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1.
iScience ; 27(2): 108869, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38318361

RESUMO

Trained immunity (TI) represents a memory-like process of innate immune cells. TI can be initiated with various compounds such as fungal ß-glucan or the tuberculosis vaccine, Bacillus Calmette-Guérin. Nevertheless, considering the clinical applications of harnessing TI against infections and cancer, there is a growing need for new, simple, and easy-to-use TI inducers. Here, we demonstrate that heat-killed Mycobacterium tuberculosis (HKMtb) induces TI both in vitro and in vivo. In human monocytes, this effect represents a truly trained process, as HKMtb confers boosted inflammatory responses against various heterologous challenges, such as lipopolysaccharide (Toll-like receptor [TLR] 4 ligand) and R848 (TLR7/8 ligand). Mechanistically, HKMtb-induced TI relies on epigenetic mechanisms in a Syk/HIF-1α-dependent manner. In vivo, HKMtb induced TI when administered both systemically and intranasally, with the latter generating a more robust TI response. Summarizing, our research has demonstrated that HKMtb has the potential to act as a mucosal immunotherapy that can successfully induce trained responses.

2.
Membranes (Basel) ; 13(8)2023 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-37623758

RESUMO

The occurrence of emerging organic contaminants, such as pharmaceuticals, is a growing global concern. In this research, for a membrane bioreactor (MBR) laboratory plant operating at a hydraulic retention time (HRT) of 24 h, fed with real urban wastewater, the heterotrophic biomass behaviour was analysed for two concentrations of erythromycin, ibuprofen, and diclofenac. The concentrations studied for the first phase were erythromycin 0.576 mg L-1, ibuprofen 0.056 mg L-1, and diclofenac 0.948 mg L-1. For Phase 2, the concentrations were increased to erythromycin 1.440 mg L-1, ibuprofen 0.140 mg L-1, and diclofenac 2.370 mg L-1. Heterotrophic biomass was affected and inhibited by the presence of pharmaceutical compounds in both phases. The system response to low concentrations of pharmaceutical compounds occurred in the initial phase of plant doping. Under these operating conditions, there was a gradual decrease in the concentration of mixed liquor suspended solids and the removal of chemical oxygen demand of the system, as it was not able to absorb the effect produced by the pharmaceutical compounds added in both phases.

3.
Membranes (Basel) ; 12(10)2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-36295741

RESUMO

The increase in industry and population, together with the need for wastewater reuse, makes it necessary to implement new technologies in the circular economy framework. The aim of this research was to evaluate the quality of the effluent of an algae membrane photobioreactor for the treatment of the effluent of an urban wastewater treatment plant, to characterise the ultrafiltration membranes, to study the effectiveness of a proposed cleaning protocol, and to analyse the performance of the photobioreactor. The photobioreactor operated under two days of hydraulic retention times feed with the effluent from the Los Vados wastewater treatment plant (WWTP) (Granada, Spain). The microalgae community in the photobioreactor grew according to the pseudo-second-order model. The effluent obtained could be reused for different uses of diverse quality with the removal of total nitrogen and phosphorus of 56.3% and 64.27%, respectively. The fouling of the polyvinylidene difluoride ultrafiltration membrane after 80 days of operation was slight, increasing the total membrane resistance by approximately 22%. Moreover, the higher temperature of the medium was, the lower intrinsic resistance of the membrane. A total of 100% recovery of the membrane was obtained in the two-phase cleaning protocol, with 42% and 58%, respectively.

4.
Bioresour Technol ; 363: 127968, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36115507

RESUMO

Every day, large quantities of wastewater are discharged from various sources that could be reused. Wastewater contains nutrients such as nitrogen or phosphorus, which can be recovered. Microalgae-based technologies have attracted attention in this sector, as they are able to bioremediate wastewater, harnessing its nutrients and generating algal biomass useful for different downstream uses, as well as having other advantages. There are multiple species of microalgae capable of growing in wastewater, achieving nutrient removal efficiencies surpassing 70%. On the other hand, microalgae contain lipids that can be extracted for energy recovery in biodiesel. Currently, there are several methods of lipid extraction from microalgae. Other biofuels can also be obtained from microalgae biomass, such as bioethanol, biohydrogen or biogas. This review also provides information on bioenergy products and products in the agri-food industry as well as in the field of human health based on microalgae biomass within the concept of circular bioeconomy.


