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1.
Nucleic Acids Res ; 49(D1): D947-D955, 2021 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-32663312

RESUMO

Housekeeping (HK) genes are constitutively expressed genes that are required for the maintenance of basic cellular functions. Despite their importance in the calibration of gene expression, as well as the understanding of many genomic and evolutionary features, important discrepancies have been observed in studies that previously identified these genes. Here, we present Housekeeping and Reference Transcript Atlas (HRT Atlas v1.0, www.housekeeping.unicamp.br) a web-based database which addresses some of the previously observed limitations in the identification of these genes, and offers a more accurate database of human and mouse HK genes and transcripts. The database was generated by mining massive human and mouse RNA-seq data sets, including 11 281 and 507 high-quality RNA-seq samples from 52 human non-disease tissues/cells and 14 healthy tissues/cells of C57BL/6 wild type mouse, respectively. User can visualize the expression and download lists of 2158 human HK transcripts from 2176 HK genes and 3024 mouse HK transcripts from 3277 mouse HK genes. HRT Atlas also offers the most stable and suitable tissue selective candidate reference transcripts for normalization of qPCR experiments. Specific primers and predicted modifiers of gene expression for some of these HK transcripts are also proposed. HRT Atlas has also been integrated with a regulatory elements resource from Epiregio server.


Assuntos
Bases de Dados Genéticas , Perfilação da Expressão Gênica/métodos , Genes Essenciais/genética , RNA-Seq/métodos , Transcrição Gênica/genética , Animais , Mineração de Dados/métodos , Humanos , Internet , Camundongos Endogâmicos C57BL , Elementos Reguladores de Transcrição/genética
2.
Sci Rep ; 10(1): 11056, 2020 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-32632086

RESUMO

The extent to which mammalian cells share similar transcriptomes remains unclear. Notwithstanding, such cross-species gene expression inquiries have been scarce for defined cell types and most lack the dissection of gene regulatory landscapes. Therefore, the work was aimed to determine C-MYC relative expression across mammalian fibroblasts (Ovis aries and Bos taurus) via cross-species RT-qPCR and comprehensively explore its regulatory landscape by in silico tools. The prediction of transcription factor binding sites in C-MYC and its 2.5 kb upstream sequence revealed substantial variation, thus indicating evolutionary-driven re-wiring of cis-regulatory elements. C-MYC and its downstream target TBX3 were up-regulated in Bos taurus fibroblasts. The relative expression of C-MYC regulators [RONIN (also known as THAP11), RXRß, and TCF3] and the C-MYC-associated transcript elongation factor CDK9 did not differ between species. Additional in silico analyses suggested Bos taurus-specific C-MYC exonization, alternative splicing, and binding sites for non-coding RNAs. C-MYC protein orthologs were highly conserved, while variation was in the transactivation domain and the leucine zipper motif. Altogether, mammalian fibroblasts display evolutionary-driven C-MYC relative expression that should be instructive for understanding cellular physiology, cellular reprogramming, and C-MYC-related diseases.


Assuntos
Bovinos/genética , Evolução Molecular , Genes myc , Carneiro Doméstico/genética , Sequência de Aminoácidos , Animais , Bovinos/metabolismo , Quinase 9 Dependente de Ciclina/genética , Fibroblastos/metabolismo , Expressão Gênica , Processamento de Proteína Pós-Traducional , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Elementos Reguladores de Transcrição , Homologia de Sequência de Aminoácidos , Carneiro Doméstico/metabolismo , Especificidade da Espécie , Proteínas com Domínio T/genética , Transcriptoma
3.
Mycopathologia ; 185(3): 415-424, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32277380

RESUMO

Fungi of the genus Candida are important etiological agents of superficial and life-threatening infections in individuals with a compromised immune system. One of the main characteristics of Candida is its ability to form highly drug tolerance biofilms in the human host. Biofilms are a dynamic community of multiple cell types whose formation over time is orchestrated by a network of transcription regulators. In this brief review, we provide an update of the processes involved in biofilm formation by Candida spp. (formation, treatment, and control), as well as the transcriptional circuitry that regulates its development and interactions with other microorganisms. Candida albicans is known to build mixed species biofilms with other Candida species and with various other bacterial species in different host niches. Taken together, these properties play a key role in Candida pathogenesis. In addition, this review gathers recent studies with new insights and perspectives for the treatment and control of Candida biofilms.


