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1.
Chromosoma ; 133(3): 203-216, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38922437

RESUMEN

Transgenerational gene expression depends on both underlying DNA sequences and epigenetic modifications. The latter, which can result in transmission of variegated gene expression patterns across multiple generations without DNA alterations, has been termed epigenetic inheritance and has been documented in plants, worms, flies and mammals. Whereas transcription factors binding to cognate DNA sequence elements regulate gene expression, the molecular basis for epigenetic inheritance has been linked to histone and DNA modifications and non-coding RNA. Here we report that mutation of the CCAAT box promoter element abrogates NF-Y binding and disrupts the stable transgenerational expression of an MHC class I transgene. Transgenic mice with a mutated CCAAT box in the MHC class I transgene display variegated expression of the transgene among littermates and progeny in multiple independently derived transgenic lines. After 4 generations, CCAAT mutant transgenic lines derived from a single founder stably displayed distinct patterns of expression. Histone modifications and RNA polymerase II binding correlate with expression of CCAAT mutant transgenic lines, whereas DNA methylation and nucleosome occupancy do not. Mutation of the CCAAT box also results in changes to CTCF binding and DNA looping patterns across the transgene that correlate with expression status. These studies identify the CCAAT promoter element as a regulator of stable transgenerational gene expression such that mutation of the CCAAT box results in variegated transgenerational inheritance. Considering that the CCAAT box is present in 30% of eukaryotic promoters, this study provides insights into how fidelity of gene expression patterns is maintained through multiple generations.


Asunto(s)
Ratones Transgénicos , Regiones Promotoras Genéticas , Animales , Ratones , Metilación de ADN , Epigénesis Genética , Factor de Unión a CCAAT/genética , Factor de Unión a CCAAT/metabolismo , Regulación de la Expresión Génica , Genes MHC Clase I , Mutación , Histonas/metabolismo , Histonas/genética , ARN Polimerasa II/metabolismo , ARN Polimerasa II/genética , Factor de Unión a CCCTC/metabolismo , Factor de Unión a CCCTC/genética , Transgenes , Nucleosomas/metabolismo , Nucleosomas/genética
2.
Microbiol Spectr ; 11(3): e0518822, 2023 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-37140376

RESUMEN

Aspergillus fumigatus is a ubiquitous environmental mold that can cause severe disease in immunocompromised patients and chronic disease in individuals with underlying lung conditions. Triazoles are the most widely used class of antifungal drugs to treat A. fumigatus infections, but their use in the clinic is threatened by the emergence of triazole-resistant isolates worldwide, reinforcing the need for a better understanding of resistance mechanisms. The predominant mechanisms of A. fumigatus triazole resistance involve mutations affecting the promoter region or coding sequence of the target enzyme of the triazoles, Cyp51A. However, triazole-resistant isolates without cyp51A-associated mutations are frequently identified. In this study, we investigate a pan-triazole-resistant clinical isolate, DI15-105, that simultaneously carries the mutations hapEP88L and hmg1F262del, with no mutations in cyp51A. Using a Cas9-mediated gene-editing system, hapEP88L and hmg1F262del mutations were reverted in DI15-105. Here, we show that the combination of these mutations accounts for pan-triazole resistance in DI15-105. To our knowledge, DI15-105 is the first clinical isolate reported to simultaneously carry mutations in hapE and hmg1 and only the second with the hapEP88L mutation. IMPORTANCE Triazole resistance is an important cause of treatment failure and high mortality rates for A. fumigatus human infections. Although Cyp51A-associated mutations are frequently identified as the cause of A. fumigatus triazole resistance, they do not explain the resistance phenotypes for several isolates. In this study, we demonstrate that hapE and hmg1 mutations additively contribute to pan-triazole resistance in an A. fumigatus clinical isolate lacking cyp51-associated mutations. Our results exemplify the importance of and the need for a better understanding of cyp51A-independent triazole resistance mechanisms.


