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1.
Infect Immun ; 82(12): 5154-65, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25267836

RESUMO

Tuberculosis (TB) remains a major global health problem, and although multiple studies have addressed the relationship between Mycobacterium tuberculosis and the host on an immunological level, few studies have addressed the impact of host physiological responses. Proteases produced by bacteria have been associated with important alterations in the host tissues, and a limited number of these enzymes have been characterized in mycobacterial species. M. tuberculosis produces a protease called Zmp1, which appears to be associated with virulence and has a putative action as an endothelin-converting enzyme. Endothelins are a family of vasoactive peptides, of which 3 distinct isoforms exist, and endothelin 1 (ET-1) is the most abundant and the best-characterized isoform. The aim of this work was to characterize the Zmp1 protease and evaluate its role in pathogenicity. Here, we have shown that M. tuberculosis produces and secretes an enzyme with ET-1 cleavage activity. These data demonstrate a possible role of Zmp1 for mycobacterium-host interactions and highlights its potential as a drug target. Moreover, the results suggest that endothelin pathways have a role in the pathogenesis of M. tuberculosis infections, and ETA or ETB receptor signaling can modulate the host response to the infection. We hypothesize that a balance between Zmp1 control of ET-1 levels and ETA/ETB signaling can allow M. tuberculosis adaptation and survival in the lung tissues.


Assuntos
Proteínas de Bactérias/metabolismo , Endotelina-1/metabolismo , Interações Hospedeiro-Patógeno , Metaloproteases/metabolismo , Mycobacterium tuberculosis/fisiologia , Tuberculose/microbiologia , Animais , Modelos Animais de Doenças , Feminino , Camundongos Endogâmicos C57BL , Mycobacterium tuberculosis/enzimologia , Proteólise , Fatores de Virulência/metabolismo
2.
Planta Med ; 80(18): 1746-52, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25412318

RESUMO

As part of our continuing chemical and biological analyses of Rubiaceae species from Cerrado, we isolated novel alkaloids 1 and 2, along with known compounds epicatechin, ursolic acid, and oleanolic acid, from Galianthe ramosa. Alkaloid 2 inhibited malate synthase from the pathogenic fungus Paracoccidioides spp. This enzyme is considered an important molecular target because it is not found in humans. Molecular docking simulations were used to describe the interactions between the alkaloids and malate synthase.


Assuntos
Antifúngicos/farmacologia , Carbolinas/farmacologia , Inibidores Enzimáticos/farmacologia , Malato Sintase/antagonistas & inibidores , Paracoccidioides/enzimologia , Alcaloides/química , Alcaloides/farmacologia , Antifúngicos/química , Carbolinas/química , Inibidores Enzimáticos/química , Proteínas Fúngicas/metabolismo , Concentração Inibidora 50 , Malato Sintase/química , Malato Sintase/metabolismo , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Estrutura Molecular , Paracoccidioides/efeitos dos fármacos , Paracoccidioides/patogenicidade , Componentes Aéreos da Planta/química , Rubiaceae/química
3.
Environ Sci Technol ; 46(7): 4223-7, 2012 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-22352312

RESUMO

Carbon capture and geological sequestration is the only available technology that both allows continued use of fossil fuels in the power sector and reduces significantly the associated CO(2) emissions. Geological sequestration requires a deep permeable geological formation into which captured CO(2)can be injected, and an overlying impermeable formation, called a caprock, that keeps the buoyant CO(2) within the injection formation. Shale formations typically have very low permeability and are considered to be good caprock formations. Production of natural gas from shale and other tight formations involves fracturing the shale with the explicit objective to greatly increase the permeability of the shale. As such, shale gas production is in direct conflict with the use of shale formations as a caprock barrier to CO(2) migration. We have examined the locations in the United States where deep saline aquifers, suitable for CO(2) sequestration, exist, as well as the locations of gas production from shale and other tight formations. While estimated sequestration capacity for CO(2) sequestration in deep saline aquifers is large, up to 80% of that capacity has areal overlap with potential shale-gas production regions and, therefore, could be adversely affected by shale and tight gas production. Analysis of stationary sources of CO(2) shows a similar effect: about two-thirds of the total emissions from these sources are located within 20 miles of a deep saline aquifer, but shale and tight gas production could affect up to 85% of these sources. These analyses indicate that colocation of deep saline aquifers with shale and tight gas production could significantly affect the sequestration capacity for CCS operations. This suggests that a more comprehensive management strategy for subsurface resource utilization should be developed.