Assuntos
Biofilmes/crescimento & desenvolvimento , Candida/fisiologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Candida/genética , Candida/ultraestrutura , Adesão Celular/genética , Adesão Celular/fisiologia , Estudo de Associação Genômica Ampla , Humanos , Microscopia Eletrônica de Varredura , Nanotecnologia/tendências , Elementos Reguladores de Transcrição/genética , Elementos Reguladores de Transcrição/fisiologia
4.
PLoS One ; 15(2): e0228219, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32023282

RESUMO

The protein phosphatase 2As (PP2As) play a key role in manipulating protein phosphorylation. Although a number of proteins in the latex of laticifers are phosphorylated during latex regeneration in rubber tree, information about the PP2A family is limited. In the present study, 36 members of the HbPP2A family were genome-wide identified. They were clustered into five subgroups: the subgroup HbPP2AA (4), HbPP2AB' (14), HbPP2AB'' (6), HbPP2AB55 (4), and HbPP2AC (8). The members within the same subgroup shared highly conserved gene structures and protein motifs. Most of HbPP2As possessed ethylene- and wounding-responsive cis-acting elements. The transcripts of 29 genes could be detected in latex by using published high-throughput sequencing data. Of the 29 genes, seventeen genes were significantly down-regulated while HbPP2AA1-1 and HbPP2AB55α/Bα-1were up-regulated by tapping. Of the 17 genes, 14 genes were further significantly down-regulated by ethrel application. The down-regulated expression of a large number of HbPP2As may attribute to the enhanced phosphorylation of the proteins in latex from the tapped trees and the trees treated with ethrel application.


Assuntos
Genoma de Planta , Hevea/genética , Proteínas de Plantas/metabolismo , Proteína Fosfatase 2/metabolismo , Regulação da Expressão Gênica de Plantas , Hevea/enzimologia , Látex/metabolismo , Filogenia , Proteínas de Plantas/classificação , Proteínas de Plantas/genética , Proteína Fosfatase 2/classificação , Proteína Fosfatase 2/genética , Elementos Reguladores de Transcrição/genética
5.
Biochimie ; 160: 46-54, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30763640

RESUMO

Bacterial survive and respond to adverse changes in the environment by regulating gene transcription through two-component regulatory systems. In Salmonella Typhimurium the STM1485 gene expression is induced under low pH (4.5) during replication inside the epithelial host cell, but it is not involved in sensing or resisting to this condition. Since the RcsCDB system is activated under acidic conditions, we investigated whether this system is able to modulate STM1485 expression. We demonstrated that acid-induced activation of the RcsB represses STM1485 transcription by directly binding to the promoter. Under the same condition, the RstA regulator activates the expression of this gene. Physiologically, we observed that RcsB-dependent repression is required for the survival of bacteria when they are exposed to pancreatic fluids. We hypothesized that STM1485 plays an important role in Salmonella adaptation to pH changes, during transition in the gastrointestinal tract. We suggest that bacteria surviving the gastrointestinal environment invade the epithelial cells, where they can remain in vacuoles. In this new environment, acidity and magnesium starvation activate the expression of the RstA regulator in a PhoPQ-dependent manner, which in turn induces STM1485 expression. These levels of STM1485 allow increased bacterial replication within vacuoles to continue the course of infection.


Assuntos
Ácidos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Salmonella typhimurium/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica , Sequência de Bases , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/microbiologia , Viabilidade Microbiana , Regiões Promotoras Genéticas , Elementos Reguladores de Transcrição , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Transdução de Sinais , Fatores de Transcrição/genética
6.
Genetics ; 210(1): 113-128, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30002080

RESUMO

Adherence, an important virulence factor, is mediated by the EPA (Epithelial Adhesin) genes in the opportunistic pathogen Candida glabrata Expression of adhesin-encoding genes requires tight regulation to respond to harsh environmental conditions within the host. The majority of EPA genes are localized in subtelomeric regions regulated by subtelomeric silencing, which depends mainly on Rap1 and the Sir proteins. In vitro adhesion to epithelial cells is primarily mediated by Epa1. EPA1 forms a cluster with EPA2 and EPA3 in the right telomere of chromosome E (E-R). This telomere contains a cis-acting regulatory element, the protosilencer Sil2126 between EPA3 and the telomere. Interestingly, Sil2126 is only active in the context of its native telomere. Replacement of the intergenic regions between EPA genes in E-R revealed that cis-acting elements between EPA2 and EPA3 are required for Sil2126 activity when placed 32 kb away from the telomere (Sil@-32kb). Sil2126 contains several putative binding sites for Rap1 and Abf1, and its activity depends on these proteins. Indeed, Sil2126 binds Rap1 and Abf1 at its native position and also when inserted at -32 kb, a silencing-free environment in the parental strain. In addition, we found that Sil@-32kb and Sil2126 at its native position can physically interact with the intergenic regions between EPA1-EPA2 and EPA2-EPA3 respectively, by chromosome conformation capture assays. We speculate that Rap1 and Abf1 bound to Sil2126 can recruit the Silent Information Regulator complex, and together mediate silencing in this region, probably through the formation of a chromatin loop.