Asunto(s)
Aspergilosis , Aspergillus fumigatus , Humanos , Aspergillus fumigatus/genética , Triazoles/farmacología , Proteínas Fúngicas/genética , Farmacorresistencia Fúngica/genética , Aspergilosis/tratamiento farmacológico , Aspergilosis/microbiología , Antifúngicos/farmacología , Pruebas de Sensibilidad Microbiana
3.
Structure ; 30(7): 934-946.e4, 2022 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-35472306

RESUMEN

The heterotrimeric CCAAT-binding complex (CBC) is a fundamental eukaryotic transcription factor recognizing the CCAAT box. In certain fungi, like Aspergilli, the CBC cooperates with the basic leucine zipper HapX to control iron metabolism. HapX functionally depends on the CBC, and the stable interaction of both requires DNA. To study this cooperative effect, X-ray structures of the CBC-HapX-DNA complex were determined. Downstream of the CCAAT box, occupied by the CBC, a HapX dimer binds to the major groove. The leash-like N terminus of the distal HapX subunit contacts the CBC, and via a flexible polyproline type II helix mediates minor groove interactions that stimulate sequence promiscuity. In vitro and in vivo mutagenesis suggest that the structural and functional plasticity of HapX results from local asymmetry and its ability to target major and minor grooves simultaneously. The latter feature may also apply to related transcription factors such as yeast Hap4 and distinct Yap family members.


Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico , Factores de Transcripción , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , ADN/metabolismo , Dominios Proteicos , Saccharomyces cerevisiae/metabolismo , Factores de Transcripción/metabolismo
4.
Cancers (Basel) ; 13(12)2021 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-34208636

RESUMEN

NF-Y is the CCAAT-binding trimer formed by the histone fold domain (HFD), NF-YB/NF-YC and NF-YA. The CCAAT box is generally prevalent in promoters of "cancer" genes. We reported the overexpression of NF-YA in BRCA, LUAD and LUSC, and of all subunits in HCC. Altered splicing of NF-YA was found in breast and lung cancer. We analyzed RNA-seq datasets of TCGA and cell lines of head and neck squamous cell carcinomas (HNSCC). We partitioned all TCGA data into four subtypes, deconvoluted single-cell RNA-seq of tumors and derived survival curves. The CCAAT box was enriched in the promoters of overexpressed genes. The "short" NF-YAs was overexpressed in all subtypes and the "long" NF-YAl in Mesenchymal. The HFD subunits are overexpressed, except Basal (NF-YB) and Atypical (NF-YC); NF-YAl is increased in p53 mutated tumors. In HPV-positive tumors, high levels of NF-YAs, p16 and ΔNp63 correlate with better prognosis. Deconvolution of single cell RNA-seq (scRNA-seq) found a correlation of NF-YAl with Cancer Associated Fibroblasts (CAFs) and p-EMT cells, a population endowed with metastatic potential. We conclude that overexpression of HFD subunits and NF-YAs is protective in HPV-positive tumors; expression of NF-YAl is largely confined to mutp53 tumors and malignant p-EMT cells.

5.
Oncol Rep ; 46(1)2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34013373

RESUMEN

Macrophage migration inhibitory factor (MIF) has been confirmed as an oncogene in solid tumor development, and its overexpression causes cell proliferation in T acute lymphoblastic leukemia (T­ALL); however, the underlying mechanisms remain unclear. The overexpression of MIF promotes cellular transformation and proliferation, in part, through interaction with UHRF1. Nevertheless, overexpression of UHRF1 cannot upregulate MIF expression in T­ALL. New insights into MIF regulation in T­ALL are imperative to offer the opportunity for therapeutic intervention. In the present study, using RT­qPCR, western blot analysis, confocal microscopy and RNA sequence, we report the identification and validation of UHRF1 as a negative regulator of MIF, which functions to downregulate MIF expression by binding to the CATT repeat sequence of the MIF promoter. By contrast, HMG­box protein 1 (HBP1) functions as a positive regulator of MIF. Moreover, we demonstrated that HBP1 suppressive signaling is reduced by UHRF1 through promotion of the interaction between MIF and HBP1. MIF deficiency caused by UHRF1 knockdown resulted in enhanced apoptosis in T­ALL as compared with that caused by decreased MIF or increased HBP1 expression alone. These results identify UHRF1 as a key regulator of MIF transcription in T­ALL, although these transcription factors possess opposite regulatory functions. Thus, this mechanism may provide insight into how to effectively prevent MIF­dependent oncogenic activity. Finally, T­ALL mice possessing high HBP1 or low UHRF1 expression levels are associated with longer survival as compared with control mice, with UHRF1­knockdown mice living the longest. Taken together, these findings indicate that MIF and its regulators are potential treatment targets and biomarkers for the prediction of prognosis in T­ALL.


