets involved in extracellular matrix-receptor interaction and focal adhesion regulated by the C-TAD, resulting in FAK phosphorylation, distinct from the N-TAD targets that are common to p53 and are involved in growth inhibition. Interestingly, the C-TAD targets are also regulated by the oncogenic, amino-terminal-deficient DNp73ß isoform. Consistently, mutation of C-TAD reduces cellular migration and proliferation. Mechanistically, selective binding of TAp73ß to DNAJA1 is required for the transactivation of C-TAD target genes, and silencing DNAJA1 expression abrogated all C-TAD-mediated effects. Taken together, our results provide a mechanistic basis for the dichotomous functions of TAp73 in the regulation of cellular growth through its distinct TADs.


Assuntos
Proliferação de Células , Domínios Proteicos , Ativação Transcricional , Proteína Tumoral p73 , Proteína Tumoral p73/metabolismo , Proteína Tumoral p73/genética , Humanos , Movimento Celular/genética , Mutação , Linhagem Celular Tumoral , Isoformas de Proteínas/metabolismo , Isoformas de Proteínas/genética , Proteína Supressora de Tumor p53/metabolismo , Proteína Supressora de Tumor p53/genética , Fosforilação , Proteínas Supressoras de Tumor/metabolismo , Proteínas Supressoras de Tumor/genética
11.
PLoS Genet ; 20(5): e1011277, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38781242

RESUMO

How enhancers regulate their target genes in the context of 3D chromatin organization is extensively studied and models which do not require direct enhancer-promoter contact have recently emerged. Here, we use the activation of estrogen receptor-dependent enhancers in a breast cancer cell line to study enhancer-promoter communication at two loci. This allows high temporal resolution tracking of molecular events from hormone stimulation to efficient gene activation. We examine how both enhancer-promoter spatial proximity assayed by DNA fluorescence in situ hybridization, and contact frequencies resulting from chromatin in situ fragmentation and proximity ligation, change dynamically during enhancer-driven gene activation. These orthogonal methods produce seemingly paradoxical results: upon enhancer activation enhancer-promoter contact frequencies increase while spatial proximity decreases. We explore this apparent discrepancy using different estrogen receptor ligands and transcription inhibitors. Our data demonstrate that enhancer-promoter contact frequencies are transcription independent whereas altered enhancer-promoter proximity depends on transcription. Our results emphasize that the relationship between contact frequencies and physical distance in the nucleus, especially over short genomic distances, is not always a simple one.


Assuntos
Cromatina , Elementos Facilitadores Genéticos , Estrogênios , Regiões Promotoras Genéticas , Humanos , Cromatina/genética , Cromatina/metabolismo , Estrogênios/metabolismo , Transcrição Gênica , Células MCF-7 , Neoplasias da Mama/genética , Feminino , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Hibridização in Situ Fluorescente , Receptores de Estrogênio/metabolismo , Receptores de Estrogênio/genética , Ativação Transcricional , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo
12.
Nat Commun ; 15(1): 4561, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38811575

RESUMO

The mammalian SWI/SNF-like BAF complexes play critical roles during animal development and pathological conditions. Previous gene deletion studies and characterization of human gene mutations implicate that the complexes both repress and activate a large number of genes. However, the direct function of the complexes in cells remains largely unclear due to the relatively long-term nature of gene deletion or natural mutation. Here we generate a mouse line by knocking in the auxin-inducible degron tag (AID) to the Smarca4 gene, which encodes BRG1, the essential ATPase subunit of the BAF complexes. We show that the tagged BRG1 can be efficiently depleted by osTIR1 expression and auxin treatment for 6 to 10 h in CD4 + T cells, hepatocytes, and fibroblasts isolated from the knock-in mice. The acute depletion of BRG1 leads to decreases in nascent RNAs and RNA polymerase II binding at a large number of genes, which are positively correlated with the loss of BRG1. Further, these changes are correlated with diminished accessibility at DNase I Hypersensitive Sites (DHSs) and p300 binding. The acute BRG1 depletion results in three major patterns of nucleosome shifts leading to narrower nucleosome spacing surrounding transcription factor motifs and at enhancers and transcription start sites (TSSs), which are correlated with loss of BRG1, decreased chromatin accessibility and decreased nascent RNAs. Acute depletion of BRG1 severely compromises the Trichostatin A (TSA) -induced histone acetylation, suggesting a substantial interplay between the chromatin remodeling activity of BRG1 and histone acetylation. Our data suggest BRG1 mainly plays a direct positive role in chromatin accessibility, RNAPII binding, and nascent RNA production by regulating nucleosome positioning and facilitating transcription factor binding to their target sites.


