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1.
Am J Surg Pathol ; 46(2): 258-267, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34799484

RESUMO

Bizarre (atypical/symplastic) cells have been described in various gynecologic normal tissues and benign neoplasms. This type of bizarre cytologic change is usually an incidental finding and is regarded as a benign process. We describe 17 cases of bizarre chorionic-type trophoblast in second-trimester and third-trimester placentas that created concern for an underlying/undersampled or incipient intraplacental trophoblastic neoplasm, predominantly found in intervillous trophoblastic islands (11/17), placental septae (6/17), chorionic plate (1/17), and/or the chorion layer of fetal membranes (2/17). The bizarre trophoblastic cells exhibited sheet-like or nested architecture, had a multifocal/patchy distribution, and/or were present as individual cells within hyaline stroma; they were characterized by large nuclei with smudgy chromatin and occasional intranuclear pseudoinclusions. The degree of atypia was classified as mild (0/17), moderate (3/17), or severe (14/17). Mitotic figures and necrosis were not identified. A dual immunohistochemical stain for trophoblast (hydroxyl-delta-5-steroid dehydrogenase) and a proliferation marker (Ki-67), performed in 15 cases, demonstrated 0% to very low proliferative activity within the bizarre trophoblast (0% to 2% [10/15], 3% to 8% [5/15]). Immunohistochemical stains for fumarate hydratase showed intact/retained expression in the bizarre cells in 7 of 7 cases. Clinical follow-up ranged from 1 to 45 months, and all patients were alive and well without subsequent evidence of a gestational trophoblastic or other neoplasms. We conclude that bizarre chorionic-type trophoblast in second-trimester or third-trimester placentas have the potential to mimic an intraplacental trophoblastic neoplasm but are likely a benign degenerative change. This study expands the spectrum of bizarre cells that occur in the gynecologic tract.


Assuntos
Doenças Placentárias/patologia , Neoplasias Trofoblásticas/patologia , Trofoblastos/patologia , Neoplasias Uterinas/patologia , Adolescente , Adulto , Biópsia , Diagnóstico Diferencial , Feminino , Fumarato Hidratase/análise , Humanos , Imuno-Histoquímica , Antígeno Ki-67/análise , Pessoa de Meia-Idade , Complexos Multienzimáticos/análise , Doenças Placentárias/metabolismo , Valor Preditivo dos Testes , Gravidez , Segundo Trimestre da Gravidez , Terceiro Trimestre da Gravidez , Progesterona Redutase/análise , Esteroide Isomerases/análise , Neoplasias Trofoblásticas/química , Trofoblastos/química , Estados Unidos , Neoplasias Uterinas/química , Adulto Jovem
2.
Methods Mol Biol ; 2261: 73-78, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33420985

RESUMO

We describe a standard protocol for phosphate-affinity fluorescent gel staining that uses a fluorophore-labeled dizinc(II) complex of a derivative of the phosphate-binding tag molecule Phos-tag to detect His- and Asp-phosphorylated proteins separated by SDS-PAGE. The procedure permits the quantitative monitoring of phosphorylated histidine kinases (His-phosphoproteins) and their cognate phosphorylated response regulators (Asp-phosphoproteins) in bacterial two-component signaling transduction systems. The total time required for each gel staining operation is about 2 h at room temperature.


Assuntos
Proteínas da Membrana Bacteriana Externa/análise , Proteínas de Bactérias/análise , Eletroforese em Gel de Poliacrilamida , Proteínas de Escherichia coli/análise , Escherichia coli/metabolismo , Complexos Multienzimáticos/análise , Fosfoproteínas/análise , Proteômica , Piridinas/química , Transativadores/análise , Ácido Aspártico , Corantes Fluorescentes , Histidina , Fosforilação
3.
Theranostics ; 9(12): 3639-3652, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31281503