Asunto(s)
Proteínas Potenciadoras de Unión a CCAAT/metabolismo , Regulación hacia Abajo , Proteínas del Grupo de Alta Movilidad/metabolismo , Oxidorreductasas Intramoleculares/genética , Factores Inhibidores de la Migración de Macrófagos/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/mortalidad , Proteínas Represoras/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Animales , Supervivencia Celular , Regulación Neoplásica de la Expresión Génica , Técnicas de Silenciamiento del Gen , Células HeLa , Humanos , Células Jurkat , Ratones , Trasplante de Neoplasias , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Regiones Promotoras Genéticas , Análisis de Supervivencia
6.
Mol Biol Rep ; 48(2): 1589-1599, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33512627

RESUMEN

Nuclear Factor Y (NF-Y) gene family regulates numbers of flowering processes. Two independent transgenic Arabidopsis lines overexpressing (OX) GmNFY-B1 and GmNFYB1-GR (GmNFYB1 fused with the glucocorticoid receptor) were used to investigate the function of NFY-B1 in flowering. Furthermore, GmNFYB1-GR lines were chemically treated with dexamethasone (Dex, synthetic steroid hormone), cycloheximide (Cyc, an inhibitor of protein biosynthesis), and ethanol to examine their effects on different flowering related marker genes. Our results indicated that the transgenic lines produced longer hypocotyl lengths and had fewer numbers of rosette leaves compared to the wild-type and nf-yb1 mutant plants under both long and short-day (LD and SD) conditions. The qRT-PCR assays revealed that transcript levels of all flowering time regulating genes, i.e. SOC, FLC, FT, TSF, LFY, GI2, AGL, and FCA showed higher transcript abundance in lines OX GmNFYB1-GR. However, FT and GI genes showed higher transcript levels under Dex and Dex/Cyc treatments compared to Cyc and ethanol. Additionally, 24 differentially expressed genes were identified and verified through RNA-seq and RT-qPCR in GmNF-YB1-GR lines under Cyc and Dex/Cyc treatments from which 14 genes were up-regulated and 10 were down-regulated. These genes are involved in regulatory functions of circadian rhythm, regulation of flower development in photoperiodic, and GA pathways. The overexpression of GmNF-YB1 and GmNF-YB1-GR promote flowering through the higher expression of flowering-related genes. Further GmNF-YB1 and its attachment with the GR receptor can regulate its target genes under Dex/Cyc treatment and might act as flowering inducer under LD and SD conditions.


Asunto(s)
Factor de Unión a CCAAT/genética , Flores/genética , Glycine max/genética , Proteínas de Soja/genética , Arabidopsis/genética , Flores/crecimiento & desarrollo , Regulación de la Expresión Génica de las Plantas , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/crecimiento & desarrollo , Factores de Transcripción/genética
7.
Plant J ; 105(1): 49-61, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33098724

RESUMEN

NF-Y transcription factor comprises three subunits: NF-YA, NF-YB and NF-YC. NF-YB and NF-YC dimerize through their histone fold domain (HFD), which can bind DNA in a non-sequence-specific fashion while serving as a scaffold for NF-YA trimerization. Upon trimerization, NF-YA specifically recognizes the CCAAT box sequence on promoters and enhancers. In plants, each NF-Y subunit is encoded by several genes giving rise to hundreds of potential heterotrimeric combinations. In addition, plant NF-YBs and NF-YCs interact with other protein partners to recognize a plethora of genomic motifs, as the CCT protein family that binds CORE sites. The NF-Y subunit organization and its DNA-binding properties, together with the NF-Y HFD capacity to adapt different protein modules, represent plant-specific features that play a key role in development, growth and reproduction. Despite their relevance, these features are still poorly understood at the molecular level. Here, we present the structures of Arabidopsis and rice NF-YB/NF-YC dimers, and of an Arabidopsis NF-Y trimer in complex with the FT CCAAT box, together with biochemical data on NF-Y mutants. The dimeric structures identify the key residues for NF-Y HFD stabilization. The NF-Y/DNA structure and the mutation experiments shed light on HFD trimerization interface properties and the NF-YA sequence appetite for the bases flanking the CCAAT motif. These data explain the logic of plant NF-Y gene expansion: the trimerization adaptability and the flexible DNA-binding rules serve the scopes of accommodating the large number of NF-YAs, CCTs and possibly other NF-Y HFD binding partners and a diverse audience of genomic motifs.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Factor de Unión a CCAAT/metabolismo , ADN de Plantas/metabolismo , Secuencia de Aminoácidos , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Sitios de Unión , Factor de Unión a CCAAT/química , Factor de Unión a CCAAT/genética , ADN de Plantas/química , Dimerización , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estructura Terciaria de Proteína
8.
Int J Mol Sci ; 21(23)2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-33271832