Assuntos
Microalgas , Biocombustíveis , Biomassa , Reatores Biológicos , Humanos , Lipídeos , Nitrogênio/análise , Nutrientes , Fósforo , Águas Residuárias
5.
BMJ Open ; 12(2): e051187, 2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-35115349

RESUMO

OBJECTIVE: Successful clinical trials are subject to recruitment. Recently, the REJUVENATE trial, a prospective phase 2a open-label, single-arm interventional clinical trial conducted within the Innovative Medicines Initiative-supported Combatting Bacterial Resistance in Europe-Carbapenem Resistance project, was published, with 85% of the recruitment performed in Spain. We analysed the recruitment success in this trial by establishing a model of recruitment practice. METHODS: A descriptive qualitative study was performed from May 2016 to October 2017 at 10 participating Spanish centres. Data were extracted from: (1) feasibility questionnaires to assess the centre's potential for patient enrolment; (2) delegation of responsibility records; (3) pre-screening records including an anonymised list of potentially eligible and (4) screening and enrolment records. A descriptive analysis of the features was performed by the participating centre. Pearson's and Spearman's correlation coefficients were calculated to determine factors of recruitment success. RESULTS: The highest recruitment rate was observed in Hospitals 3 and 6 (58.8 and 47.0 patients per month, respectively). All the study teams were multidisciplinary with a median of 15 members (range: 7-22). Only Hospitals 3, 5 and 6 had dedicated nursing staff appointed exclusively to this study. Moreover, in those three hospitals and in Hospital 9, the study coordinator performed exclusive functions as a research planner, and did not assume these functions for the other hospitals. The univariate analysis showed a significant association between recruitment success and months of recruitment (p=0.024), number of staff (p<0.001), higher number of pharmacists (p=0.005), infectious disease specialists (p<0.001), the presence of microbiologist in the research team (p=0.018) and specifically dedicated nursing staff (p=0.036). CONCLUSIONS: The existence of broad multidisciplinary teams with staff dedicated exclusively to the study as well as the implementation of a well-designed local patient assessment strategy were the essential optimisation factors for recruitment success in Spain. TRIAL REGISTRATION NUMBER: NCT02655419; EudraCT 2015-002726-39; analysis of pre-screened patients.


Assuntos
Aztreonam , Compostos Azabicíclicos , Humanos , Estudos Prospectivos , Espanha , Inquéritos e Questionários
6.
Cir Cir ; 88(6): 703-707, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33254196

RESUMO

BACKGROUND: Intermittent intraoperative neuromonitoring of the recurrent laryngeal nerve is the ideal complement in thyroid surgeries, decreasing thyroid injuries. OBJECTIVE: To analyze the prevalence of recurrent laryngeal nerve injuries with the use and without the use of neuromonitoring in thyroid surgery. METHOD: Observational, descriptive and retrospective study, in which a total of 571 patients were included between the years 2012-2018. Of which 180 neuromonitoring was used and 391 were not used. RESULTS: Of the 180 patients who underwent total thyroidectomy with the use of neuromonitoring, we had a total of 8 (4.4%) transient paralysis and 2 (1.1%) definitive. Without the use of neuromonitoring we obtain 12 (3%) transient paralysis and 7 (1.85%) definitive. CONCLUSIONS: We believe that the use of neuromonitoring complementary to surgery should be used routinely to the usual technique. And we also obtain significant results regarding the reduction of recurrent laryngeal nerve injuries with the use of intraoperative neuromonitoring.