RESUMO

Reprogramming of cellular metabolism is one of the hallmarks for cancer, in which tumor cells rewire their metabolic fluxes to generate sufficient energy and biosynthetic intermediates. Therefore, elucidating the correlation between cellular metabolism and hepatocellular carcinoma (HCC) progression may provide insights into novel approaches to cancer therapy. Methods: We assembled an integrated pathway-level metabolic profiling by mining metabolomic, transcriptomic and proteomic data of three HCC cell lines with increasing metastatic potentials. Immunohistochemical staining was performed in a tissue microarray from 185 HCC clinical specimens. Kaplan-Meier survival and Cox regression analyses were applied to test the association between gene expression and survival outcome. In vitro assays were conducted to investigate the functional role of enolase-phosphatase 1 (ENOPH1) in HCC malignant behaviors. Reversed genetics analysis was performed to determine the function of ENOPH1 in HCC metastasis. An intrahepatic mouse model further confirmed the role of ENOPH1 in metastasis. Results: We have determined that HCC cell metastasis is associated with alterations in metabolite levels and expressions of metabolic enzymes in the cysteine/methionine metabolism pathway, and show that one of metabolic enzymes, enolase-phosphatase 1 (ENOPH1), is persistently upregulated with an increase in metastatic potential. The upregulation of ENOPH1 expression was observed as an independent prognostic factor for HCC patients. ENOPH1 overexpression promoted cell migration and invasion, whereas ENOPH1 downregulation inhibited cell migration and invasion. Furthermore, an enhanced phosphorylation of AKT with ENOPH1 upregulation was observed. ENOPH1-mediated malignant capacity in HCC cells can be rescued by an AKT inhibitor. Conclusion: Taken together, our findings illustrate that ENOPH1 promotes HCC progression and could serve as a novel biomarker and therapeutic target for HCC.


Assuntos
Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/fisiopatologia , Neoplasias Hepáticas/fisiopatologia , Neoplasias Hepáticas/secundário , Metabolômica , Complexos Multienzimáticos/metabolismo , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Progressão da Doença , Perfilação da Expressão Gênica , Humanos , Imuno-Histoquímica , Neoplasias Hepáticas/patologia , Camundongos , Complexos Multienzimáticos/análise , Proteômica , Análise de Sobrevida
4.
J Zhejiang Univ Sci B ; 20(3): 264-272, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30829013

RESUMO

ß-Glucosidase activity assays constitute an important indicator for the early diagnosis of neonatal necrotizing enterocolitis and qualitative changes in medicinal plants. The drawbacks of the existing methods are high consumption of both time and reagents, complexity in operation, and requirement of expensive instruments and highly trained personnel. The present study provides a simplified, highly selective, and miniaturized glucometer-based strategy for the detection of ß-glucosidase activity. Single-factor experiments showed that optimum ß-glucosidase activity was exhibited at 50 °C and pH 5.0 in a citric acid-sodium citrate buffer when reacting with 0.03 g/mL salicin for 30 min. The procedure for detection was simplified without the need of a chromogenic reaction. Validation of the analytical method demonstrated that the accuracy, precision, repeatability, stability, and durability were good. The linear ranges of ß-glucosidase in a buffer solution and rat serum were 0.0873-1.5498 U/mL and 0.4076-2.9019 U/mL, respectively. The proposed method was free from interference from ß-dextranase, snailase, ß-galactosidase, hemicellulase, and glucuronic acid released by baicalin. This demonstrated that the proposed assay had a higher selectivity than the conventional dinitrosalicylic acid (DNS) assay because of the specificity for salicin and unique recognition of glucose by a personal glucose meter. Miniaturization of the method resulted in a microassay for ß-glucosidase activity. The easy-to-operate method was successfully used to detect a series of ß-glucosidases extracted from bitter almonds and cultured by Aspergillus niger. In addition, the simplified and miniaturized glucometer-based assay has potential application in the point-of-care testing of ß-glucosidase in many fields, including medical diagnostics, food safety, and environmental monitoring.


Assuntos
Química Clínica/instrumentação , Glucose/análise , beta-Glucosidase/análise , Animais , Aspergillus niger , Calibragem , Celulase/análise , Química Clínica/métodos , Dextranase/análise , Enterocolite Necrosante/sangue , Enterocolite Necrosante/diagnóstico , Desenho de Equipamento , Flavonoides/análise , Ácido Glucurônico/análise , Glucuronidase/análise , Glicosídeo Hidrolases/análise , Concentração de Íons de Hidrogênio , Modelos Lineares , Complexos Multienzimáticos/análise , Plantas Medicinais , Poligalacturonase/análise , Ratos , Reprodutibilidade dos Testes , beta-Galactosidase/análise
5.
Biochem Biophys Res Commun ; 511(4): 916-920, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30851938

RESUMO

Leydig cells play a pivotal function in the synthesis of a male sex steroid, testosterone. The ability of the steroid production is dependent on the expression of the steroidogenic genes, such as HSD3B (3ß-hydroxysteroid dehydrogenase/Δ5- Δ4 isomerase). It has been established that two different types of Leydig cells, fetal Leydig cells (FLCs) and adult Leydig cells (ALCs), are developed in mammalian testes. FLCs and ALCs are characterized by different sets of marker gene expression. In the case of mouse Leydig cells, Hsd3b1 (Hsd3b type 1) is expressed both in FLCs and ALCs whereas Hsd3b6 (Hsd3b type 6) is expressed in ALCs but not in FLCs. However, because the antibodies established so far for HSD3B were unable to distinguish between the HSD3B1 and HSD3B6 isoforms, it remained unclear whether both of them are expressed in every ALC. Therefore, in the present study, we generated a rat monoclonal antibody specific for mouse HSD3B1. Intriguingly, this monoclonal antibody together with an antibody specific for HSD3B6 identified three populations of ALCs based on the expression levels of these HSD3Bs.