Assuntos
Dióxido de Carbono/análise , Sedimentos Geológicos/química , Gás Natural/análise , Geografia , Salinidade
4.
BMC Genomics ; 11: 130, 2010 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-20178623

RESUMO

BACKGROUND: Paracoccidioides brasiliensis (Eukaryota, Fungi, Ascomycota) is a thermodimorphic fungus, the etiological agent of paracoccidioidomycosis, the most important systemic mycoses in Latin America. Three isolates corresponding to distinct phylogenetic lineages of the Paracoccidioides species complex had their genomes sequenced. In this study the identification and characterization of class II transposable elements in the genomes of these fungi was carried out. RESULTS: A genomic survey for DNA transposons in the sequence assemblies of Paracoccidioides, a genus recently proposed to encompass species P. brasiliensis (harboring phylogenetic lineages S1, PS2, PS3) and P. lutzii (Pb01-like isolates), has been completed. Eight new Tc1/mariner families, referred to as Trem (Transposable element mariner), labeled A through H were identified. Elements from each family have 65-80% sequence similarity with other Tc1/mariner elements. They are flanked by 2-bp TA target site duplications and different termini. Encoded DDD-transposases, some of which have complete ORFs, indicated that they could be functionally active. The distribution of Trem elements varied between the genomic sequences characterized as belonging to P. brasiliensis (S1 and PS2) and P. lutzii. TremC and H elements would have been present in a hypothetical ancestor common to P. brasiliensis and P. lutzii, while TremA, B and F elements were either acquired by P. brasiliensis or lost by P. lutzii after speciation. Although TremD and TremE share about 70% similarity, they are specific to P. brasiliensis and P. lutzii, respectively. This suggests that these elements could either have been present in a hypothetical common ancestor and have evolved divergently after the split between P. brasiliensis and P. Lutzii, or have been independently acquired by horizontal transfer. CONCLUSIONS: New families of Tc1/mariner DNA transposons in the genomic assemblies of the Paracoccidioides species complex are described. Families were distinguished based on significant BLAST identities between transposases and/or TIRs. The expansion of Trem in a putative ancestor common to the species P. brasiliensis and P. lutzii would have given origin to TremC and TremH, while other elements could have been acquired or lost after speciation had occurred. The results may contribute to our understanding of the organization and architecture of genomes in the genus Paracoccidioides.


Assuntos
Elementos de DNA Transponíveis , Genoma Fúngico , Paracoccidioides/genética , Sequência de Aminoácidos , Biologia Computacional , DNA Fúngico/genética , Bases de Dados Genéticas , Dados de Sequência Molecular , Filogenia , Técnica de Amplificação ao Acaso de DNA Polimórfico , Alinhamento de Sequência , Análise de Sequência de DNA
5.
BMC Microbiol ; 10: 292, 2010 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-21080956

RESUMO

BACKGROUND: Paracoccidioides brasiliensis is a thermodimorphic fungus, the causative agent of paracoccidioidomycosis (PCM). Serine proteases are widely distributed and this class of peptidase has been related to pathogenesis and nitrogen starvation in pathogenic fungi. RESULTS: A cDNA (Pbsp) encoding a secreted serine protease (PbSP), was isolated from a cDNA library constructed with RNAs of fungal yeast cells recovered from liver of infected mice. Recombinant PbSP was produced in Escherichia coli, and used to develop polyclonal antibodies that were able to detect a 66 kDa protein in the P. brasiliensis proteome. In vitro deglycosylation assays with endoglycosidase H demonstrated that PbSP is a N-glycosylated molecule. The Pbsp transcript and the protein were induced during nitrogen starvation. The Pbsp transcript was also induced in yeast cells infecting murine macrophages. Interactions of PbSP with P. brasiliensis proteins were evaluated by two-hybrid assay in the yeast Saccharomyces cerevisiae. PbSP interacts with a peptidyl prolyl cis-trans isomerase, calnexin, HSP70 and a cell wall protein PWP2. CONCLUSIONS: A secreted subtilisin induced during nitrogen starvation was characterized indicating the possible role of this protein in the nitrogen acquisition. PbSP interactions with other P. brasiliensis proteins were reported. Proteins interacting with PbSP are related to folding process, protein trafficking and cytoskeleton reorganization.