ANTECEDENTES: La neuromonitorización intraoperatoria intermitente del nervio laríngeo recurrente es el complemento ideal en las cirugías tiroideas, ya que disminuye las lesiones. OBJETIVO: Analizar la prevalencia de lesiones del nervio laríngeo recurrente con y sin el uso de neuromonitorización en cirugía de tiroides. MÉTODO: Estudio observacional, descriptivo y retrospectivo, en el que se incluyeron 571 pacientes entre los años 2012 y 2018. De ellos, en 180 se utilizó neuromonitorización y en 391 no. RESULTADOS: De los 180 pacientes que se sometieron a tiroidectomía total con neuromonitorización hubo 8 (4.4%) parálisis transitorias y 2 (1.1%) parálisis definitivas. Sin el uso de neuromonitorización hubo 12 (3%) parálisis transitorias y 7 (1.85%) definitivas. CONCLUSIONES: Creemos que la neuromonitorización debe usarse sistemáticamente con la técnica habitual. Obtenemos resultados significativos con respecto a la reducción de las lesiones del nervio laríngeo recurrente con el uso de neuromonitorización intraoperatoria.


Assuntos
Traumatismos do Nervo Laríngeo Recorrente , Humanos , Nervo Laríngeo Recorrente , Traumatismos do Nervo Laríngeo Recorrente/epidemiologia , Traumatismos do Nervo Laríngeo Recorrente/prevenção & controle , Estudos Retrospectivos , Tireoidectomia
7.
Cir. Esp. (Ed. impr.) ; 96(9): 529-536, nov. 2018. ilus
Artigo em Espanhol | IBECS | ID: ibc-176543

RESUMO

El uso de la fluorescencia en cirugía se ha ampliado y difundido en los últimos años, lo que ha constituido un auténtico fenómeno tecnológico ligado a la aparición de dispositivos adaptados a su utilización en los abordajes laparoscópicos y robóticos. La cirugía guiada por fluorescencia en el campo de la cirugía endocrina está igualmente en auge. Cada vez son más los artículos que describen su uso en la cirugía de las glándulas tiroides, paratiroides y suprarrenal, aunque con series aun modestas y con protocolos diversos no estandarizados. Existen actualmente diversas áreas de desarrollo de la aplicación de la fluorescencia en cirugía endocrina. Cabe destacar el uso de la fluorescencia con verde de indocianina en cirugía suprarrenal, la identificación y predicción de la perfusión paratiroidea con verde de indocianina, y la autofluorescencia de las glándulas paratiroides. El objetivo de este artículo es revisar las actuales aplicaciones de la fluorescencia en cirugía endocrina


The use of fluorescence in surgery has expanded and become widespread in recent years, which has led to a real technological phenomenon with the emergence of devices adapted for use in laparoscopic and robotic approaches. Fluorescence-guided surgery in the field of endocrine surgery is also on the rise. More and more articles describe its use in surgery of the thyroid, parathyroid and adrenal glands, although the series are still modest in size and protocols have not been standardized. There are currently several developing areas for the application of fluorescence in endocrine surgery, including the use of fluorescence with indocyanine green in adrenal gland surgery, the identification and prediction of parathyroid perfusion with indocyanine green, and autofluorescence of the parathyroid glands. The objective of this article is to review the current applications of fluorescence in endocrine surgery


Assuntos
Humanos , Procedimentos Cirúrgicos Endócrinos/tendências , Fluorescência , Cirurgia Assistida por Computador/tendências , Glândula Tireoide/cirurgia , Glândulas Paratireoides/cirurgia , Glândulas Suprarrenais/cirurgia , Verde de Indocianina , Veia Cava Inferior/diagnóstico por imagem , Glândulas Paratireoides/diagnóstico por imagem , Traçadores Radioativos
8.
Cir Esp (Engl Ed) ; 96(9): 529-536, 2018 Nov.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-30327136

RESUMO

The use of fluorescence in surgery has expanded and become widespread in recent years, which has led to a real technological phenomenon with the emergence of devices adapted for use in laparoscopic and robotic approaches. Fluorescence-guided surgery in the field of endocrine surgery is also on the rise. More and more articles describe its use in surgery of the thyroid, parathyroid and adrenal glands, although the series are still modest in size and protocols have not been standardized. There are currently several developing areas for the application of fluorescence in endocrine surgery, including the use of fluorescence with indocyanine green in adrenal gland surgery, the identification and prediction of parathyroid perfusion with indocyanine green, and autofluorescence of the parathyroid glands. The objective of this article is to review the current applications of fluorescence in endocrine surgery.