Assuntos
Células Intersticiais do Testículo/citologia , Complexos Multienzimáticos/análise , Progesterona Redutase/análise , Esteroide Isomerases/análise , Testículo/citologia , Animais , Anticorpos Monoclonais/química , Linhagem da Célula , Imunofluorescência , Masculino , Camundongos , Isoformas de Proteínas/análise , Ratos , Testículo/embriologia
6.
Cell Mol Life Sci ; 76(12): 2329-2348, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30879092

RESUMO

Many secreted peptides used for cell-cell communication require conversion of a C-terminal glycine to an amide for bioactivity. This reaction is catalyzed only by the integral membrane protein peptidylglycine α-amidating monooxygenase (PAM). PAM has been highly conserved and is found throughout the metazoa; PAM-like sequences are also present in choanoflagellates, filastereans, unicellular and colonial chlorophyte green algae, dinoflagellates and haptophytes. Recent studies have revealed that in addition to playing a key role in peptidergic signaling, PAM also regulates ciliogenesis in vertebrates, planaria and chlorophyte algae, and is required for the stability of actin-based microvilli. Here we briefly introduce the basic principles involved in ciliogenesis, the sequential reactions catalyzed by PAM and the trafficking of PAM through the secretory and endocytic pathways. We then discuss the multi-faceted roles this enzyme plays in the formation and maintenance of cytoskeleton-based cellular protrusions and propose models for how PAM protein and amidating activity might contribute to ciliogenesis. Finally, we consider why some ciliated organisms lack PAM, and discuss the potential ramifications of ciliary localized PAM for the endocrine features commonly observed in patients with ciliopathies.


Assuntos
Chlamydomonas/enzimologia , Cílios/metabolismo , Oxigenases de Função Mista/metabolismo , Complexos Multienzimáticos/metabolismo , Peptídeos/metabolismo , Proteínas de Plantas/metabolismo , Actinas/metabolismo , Chlamydomonas/citologia , Chlamydomonas/metabolismo , Chlamydomonas/ultraestrutura , Cílios/ultraestrutura , Oxigenases de Função Mista/análise , Modelos Moleculares , Complexos Multienzimáticos/análise , Proteínas de Plantas/análise , Biossíntese de Proteínas , Transporte Proteico , Transdução de Sinais
7.
Braz J Med Biol Res ; 51(11): e7660, 2018 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-30304133

RESUMO

Lactate modulates the expression of lactate oxidation complex (LOC)-related genes and cardiac blood flow under physiological conditions, but its modulatory role remains to be elucidated regarding pathological cardiac stress. The present study evaluated the effect of lactate on LOC-related genes expression and hemodynamics of hearts submitted to myocardial infarction (MI). Four weeks after MI or sham operation, isolated hearts of male Wistar rats were perfused for 60 min with Na+-lactate (20 mM). As expected, MI reduced cardiac contractility and relaxation with no changes in perfusion. The impaired cardiac hemodynamics were associated with increased reactive oxygen species (ROS) levels (Sham: 19.3±0.5 vs MI: 23.8±0.3 µM), NADPH oxidase (NOX) activity (Sham: 42.2±1.3 vs MI: 60.5±1.5 nmol·h-1·mg-1) and monocarboxylate transporter 1 (mct1) mRNA levels (Sham: 1.0±0.06 vs MI: 1.7±0.2 a.u.), but no changes in superoxide dismutase (SOD), catalase, NADH oxidase (NADox), and xanthine oxidase activities. Lactate perfusion in MI hearts had no additional effect on ROS levels, NADox, and NOX activity, however, it partially reduced mct1 mRNA expression (MI-Lactate 1.3±0.08 a.u.). Interestingly, lactate significantly decreased SOD (MI-Lactate: 54.5±4.2 µmol·mg-1·min-1) and catalase (MI: 1.1±0.1 nmol·mg-1·min-1) activities in MI. Collectively, our data suggest that under pathological stress, lactate lacks its ability to modulate the expression of cardiac LOC-related genes and the perfused pressure in hearts submitted to chronic MI. Together, these data contribute to elucidate the mechanisms involved in the pathogenesis of heart failure induced by MI.