Assuntos
Candida glabrata/genética , Cromatina/genética , Proteínas Fúngicas/genética , Lectinas/genética , Montagem e Desmontagem da Cromatina , Proteínas de Ligação a DNA/genética , Células Epiteliais/metabolismo , Regulação Fúngica da Expressão Gênica , Inativação Gênica , Elementos Reguladores de Transcrição , Telômero/genética , Fatores de Transcrição/genética
7.
Arch Endocrinol Metab ; 62(2): 205-211, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29641740

RESUMO

OBJECTIVE: The transcriptional repressor DREAM is involved in thyroid-specific gene expression, thyroid enlargement and nodular development, but its clinical utility is still uncertain. In this study we aimed to investigate whether DREAM mRNA levels differ in different thyroid tumors and how this possible difference would allow the use of DREAM gene expression as molecular marker for diagnostic and/or prognosis purpose. MATERIALS AND METHODS: We quantified DREAM gene mRNA levels and investigated its mutational status, relating its expression and genetic changes to diagnostic and prognostic features of 200 thyroid tumors, being 101 malignant [99 papillary thyroid carcinomas (PTC) and 2 anaplastic thyroid carcinomas] and 99 benign thyroid lesions [49 goiter and 50 follicular adenomas (FA)]. RESULTS: Levels of mRNA of DREAM gene were higher in benign (0.7909 ± 0.6274 AU) than in malignant (0.3373 ± 0.6274 AU) thyroid lesions (p < 0.0001). DREAM gene expression was able to identify malignancy with 66.7% sensitivity, 85.4% specificity, 84.2% positive predictive value (PPV), 68.7% negative predictive value (NPV), and 75.3% accuracy. DREAM mRNA levels were also useful distinguishing the follicular lesions FA and FVPTC with 70.2% sensitivity, 73.5% specificity, 78.5% PPV, 64.1% NPV, and 71.6% accuracy. However, DREAM gene expression was neither associated with clinical features of tumor aggressiveness, nor with recurrence or survival. Six different genetic changes in non-coding regions of DREAM gene were also found, not related to DREAM gene expression or tumor features. CONCLUSION: We suggest that DREAM gene expression may help diagnose thyroid nodules, identifying malignancy and characterizing follicular-patterned thyroid lesions; however, it is not useful as a prognostic marker.


Assuntos
Biomarcadores Tumorais/genética , Proteínas Interatuantes com Canais de Kv/genética , RNA Mensageiro/genética , Elementos Reguladores de Transcrição/genética , Proteínas Repressoras/genética , Neoplasias da Glândula Tireoide/diagnóstico , Biomarcadores Tumorais/metabolismo , Feminino , Humanos , Proteínas Interatuantes com Canais de Kv/metabolismo , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Proteínas Repressoras/metabolismo , Sensibilidade e Especificidade , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/metabolismo
8.
Arch. endocrinol. metab. (Online) ; 62(2): 205-211, Mar.-Apr. 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-887654