Assuntos
DNA Helicases , Proteínas Nucleares , Fatores de Transcrição , Animais , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , DNA Helicases/metabolismo , DNA Helicases/genética , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , Camundongos , Nucleossomos/metabolismo , Nucleossomos/genética , Ácidos Indolacéticos/metabolismo , RNA Polimerase II/metabolismo , Fibroblastos/metabolismo , Técnicas de Introdução de Genes , Hepatócitos/metabolismo , Proteína p300 Associada a E1A/metabolismo , Proteína p300 Associada a E1A/genética , Ativação Transcricional , Transcrição Gênica , Histonas/metabolismo , Desoxirribonuclease I/metabolismo , Cromatina/metabolismo , Humanos
13.
Plant Mol Biol ; 114(3): 54, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714535

RESUMO

Sugars, synthesized by photosynthesis in source organs, are loaded and utilized as an energy source and carbon skeleton in sink organs, and also known to be important signal molecules regulating gene expression in higher plants. The expression of genes coding for sporamin and ß-amylase, the two most abundant proteins in storage roots of sweet potato, is coordinately induced by sugars. We previously reported on the identification of the carbohydrate metabolic signal-responsible element-1 (CMSRE-1) essential for the sugar-responsible expression of two genes. However, transcription factors that bind to this sequence have not been identified. In this study, we performed yeast one-hybrid screening using the sugar-responsible minimal promoter region of the ß-amylase gene as bait and a library composed only transcription factor cDNAs of Arabidopsis. Two clones, named Activator protein binding to CMSRE-1 (ACRE), encoding AP2/ERF transcription factors were isolated. ACRE showed transactivation activity of the sugar-responsible minimal promoter in a CMSRE-1-dependent manner in Arabidopsis protoplasts. Electric mobility shift assay (EMSA) using recombinant proteins and transient co-expression assay in Arabidopsis protoplasts revealed that ACRE could actually act to the CMSRE-1. Among the DEHYDRATION -RESPONSIVE ELEMENT BINDING FACTOR (DREB) subfamily, almost all homologs including ACRE, could act on the DRE, while only three ACREs could act to the CMSRE-1. Moreover, ACRE-homologs of Japanese morning glory also have the same property of DNA-binding preference and transactivation activity through the CMSRE-1. These findings suggested that ACRE plays an important role in the mechanism regulating the sugar-responsible gene expression through the CMSRE-1 conserved across plant species.


Assuntos
Arabidopsis , Regulação da Expressão Gênica de Plantas , Ipomoea batatas , Proteínas de Plantas , Regiões Promotoras Genéticas , Fatores de Transcrição , beta-Amilase , Arabidopsis/genética , Arabidopsis/metabolismo , beta-Amilase/genética , beta-Amilase/metabolismo , Ipomoea batatas/genética , Ipomoea batatas/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional/genética
14.
Sci Signal ; 17(838): eado6266, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38805583