Assuntos
Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/metabolismo , Ácido Láctico/metabolismo , Ácido Láctico/farmacologia , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Animais , Catalase/análise , Expressão Gênica , Ácido Láctico/análise , Masculino , Complexos Multienzimáticos/análise , NADH NADPH Oxirredutases/análise , NADPH Oxidases/análise , Oxirredução/efeitos dos fármacos , Perfusão , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Valores de Referência , Superóxido Dismutase/análise , Fatores de Tempo , Regulação para Cima/efeitos dos fármacos , Xantina Oxidase/análise
8.
Nat Microbiol ; 3(1): 99-107, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29109478

RESUMO

Cultivation of microbial consortia provides low-complexity communities that can serve as tractable models to understand community dynamics. Time-resolved metagenomics demonstrated that an aerobic cellulolytic consortium cultivated from compost exhibited community dynamics consistent with the definition of an endogenous heterotrophic succession. The genome of the proposed pioneer population, 'Candidatus Reconcilibacillus cellulovorans', possessed a gene cluster containing multidomain glycoside hydrolases (GHs). Purification of the soluble cellulase activity from a 300litre cultivation of this consortium revealed that ~70% of the activity arose from the 'Ca. Reconcilibacillus cellulovorans' multidomain GHs assembled into cellulase complexes through glycosylation. These remarkably stable complexes have supramolecular structures for enzymatic cellulose hydrolysis that are distinct from cellulosomes. The persistence of these complexes during cultivation indicates that they may be active through multiple cultivations of this consortium and act as public goods that sustain the community. The provision of extracellular GHs as public goods may influence microbial community dynamics in native biomass-deconstructing communities relevant to agriculture, human health and biotechnology.


Assuntos
Bactérias/classificação , Bactérias/enzimologia , Celulase/análise , Celulose/metabolismo , Consórcios Microbianos/fisiologia , Complexos Multienzimáticos/análise , Filogenia , Bactérias/metabolismo , Proteínas de Bactérias/análise , Proteínas de Bactérias/isolamento & purificação , Evolução Biológica , Celulase/isolamento & purificação , Compostagem , Genoma Bacteriano/genética , Glicosídeo Hidrolases/análise , Glicosídeo Hidrolases/isolamento & purificação , Glicosilação , Processos Heterotróficos , Metagenômica , Modelos Biológicos , Complexos Multienzimáticos/isolamento & purificação , Microbiologia do Solo
9.
Braz. j. med. biol. res ; 51(11): e7660, 2018. tab, graf
Artigo em Inglês | LILACS | ID: biblio-951727

RESUMO

Lactate modulates the expression of lactate oxidation complex (LOC)-related genes and cardiac blood flow under physiological conditions, but its modulatory role remains to be elucidated regarding pathological cardiac stress. The present study evaluated the effect of lactate on LOC-related genes expression and hemodynamics of hearts submitted to myocardial infarction (MI). Four weeks after MI or sham operation, isolated hearts of male Wistar rats were perfused for 60 min with Na+-lactate (20 mM). As expected, MI reduced cardiac contractility and relaxation with no changes in perfusion. The impaired cardiac hemodynamics were associated with increased reactive oxygen species (ROS) levels (Sham: 19.3±0.5 vs MI: 23.8±0.3 µM), NADPH oxidase (NOX) activity (Sham: 42.2±1.3 vs MI: 60.5±1.5 nmol·h−1·mg−1) and monocarboxylate transporter 1 (mct1) mRNA levels (Sham: 1.0±0.06 vs MI: 1.7±0.2 a.u.), but no changes in superoxide dismutase (SOD), catalase, NADH oxidase (NADox), and xanthine oxidase activities. Lactate perfusion in MI hearts had no additional effect on ROS levels, NADox, and NOX activity, however, it partially reduced mct1 mRNA expression (MI-Lactate 1.3±0.08 a.u.). Interestingly, lactate significantly decreased SOD (MI-Lactate: 54.5±4.2 µmol·mg−1·min−1) and catalase (MI: 1.1±0.1 nmol·mg−1·min−1) activities in MI. Collectively, our data suggest that under pathological stress, lactate lacks its ability to modulate the expression of cardiac LOC-related genes and the perfused pressure in hearts submitted to chronic MI. Together, these data contribute to elucidate the mechanisms involved in the pathogenesis of heart failure induced by MI.