RESUMEN

NF-Y is a pioneer trimeric transcription factor formed by the Histone Fold Domain (HFD) NF-YB/NF-YC subunits and NF-YA. Three subunits are required for DNA binding. CCAAT-specificity resides in NF-YA and transactivation resides in Q-rich domains of NF-YA and NF-YC. They are involved in alternative splicing (AS). We recently showed that NF-YA is overexpressed in breast and lung carcinomas. We report here on the overexpression of all subunits in the liver hepatocellular carcinoma (HCC) TCGA database, specifically the short NF-YAs and NF-YC2 (37 kDa) isoforms. This is observed at all tumor stages, in viral-infected samples and independently from the inflammatory status. Up-regulation of NF-YAs and NF-YC, but not NF-YB, is associated to tumors with mutant p53. We used a deep-learning-based method (DeepCC) to extend the partitioning of the three molecular clusters to all HCC TCGA tumors. In iCluster3, CCAAT is a primary matrix found in promoters of up-regulated genes, and cell-cycle pathways are enriched. Finally, clinical data indicate that, globally, only NF-YAs, but not HFD subunits, correlate with the worst prognosis; in iCluster1 patients, however, all subunits correlate. The data show a difference with other epithelial cancers, in that global overexpression of the three subunits is reported and clinically relevant in a subset of patients; yet, they further reinstate the regulatory role of the sequence-specific subunit.


Asunto(s)
Factor de Unión a CCAAT/genética , Carcinoma Hepatocelular/genética , Regulación Neoplásica de la Expresión Génica , Neoplasias Hepáticas/genética , Biomarcadores de Tumor , Factor de Unión a CCAAT/química , Factor de Unión a CCAAT/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Perfilación de la Expresión Génica , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Estadificación de Neoplasias , Regiones Promotoras Genéticas , Isoformas de Proteínas , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteína p53 Supresora de Tumor/genética
9.
Cells ; 9(11)2020 10 29.
Artículo en Inglés | MEDLINE | ID: mdl-33138093

RESUMEN

NF-Y is a transcription factor (TF) comprising three subunits (NF-YA, NF-YB, NF-YC) that binds with high specificity to the CCAAT sequence, a widespread regulatory element in gene promoters of prosurvival, cell-cycle-promoting, and metabolic genes. Tumor cells undergo "metabolic rewiring" through overexpression of genes involved in such pathways, many of which are under NF-Y control. In addition, NF-YA appears to be overexpressed in many tumor types. Thus, limiting NF-Y activity may represent a desirable anti-cancer strategy, which is an ongoing field of research. With virtual-screening docking simulations on a library of pharmacologically active compounds, we identified suramin as a potential NF-Y inhibitor. We focused on suramin given its high water-solubility that is an important factor for in vitro testing, since NF-Y is sensitive to DMSO. By electrophoretic mobility shift assays (EMSA), isothermal titration calorimetry (ITC), STD NMR, X-ray crystallography, and molecular dynamics (MD) simulations, we showed that suramin binds to the histone fold domains (HFDs) of NF-Y, preventing DNA-binding. Our analyses, provide atomic-level detail on the interaction between suramin and NF-Y and reveal a region of the protein, nearby the suramin-binding site and poorly conserved in other HFD-containing TFs, that may represent a promising starting point for rational design of more specific and potent inhibitors with potential therapeutic applications.