RESUMO

Phosphoinositides are essential signaling molecules. The PI5P4K family of phosphoinositide kinases and their substrates and products, PI5P and PI4,5P2, respectively, are emerging as intracellular metabolic and stress sensors. We performed an unbiased screen to investigate the signals that these kinases relay and the specific upstream regulators controlling this signaling node. We found that the core Hippo pathway kinases MST1/2 phosphorylated PI5P4Ks and inhibited their signaling in vitro and in cells. We further showed that PI5P4K activity regulated several Hippo- and YAP-related phenotypes, specifically decreasing the interaction between the key Hippo proteins MOB1 and LATS and stimulating the YAP-mediated genetic program governing epithelial-to-mesenchymal transition. Mechanistically, we showed that PI5P interacted with MOB1 and enhanced its interaction with LATS, thereby providing a signaling connection between the Hippo pathway and PI5P4Ks. These findings reveal how these two important evolutionarily conserved signaling pathways are integrated to regulate metazoan development and human disease.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Via de Sinalização Hippo , Proteínas Serina-Treonina Quinases , Transdução de Sinais , Fatores de Transcrição , Proteínas de Sinalização YAP , Humanos , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Via de Sinalização Hippo/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Proteínas de Sinalização YAP/metabolismo , Proteínas de Sinalização YAP/genética , Ativação Transcricional , Fosforilação , Células HEK293 , Transição Epitelial-Mesenquimal , Fosfoproteínas/metabolismo , Fosfoproteínas/genética , Animais , Serina-Treonina Quinase 3 , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética
15.
Cell Rep ; 43(5): 114170, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38700983

RESUMO

During cell fate transitions, cells remodel their transcriptome, chromatin, and epigenome; however, it has been difficult to determine the temporal dynamics and cause-effect relationship between these changes at the single-cell level. Here, we employ the heterokaryon-mediated reprogramming system as a single-cell model to dissect key temporal events during early stages of pluripotency conversion using super-resolution imaging. We reveal that, following heterokaryon formation, the somatic nucleus undergoes global chromatin decompaction and removal of repressive histone modifications H3K9me3 and H3K27me3 without acquisition of active modifications H3K4me3 and H3K9ac. The pluripotency gene OCT4 (POU5F1) shows nascent and mature RNA transcription within the first 24 h after cell fusion without requiring an initial open chromatin configuration at its locus. NANOG, conversely, has significant nascent RNA transcription only at 48 h after cell fusion but, strikingly, exhibits genomic reopening early on. These findings suggest that the temporal relationship between chromatin compaction and gene activation during cellular reprogramming is gene context dependent.


Assuntos
Reprogramação Celular , Montagem e Desmontagem da Cromatina , Histonas , Humanos , Reprogramação Celular/genética , Histonas/metabolismo , Análise de Célula Única , Ativação Transcricional , Fator 3 de Transcrição de Octâmero/metabolismo , Fator 3 de Transcrição de Octâmero/genética , Cromatina/metabolismo , Proteína Homeobox Nanog/metabolismo , Proteína Homeobox Nanog/genética , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/citologia
16.
J Nat Prod ; 87(4): 935-947, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38575516

RESUMO

We report on the use of nitric oxide-mediated transcriptional activation (NOMETA) as an innovative means to detect and access new classes of microbial natural products encoded within silent biosynthetic gene clusters. A small library of termite nest- and mangrove-derived fungi and actinomyces was subjected to cultivation profiling using a miniaturized 24-well format approach (MATRIX) in the presence and absence of nitric oxide, with the resulting metabolomes subjected to comparative chemical analysis using UPLC-DAD and GNPS molecular networking. This strategy prompted study of Talaromyces sp. CMB-TN6F and Coccidiodes sp. CMB-TN39F, leading to discovery of the triterpene glycoside pullenvalenes A-D (1-4), featuring an unprecedented triterpene carbon skeleton and rare 6-O-methyl-N-acetyl-d-glucosaminyl glycoside residues. Structure elucidation of 1-4 was achieved by a combination of detailed spectroscopic analysis, chemical degradation, derivatization and synthesis, and biosynthetic considerations.


Assuntos
Aminoglicosídeos , Isópteros , Óxido Nítrico , Triterpenos , Animais , Triterpenos/farmacologia , Triterpenos/química , Triterpenos/metabolismo , Óxido Nítrico/biossíntese , Óxido Nítrico/metabolismo , Estrutura Molecular , Isópteros/microbiologia , Aminoglicosídeos/farmacologia , Austrália , Ativação Transcricional/efeitos dos fármacos , Fungos/metabolismo , Talaromyces/química , Talaromyces/metabolismo , Actinomyces/metabolismo , Actinomyces/efeitos dos fármacos
17.
J Orthop Surg Res ; 19(1): 260, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38659042