RESUMO

ABSTRACT Objective The transcriptional repressor DREAM is involved in thyroid-specific gene expression, thyroid enlargement and nodular development, but its clinical utility is still uncertain. In this study we aimed to investigate whether DREAM mRNA levels differ in different thyroid tumors and how this possible difference would allow the use of DREAM gene expression as molecular marker for diagnostic and/or prognosis purpose. Materials and methods We quantified DREAM gene mRNA levels and investigated its mutational status, relating its expression and genetic changes to diagnostic and prognostic features of 200 thyroid tumors, being 101 malignant [99 papillary thyroid carcinomas (PTC) and 2 anaplastic thyroid carcinomas] and 99 benign thyroid lesions [49 goiter and 50 follicular adenomas (FA)]. Results Levels of mRNA of DREAM gene were higher in benign (0.7909 ± 0.6274 AU) than in malignant (0.3373 ± 0.6274 AU) thyroid lesions (p < 0.0001). DREAM gene expression was able to identify malignancy with 66.7% sensitivity, 85.4% specificity, 84.2% positive predictive value (PPV), 68.7% negative predictive value (NPV), and 75.3% accuracy. DREAM mRNA levels were also useful distinguishing the follicular lesions FA and FVPTC with 70.2% sensitivity, 73.5% specificity, 78.5% PPV, 64.1% NPV, and 71.6% accuracy. However, DREAM gene expression was neither associated with clinical features of tumor aggressiveness, nor with recurrence or survival. Six different genetic changes in non-coding regions of DREAM gene were also found, not related to DREAM gene expression or tumor features. Conclusion We suggest that DREAM gene expression may help diagnose thyroid nodules, identifying malignancy and characterizing follicular-patterned thyroid lesions; however, it is not useful as a prognostic marker.


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Proteínas Repressoras/genética , RNA Mensageiro/genética , Neoplasias da Glândula Tireoide/diagnóstico , Biomarcadores Tumorais/genética , Proteínas Interatuantes com Canais de Kv/genética , Elementos Reguladores de Transcrição/genética , Prognóstico , Proteínas Repressoras/metabolismo , RNA Mensageiro/metabolismo , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/metabolismo , Biomarcadores Tumorais/metabolismo , Sensibilidade e Especificidade , Proteínas Interatuantes com Canais de Kv/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Estadiamento de Neoplasias
9.
Mol Microbiol ; 104(5): 804-821, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28294433

RESUMO

Bacterial adherence to extracellular matrix proteins (ECMp) plays important roles during host-pathogen interaction, however its genetic regulation remains poorly understood. yloA of the model bacterium Bacillus subtilis shows high homology to genes encoding fibronectin-binding proteins of Gram-positive pathogens. Here, we characterized the regulatory network of YloA-dependent adhesive properties of the probiotic B. subtilis natto (Bsn). YloA-proficient, but not YloA-deficient, Bsn specifically bound to ECMp in a concentration-dependent manner and were proficient in biofilm formation. yloA expression showed a continuous increase in activity during the growth phase and decreased during the stationary phase. The transcription factors AbrB and DegU downregulated yloA expression during the logarithmic and stationary growth phases respectively. Analysis of the yloA promoter region revealed the presence of AT-rich direct and inverted repeats previously reported to function as DegU-recognized binding sites. In spo0A cells, yloA expression was completely turned off because of upregulation of AbrB throughout growth. Accordingly, DNase I footprinting analysis confirmed that AbrB bound to the promoter region of yloA. Interestingly, Bsn bound fibronectin with higher affinity, lower Kd, than several bacterial pathogens and competitively excluded them from binding to immobilized-fibronectin, a finding that might be important for the anti-infective properties of B. subtilis and its relatives.


Assuntos
Bacillus subtilis/metabolismo , Proteínas de Transporte/metabolismo , Matriz Extracelular/metabolismo , Fibronectinas/metabolismo , Bacillus subtilis/citologia , Bacillus subtilis/genética , Aderência Bacteriana/fisiologia , Proteínas de Bactérias/metabolismo , Sequência de Bases , Proteínas de Ligação a DNA/metabolismo , Matriz Extracelular/microbiologia , Proteínas da Matriz Extracelular/metabolismo , Regulação Bacteriana da Expressão Gênica , Interações Hospedeiro-Patógeno , Humanos , Filogenia , Regiões Promotoras Genéticas , Elementos Reguladores de Transcrição , Fatores de Transcrição/metabolismo , Transcrição Gênica
10.
FEMS Microbiol Lett ; 362(15): fnv108, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26152700

RESUMO

Autotrophic fixation of carbon dioxide into cellular carbon occurs via several pathways but quantitatively, the Calvin-Benson-Bassham cycle is the most important. CbbR regulates the expression of the cbb genes involved in CO2 fixation via the Calvin-Benson-Bassham cycle in a number of autotrophic bacteria. A gene potentially encoding CbbR (cbbR(AF)) has been predicted in the genome of the chemolithoautotrophic, extreme acidophile Acidithiobacillus ferrooxidans. However, this microorganism is recalcitrant to genetic manipulation impeding the experimental validation of bioinformatic predictions. Two novel functional assays were devised to advance our understanding of cbbR(AF) function using the mutated facultative autotroph Ralstonia eutropha H14 ΔcbbR as a surrogate host to test gene function: (i) cbbR(AF) was expressed in R. eutropha and was able to complement ΔcbbR; and (ii) CbbR(AF) was able to regulate the in vivo activity of four A. ferrooxidans cbb operon promoters in R. eutropha. These results open up the use of R. eutropha as a surrogate host to explore cbbR(AF) activity.