Assuntos
Proteínas Fúngicas/metabolismo , Paracoccidioides/enzimologia , Paracoccidioidomicose/microbiologia , Serina Proteases/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Feminino , Proteínas Fúngicas/genética , Humanos , Fígado/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Paracoccidioides/genética , Ligação Proteica , Transporte Proteico , Serina Proteases/genética
6.
Curr Pharm Des ; 26(14): 1509-1520, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32183659

RESUMO

Fungal diseases are life-threatening to human health and responsible for millions of deaths around the world. Fungal pathogens lead to a high number of morbidity and mortality. Current antifungal treatment comprises drugs, such as azoles, echinocandins, and polyenes and the cure is not guaranteed. In addition, such drugs are related to severe side effects and the treatment lasts for an extended period. Thus, setting new routes for the discovery of effective and safe antifungal drugs should be a priority within the health care system. The discovery of alternative and efficient antifungal drugs showing fewer side effects is time-consuming and remains a challenge. Natural products can be a source of antifungals and used in combinatorial therapy. The most important natural products are antifungal peptides, antifungal lectins, antifungal plants, and fungi secondary metabolites. Several proteins, enzymes, and metabolic pathways could be targets for the discovery of efficient inhibitor compounds and recently, heat shock proteins, calcineurin, salinomycin, the trehalose biosynthetic pathway, and the glyoxylate cycle have been investigated in several fungal species. HSP protein inhibitors and echinocandins have been shown to have a fungicidal effect against azole-resistant fungi strains. Transcriptomic and proteomic approaches have advanced antifungal drug discovery and pointed to new important specific-pathogen targets. Certain enzymes, such as those from the glyoxylate cycle, have been a target of antifungal compounds in several fungi species. Natural and synthetic compounds inhibited the activity of such enzymes and reduced the ability of fungal cells to transit from mycelium to yeast, proving to be promisor antifungal agents. Finally, computational biology has developed effective approaches, setting new routes for early antifungal drug discovery since normal approaches take several years from discovery to clinical use. Thus, the development of new antifungal strategies might reduce the therapeutic time and increase the quality of life of patients.


Assuntos
Antifúngicos , Descoberta de Drogas , Fungos/efeitos dos fármacos , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Farmacorresistência Fúngica/efeitos dos fármacos , Humanos , Proteômica , Qualidade de Vida
7.
Transp Porous Media ; 127(1): 143-155, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30880855

RESUMO

Coated paper is an example of a multi-layer porous medium, involving a coating layer along the two surfaces of the paper and a fibrous layer in the interior of the paper. The interface between these two media needs to be characterized in order to develop relevant modeling tools. After careful cutting of the paper, a cross section was imaged using focused ion beam scanning electron microscopy. The resulting image was analyzed to characterize the coating layer and its transition to the fibrous layer. Such image analysis showed that the coating layer thickness is highly variable, with a significant fraction of it being thinner than a minimum thickness required to keep ink from invading into the fibrous layer. The overall structure of the coating and fibrous layers observed in this analysis provide insights into how the system should be modeled, with the resulting conclusion pointing to a specific kind of multi-scale modeling approach.

8.
Microbes Infect ; 10(1): 12-20, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18096424

RESUMO

Paracoccidioides brasiliensis is the etiologic agent of the Paracoccidioidomycosis the most common systemic mycosis in Latin America. Little is known about the regulation of genes involved in the innate immune host response to P. brasiliensis. We therefore examined the kinetic profile of gene expression of peritoneal macrophage infected with P. brasiliensis. Total RNA from macrophages at 6, 24 and 48h was extracted, hybridized onto nylon membranes and analyzed. An increase in the transcription of a number of pro-inflammatory molecules encoding membrane proteins, metalloproteases, involved in adhesion and phagocytosis, are described. We observed also the differential expression of genes whose products may cause apoptotic events induced at 24h. In addition, considering the simultaneous analyses of differential gene expression for the pathogen reported before by our group, at six hours post infection, we propose a model at molecular level for the P. brasiliensis-macrophage early interaction. In this regard, P. brasiliensis regulates genes specially related to stress and macrophages, at the same time point, up-regulate genes related to inflammation and phagocytosis, probably as an effort to counteract infection by the fungus.