Assuntos
Procedimentos Cirúrgicos Endócrinos/métodos , Doenças do Sistema Endócrino/diagnóstico por imagem , Doenças do Sistema Endócrino/cirurgia , Imagem Óptica , Corantes , Humanos , Verde de Indocianina
9.
BMC Bioinformatics ; 14: 341, 2013 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-24274019

RESUMO

BACKGROUND: A novel highly conserved protein domain, DUF162 [Pfam: PF02589], can be mapped to two proteins: LutB and LutC. Both proteins are encoded by a highly conserved LutABC operon, which has been implicated in lactate utilization in bacteria. Based on our analysis of its sequence, structure, and recent experimental evidence reported by other groups, we hereby redefine DUF162 as the LUD domain family. RESULTS: JCSG solved the first crystal structure [PDB:2G40] from the LUD domain family: LutC protein, encoded by ORF DR_1909, of Deinococcus radiodurans. LutC shares features with domains in the functionally diverse ISOCOT superfamily. We have observed that the LUD domain has an increased abundance in the human gut microbiome. CONCLUSIONS: We propose a model for the substrate and cofactor binding and regulation in LUD domain. The significance of LUD-containing proteins in the human gut microbiome, and the implication of lactate metabolism in the radiation-resistance of Deinococcus radiodurans are discussed.


Assuntos
Proteínas de Bactérias/metabolismo , Deinococcus/química , Deinococcus/metabolismo , Ácido Láctico/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Cristalografia por Raios X , Deinococcus/genética , Humanos , Microbiota/efeitos da radiação , Dados de Sequência Molecular , Estrutura Terciária de Proteína
10.
J Pharmacol Exp Ther ; 346(1): 113-20, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23633618

RESUMO

An X-ray crystal structure of CYP2B4 in complex with the drug paroxetine [(3S,4R)-3-[(2H-1,3-benzodioxol-5-yloxy)methyl]-4-(4-fluorophenyl)piperidine] was solved at 2.14 Å resolution. The structure revealed a conformation intermediate to that of the recently solved complex with amlodipine and that of the more compact complex with 4-(4-chlorophenyl)imidazole in terms of the placement of the F-G cassette. Moreover, comparison of the new structure with 15 previously solved structures of CYP2B4 revealed some new insights into the determinants of active-site size and shape. The 2B4-paroxetine structure is nearly superimposable on a previously solved closed structure in a ligand-free state. Despite the overall conformational similarity among multiple closed structures, the active-site cavity volume of the paroxetine complex is enlarged. Further analysis of the accessible space and binding pocket near the heme reveals a new subchamber that resulted from the movement of secondary structural elements and rearrangements of active-site side chains. Overall, the results from the comparison of all 16 structures of CYP2B4 demonstrate a cluster of protein conformations that were observed in the presence or absence of various ligands.


Assuntos
Antidepressivos de Segunda Geração/química , Hidrocarboneto de Aril Hidroxilases/química , Inibidores Enzimáticos/química , Modelos Moleculares , Paroxetina/química , Substituição de Aminoácidos , Animais , Antidepressivos de Segunda Geração/metabolismo , Antidepressivos de Segunda Geração/farmacologia , Hidrocarboneto de Aril Hidroxilases/antagonistas & inibidores , Hidrocarboneto de Aril Hidroxilases/genética , Hidrocarboneto de Aril Hidroxilases/metabolismo , Domínio Catalítico/efeitos dos fármacos , Cristalografia por Raios X , Inibidores das Enzimas do Citocromo P-450 , Sistema Enzimático do Citocromo P-450/química , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Família 2 do Citocromo P450 , Bases de Dados de Proteínas , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Ligantes , Conformação Molecular/efeitos dos fármacos , Proteínas Mutantes/antagonistas & inibidores , Proteínas Mutantes/química , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Paroxetina/metabolismo , Paroxetina/farmacologia , Fragmentos de Peptídeos/antagonistas & inibidores , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Ligação Proteica , Estrutura Secundária de Proteína/efeitos dos fármacos , Coelhos , Ratos , Proteínas Recombinantes/antagonistas & inibidores , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Inibidores Seletivos de Recaptação de Serotonina/química , Inibidores Seletivos de Recaptação de Serotonina/metabolismo , Inibidores Seletivos de Recaptação de Serotonina/farmacologia
11.
Biochemistry ; 51(37): 7225-38, 2012 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-22909231