Assuntos
Acidithiobacillus/genética , Proteínas de Bactérias/genética , Cupriavidus necator/genética , Proteínas de Ligação a DNA/genética , Fotossíntese/genética , Elementos Reguladores de Transcrição , Fatores de Transcrição/genética , Acidithiobacillus/metabolismo , Proteínas de Bactérias/metabolismo , Sequência de Bases , Ciclo do Carbono , Clonagem Molecular , Cupriavidus necator/fisiologia , Proteínas de Ligação a DNA/metabolismo , Regulação Bacteriana da Expressão Gênica , Óperon , Fotossíntese/fisiologia , Regiões Promotoras Genéticas , Alinhamento de Sequência , Fatores de Transcrição/metabolismo
11.
J Virol ; 89(6): 3430-7, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25589642

RESUMO

The dengue virus genome is a dynamic molecule that adopts different conformations in the infected cell. Here, using RNA folding predictions, chemical probing analysis, RNA binding assays, and functional studies, we identified new cis-acting elements present in the capsid coding sequence that facilitate cyclization of the viral RNA by hybridization with a sequence involved in a local dumbbell structure at the viral 3' untranslated region (UTR). The identified interaction differentially enhances viral replication in mosquito and mammalian cells.


Assuntos
Proteínas do Capsídeo/genética , Vírus da Dengue/genética , Regulação Viral da Expressão Gênica , Genoma Viral , RNA Viral/química , RNA Viral/genética , Elementos Reguladores de Transcrição , Regiões 3' não Traduzidas , Animais , Sequência de Bases , Proteínas do Capsídeo/química , Proteínas do Capsídeo/metabolismo , Culicidae/virologia , Replicação do DNA , Vírus da Dengue/química , Vírus da Dengue/metabolismo , Dados de Sequência Molecular , Conformação de Ácido Nucleico , RNA Viral/metabolismo
12.
Genet Mol Res ; 13(3): 7217-38, 2014 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-25222227

RESUMO

This study was directed at the understanding of the function of CCoAOMT isolated from Acacia auriculiformis x Acacia mangium. Full length cDNA of the Acacia hybrid CCoAOMT (AhCCoAOMT) was 1024-bp long, containing 750-bp coding regions, with one major open reading frame of 249 amino acids. On the other hand, full length genomic sequence of the CCoAOMT (AhgflCCoAOMT) was 2548 bp long, containing three introns and four exons with a 5' untranslated region (5'UTR) of 391 bp in length. The 5'UTR of the characterized CCoAOMT gene contains various regulatory elements. Southern analysis revealed that the Acacia hybrid has more than three copies of the CCoAOMT gene. Real-time PCR showed that this gene was expressed in root, inner bark, leaf, flower and seed pod of the Acacia hybrid. Downregulation of the homologous CCoAOMT gene in tobacco by antisense (AS) and intron-containing hairpin (IHP) constructs containing partial AhCCoAOMT led to reduction in lignin content. Expression of the CCoAOMT in AS line (pART-HAS78-03) and IHP line (pART-HIHP78-06) was reduced respectively by 37 and 75% compared to the control, resulting in a decrease in the estimated lignin content by 24 and 56%, respectively. AhCCoAOMT was found to have altered not only S and G units but also total lignin content, which is of economic value to the pulp industry. Subsequent polymorphism analysis of this gene across eight different genetic backgrounds each of A. mangium and A. auriculiformis revealed 47 single nucleotide polymorphisms (SNPs) in A. auriculiformis CCoAOMT and 30 SNPs in A. mangium CCoAOMT.