Asunto(s)
Factor de Unión a CCAAT/antagonistas & inhibidores , Factor de Unión a CCAAT/química , Suramina/química , Suramina/farmacología , Factores de Transcripción/antagonistas & inhibidores , Factores de Transcripción/química , Secuencia de Aminoácidos , Fenómenos Biofísicos , ADN/metabolismo , Humanos , Espectroscopía de Resonancia Magnética , Simulación de Dinámica Molecular , Multimerización de Proteína , Relación Estructura-Actividad
10.
Genes (Basel) ; 11(2)2020 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-32075093

RESUMEN

The trimeric transcription factor (TF) NF-Y regulates the CCAAT box, a DNA element enriched in promoters of genes overexpressed in many types of cancer. The regulatory NF-YA is present in two major isoforms, NF-YAl ("long") and NF-YAs ("short"). There is growing indication that NF-YA levels are increased in tumors. Here, we report interrogation of RNA-Seq TCGA (The Cancer Genome Atlas)-all 576 samples-and GEO (Gene Expression Ominibus) datasets of lung adenocarcinoma (LUAD). NF-YAs is overexpressed in the three subtypes, proliferative, inflammatory, and TRU (terminal respiratory unit). CCAAT is enriched in promoters of tumor differently expressed genes (DEG) and in the proliferative/inflammatory intersection, matching with KEGG (Kyoto Encyclopedia of Genes and Genomes) terms cell-cycle and signaling. Increasing levels of NF-YAs are observed from low to high CpG island methylator phenotypes (CIMP). We identified 166 genes overexpressed in LUAD cell lines with low NF-YAs/NF-YAl ratios: applying this centroid to TCGA samples faithfully predicted tumors' isoform ratio. This signature lacks CCAAT in promoters. Finally, progression-free intervals and hazard ratios concurred with the worst prognosis of patients with either a low or high NF-YAs/NF-YAl ratio. In conclusion, global overexpression of NF-YAs is documented in LUAD and is associated with aggressive tumor behavior; however, a similar prognosis is recorded in tumors with high levels of NF-YAl and overexpressed CCAAT-less genes.


Asunto(s)
Adenocarcinoma del Pulmón/clasificación , Factor de Unión a CCAAT/genética , Islas de CpG , Perfilación de la Expresión Génica/métodos , Neoplasias Pulmonares/clasificación , Regulación hacia Arriba , Adenocarcinoma del Pulmón/genética , Línea Celular Tumoral , Bases de Datos Genéticas , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , Humanos , Neoplasias Pulmonares/genética , Pronóstico , Regiones Promotoras Genéticas , Análisis de Secuencia de ARN
11.
BMC Plant Biol ; 19(1): 462, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31675987

RESUMEN

BACKGROUND: Flowering time is one of the most important agronomic characteristics that ultimately determine yield potential and eco-geographical adaptation in crops. Ghd8 and Ghd7, two major flowering genes, have similar functions and large pleiotropic effects in controlling the heading date, plant height and grain yield of rice. However, these gene interactions at the genetic and molecular levels have not been determined to date. RESULTS: In this study, we investigated the genetic interaction between Ghd8 and Ghd7 by using a set of near-isogenic lines and a panel of natural germplasm accessions in rice. We found that Ghd8 affected multiple agronomic traits in a functional Ghd7-dependent manner. Both functional Ghd8 and Ghd7 are pivotal for rice photoperiod sensitivity controlled by Hd1 and Hd3a. GHD8 could form a heterotrimeric complex with HD1 and OsHAP5b to activate the transcription of Ghd7 by binding directly to the promoter region of Ghd7, which contains the CCAAT-box motif. CONCLUSIONS: The results of this study help to elucidate the genetic and molecular bases of Ghd8 and Ghd7 interactions, indicating that Ghd8 acts upstream of Ghd7 to activate its transcription, which inhibits Hd3a expression and thus affects flowering time and rice adaptation.