Assuntos
Perfilação da Expressão Gênica , Macrófagos Peritoneais/microbiologia , Paracoccidioides/imunologia , Animais , Apoptose , Células Cultivadas , Inflamação/genética , Inflamação/imunologia , Mediadores da Inflamação/metabolismo , Camundongos , Modelos Biológicos , Fagocitose , Fatores de Tempo , Regulação para Cima
9.
Fungal Genet Biol ; 45(5): 605-12, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18364259

RESUMO

By means of genealogical concordance phylogenetic species recognition (GCPSR), we have investigated coding and non-coding regions from various genes and the ITS sequences of 7 new and 14 known isolates of Paracoccidioides brasiliensis. Such isolates grouped within the three phylogenetic groups recently reported in the genus Paracoccidioides, with one single exception, i.e., Pb01, a strain that has been the subject of intense molecular studies for many years. This isolate clearly separates from all other Paracoccidioides isolates in phylogenetic analyses and greatly increases the genomic variation known in this genus.


Assuntos
Paracoccidioides/classificação , Paracoccidioides/genética , Polimorfismo Genético , Animais , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Humanos , Dados de Sequência Molecular , Paracoccidioides/isolamento & purificação , Paracoccidioidomicose/microbiologia , Filogenia , Análise de Sequência de DNA , Homologia de Sequência , Microbiologia do Solo
10.
Int J Biol Macromol ; 43(1): 54-61, 2008 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-18187189

RESUMO

Trypsin was immobilized on chitosan gels coagulated with 0.1 or 1 M NaOH and activated with glutaraldehyde or glycidol. The derivatives were characterized by their recovered activity, thermal (40, 55 and 70 degrees C) and alkaline (pH 11) stabilities, amount of enzyme immobilized on gels for several enzyme loads (8-14 mg(protein)/g(Gel)) and compared to agarose derivatives. Enzyme loads higher than 14 mg(protein)/g(Gel) can be immobilized on glutaraldehyde derivatives, which showed 100% immobilization yield and, for loads up to 8 mg(protein)/g(Gel), 100% recovered activity. Activation with glycidol led to lower immobilization yields than the ones obtained with glutaraldehyde, 61% for agarose-glyoxyl (AgGly) with low grade of activation and 16% for the chitosan-glyoxyl (ChGly), but allowed obtaining the most stable derivative (ChGly), that was 660-fold more stable than the soluble enzyme at 55 and 70 degrees C-approximately threefold more stable than AgGly. The ChGly derivative presented also the highest stability during incubation at pH 11. Analyses of lysine residue contents in soluble and immobilized trypsin indicated formation of multipoint bonds between enzyme and support, for glyoxyl derivatives.


Assuntos
Quitosana/química , Enzimas Imobilizadas/química , Tripsina/química , Tripsina/metabolismo , Ácidos/química , Álcalis/química , Animais , Bovinos , Ativação Enzimática , Estabilidade Enzimática , Géis , Concentração de Íons de Hidrogênio , Hidrólise , Pâncreas/enzimologia , Solubilidade , Temperatura
11.
Int J Biol Macromol ; 113: 1214-1220, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29518446

RESUMO

A critical step in the lifecycle of many fungal pathogens is the ability to switch between filamentous and yeast growth, a process known as dimorphism. cAMP-dependent protein kinase (PKA) controls morphological changes and the pathogenicity of several animal and plant pathogenic fungi. In this work, we report the analysis of PKA activity during the mycelium to yeast transition in the pathogenic fungus Paracoccidioides lutzii. This fungus, as well as the closely related species Paracoccidioides brasiliensis, causes paracoccidioidomycosis, a systemic mycosis that affects thousands of people in Latin America. Infection occurs when hypha fragments or spores released from mycelium are inhaled by the host, an event that triggers the morphological switch. We show here that PKA activity is regulated in the fungus phase, increasing during the mycelium to yeast transition. Also, morphological transition from mycelium to yeast is blocked by the compound H89, a specific PKA inhibitor. Nevertheless, the fungus recovers its ability to change morphology when H89 is removed from the culture media. This recovery is accompanied by a significant increase in PKA activity. Our results strongly indicate that PKA directly affects phase transition in P. lutzii.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Paracoccidioides/efeitos dos fármacos , Paracoccidioides/crescimento & desenvolvimento , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/química , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Simulação de Acoplamento Molecular , Conformação Proteica , Inibidores de Proteínas Quinases/metabolismo
12.
Fungal Biol ; 122(6): 386-399, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29801782