RESUMO

Structures of human cytochrome P450 2B6 and rabbit cytochrome P450 2B4 in complex with two molecules of the calcium channel blocker amlodipine have been determined by X-ray crystallography. The presence of two drug molecules suggests clear substrate access channels in each P450. According to a previously established nomenclature, amlodipine molecules were trapped in access pathway 2f in P450 2B6 and in pathway 2a or 2f in P450 2B4. These pathways overlap for part of the length and then diverge as they extend toward the protein surface. A previously described solvent channel was also found in each enzyme. The results indicate that key residues located on the surface and at the entrance of the substrate access channels in each of these P450s may play a crucial role in guiding substrate entry. In addition, the region of P450 2B6 and 2B4 involving helices B', F, F', and G' and part of helix G is substantially more open in the amlodipine complexes than in the corresponding 4-(4-chlorophenyl)imidazole complexes. The increased active site volume observed results from the major retraction of helices F, F', and B' and the ß4 sheet region located close to the binding cavity to accommodate amlodipine. These structures demonstrate novel insight into distinct conformational states not observed with previous P450 2B structures and provide clear evidence of the substrate access channels in two drug-metabolizing P450s. In addition, the structures exhibit the versatility that can be exploited via in silico studies with other P450 2B6 ligands as large as raloxifene and itraconazole.


Assuntos
Anlodipino/química , Hidrocarboneto de Aril Hidroxilases/química , Bloqueadores dos Canais de Cálcio/química , Oxirredutases N-Desmetilantes/química , Anlodipino/metabolismo , Animais , Hidrocarboneto de Aril Hidroxilases/metabolismo , Bloqueadores dos Canais de Cálcio/metabolismo , Cristalografia por Raios X , Citocromo P-450 CYP2B6 , Família 2 do Citocromo P450 , Humanos , Oxirredutases N-Desmetilantes/metabolismo , Ligação Proteica/efeitos dos fármacos , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Coelhos , Especificidade por Substrato
12.
Bioresour Technol ; 121: 119-26, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22858475

RESUMO

Different types of carriers were tested as support material in a lab-scale moving bed biofilm reactor (MBBR) used to treat urban wastewater under three different conditions of hydraulic retention time (HRT) and carrier filling ratios (FR). The bacterial diversity developed on the biofilms responsible of the treatment was studied using a cultivation-independent approach based on the polymerase chain reaction-temperature gradient gel electrophoresis technique (PCR-TGGE). Cluster analysis of TGGE fingerprints showed significant differences of community structure dependent upon the different operational conditions applied. Redundancy analysis (RDA) was used to determine the relationship between the operational conditions (type of carrier, HRT, FR) and bacterial biofilm diversity, demonstrating a significant effect of FR=50%. Phylogenetic analysis of PCR-reamplified and sequenced TGGE bands revealed that the prevalent Bacteria populations in the biofilm were related to Betaproteobacteria (46%), Firmicutes (34%),Alphaproteobacteria (14%) and Gammaproteobacteria (9%).


Assuntos
Bactérias/genética , Biofilmes , Reatores Biológicos/microbiologia , Cidades , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Análise de Variância , Bactérias/ultraestrutura , Sequência de Bases , Análise por Conglomerados , Impressões Digitais de DNA , Eletroforese , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Especificidade da Espécie , Fatores de Tempo
13.
Mol Pharmacol ; 80(6): 1047-55, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21875942