Assuntos
Acacia/genética , Acacia/metabolismo , Hibridização Genética , Lignina/biossíntese , Metiltransferases/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , DNA Complementar/química , DNA Complementar/genética , Expressão Gênica , Regulação da Expressão Gênica de Plantas , Ordem dos Genes , Vetores Genéticos/genética , Metiltransferases/química , Dados de Sequência Molecular , Especificidade de Órgãos/genética , Caules de Planta/citologia , Caules de Planta/genética , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Elementos Reguladores de Transcrição , Alinhamento de Sequência , Nicotiana/genética , Nicotiana/metabolismo
13.
Diabetes ; 63(12): 4206-17, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25028525

RESUMO

Islet-1 (Isl-1) is essential for the survival and ensuing differentiation of pancreatic endocrine progenitors. Isl-1 remains expressed in all adult pancreatic endocrine lineages; however, its specific function in the postnatal pancreas is unclear. Here we determine whether Isl-1 plays a distinct role in the postnatal ß-cell by performing physiological and morphometric analyses of a tamoxifen-inducible, ß-cell-specific Isl-1 loss-of-function mouse: Isl-1(L/L); Pdx1-CreER(Tm). Ablating Isl-1 in postnatal ß-cells reduced glucose tolerance without significantly reducing ß-cell mass or increasing ß-cell apoptosis. Rather, islets from Isl-1(L/L); Pdx1-CreER(Tm) mice showed impaired insulin secretion. To identify direct targets of Isl-1, we integrated high-throughput gene expression and Isl-1 chromatin occupancy using islets from Isl-1(L/L); Pdx1-CreER(Tm) mice and ßTC3 insulinoma cells, respectively. Ablating Isl-1 significantly affected the ß-cell transcriptome, including known targets Insulin and MafA as well as novel targets Pdx1 and Slc2a2. Using chromatin immunoprecipitation sequencing and luciferase reporter assays, we found that Isl-1 directly occupies functional regulatory elements of Pdx1 and Slc2a2. Thus Isl-1 is essential for postnatal ß-cell function, directly regulates Pdx1 and Slc2a2, and has a mature ß-cell cistrome distinct from that of pancreatic endocrine progenitors.


Assuntos
Resistência à Insulina/genética , Células Secretoras de Insulina/metabolismo , Proteínas com Homeodomínio LIM/genética , Elementos Reguladores de Transcrição/genética , Fatores de Transcrição/genética , Animais , Apoptose/genética , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Perfilação da Expressão Gênica , Teste de Tolerância a Glucose , Transportador de Glucose Tipo 2/genética , Transportador de Glucose Tipo 2/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Insulina/genética , Insulina/metabolismo , Proteínas com Homeodomínio LIM/metabolismo , Fatores de Transcrição Maf Maior/genética , Fatores de Transcrição Maf Maior/metabolismo , Camundongos , Camundongos Knockout , Transativadores/genética , Transativadores/metabolismo , Fatores de Transcrição/metabolismo
14.
PLoS One ; 9(6): e99366, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24941042

RESUMO

In this work, we report the in silico identification of the cis-regulatory elements for XYR1 and CRE1 proteins in the filamentous fungus Trichoderma reesei, two regulators that play a central role in the expression of cellulase genes. Using four datasets of condition-dependent genes from RNA-seq and RT-qPCR experiments, we performed unsupervised motif discovery and found two short motifs resembling the proposed binding consensus for XYR1 and CRE1. Using these motifs, we analysed the presence and arrangement of putative cis-regulatory elements recognized by both regulators and found that shortly spaced sites were more associated with XYR1- and CRE1-dependent promoters than single, high-score sites. Furthermore, the approach used here allowed the identification of the previously reported XYR1-binding sites from cel7a and xyn1 promoters, and we also mapped the potential target sequence for this regulator at the cel6a promoter that has been suggested but not identified previously. Additionally, seven other promoters (for cel7b, cel61a, cel61b, cel3c, cel3d, xyn3 and swo genes) presented a putative XYR1-binding site, and strong sites for CRE1 were found at the xyr1 and cel7b promoters. Using the cis-regulatory architectures nearly defined for XYR1 and CRE1, we performed genome-wide identification of potential targets for direct regulation by both proteins and important differences on their functional regulons were elucidated. Finally, we performed binding site mapping on the promoters of differentially expressed genes found in T. reesei mutant strains lacking xyr1 or cre1 and found that indirect regulation plays a key role on their signalling pathways. Taken together, the data provided here sheds new light on the mechanisms for signal integration mediated by XYR1 and CRE1 at cellulase promoters.