Assuntos
Animais , Masculino , Ácido Láctico/metabolismo , Ácido Láctico/farmacologia , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/metabolismo , Infarto do Miocárdio/genética , Infarto do Miocárdio/metabolismo , Perfusão , Fatores de Tempo , Catalase/análise , Expressão Gênica , Ratos Wistar , Ácido Láctico/análise , Complexos Multienzimáticos/análise , NADH NADPH Oxirredutases/análise
10.
Neuromolecular Med ; 19(4): 518-524, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28866774

RESUMO

Despite reports implicating disrupted purine metabolism in causing a wide spectrum of neurological defects, the mechanistic details of purine biosynthesis in neurons are largely unknown. As an initial step in filling that gap, we examined the expression and subcellular distribution of three purine biosynthesis enzymes (PFAS, PAICS and ATIC) in rat hippocampal neurons. Using immunoblotting and high-resolution light and electron microscopic analysis, we find that all three enzymes are broadly distributed in hippocampal neurons with pools of these enzymes associated with mitochondria. These findings suggest a potential link between purine metabolism and mitochondrial function in neurons and provide an impetus for further studies.


Assuntos
Hipocampo/metabolismo , Neurônios/metabolismo , Purinas/biossíntese , Animais , Carbono-Nitrogênio Ligases com Glutamina como Doadora de N-Amida/análise , Células Cultivadas , Células HeLa , Hipocampo/citologia , Hipocampo/embriologia , Humanos , Hidroximetil e Formil Transferases/análise , Microscopia Eletrônica , Microscopia de Fluorescência , Mitocôndrias/enzimologia , Complexos Multienzimáticos/análise , Proteínas do Tecido Nervoso/análise , Neurônios/enzimologia , Neurônios/ultraestrutura , Nucleotídeo Desaminases/análise , Peptídeo Sintases/análise , Cultura Primária de Células , Ratos , Frações Subcelulares/enzimologia
12.
Med Mycol ; 55(4): 445-452, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-27664992

RESUMO

Aspergillus fumigatus is the most common airborne pathogen causing fatal mycoses in immunocompromised patients. During the first 8 hours of development A. fumigatus conidia break dormancy, expand isotopically, establish an axis of polarity, and begin to extend germ tubes in a polar manner. The transition from isotropic to polar growth is critical for tissue invasion and pathogenesis. In the current work, we used two-color microarrays to examine the A. fumigatus transcriptome during early development, focusing on the isotropic to polar switch. The most highly regulated transcripts in the isotropic to polar switch did not include known polarity genes. Transcripts encoding the Cdc42 module, polarisome components, and septins, known to be critical players in polarity, showed relatively steady levels during the isotropic to polar switch. Indeed, these transcripts were present in dormant conidia, and their levels changed little from dormancy through germ tube emergence. Not only did the isotropic to polar switch show little change in the expression of key polarity genes of the Cdc42 module, polarisome, and septins, it also showed the lowest overall levels of both up- and downregulation in early development.


Assuntos
Aspergillus fumigatus/crescimento & desenvolvimento , Aspergillus fumigatus/genética , Perfilação da Expressão Gênica , Complexos Multienzimáticos/análise , Septinas/biossíntese , Proteína cdc42 de Ligação ao GTP/biossíntese , Análise em Microsséries , Complexos Multienzimáticos/genética , Septinas/genética
13.
PLoS One ; 11(12): e0169259, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28036377

RESUMO

We describe a gentle and rapid method to purify the intact multiprotein DNA replication complex using free flow electrophoresis (FFE). In particular, we applied FFE to purify the human cell DNA synthesome, which is a multiprotein complex that is fully competent to carry-out all phases of the DNA replication process in vitro using a plasmid containing the simian virus 40 (SV40) origin of DNA replication and the viral large tumor antigen (T-antigen) protein. The isolated native DNA synthesome can be of use in studying the mechanism by which mammalian DNA replication is carried-out and how anti-cancer drugs disrupt the DNA replication or repair process. Partially purified extracts from HeLa cells were fractionated in a native, liquid based separation by FFE. Dot blot analysis showed co-elution of many proteins identified as part of the DNA synthesome, including proliferating cell nuclear antigen (PCNA), DNA topoisomerase I (topo I), DNA polymerase δ (Pol δ), DNA polymerase ɛ (Pol ɛ), replication protein A (RPA) and replication factor C (RFC). Previously identified DNA synthesome proteins co-eluted with T-antigen dependent and SV40 origin-specific DNA polymerase activity at the same FFE fractions. Native gels show a multiprotein PCNA containing complex migrating with an apparent relative mobility in the megadalton range. When PCNA containing bands were excised from the native gel, mass spectrometric sequencing analysis identified 23 known DNA synthesome associated proteins or protein subunits.