RESUMO

The topic of 'fungal stress' is central to many important disciplines, including medical mycology, chronobiology, plant and insect pathology, industrial microbiology, material sciences, and astrobiology. The International Symposium on Fungal Stress (ISFUS) brought together researchers, who study fungal stress in a variety of fields. The second ISFUS was held in May 8-11 2017 in Goiania, Goiás, Brazil and hosted by the Instituto de Patologia Tropical e Saúde Pública at the Universidade Federal de Goiás. It was supported by grants from CAPES and FAPEG. Twenty-seven speakers from 15 countries presented their research related to fungal stress biology. The Symposium was divided into seven topics: 1. Fungal biology in extreme environments; 2. Stress mechanisms and responses in fungi: molecular biology, biochemistry, biophysics, and cellular biology; 3. Fungal photobiology in the context of stress; 4. Role of stress in fungal pathogenesis; 5. Fungal stress and bioremediation; 6. Fungal stress in agriculture and forestry; and 7. Fungal stress in industrial applications. This article provides an overview of the science presented and discussed at ISFUS-2017.


Assuntos
Fungos/fisiologia , Fungos/patogenicidade , Estresse Fisiológico , Brasil , Microbiologia Ambiental , Microbiologia Industrial , Micologia
13.
Microbes Infect ; 9(5): 583-90, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17387029

RESUMO

Paracoccidioides brasiliensis, a thermal dimorphic fungus, is the etiologic agent of the most common systemic mycosis in Latin America, paracoccidioidomycosis. The yeast form of P. brasiliensis acts as a facultative intracellular pathogen being able to survive and replicate within the phagosome of nonactivated murine and human macrophages. This ability has been proposed to be crucial to the development of disease. Thus, P. brasiliensis may have evolved mechanisms that counteract the constraints imposed by phagocytic cells. By using cDNA microarray technology we evaluated the early transcriptional response of this fungus to the environment of peritoneal murine macrophages in order to shed light on the mechanisms used by P. brasiliensis to survive within phagocytic cells. Of the 1152 genes analyzed, we identified 152 genes that were differentially transcribed. Intracellularly expressed genes were primarily associated with glucose and amino acid limitation, cell wall construction, and oxidative stress. For the first time, a comprehensive gene expression tool is used for the expression analysis of P. brasiliensis genes when interacting with macrophages. Overall, our data show a transcriptional plasticity of P. brasiliensis in response to the harsh environment of macrophages which may lead to adaptation and consequent survival of this pathogen.


Assuntos
Perfilação da Expressão Gênica , Macrófagos/microbiologia , Paracoccidioides/genética , Paracoccidioides/metabolismo , Transcrição Gênica , Animais , DNA Fúngico/análise , Regulação Fúngica da Expressão Gênica , Macrófagos/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Análise em Microsséries
14.
BMC Microbiol ; 7: 29, 2007 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-17425801

RESUMO

BACKGROUND: Paracoccidioides brasiliensis is a human pathogen with a broad distribution in Latin America. The fungus is thermally dimorphic with two distinct forms corresponding to completely different lifestyles. Upon elevation of the temperature to that of the mammalian body, the fungus adopts a yeast-like form that is exclusively associated with its pathogenic lifestyle. We describe expressed sequence tags (ESTs) analysis to assess the expression profile of the mycelium to yeast transition. To identify P. brasiliensis differentially expressed sequences during conversion we performed a large-scale comparative analysis between P. brasiliensis ESTs identified in the transition transcriptome and databases. RESULTS: Our analysis was based on 1107 ESTs from a transition cDNA library of P. brasiliensis. A total of 639 consensus sequences were assembled. Genes of primary metabolism, energy, protein synthesis and fate, cellular transport, biogenesis of cellular components were represented in the transition cDNA library. A considerable number of genes (7.51%) had not been previously reported for P. brasiliensis in public databases. Gene expression analysis using in silico EST subtraction revealed that numerous genes were more expressed during the transition phase when compared to the mycelial ESTs 1. Classes of differentially expressed sequences were selected for further analysis including: genes related to the synthesis/remodeling of the cell wall/membrane. Thirty four genes from this family were induced. Ten genes related to signal transduction were increased. Twelve genes encoding putative virulence factors manifested increased expression. The in silico approach was validated by northern blot and semi-quantitative RT-PCR. CONCLUSION: The developmental program of P. brasiliensis is characterized by significant differential positive modulation of the cell wall/membrane related transcripts, and signal transduction proteins, suggesting the related processes important contributors to dimorphism. Also, putative virulence factors are more expressed in the transition process suggesting adaptation to the host of the yeast incoming parasitic phase. Those genes provide ideal candidates for further studies directed at understanding fungal morphogenesis and its regulation.