Asunto(s)
Flores/crecimiento & desarrollo , Oryza/genética , Fotoperiodo , Proteínas de Plantas/genética , Aclimatación/genética , Adaptación Biológica , Flores/genética , Flores/efectos de la radiación , Oryza/efectos de la radiación , Fenotipo , Proteínas de Plantas/metabolismo
12.
Genes (Basel) ; 10(11)2019 11 17.
Artículo en Inglés | MEDLINE | ID: mdl-31744190

RESUMEN

The CCAAT box is recognized by the trimeric transcription factor NF-Y, whose NF-YA subunit is present in two major splicing isoforms, NF-YAl ("long") and NF-YAs ("short"). Little is known about the expression levels of NF-Y subunits in tumors, and nothing in lung cancer. By interrogating RNA-seq TCGA and GEO datasets, we found that, unlike NF-YB/NF-YC, NF-YAs is overexpressed in lung squamous cell carcinomas (LUSC). The ratio of the two isoforms changes from normal to cancer cells, with NF-YAs becoming predominant in the latter. NF-YA increased expression correlates with common proliferation markers. We partitioned all 501 TCGA LUSC tumors in the four molecular cohorts and verified that NF-YAs is similarly overexpressed. We analyzed global and subtype-specific RNA-seq data and found that CCAAT is the most abundant DNA matrix in promoters of genes overexpressed in all subtypes. Enriched Gene Ontology terms are cell-cycle and signaling. Survival curves indicate a worse clinical outcome for patients with increasing global amounts of NF-YA; same with hazard ratios with very high and, surprisingly, very low NF-YAs/NF-YAl ratios. We then analyzed gene expression in this latter cohort and identified a different, pro-migration signature devoid of CCAAT. We conclude that overexpression of the NF-Y regulatory subunit in LUSC has the scope of increasing CCAAT-dependent, proliferative (NF-YAshigh) or CCAAT-less, pro-migration (NF-YAlhigh) genes. The data further reinstate the importance of analysis of single isoforms of TFs involved in tumor development.


Asunto(s)
Factor de Unión a CCAAT/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Células Escamosas/genética , Regulación Neoplásica de la Expresión Génica , Neoplasias Pulmonares/genética , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/patología , Movimiento Celular/genética , Proliferación Celular/genética , Estudios de Cohortes , Conjuntos de Datos como Asunto , Ontología de Genes , Humanos , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Pronóstico , Regiones Promotoras Genéticas/genética , Isoformas de Proteínas/metabolismo , RNA-Seq , Análisis de Supervivencia
13.
Front Microbiol ; 10: 1645, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31379791

RESUMEN

The CCAAT box-harboring proteins represent a family of heterotrimeric transcription factors which is highly conserved in eukaryotes. In fungi, one of the particularly important homologs of this family is the Hap complex that separates the DNA-binding domain from the activation domain and imposes essential impacts on regulation of a wide range of cellular functions. So far, a comprehensive summary of this complex has been described in filamentous fungi but not in the yeast. In this review, we summarize a number of studies related to the structure and assembly mode of the Hap complex in a list of representative yeasts. Furthermore, we emphasize recent advances in understanding the regulatory functions of this complex, with a special focus on its role in regulating respiration, production of reactive oxygen species (ROS) and iron homeostasis.

14.
Trends Microbiol ; 27(8): 703-714, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31076245

RESUMEN

The eukaryotic lineage arose from bacterial and archaeal cells that underwent a symbiotic merger. At the origin of the eukaryote lineage, the bacterial partner contributed genes, metabolic energy, and the building blocks of the endomembrane system. What did the archaeal partner donate that made the eukaryotic experiment a success? The archaeal partner provided the potential for complex information processing. Archaeal histones were crucial in that regard by providing the basic functional unit with which eukaryotes organize DNA into nucleosomes, exert epigenetic control of gene expression, transcribe genes with CCAAT-box promoters, and a manifest cell cycle with condensed chromosomes. While mitochondrial energy lifted energetic constraints on eukaryotic protein production, histone-based chromatin organization paved the path to eukaryotic genome complexity, a critical hurdle en route to the evolution of complex cells.