Assuntos
DNA Polimerase Dirigida por DNA/análise , DNA Polimerase Dirigida por DNA/isolamento & purificação , Eletroforese/métodos , Complexos Multienzimáticos/análise , Complexos Multienzimáticos/isolamento & purificação , Antígenos Virais de Tumores/genética , Extratos Celulares/química , Linhagem Celular Tumoral , DNA Polimerase I/isolamento & purificação , DNA Polimerase II/isolamento & purificação , DNA Polimerase III/isolamento & purificação , Replicação do DNA , DNA Topoisomerases Tipo I/isolamento & purificação , Células HeLa , Humanos , Antígeno Nuclear de Célula em Proliferação/análise , Origem de Replicação/genética , Proteína de Replicação A/isolamento & purificação , Proteína de Replicação C/isolamento & purificação , Vírus 40 dos Símios/genética
14.
Biosens Bioelectron ; 86: 1038-1046, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27501341

RESUMO

Citrate synthase (CS) is one of the key metabolic enzymes in the Krebs tricarboxylic acid (TCA) cycle. It regulates energy generation in mitochondrial respiration by catalysing the reaction between oxaloacetic acid (OAA) and acetyl coenzyme A (Ac-CoA) to generate citrate and coenzyme A (CoA). CS has been shown to be a biomarker of neurological diseases and various kinds of cancers. Here, a label-free fluorescent assay has been developed for homogeneously detecting CS and its inhibitor based on the in situ generation of CoA-Au(I) co-ordination polymer (CP) and the fluorescence signal-on by SYBR Green II-stained CoA-Au(I) CP. Because of the unique property of the CoA-Au(I) CP, this CS activity assay method could achieve excellent selectivity and sensitivity, with a linear range from 0.0033 U/µL to 0.264 U/µL and a limit of detection to be 0.00165 U/µL. Meanwhile, this assay method has advantages of being facile and cost effective with quick detection. Moreover, based on this method, a biomimetic logic system was established by rationally exploiting the cascade enzymatic interactions in TCA cycle for chemical information processing. In the TCA cycle-derived logic system, an AND-AND-AND-cascaded gate was rigorously operated step by step in one pot, and is outputted by a label-free fluorescent signal with visualized readout.


Assuntos
Acetilcoenzima A/química , Citrato (si)-Sintase/análise , Complexos Multienzimáticos/análise , Complexos Multienzimáticos/química , Ácido Oxaloacético/química , Espectrometria de Fluorescência/métodos , Citrato (si)-Sintase/química , Ativação Enzimática , Corantes Fluorescentes/síntese química , Processamento de Sinais Assistido por Computador , Coloração e Rotulagem
15.
Appl Environ Microbiol ; 82(4): 1227-1236, 2016 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-26655760

RESUMO

Pseudomonas fluorescens is able to produce the medically and industrially important exopolysaccharide alginate. The proteins involved in alginate biosynthesis and secretion form a multiprotein complex spanning the inner and outer membranes. In the present study, we developed a method by which the porin AlgE was detected by immunogold labeling and transmission electron microscopy. Localization of the AlgE protein was found to depend on the presence of other proteins in the multiprotein complex. No correlation was found between the number of alginate factories and the alginate production level, nor were the numbers of these factories affected in an algC mutant that is unable to produce the precursor needed for alginate biosynthesis. Precursor availability and growth phase thus seem to be the main determinants for the alginate production rate in our strain. Clustering analysis demonstrated that the alginate multiprotein complexes were not distributed randomly over the entire outer cell membrane surface.


Assuntos
Pseudomonas fluorescens/enzimologia , Pseudomonas fluorescens/metabolismo , Alginatos , Ácido Glucurônico/biossíntese , Ácidos Hexurônicos , Proteínas de Membrana Transportadoras/análise , Microscopia Imunoeletrônica , Complexos Multienzimáticos/análise , Porinas/análise
16.
Biochem Biophys Res Commun ; 466(1): 40-5, 2015 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-26319553