Assuntos
Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Micélio/crescimento & desenvolvimento , Paracoccidioides/crescimento & desenvolvimento , Transcrição Gênica , Adaptação Fisiológica/genética , Sequência de Bases , Northern Blotting , Membrana Celular/metabolismo , Membrana Celular/ultraestrutura , Parede Celular/metabolismo , Parede Celular/ultraestrutura , Biologia Computacional , DNA Fúngico/química , DNA Fúngico/genética , Etiquetas de Sequências Expressas , Biblioteca Gênica , Genes Fúngicos , Dados de Sequência Molecular , Morfogênese/genética , Micélio/genética , Paracoccidioides/genética , RNA Fúngico/análise , RNA Fúngico/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Transdução de Sinais/genética
15.
BMC Genomics ; 7: 208, 2006 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-16907987

RESUMO

BACKGROUND: Mycelium-to-yeast transition in the human host is essential for pathogenicity by the fungus Paracoccidioides brasiliensis and both cell types are therefore critical to the establishment of paracoccidioidomycosis (PCM), a systemic mycosis endemic to Latin America. The infected population is of about 10 million individuals, 2% of whom will eventually develop the disease. Previously, transcriptome analysis of mycelium and yeast cells resulted in the assembly of 6,022 sequence groups. Gene expression analysis, using both in silico EST subtraction and cDNA microarray, revealed genes that were differential to yeast or mycelium, and we discussed those involved in sugar metabolism. To advance our understanding of molecular mechanisms of dimorphic transition, we performed an extended analysis of gene expression profiles using the methods mentioned above. RESULTS: In this work, continuous data mining revealed 66 new differentially expressed sequences that were MIPS(Munich Information Center for Protein Sequences)-categorised according to the cellular process in which they are presumably involved. Two well represented classes were chosen for further analysis: (i) control of cell organisation - cell wall, membrane and cytoskeleton, whose representatives were hex (encoding for a hexagonal peroxisome protein), bgl (encoding for a 1,3-beta-glucosidase) in mycelium cells; and ags (an alpha-1,3-glucan synthase), cda (a chitin deacetylase) and vrp (a verprolin) in yeast cells; (ii) ion metabolism and transport - two genes putatively implicated in ion transport were confirmed to be highly expressed in mycelium cells - isc and ktp, respectively an iron-sulphur cluster-like protein and a cation transporter; and a putative P-type cation pump (pct) in yeast. Also, several enzymes from the cysteine de novo biosynthesis pathway were shown to be up regulated in the yeast form, including ATP sulphurylase, APS kinase and also PAPS reductase. CONCLUSION: Taken together, these data show that several genes involved in cell organisation and ion metabolism/transport are expressed differentially along dimorphic transition. Hyper expression in yeast of the enzymes of sulphur metabolism reinforced that this metabolic pathway could be important for this process. Understanding these changes by functional analysis of such genes may lead to a better understanding of the infective process, thus providing new targets and strategies to control PCM.


Assuntos
Regulação Fúngica da Expressão Gênica/genética , Micélio/genética , Paracoccidioides/genética , Leveduras/genética , Transporte Biológico/genética , Northern Blotting/métodos , Proteínas de Transporte de Cátions/genética , Parede Celular/genética , Parede Celular/metabolismo , Cisteína/biossíntese , Citoesqueleto/genética , Citoesqueleto/metabolismo , Etiquetas de Sequências Expressas , Proteínas Fúngicas/genética , Perfilação da Expressão Gênica/métodos , Íons/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Leveduras/citologia , beta-Glucosidase/genética
16.
FEMS Immunol Med Microbiol ; 46(2): 269-83, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16487309