Assuntos
Proteínas Fúngicas/genética , Trichoderma/genética , Sequência de Bases , Sítios de Ligação , Sequência Consenso , DNA Fúngico/genética , Regulação Fúngica da Expressão Gênica , Genes Fúngicos , Regiões Promotoras Genéticas , Elementos Reguladores de Transcrição , Análise de Sequência de DNA
15.
Clin Exp Med ; 14(1): 61-7, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23108479

RESUMO

Knee osteoarthritis (OA) is a common chronic degenerative disease characterized by the loss of articular cartilage components due to an imbalance between extracellular matrix destruction and repair. The proinflammatory cytokines involved in OA, TNFα and IL1ß, are considered the major implicated. The aim of this study was to investigate the relationship between TNFα -308 and -238 polymorphisms with messenger RNA (mRNA) and soluble TNFα expression in knee OA patients and healthy subjects (HS). Case-control study involved 50 knee OA patients classified according to 1986 ACR Classification Criteria, as well as 100 HS. The Western Ontario and McMaster Universities Osteoarthritis Index and Lequesne disability index were applied to OA patients. The -308 and -238 polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphism technique. The TNFα mRNA expression was quantified by real-time PCR using TaqMan method. The sTNFα levels were measured by enzyme-linked immunosorbent assay. The TNFα mRNA expression in knee OA patients was higher than in HS (1.56-fold). In addition, the TNFα mRNA expression was higher in carriers of G allele in the knee OA group for both polymorphisms. The sTNFα levels were increased in G/G versus G/A genotypes in both studied polymorphisms (p < 0.05). However, the TNFα -308 and -238 genotypes did not show statistical differences between groups. The G allele of TNFα -308 and -238 polymorphisms is associated with high mRNA and soluble expression in knee OA patients. However, it is not a marker of susceptibility in Western Mexico. Further studies are necessary to confirm these findings.


Assuntos
Predisposição Genética para Doença , Osteoartrite do Joelho/imunologia , Polimorfismo Genético , Regiões Promotoras Genéticas , Elementos Reguladores de Transcrição , Fator de Necrose Tumoral alfa/biossíntese , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Feminino , Perfilação da Expressão Gênica , Técnicas de Genotipagem , Humanos , Masculino , México , Pessoa de Meia-Idade , Ontário , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , RNA Mensageiro/biossíntese , Reação em Cadeia da Polimerase em Tempo Real , Adulto Jovem
16.
Bioinformatics ; 29(22): 2852-8, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24008418

RESUMO

MOTIVATION: Transcriptional regulation occurs through the concerted actions of multiple transcription factors (TFs) that bind cooperatively to cis-regulatory modules (CRMs) of genes. These CRMs usually contain a variable number of transcription factor-binding sites (TFBSs) involved in related cellular and physiological processes. Chromatin immunoprecipitation followed by sequencing (ChIP-seq) has been effective in detecting TFBSs and nucleosome location to identify potential CRMs in genome-wide studies. Although several attempts were previously reported to predict the potential binding of TFs at TFBSs within CRMs by comparing different ChIP-seq data, these have been hampered by excessive background, usually emerging as a consequence of experimental conditions. To understand these complex regulatory circuits, it would be helpful to have reliable and updated user-friendly tools to assist in the identification of TFBSs and CRMs for gene(s) of interest. RESULTS: Here we present INSECT (IN-silico SEarch for Co-occurring Transcription factors), a novel web server for identifying potential TFBSs and CRMs in gene sequences. By combining several strategies, INSECT provides flexible analysis of multiple co-occurring TFBSs, by applying differing search schemes and restriction parameters. availability and implementation: INSECT is freely available as a web server at http://bioinformatics.ibioba-mpsp-conicet.gov.ar/INSECT .


Assuntos
Elementos Reguladores de Transcrição , Análise de Sequência de DNA/métodos , Software , Fatores de Transcrição/metabolismo , Algoritmos , Sítios de Ligação , Imunoprecipitação da Cromatina , Simulação por Computador , Internet
17.
Mol Biol Rep ; 39(1): 327-34, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21556767