RESUMO

Accumulation of unfolded proteins within the endoplasmic reticulum (ER) triggers a highly conserved stress response mechanism termed the unfolded protein response (UPR). The UPR is a complex series of signaling pathways controlled by ER localized transmembrane receptors, PERK, ATF6 and IRE1α. Following activation IRE1α splices XBP-1 mRNA facilitating the formation of a potent transcription factor, spliced XBP-1. The BCL-2 family members, BAX and BAK, in addition to the mitochondrion also localize to the ER and have been demonstrated to directly interact with IRE1α promoting its activity. In this study we show that in addition to BAX and BAK, the anti-apoptotic BCL-2 protein can regulate IRE1α activity. Enhanced splicing of XBP-1 was observed in BCL-2 overexpressing cells implicating BCL-2 in the complex regulation of IRE1α activity.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Splicing de RNA , Fatores de Transcrição/genética , Resposta a Proteínas não Dobradas , Animais , Linhagem Celular , Proteínas de Ligação a DNA/análise , Proteínas de Ligação a DNA/metabolismo , Endorribonucleases/análise , Endorribonucleases/metabolismo , Camundongos , Complexos Multienzimáticos/análise , Complexos Multienzimáticos/metabolismo , Proteínas Serina-Treonina Quinases/análise , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/análise , Ratos , Fatores de Transcrição de Fator Regulador X , Transdução de Sinais , Fatores de Transcrição/análise , Fatores de Transcrição/metabolismo , Proteína 1 de Ligação a X-Box
17.
J Biol Chem ; 290(35): 21264-79, 2015 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-26170456

RESUMO

The adaptor protein-1 complex (AP-1), which transports cargo between the trans-Golgi network and endosomes, plays a role in the trafficking of Atp7a, a copper-transporting P-type ATPase, and peptidylglycine α-amidating monooxygenase (PAM), a copper-dependent membrane enzyme. Lack of any of the four AP-1 subunits impairs function, and patients with MEDNIK syndrome, a rare genetic disorder caused by lack of expression of the σ1A subunit, exhibit clinical and biochemical signs of impaired copper homeostasis. To explore the role of AP-1 in copper homeostasis in neuroendocrine cells, we used corticotrope tumor cells in which AP-1 function was diminished by reducing expression of its µ1A subunit. Copper levels were unchanged when AP-1 function was impaired, but cellular levels of Atp7a declined slightly. The ability of PAM to function was assessed by monitoring 18-kDa fragment-NH2 production from proopiomelanocortin. Reduced AP-1 function made 18-kDa fragment amidation more sensitive to inhibition by bathocuproine disulfonate, a cell-impermeant Cu(I) chelator. The endocytic trafficking of PAM was altered, and PAM-1 accumulated on the cell surface when AP-1 levels were reduced. Reduced AP-1 function increased the Atp7a presence in early/recycling endosomes but did not alter the ability of copper to stimulate its appearance on the plasma membrane. Co-immunoprecipitation of a small fraction of PAM and Atp7a supports the suggestion that copper can be transferred directly from Atp7a to PAM, a process that can occur only when both proteins are present in the same subcellular compartment. Altered luminal cuproenzyme function may contribute to deficits observed when the AP-1 function is compromised.


Assuntos
Complexo 1 de Proteínas Adaptadoras/metabolismo , Cobre/metabolismo , Endocitose , Oxigenases de Função Mista/metabolismo , Complexos Multienzimáticos/metabolismo , Complexo 1 de Proteínas Adaptadoras/análise , Adenosina Trifosfatases/análise , Adenosina Trifosfatases/metabolismo , Animais , Proteínas de Transporte de Cátions/análise , Proteínas de Transporte de Cátions/metabolismo , Linhagem Celular , Células Cultivadas , ATPases Transportadoras de Cobre , Células HeLa , Humanos , Camundongos , Oxigenases de Função Mista/análise , Complexos Multienzimáticos/análise , Hipófise/citologia , Hipófise/metabolismo , Transporte Proteico , Ratos
18.
Mitochondrion ; 23: 55-63, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26071002

RESUMO

PURPOSE: Altered energy metabolism plays an important role in the development and progression of cancer. The objective of this study was to elucidate the role of mitochondrial oxidative phosphorylation complexes and their prognostic significance in retinoblastoma (Rb). METHODS: Immunohistochemistry was performed on 109 primary enucleated retinoblastoma tissues for mitochondrial OXPHOS complexes and their expression was confirmed by western blotting. RESULTS: Histopathological high risk factors (HRFs) were identified in 42.2% cases. Mitochondrial OXPHOS complexes III, IV and V were expressed in more than 50% of primary retinoblastoma cases each whereas mitochondrial complex I was expressed in only 29/109 (26.60%) cases by immunohistochemistry. Loss of mitochondrial complex I correlated well with poor tumor differentiation and tumor invasion (p < 0.05) whereas expression of mitochondrial complexes III, IV and V was associated with better survival (Kaplan-Meier method). CONCLUSIONS: This was the first study predicting a relevant role of mitochondrial OXPHOS complexes and highlights the prognostic significance with patient outcome in retinoblastoma. Loss of mitochondrial complex I immunoexpression could prove to be a useful independent prognostic biomarker to identify high risk retinoblastoma patients. Differential expression of these mitochondrial complexes is a novel finding and may be used as an attractive future anticancer target in primary retinoblastoma tumors. FINANCIAL DISCLOSURE: The author(s) have no proprietary or commercial interest in any materials discussed in this article.