RESUMO

Circular RNAs (circRNAs) are a newly appreciated type of endogenous noncoding RNAs that play vital roles in the development of various human cancers, including osteosarcoma (OS). In this study, we investigated three circRNAs (circ_0076684, circ_0003563, circ_0076691) from the RUNX Family Transcription Factor 2 (RUNX2) gene locus in OS. We found that the expression of circ_0076684, circ_0003563, circ_0076691, and RUNX2 mRNA is upregulated in OS, which is a consequence of CBX4-mediated transcriptional activation. Among these three RUNX2-circRNAs, only circ_0076684 is significantly associated with the clinical features and prognosis of OS patients. Functional experiments indicate that circ_0076684 promotes OS progression in vitro and in vivo. Circ_0076684 acts as a sponge for miR-370-3p, miR-140-3p, and miR-193a-5p, raising Cut Like Homeobox 1 (CUX1) expression by sponging these three miRNAs. Furthermore, we presented that circ_0076684 facilitates OS progression via CUX1. In conclusion, this study found that the expression of three circRNAs and RUNX2 mRNA from the RUNX2 gene locus is significantly upregulated in OS, as a result of CBX4-mediated transcriptional activation. Circ_0076684 raises CUX1 expression by sponging miR-370-3p, miR-140-3p, and miR-193a-5p, and facilitates OS progression via CUX1.


Assuntos
Neoplasias Ósseas , Subunidade alfa 1 de Fator de Ligação ao Core , Ligases , MicroRNAs , Osteossarcoma , Proteínas do Grupo Polycomb , RNA Circular , Regulação para Cima , Osteossarcoma/genética , Osteossarcoma/patologia , Osteossarcoma/metabolismo , Humanos , RNA Circular/genética , MicroRNAs/genética , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Neoplasias Ósseas/metabolismo , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Masculino , Animais , Progressão da Doença , Linhagem Celular Tumoral , Feminino , Ativação Transcricional/genética , Prognóstico , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Camundongos , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo
18.
J Exp Clin Cancer Res ; 43(1): 116, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38637831

RESUMO

BACKGROUND: Protein arginine methyltransferase 6 (PRMT6) plays a crucial role in various pathophysiological processes and diseases. Glioblastoma (GBM; WHO Grade 4 glioma) is the most common and lethal primary brain tumor in adults, with a prognosis that is extremely poor, despite being less common than other systemic malignancies. Our current research finds PRMT6 upregulated in GBM, enhancing tumor malignancy. Yet, the specifics of PRMT6's regulatory processes and potential molecular mechanisms in GBM remain largely unexplored. METHODS: PRMT6's expression and prognostic significance in GBM were assessed using glioma public databases, immunohistochemistry (IHC), and immunoblotting. Scratch and Transwell assays examined GBM cell migration and invasion. Immunoblotting evaluated the expression of epithelial-mesenchymal transition (EMT) and Wnt-ß-catenin pathway-related proteins. Dual-luciferase reporter assays and ChIP-qPCR assessed the regulatory relationship between PRMT6 and YTHDF2. An in situ tumor model in nude mice evaluated in vivo conditions. RESULTS: Bioinformatics analysis indicates high expression of PRMT6 and YTHDF2 in GBM, correlating with poor prognosis. Functional experiments show PRMT6 and YTHDF2 promote GBM migration, invasion, and EMT. Mechanistic experiments reveal PRMT6 and CDK9 co-regulate YTHDF2 expression. YTHDF2 binds and promotes the degradation of negative regulators APC and GSK3ß mRNA of the Wnt-ß-catenin pathway, activating it and consequently enhancing GBM malignancy. CONCLUSIONS: Our results demonstrate the PRMT6-YTHDF2-Wnt-ß-Catenin axis promotes GBM migration, invasion, and EMT in vitro and in vivo, potentially serving as a therapeutic target for GBM.