Asunto(s)
Archaea/fisiología , Evolución Biológica , Células Eucariotas/fisiología , Histonas/fisiología , ADN , Mitocondrias/fisiología , Simbiosis
15.
Biochim Biophys Acta Gene Regul Mech ; 1861(5): 509-518, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29505822

RESUMEN

The heterotrimeric NF-Y complex is a pioneer factor that binds to CCAAT-genes and regulates their transcription. NF-Y cooperates with multiple transcription factors and co-regulators in order to positively or negatively influence gene transcription. The recruitment of NF-Y to CCAAT box is significantly enriched in cancer-associated gene promoters loci and positively correlates with malignancy. NF-Y subunits, in particular the DNA-binding subunit NF-YA and the histone-fold subunit NF-YC, appear overexpressed in specific types of cancer. Here we demonstrate that NF-Y subunits expression is finely regulated through transcriptional and post-translational mechanisms thus allowing control over basal expression levels. NF-Y negatively regulates the transcription of the genes encoding for its subunits. DNA pull-down/affinity purification assay coupled with Mass Spectrometry identified putative co-regulators, such as Lamin A, involved in NF-YA gene transcription level. We also evidentiate how the stability of the complex is severely affected by the absence of one subunit. Our results identified for the first time one of the mechanisms responsible for NF-Y expression, which may be involved in the aberrant expression and activity observed in tumor cells and other pathological conditions.


Asunto(s)
Factor de Unión a CCAAT/genética , Lamina Tipo A/genética , Neoplasias/genética , Transcripción Genética , Regulación de la Expresión Génica , Células HCT116 , Humanos , Espectrometría de Masas , Neoplasias/patología , Regiones Promotoras Genéticas , Unión Proteica
16.
Biochem Biophys Res Commun ; 491(3): 754-759, 2017 09 23.
Artículo en Inglés | MEDLINE | ID: mdl-28739254

RESUMEN

Small GTPases of the Rho subfamily have been implicated in many physiological and pathological processes in various cell types including embryonic stem cells (ESCs). In the present study we performed a functional analysis of the promoters of the RhoA and the RhoB genes in order to identify regulatory elements that are important for their transcriptional control in ESCs. We show that RhoA mRNA levels were significantly higher compared with the RhoB mRNA levels in ESCs as well in various cancer cell lines and this difference could be accounted for by differences in the activities of the corresponding promoters. Deletion analysis of the RhoA and RhoB promoters in ESCs revealed that the proximal regions contain regulatory elements that are critical for their activity. Both proximal promoters contain CCAAT boxes and mutagenesis of these elements decreased significantly the activity of both promoters suggesting a coordinated regulation of the two genes by CCAAT box binding factors. Finally, we show that both genes are subjects to autoregulation in ESCs and in the case of RhoB, this autoregulation requires the GTPase activity of the Rho proteins. Understanding the mechanisms that control the transcription of Rho GTPases in ESCs may shed new light into the still unknown roles of these proteins in stem cell functions.


Asunto(s)
Células Madre Embrionarias/fisiología , Regulación del Desarrollo de la Expresión Génica/genética , Regiones Promotoras Genéticas/genética , Elementos Reguladores de la Transcripción/genética , Proteína de Unión al GTP rhoA/genética , Proteína de Unión al GTP rhoB/genética , Animales , Línea Celular , Ratones
17.
Biochim Biophys Acta Gene Regul Mech ; 1860(5): 590-597, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27697431

RESUMEN

For long it has been recognized that CCAAT boxes and GC-rich elements co-occur in many human and murine promoters within 100bp upstream of the transcription start site. The trimeric transcription factor NF-Y is the major CCAAT box-binding factor, and members of the SP family of transcription factors are the major GC box-binding proteins. Recent chromatin immunoprecipitations coupled with high throughput sequencing (ChIP-seq) have examined binding of NF-Y and the ubiquitous SP factors SP1, SP2 and SP3 genome-wide, allowing for comprehensive comparison of NF-Y and SP factor actions in the context of chromatin. Here, I attempt a synthesis of the earlier single-promoter type of analysis with the more recent genome-wide studies. In particular, I also discuss different modes of genomic interactions between SP factors and NF-Y that have emerged recently, and identify a key technical issue, which needs to be taken into account in a critical evaluation of genome-wide studies. This article is part of a Special Issue entitled: Nuclear Factor Y in Development and Disease, edited by Prof. Roberto Mantovani.