RESUMO

The biochemical, biophysical, and structural analysis of the cytochrome P450 2B subfamily of enzymes has provided a wealth of information regarding conformational plasticity and substrate recognition. The recent X-ray crystal structure of the drug-metabolizing P450 2B6 in complex with 4-(4-chlorophenyl)imidazole (4-CPI) yielded the first atomic view of this human enzyme. However, knowledge of the structural basis of P450 2B6 specificity and inhibition has remained limited. In this study, structures of P450 2B6 were determined in complex with the potent inhibitors 4-benzylpyridine (4-BP) and 4-(4-nitrobenzyl)pyridine (4-NBP). Comparison of the present structures with the previous P450 2B6-4-CPI complex showed that reorientation of side chains of the active site residue Phe206 on the F-helix and Phe297 on the I-helix was necessary to accommodate the inhibitors. However, P450 2B6 does not require any major side chain rearrangement to bind 4-NBP compared with 4-BP, and the enzyme provides no hydrogen-bonding partners for the polar nitro group of 4-NBP within the hydrophobic active site. In addition, on the basis of these new structures, substitution of residue 172 with histidine as observed in the single nucleotide polymorphism Q172H and in P450 2B4 may contribute to a hydrogen bonding network connecting the E- and I-helices, thereby stabilizing active site residues on the I-helix. These results provide insight into the role of active site side chains upon inhibitor binding and indicate that the recognition of the benzylpyridines in the closed conformation structure of P450 2B6 is based solely on hydrophobicity, size, and shape.


Assuntos
Hidrocarboneto de Aril Hidroxilases/antagonistas & inibidores , Hidrocarboneto de Aril Hidroxilases/metabolismo , Oxirredutases N-Desmetilantes/antagonistas & inibidores , Oxirredutases N-Desmetilantes/metabolismo , Piridinas/metabolismo , Sequência de Aminoácidos , Hidrocarboneto de Aril Hidroxilases/química , Domínio Catalítico/fisiologia , Cristalografia por Raios X , Citocromo P-450 CYP2B6 , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Humanos , Dados de Sequência Molecular , Oxirredutases N-Desmetilantes/química , Ligação Proteica/fisiologia , Conformação Proteica , Piridinas/química , Piridinas/farmacologia
14.
Protein Sci ; 19(1): 155-61, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19845004

RESUMO

Plants use a highly evolved immune system to exhibit defense response against microbial infections. The plant TIR domain, together with the nucleotide-binding (NB) domain and/or a LRR region, forms a type of molecule, named resistance (R) proteins, that interact with microbial effector proteins and elicit hypersensitive responses against infection. Here, we report the first crystal structure of a plant TIR domain from Arabidopsis thaliana (AtTIR) solved at a resolution of 2.0 A. The structure consists of five beta-strands forming a parallel beta-sheet at the core of the protein. The beta-strands are connected by a series of alpha-helices and the overall fold mimics closely that of other mammalian and bacterial TIR domains. However, the region of the alphaD-helix reveals significant differences when compared with other TIR structures, especially the alphaD3-helix that corresponds to an insertion only present in plant TIR domains. Available mutagenesis data suggest that several conserved and exposed residues in this region are involved in the plant TIR signaling function.


Assuntos
Proteínas de Arabidopsis/química , Arabidopsis/química , Sequência de Aminoácidos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Sequência Conservada , Cristalografia por Raios X/métodos , Escherichia coli/genética , Modelos Moleculares , Dados de Sequência Molecular , Mapeamento de Interação de Proteínas , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Alinhamento de Sequência
15.
J Biol Chem ; 284(32): 21386-92, 2009 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-19535337

RESUMO

Macrophages detect pathogen infection via the activation of their plasma membrane-bound Toll-like receptor proteins (TLRs). The heterotypic interaction between the Toll/interleukin-1 receptor (TIR) domains of TLRs and adaptor proteins, like Myeloid differentiation primary response gene 88 (MyD88), is the first intracellular step in the signaling pathway of the mammalian innate immune response. The hetero-oligomerization of the TIRs of the receptor and adaptor brings about the activation of the transcription factor NF-kappaB, which regulates the synthesis of pro-inflammatory cytokines. Here, we report the first crystal structure of a bacterial TIR domain solved at 2.5 A resolution. The three-dimensional fold of Paracoccus denitrificans TIR is identical to that observed for the TIR of human TLRs and MyD88 proteins. The structure shows a unique dimerization interface involving the DD-loop and EE-loop residues, whereas leaving the BB-loop highly exposed. Peptide amide hydrogen-deuterium exchange mass spectrometry also reveals that the same region is used for dimerization in solution and in the context of the full-length protein. These results, together with a functional interaction between P. denitrificans TIR and MyD88 visualized in a co-immunoprecipitation assay, further substantiate the model that bacterial TIR proteins adopt structural mimicry of the host active receptor TIR domains to interfere with the signaling of TLRs and their adaptors to decrease the inflammatory response.