RESUMO

A full-length cDNA encoding a chitinase (Pbcts1) was cloned by screening a cDNA library from the yeast cells of Paracoccidioides brasiliensis. The cDNA consists of 1888 bp and encodes an ORF of 1218 bp corresponding to a protein of 45 kDa with 406 amino acid residues. The deduced PbCTS1 is composed of two signature family 18 catalytic domains and seems to belong to fungal/bacterial class. Phylogenetic analysis of PbCTS1 and other chitinases suggests the existence of paralogs of several chitinases to be grouped based on specialized functions, which may reflect the multiple and diverse roles played by fungi chitinases. Glycosyl hydrolase activity assays demonstrated that P. brasiliensis is able to produce and secrete these enzymes mainly during transition from yeast to mycelium. The fungus should be able to use chitin as a carbon source. The presence of an endocytic signal in the deduced protein suggests that it could be secreted by a vesicular nonclassical export pathway. The Pbcts1 expression in mycelium, yeast, during differentiation from mycelium to yeast and in yeast cells obtained from infected mice suggests the relevance of this molecule in P. brasiliensis electing PbCTS1 as an attractive drug target.


Assuntos
Quitinases , Paracoccidioides/enzimologia , Filogenia , Sequência de Aminoácidos , Animais , Sequência de Bases , Quitinases/química , Quitinases/genética , Quitinases/metabolismo , Clonagem Molecular , DNA Complementar , DNA Fúngico/análise , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Humanos , Masculino , Dados de Sequência Molecular , Micélio/enzimologia , Paracoccidioides/genética , Paracoccidioides/crescimento & desenvolvimento , Paracoccidioides/patogenicidade , Paracoccidioidomicose/microbiologia , Análise de Sequência de DNA
17.
mSphere ; 1(5)2016.
Artigo em Inglês | MEDLINE | ID: mdl-27704050

RESUMO

The Paracoccidioides genus includes two species of thermally dimorphic fungi that cause paracoccidioidomycosis, a neglected health-threatening human systemic mycosis endemic to Latin America. To examine the genome evolution and the diversity of Paracoccidioides spp., we conducted whole-genome sequencing of 31 isolates representing the phylogenetic, geographic, and ecological breadth of the genus. These samples included clinical, environmental and laboratory reference strains of the S1, PS2, PS3, and PS4 lineages of P. brasiliensis and also isolates of Paracoccidioides lutzii species. We completed the first annotated genome assemblies for the PS3 and PS4 lineages and found that gene order was highly conserved across the major lineages, with only a few chromosomal rearrangements. Comparing whole-genome assemblies of the major lineages with single-nucleotide polymorphisms (SNPs) predicted from the remaining 26 isolates, we identified a deep split of the S1 lineage into two clades we named S1a and S1b. We found evidence for greater genetic exchange between the S1b lineage and all other lineages; this may reflect the broad geographic range of S1b, which is often sympatric with the remaining, largely geographically isolated lineages. In addition, we found evidence of positive selection for the GP43 and PGA1 antigen genes and genes coding for other secreted proteins and proteases and lineage-specific loss-of-function mutations in cell wall and protease genes; these together may contribute to virulence and host immune response variation among natural isolates of Paracoccidioides spp. These insights into the recent evolutionary events highlight important differences between the lineages that could impact the distribution, pathogenicity, and ecology of Paracoccidioides. IMPORTANCE Characterization of genetic differences between lineages of the dimorphic human-pathogenic fungus Paracoccidioides can identify changes linked to important phenotypes and guide the development of new diagnostics and treatments. In this article, we compared genomes of 31 diverse isolates representing the major lineages of Paracoccidioides spp. and completed the first annotated genome sequences for the PS3 and PS4 lineages. We analyzed the population structure and characterized the genetic diversity among the lineages of Paracoccidioides, including a deep split of S1 into two lineages (S1a and S1b), and differentiated S1b, associated with most clinical cases, as the more highly recombining and diverse lineage. In addition, we found patterns of positive selection in surface proteins and secreted enzymes among the lineages, suggesting diversifying mechanisms of pathogenicity and adaptation across this species complex. These genetic differences suggest associations with the geographic range, pathogenicity, and ecological niches of Paracoccidioides lineages.