Asunto(s)
Factor de Unión a CCAAT/metabolismo , Elementos de Respuesta/fisiología , Factores de Transcripción Sp/metabolismo , Animales , Factor de Unión a CCAAT/genética , Inmunoprecipitación de Cromatina , Estudio de Asociación del Genoma Completo , Humanos , Ratones , Factores de Transcripción Sp/genética
18.
Oncotarget ; 8(69): 113987-114001, 2017 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-29371963

RESUMEN

Little is known about transcription factor regulation during the Plasmodium falciparum intraerythrocytic cycle. In order to elucidate the role of the P. falciparum (Pf)NF-YB transcription factor we searched for target genes in the entire genome. PfNF-YB mRNA is highly expressed in late trophozoite and schizont stages relative to the ring stage. In order to determine the candidate genes bound by PfNF-YB a ChIP-on-chip assay was carried out and 297 genes were identified. Ninety nine percent of PfNF-YB binding was to putative promoter regions of protein coding genes of which only 16% comprise proteins of known function. Interestingly, our data reveal that PfNF-YB binding is not exclusively to a canonical CCAAT box motif. PfNF-YB binds to genes coding for proteins implicated in a range of different biological functions, such as replication protein A large subunit (DNA replication), hypoxanthine phosphoribosyltransferase (nucleic acid metabolism) and multidrug resistance protein 2 (intracellular transport).

19.
Biochim Biophys Acta Gene Regul Mech ; 1860(5): 581-589, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27769808

RESUMEN

NF-Y is a trimeric transcription factor that binds on DNA the CCAAT-box motif. In this article we reviewed and complemented with additional bioinformatic analysis existing data on genome-wide NF-Y binding characterization in human, reaching the following main conclusions: (1) about half of NF-Y binding sites are located at promoters, about 60-80 base pairs from transcription start sites; NF-Y binding to distal genomic regions takes place at inactive chromatin loci and/or DNA repetitive elements more often than active enhancers; (2) on almost half of its binding sites, regardless of their genomic localization (promoters or distal regions), NF-Y finds on DNA more than one CCAAT-box, and most of those multiple CCAAT binding loci present precise spacing and organization of the elements composing them; (3) there exists a well defined class of transcription factors that show genome-wide co-localization with NF-Y. Some of them lack their canonical binding site in binding regions overlapping with NF-Y, hence hinting at NF-Y mediated recruitment, while others show a precise positioning on DNA of their binding sites with respect to the CCAAT box bound by NF-Y. This article is part of a Special Issue entitled: Nuclear Factor Y in Development and Disease, edited by Prof. Roberto Mantovani.


Asunto(s)
Factor de Unión a CCAAT/metabolismo , Cromatina/metabolismo , Elementos de Respuesta/fisiología , Factor de Unión a CCAAT/genética , Cromatina/genética , Estudio de Asociación del Genoma Completo , Células HeLa , Humanos , Células K562
20.
Biochim Biophys Acta Gene Regul Mech ; 1860(5): 604-616, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27939755

RESUMEN

NF-Y is a ubiquitous heterotrimeric transcription factor with a binding affinity for the CCAAT consensus motif, one of the most common cis-acting element in the promoter and enhancer regions of eukaryote genes in direct (CCAAT) or reverse (ATTGG) orientation. NF-Y consists of three subunits, NF-YA, the regulatory subunit of the trimer, NF-YB, and NF-YC, all required for CCAAT binding. Growing evidence in cells and animal models support the notion that NF-Y, driving transcription of a plethora of cell cycle regulatory genes, is a key player in the regulation of proliferation. Proper control of cellular growth is critical for cancer prevention and uncontrolled proliferation is a hallmark of cancer cells. Indeed, during cell transformation aberrant molecular pathways disrupt mechanisms controlling proliferation and many growth regulatory genes are altered in tumors. Here, we review bioinformatics, molecular and functional evidence indicating the involvement of the cell cycle regulator NF-Y in cancer-associated pathways. This article is part of a Special Issue entitled: Nuclear Factor Y in Development and Disease, edited by Prof. Roberto Mantovani.


Asunto(s)
Factor de Unión a CCAAT/metabolismo , Proliferación Celular , Transformación Celular Neoplásica/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Animales , Factor de Unión a CCAAT/genética , Transformación Celular Neoplásica/genética , Transformación Celular Neoplásica/patología , Humanos , Proteínas de Neoplasias/genética , Neoplasias/genética , Neoplasias/patología
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