Assuntos
Proteínas de Bactérias/química , Escherichia coli/metabolismo , Fator 88 de Diferenciação Mieloide/fisiologia , Paracoccus denitrificans/metabolismo , Cristalografia por Raios X/métodos , Citocinas/metabolismo , Dimerização , Humanos , Imunoprecipitação , Inflamação , Modelos Biológicos , Modelos Moleculares , Conformação Molecular , Fator 88 de Diferenciação Mieloide/química , Estrutura Terciária de Proteína , Receptores Toll-Like/química
16.
Proc Natl Acad Sci U S A ; 105(5): 1528-32, 2008 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-18218778

RESUMO

Bcl-2 inhibitor of transcription (Bit1) is a mitochondrial protein that functions as a peptidyl-tRNA hydrolase, but, when released into the cytoplasm, it elicits apoptosis. The proapoptotic function is uniquely counteracted by integrin-mediated cell attachment. We generated a conditional KO mouse of the Bit1 gene by using the Cre-LoxP recombination system. Bit1-null mice were born alive but with some developmental abnormalities. They developed a runting syndrome after birth and died within the first 2 weeks. Cultured fibroblasts from the Bit1-null embryos [mouse embryo fibroblasts (MEFs)] were more resistant to cell death induced by loss of attachment to extracellular matrix (anoikis) than cells from the wild-type or heterozygous littermates. MEFs and tissues from Bit1 KO mice displayed a marked increase in Erk phosphorylation. Knocking down Bit1 expression in cultured cells resulted in increased Erk activation, and partially knocking down Erk reversed the increased anoikis resistance of Bit1 knockdown. The enhanced Erk activation was associated with decreased Erk phosphatase activity. These studies establish the physiological significance of Bit1 activity and begin to delineate a Bit1 signaling pathway that acts through Erk regulation.


Assuntos
Anoikis/genética , Hidrolases de Éster Carboxílico/fisiologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Animais , Ataxia/genética , Hidrolases de Éster Carboxílico/genética , MAP Quinases Reguladas por Sinal Extracelular/genética , Desenvolvimento Fetal/genética , Camundongos , Camundongos Knockout , Distrofias Musculares/genética , Neutropenia/genética , Fosforilação , Síndrome
17.
J Biol Chem ; 283(4): 2098-107, 2008 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-18006495

RESUMO

The transthyretin amyloidoses appear to be caused by rate-limiting tetramer dissociation and partial monomer unfolding of the human serum protein transthyretin, resulting in aggregation and extracellular deposition of amorphous aggregates and amyloid fibrils. Mice transgenic for few copies of amyloid-prone human transthyretin variants, including the aggressive L55P mutant, failed to develop deposits. Silencing the murine transthyretin gene in the presence of the L55P human gene resulted in enhanced tissue deposition. To test the hypothesis that the murine protein interacted with human transthyretin, preventing the dissociation and partial unfolding required for amyloidogenesis, we produced recombinant murine transthyretin and human/murine transthyretin heterotetramers and compared their structures and biophysical properties to recombinant human transthyretin. We found no significant differences between the crystal structures of murine and human homotetramers. Murine transthyretin is not amyloidogenic because the native homotetramer is kinetically stable under physiologic conditions and cannot dissociate into partially unfolded monomers, the misfolding and aggregation precursor. Heterotetramers composed of murine and human subunits are also kinetically stable. These observations explain the lack of transthyretin deposition in transgenics carrying a low copy number of human transthyretin genes. The incorporation of mouse subunits into tetramers otherwise composed of human amyloid-prone transthyretin subunits imposes kinetic stability, preventing dissociation and subsequent amyloidogenesis.