18.
Microbes Infect ; 7(1): 66-77, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15716068

RESUMO

Paracoccidioides brasiliensis is a well-characterized pathogen of humans. To identify proteins involved in the fungus-host interaction, P. brasiliensis yeast proteins were separated by liquid isoelectric focusing, and fractions were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis. Immunoreactive bands were detected with pooled sera of patients with P. brasiliensis infection. A protein species with a molecular mass of 45 kDa was subsequently purified to homogeneity by preparative gel electrophoresis. The amino acid sequence of four endoproteinase Lys-C-digested peptides indicated that the protein was a formamidase (FMD) (E.C. 3.5.1.49) of P. brasiliensis. The complete cDNA and a genomic clone (Pbfmd) encoding the isolated FMD were isolated. An open reading frame predicted a 415-amino acid protein. The sequence contained each of the peptide sequences obtained from amino acid sequencing. The Pbfmd gene contained five exons interrupted by four introns. Northern and Southern blot analysis suggested that there is one copy of the gene in P. brasiliensis and that it is preferentially expressed in mycelium. The complete coding cDNA was expressed in Escherichia coli to produce a recombinant fusion protein with glutathione S-transferase (GST). The purified recombinant protein was recognized by sera of patients with proven paracoccidioidomycosis and not by sera of healthy individuals. The recombinant 45-kDa protein was shown to be catalytically active; FMD activity was detected in P. brasiliensis yeast and mycelium.


Assuntos
Amidoidrolases/genética , Amidoidrolases/metabolismo , Antígenos de Fungos/genética , Antígenos de Fungos/metabolismo , Paracoccidioides/genética , Amidoidrolases/biossíntese , Sequência de Aminoácidos , Antígenos de Fungos/biossíntese , Sequência de Bases , Clonagem Molecular , DNA Complementar/biossíntese , Epitopos , Escherichia coli/metabolismo , Formamidas/metabolismo , Dados de Sequência Molecular , Peso Molecular , Paracoccidioides/enzimologia , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Especificidade por Substrato
19.
FEMS Immunol Med Microbiol ; 45(3): 369-81, 2005 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-16061364

RESUMO

Paracoccidioides brasiliensis is a dimorphic and thermo-regulated fungus which is the causative agent of paracoccidioidomycosis, an endemic disease widespread in Latin America. Pathogenicity is assumed to be a consequence of the cellular differentiation process that this fungus undergoes from mycelium to yeast cells during human infection. In an effort to elucidate the molecular mechanisms involved in this process a network of Brazilian laboratories carried out a transcriptome project for both cell types. This review focuses on the data analysis yielding a comprehensive view of the fungal metabolism and the molecular adaptations during dimorphism in P. brasiliensis from analysis of 6022 groups, related to expressed genes, which were generated from both mycelium and yeast phases.


Assuntos
Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Genoma Fúngico , Paracoccidioides/crescimento & desenvolvimento , Paracoccidioidomicose/microbiologia , Etiquetas de Sequências Expressas , Proteínas Fúngicas/genética , Humanos , Paracoccidioides/genética , Paracoccidioides/metabolismo , Paracoccidioides/patogenicidade , Transcrição Gênica
20.
Rev Iberoam Micol ; 22(4): 203-12, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16499412

RESUMO

Paracoccidioides brasiliensis is a dimorphic and thermo-regulated fungus which is the causative agent of paracoccidioidomycosis, an endemic disease widespread in Latin America that affects 10 million individuals. Pathogenicity is assumed to be a consequence of the dimorphic transition from mycelium to yeast cells during human infection. This review shows the results of the P. brasiliensis transcriptome project which generated 6,022 assembled groups from mycelium and yeast phases. Computer analysis using the tools of bioinformatics revealed several aspects from the transcriptome of this pathogen such as: general and differential metabolism in mycelium and yeast cells; cell cycle, DNA replication, repair and recombination; RNA biogenesis apparatus; translation and protein fate machineries; cell wall; hydrolytic enzymes; proteases; GPI-anchored proteins; molecular chaperones; insights into drug resistance and transporters; oxidative stress response and virulence. The present analysis has provided a more comprehensive view of some specific features considered relevant for the understanding of basic and applied knowledge of P. brasiliensis.


Assuntos
Genoma Fúngico , Paracoccidioides/genética , Parede Celular/metabolismo , Quitosana/metabolismo , Farmacorresistência Fúngica/genética , Proteínas Fúngicas/genética , Perfilação da Expressão Gênica , Genes Fúngicos , Humanos , América Latina/epidemiologia , Chaperonas Moleculares/genética , Estresse Oxidativo/genética , Paracoccidioides/ultraestrutura , Paracoccidioidomicose/epidemiologia , Paracoccidioidomicose/microbiologia , Transcrição Gênica , Virulência/genética
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