Assuntos
Glioblastoma , Glioma , Animais , Camundongos , Glioblastoma/patologia , beta Catenina/genética , beta Catenina/metabolismo , Ativação Transcricional , Camundongos Nus , Linhagem Celular Tumoral , Fatores de Transcrição/metabolismo , Glioma/patologia , Via de Sinalização Wnt , Transição Epitelial-Mesenquimal/genética , Proliferação de Células/genética , Movimento Celular , Regulação Neoplásica da Expressão Gênica
19.
Cell Signal ; 119: 111180, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38642782

RESUMO

CXXC5, a zinc-finger protein, is known for its role in epigenetic regulation via binding to unmethylated CpG islands in gene promoters. As a transcription factor and epigenetic regulator, CXXC5 modulates various signaling processes and acts as a key coordinator. Altered expression or activity of CXXC5 has been linked to various pathological conditions, including tumorigenesis. Despite its known role in cancer, CXXC5's function and mechanism in ovarian cancer are unclear. We analyzed multiple public databases and found that CXXC5 is highly expressed in ovarian cancer, with high expression correlating with poor patient prognosis. We show that CXXC5 expression is regulated by oxygen concentration and is a direct target of HIF1A. CXXC5 is critical for maintaining the proliferative potential of ovarian cancer cells, with knockdown decreasing and overexpression increasing cell proliferation. Loss of CXXC5 led to inactivation of multiple inflammatory signaling pathways, while overexpression activated these pathways. Through in vitro and in vivo experiments, we confirmed ZNF143 and EGR1 as downstream transcription factors of CXXC5, mediating its proliferative potential in ovarian cancer. Our findings suggest that the CXXC5-ZNF143/EGR1 axis forms a network driving ovarian cell proliferation and tumorigenesis, and highlight CXXC5 as a potential therapeutic target for ovarian cancer treatment.


Assuntos
Proliferação de Células , Proteínas de Ligação a DNA , Proteína 1 de Resposta de Crescimento Precoce , Regulação Neoplásica da Expressão Gênica , Inflamação , Neoplasias Ovarianas , Transativadores , Ativação Transcricional , Humanos , Feminino , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Proteína 1 de Resposta de Crescimento Precoce/genética , Linhagem Celular Tumoral , Transativadores/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Animais , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Camundongos Nus , Transdução de Sinais , Camundongos
20.
New Phytol ; 242(6): 2652-2668, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38649769

RESUMO

Development of protein-enriched chickpea varieties necessitates an understanding of specific genes and key regulatory circuits that govern the synthesis of seed storage proteins (SSPs). Here, we demonstrated the novel involvement of Ca-miR164e-CaNAC100 in regulating SSP synthesis in chickpea. Ca-miRNA164e was significantly decreased during seed maturation, especially in high-protein accessions. The miRNA was found to directly target the transactivation conferring C-terminal region of a nuclear-localized transcription factor, CaNAC100 as revealed using RNA ligase-mediated-rapid amplification of cDNA ends and target mimic assays. The functional role of CaNAC100 was demonstrated through seed-specific overexpression (NACOE) resulting in significantly augmented seed protein content (SPC) consequential to increased SSP transcription. Further, NACOE lines displayed conspicuously enhanced seed weight but reduced numbers and yield. Conversely, a downregulation of CaNAC100 and SSP transcripts was evident in seed-specific overexpression lines of Ca-miR164e that culminated in significantly lowered SPC. CaNAC100 was additionally demonstrated to transactivate the SSP-encoding genes by directly binding to their promoters as demonstrated using electrophoretic mobility shift and dual-luciferase reporter assays. Taken together, our study for the first time established a distinct role of CaNAC100 in positively influencing SSP synthesis and its critical regulation by CamiR164e, thereby serving as an understanding that can be utilized for developing SPC-rich chickpea varieties.


Assuntos
Cicer , Regulação da Expressão Gênica de Plantas , MicroRNAs , Proteínas de Armazenamento de Sementes , Sementes , Fatores de Transcrição , Cicer/genética , Cicer/metabolismo , Cicer/crescimento & desenvolvimento , MicroRNAs/genética , MicroRNAs/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Proteínas de Armazenamento de Sementes/metabolismo , Proteínas de Armazenamento de Sementes/genética , Sementes/metabolismo , Sementes/genética , Regiões Promotoras Genéticas/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Sequência de Bases , Ativação Transcricional/genética , Plantas Geneticamente Modificadas
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