Assuntos
Biomarcadores Tumorais/análise , Complexos Multienzimáticos/análise , Oxirredutases/análise , Retinoblastoma/patologia , Western Blotting , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Fosforilação Oxidativa , Prognóstico
19.
J Biol Chem ; 290(11): 6705-13, 2015 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-25605736

RESUMO

Enzymes in the de novo purine biosynthesis pathway are recruited to form a dynamic metabolic complex referred to as the purinosome. Previous studies have demonstrated that purinosome assembly responds to purine levels in culture medium. Purine-depleted medium or 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole (DMAT) treatment stimulates the purinosome assembly in HeLa cells. Here, several metabolomic technologies were applied to quantify the static cellular levels of purine nucleotides and measure the de novo biosynthesis rate of IMP, AMP, and GMP. Direct comparison of purinosome-rich cells (cultured in purine-depleted medium) and normal cells showed a 3-fold increase in IMP concentration in purinosome-rich cells and similar levels of AMP, GMP, and ratios of AMP/GMP and ATP/ADP for both. In addition, a higher level of IMP was also observed in HeLa cells treated with DMAT. Furthermore, increases in the de novo IMP/AMP/GMP biosynthetic flux rate under purine-depleted condition were observed. The synthetic enzymes, adenylosuccinate synthase (ADSS) and inosine monophosphate dehydrogenase (IMPDH), downstream of IMP were also shown to be part of the purinosome. Collectively, these results provide further evidence that purinosome assembly is directly related to activated de novo purine biosynthesis, consistent with the functionality of the purinosome.


Assuntos
Metabolômica/métodos , Complexos Multienzimáticos/metabolismo , Nucleotídeos de Purina/metabolismo , Purinas/metabolismo , Adenilossuccinato Sintase/análise , Adenilossuccinato Sintase/metabolismo , Benzimidazóis/metabolismo , Carbono-Nitrogênio Ligases com Glutamina como Doadora de N-Amida/análise , Carbono-Nitrogênio Ligases com Glutamina como Doadora de N-Amida/metabolismo , Células HeLa , Humanos , IMP Desidrogenase/análise , IMP Desidrogenase/metabolismo , Espectroscopia de Ressonância Magnética , Complexos Multienzimáticos/análise , Nucleotídeos de Purina/análise , Purinas/análise , Espectrometria de Massas por Ionização por Electrospray
20.
Nucleic Acids Res ; 42(22): 13696-705, 2014 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-25416798

RESUMO

In a fast-growing Escherichia coli cell, most RNA polymerase (RNAP) is allocated to rRNA synthesis forming transcription foci at clusters of rrn operons or bacterial nucleolus, and each of the several nascent nucleoids contains multiple pairs of replication forks. The composition of transcription foci has not been determined. In addition, how the transcription machinery is three-dimensionally organized to promote cell growth in concord with replication machinery in the nucleoid remains essentially unknown. Here, we determine the spatial and functional landscapes of transcription and replication machineries in fast-growing E. coli cells using super-resolution-structured illumination microscopy. Co-images of RNAP and DNA reveal spatial compartmentation and duplication of the transcription foci at the surface of the bacterial chromosome, encompassing multiple nascent nucleoids. Transcription foci cluster with NusA and NusB, which are the rrn anti-termination system and are associated with nascent rRNAs. However, transcription foci tend to separate from SeqA and SSB foci, which track DNA replication forks and/or the replisomes, demonstrating that transcription machinery and replisome are mostly located in different chromosomal territories to maintain harmony between the two major cellular functions in fast-growing cells. Our study suggests that bacterial chromosomes are spatially and functionally organized, analogous to eukaryotes.


Assuntos
DNA Polimerase Dirigida por DNA/análise , Escherichia coli/genética , Complexos Multienzimáticos/análise , Transcrição Gênica , Proteínas de Bactérias/análise , Replicação do DNA , Escherichia coli/crescimento & desenvolvimento , Proteínas de Escherichia coli/análise , Genes de RNAr , Fatores de Alongamento de Peptídeos/análise , Proteínas de Ligação a RNA/análise , Fatores de Transcrição/análise , Fatores de Elongação da Transcrição
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