Assuntos
Amiloide/química , Pré-Albumina/química , Dobramento de Proteína , Amiloide/genética , Amiloide/metabolismo , Animais , Cristalografia por Raios X , Humanos , Cinética , Camundongos , Pré-Albumina/genética , Pré-Albumina/metabolismo , Estrutura Quaternária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidade da Espécie
18.
Cell Cycle ; 6(21): 2628-32, 2007 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-17957138

RESUMO

The archetype of MAPK cascade activation is somewhat challenged by the most recent discovery of unexpected phosphorylation patterns, alternative activation mechanisms and sub-cellular localization, in various members of this protein kinase family. In particular, activation by autophosphorylation pathways has now been described for the three best understood MAPK subgroups: ERK1/2; JNK1/2 and p38 alpha/beta. Also, a form of dosage compensation between homologs has been shown to occur in the case of ERK1/2 and JNK1/2. In this paper we summarize the MAPK activation pathway, with an emphasis on non-canonical examples. We use this information to propose a model for MAPK signal transduction that considers a cross-talk between MAPKs with different activation loop sequence motifs and unique C-terminal extensions. We highlight the occurrence of non-canonical substrate specificity during MAPK auto-activation, in strong connection with MAPK homo- and hetero-dimerization events.


Assuntos
Sistema de Sinalização das MAP Quinases/fisiologia , Proteínas Quinases Ativadas por Mitógeno/química , Proteínas Quinases Ativadas por Mitógeno/fisiologia , Animais , Ativação Enzimática/fisiologia , Humanos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Especificidade por Substrato/fisiologia
19.
Cell Cycle ; 6(14): 1762-71, 2007 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-17637567

RESUMO

The c-Jun N-terminal kinases (JNKs) are ubiquitous proteins that phosphorylate their substrates, such as transcription factors, in response to physical stress, cytokines or UV radiation. This leads to changes in gene expression, ensuing either cell cycle progression or apoptosis. Active phospho JNK1 is the main in vivo kinase component of the JNK cascade, whereas JNK2 is presumed not to participate as a kinase during JNK signalling. However, there is evidence that JNK isoforms interact functionally in vivo. Also, a recent chemical genetics investigation has confirmed that JNK transient activation leads to cellular proliferation, whereas a sustained one is pro-apoptotic. Here we investigate the phosphorylation pattern of JNK2, with protein biochemistry tools and tandem mass spectrometry. We choose to focus on JNK2 because of its reported constitutive activity in glioma cells. Our results indicate that purified JNK2 from transfected nonstressed 293T cells is a mixture of the mono-sites pThr183 and pTyr185 of its activation loop and of pThr386 along its unique C-terminal region. Upon UV stimulation, its phosphorylation stoichiometry is upregulated on the activation loop, generating a mixture of mono-pTyr185 and the expected dual-pThr183/pTyr185 species, with the pThr386 specie present but unaltered respect to the basal conditions.


Assuntos
Isoenzimas/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Proteína Quinase 9 Ativada por Mitógeno/metabolismo , Animais , Linhagem Celular , Ativação Enzimática , Humanos , Isoenzimas/química , Isoenzimas/genética , Espectrometria de Massas , Camundongos , Proteína Quinase 8 Ativada por Mitógeno/química , Proteína Quinase 8 Ativada por Mitógeno/genética , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Proteína Quinase 9 Ativada por Mitógeno/química , Proteína Quinase 9 Ativada por Mitógeno/genética , Fosfopeptídeos/química , Fosfopeptídeos/metabolismo , Fosforilação , Conformação Proteica , Treonina/metabolismo , Tirosina/metabolismo
20.
Artigo em Inglês | MEDLINE | ID: mdl-17401199

RESUMO

B-cell receptor-associated protein 31 (Bap31) is an integral membrane protein located in the endoplasmic reticulum (ER) that participates in the transport and quality control of membrane proteins and plays a role in determining cell sensitivity to ER stress and apoptosis. Its cytoplasmic region contains two target sites for caspase cleavage in certain apoptotic pathways. Here, the subcloning, expression, purification and crystallization of the Homo sapiens Bap31 leucine-zipper C-terminal fragment, which spans residues Gly160-Glu246, are reported. An N-terminally His-tagged protein was overexpressed in Escherichia coli and purified by chromatographic methods. X-ray diffraction data were collected in-house to 2.5 A resolution. Crystals belong to space group P6(1)22/P6(5)22, with unit-cell parameters a = b = 70.7, c = 80.6 A. Data analysis indicates the presence of one molecule per asymmetric unit.


Assuntos
Zíper de Leucina , Proteínas de Membrana/química , Cristalização , Cristalografia por Raios X , Humanos , Conformação Proteica
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