RESUMO

The Bowman-Birk (BBI) protease inhibitors can be used as source of sulfur amino acids, can regulate endogenous protease activity during seed germination and during the defense response of plants to pathogens. In soybean this family has not been fully described. The goal of this work was to characterize in silico and analyze the expression of the members of this family in soybean. We identified 11 potential BBI genes in the soybean genome. In each one of them at least a characteristic BBI conserved domain was detected in addition to a potential signal peptide. The sequences have been positioned in the soybean physical map and the promoter regions were analyzed with respect to known regulatory elements. Elements related to seed-specific expression and also to response to biotic and abiotic stresses have been identified. Based on the in silico analysis and also on quantitative RT-PCR data it was concluded that BBI-A, BBI-CII and BBI-DII are expressed specifically in the seed. The expression profiles of these three genes are similar along seed development. Their expressions reach a maximum in the intermediate stages and decrease as the seed matures. The BBI-DII transcripts are the most abundant ones followed by those of BBI-A and BBI-CII.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento/genética , Glycine max/genética , Família Multigênica/genética , Sementes/metabolismo , Inibidor da Tripsina de Soja de Bowman-Birk/genética , Inibidor da Tripsina de Soja de Bowman-Birk/metabolismo , Sequência de Bases , Biologia Computacional , Dados de Sequência Molecular , Mapeamento Físico do Cromossomo , Regiões Promotoras Genéticas/genética , Estrutura Terciária de Proteína , Reação em Cadeia da Polimerase em Tempo Real , Elementos Reguladores de Transcrição/genética , Análise de Sequência de DNA
19.
Int J Parasitol ; 41(7): 775-82, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21447339

RESUMO

Transcription initiation is the most regulated stage for the control of gene expression. This event requires that a complex of proteins called transcription factors bind to DNA through cis-regulatory elements located in the gene promoters. However, little is known about transcription regulation in Entamoeba histolytica, the protozoan parasite responsible for human amoebiasis. Some genes encoding for proteins involved in the parasite pathogenicity contain specific upstream regulatory elements (URE1-URE5) in their promoters. Here, we identified the protein that specifically binds to the URE1 sequence (EhURE1BP). This protein contains five SNase domains and one Tudor motif, and has 21% identity and 36% similarity to the multifunctional eukaryotic protein known as the protein containing Tudor and staphyloccocal nuclease-like domains (TSN). To obtain antibodies against EhURE1BP, the recombinant protein was expressed and immunised in rabbits. Western blot and immunofluorescence assays showed that EhURE1BP is located in both nuclei and cytoplasm. Electrophoretic mobility shift assays and supershift assays demonstrated that EhURE1PB specifically binds to URE1 and that the C-terminus that includes the Tudor motif contains the DNA-binding domain of this protein. Results suggest that this TSN-like protein is the transcription factor that activates the transcription of some pathogenicity-related genes of E. histolytica.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Entamoeba histolytica/fisiologia , Regulação da Expressão Gênica , Proteínas de Protozoários/metabolismo , Elementos Reguladores de Transcrição , Motivos de Aminoácidos , Western Blotting , Núcleo Celular/química , Citoplasma/química , DNA de Protozoário/genética , DNA de Protozoário/metabolismo , Proteínas de Ligação a DNA/genética , Ensaio de Desvio de Mobilidade Eletroforética , Entamoeba histolytica/genética , Entamoeba histolytica/metabolismo , Microscopia de Fluorescência , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas de Protozoários/genética , Homologia de Sequência de Aminoácidos
20.
Biochemistry ; 49(48): 10277-86, 2010 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-21047141

RESUMO

Binding cooperativity guides the formation of protein-nucleic acid complexes, in particular those that are highly regulated such as replication origins and transcription sites. Using the DNA binding domain of the origin binding and transcriptional regulator protein E2 from human papillomavirus type 16 as model, and through isothermal titration calorimetry analysis, we determined a positive, entropy-driven cooperativity upon binding of the protein to its cognate tandem double E2 site. This cooperativity is associated with a change in DNA structure, where the overall B conformation is maintained. Two homologous E2 domains, those of HPV18 and HPV11, showed that the enthalpic-entropic components of the reaction and DNA deformation can diverge. Because the DNA binding helix is almost identical in the three domains, the differences must lie dispersed throughout this unique dimeric ß-barrel fold. This is in surprising agreement with previous results for this domain, which revealed a strong coupling between global dynamics and DNA recognition.


Assuntos
Proteínas de Ligação a DNA/metabolismo , DNA/genética , DNA/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Elementos Reguladores de Transcrição/genética , Origem de Replicação/genética , Transcrição Gênica/genética , Sequência de Bases , Sítios de Ligação , DNA/química , Proteínas de Ligação a DNA/química , Papillomavirus Humano 16/química , Cinética , Modelos Moleculares , Conformação de Ácido Nucleico , Proteínas Oncogênicas Virais/química , Ligação Proteica , Estrutura Terciária de Proteína , Termodinâmica
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