Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 164
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Plant Biol (Stuttg) ; 25(5): 687-695, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37070345

RESUMO

The reproductive characteristics of understory bamboo and the effects of dieback on overstory tree seedlings through temporal changes in the environment at the forest floor have only been examined in a few bamboo species, due to the unpredictable occurrence of flowering events and long intervals between them but provide valuable information on tree regeneration and succession in a forest with dense dwarf bamboo cover. We investigated environmental conditions and assessed seedlings (< 30-cm tall) of the dwarf bamboo Sasa borealis and overstory tree species at 44-50 measurement points during 2016-2021, which included a S. borealis mass flowering event in 2017. We also conducted seed germination tests to determine germination rates and patterns in S. borealis. Environmental factors affecting seedling recruitment of S. borealis and of overstory trees were analysed using spatiotemporal generalized linear mixed models in the Bayesian framework. We observed gradual temporal changes in the environment, including increasing canopy openness and decreasing maximum height of dead S. borealis culms. The seeds germinated slowly and the emergence of current-year S. borealis seedlings peaked in spring-summer in 2019. The tree seedling density after 2019 increased significantly compared to that before the dieback. The model results suggest that tree seedling establishment was enhanced by increased light availability. Continuous field observation beginning before S. borealis dieback revealed gradually enhanced tree recruitment in response to slow decay of the remaining dead culms and slow recovery of S. borealis. The seedling regeneration pattern of understory bamboo partly contributes to a prolonged opportunity for overstory tree regeneration.


Assuntos
Florestas , Plântula , Japão , Teorema de Bayes , Plântula/fisiologia , Germinação , Ecossistema
2.
J Appl Microbiol ; 113(1): 155-62, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22519947

RESUMO

AIMS: To investigate the influence of heat-killed Lactobacillus gasseri TMC0356 on changes in respiratory immune function and intestinal microbiota in a diet-induced obese mouse model. METHODS AND RESULTS: Male C57BL/6J mice were fed a high-fat diet for 16 weeks. After 8 weeks, the high-fat-diet-induced obese mice (DIO mice) were randomly divided into two 0067roups, the DIO and DIO0356 groups. DIO0356 group mice were orally fed with heat-killed TMC0356 every day for 8 weeks, while DIO group mice were exposed to 0·85% NaCl over the same time period as controls. After intervention, the pulmonary mRNA expression of cytokines and other immune molecules in DIO0356 mice compared to those in DIO group mice was significantly increased (P < 0·05, P < 0·01). In faecal bacterial profiles, analysed using the terminal restriction fragment length polymorphism (T-RFLP) method, T-RFLP patterns in 75% of the DIO0356 group mice were apparently changed compared with those in control group mice. CONCLUSION: These results suggest that inactive lactobacilli may stimulate the respiratory immune responses of obese host animals to enhance their natural defences against respiratory infection, partially associating with their potent impact on intestinal microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: We have demonstrated that oral administration of inactive lactobacilli may protect host animals from the lung immune dysfunction caused by obesity.


Assuntos
Intestinos/microbiologia , Lactobacillus/imunologia , Pulmão/imunologia , Metagenoma , Obesidade/imunologia , Administração Oral , Animais , Citocinas/genética , Citocinas/metabolismo , Dieta Hiperlipídica/efeitos adversos , Fezes/microbiologia , Mucosa Intestinal/metabolismo , Células Matadoras Naturais/imunologia , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/microbiologia , Polimorfismo de Fragmento de Restrição , Probióticos/administração & dosagem , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Baço/citologia , Baço/imunologia
3.
Lett Appl Microbiol ; 53(2): 210-6, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21623846

RESUMO

AIMS: The aim of this study was to investigate the influence of heat treatment and culture media on the immunoregulatory effects of a probiotic strain, Lactobacillus gasseri TMC0356 (TMC0356). METHODS AND RESULTS: TMC0356 cultured in deMan-Rogosa-Sharpe and same food grade (FG) media were inactivated with the heat treatment at 70 and 90°C. Viable and heat-killed TMC0356 were tested for their ability to induce interleukin (IL)-12 production in the murine macrophage cell line J774.1. These TMC0356 were examined for their resistance to N-acetylmuramidase. Their morphology was observed by scanning electron microscopy. The heat-killed TMC0356 significantly induced IL-12 production in J774.1 cells and exhibited enhanced resistance to N-acetylmuramidase compared with viable TMC0356. Morphological changes were observed in TMC0356 when cultured in FG medium. Cell morphology and induction of IL-12 production in J774.1 cells were also associated. CONCLUSIONS: These results suggest that heat treatment and culture medium composition modified the immunoregulatory effects of TMC0356 to induce IL-12 production in macrophages. SIGNIFICANCE AND IMPACT OF THE STUDY: These results demonstrate that probiotic immunoregulatory effects may be modified by the processing technology of cell preparation.


Assuntos
Meios de Cultura/metabolismo , Lactobacillus/crescimento & desenvolvimento , Probióticos/farmacologia , Animais , Linhagem Celular , Glicosídeo Hidrolases/toxicidade , Temperatura Alta , Interleucina-12/metabolismo , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Viabilidade Microbiana
4.
J Cell Biol ; 119(6): 1413-27, 1992 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1469042

RESUMO

The alphoid DNA-CENP-B (centromere protein B) complex is the first sequence-specific DNA/protein complex detected in the centromeric region of human chromosomes. In the reaction, CENP-B recognizes a 17-bp sequence (CENP-B box) and assembles two alphoid DNA molecules into a complex, which is designated complex A (Muro, Y., H. Masumoto, K. Yoda, N. Nozaki, M. Ohashi, and T. Okazaki. 1992. J. Cell Biol. 116:585-596). Since CENP-B gene is conserved in mammalian species and CENP-B boxes are found also in mouse centromere satellite DNA (minor satellite), this sequence-specific DNA-protein interaction may be important for some kind of common centromere function. In this study we have characterized the structure of CENP-B and CENP-B-alphoid DNA complex. We have shown by chemical cross-linking that CENP-B formed a dimer, and have estimated by molecular weight determination the composition of complex A to be a CENP-B dimer and two molecules of alphoid DNA. The DNA binding domain has been delimited within the NH2-terminal 125-amino acid region containing four potential alpha-helices using truncated CENP-B made in Escherichia coli cells. We have shown that CENP-B had sites highly sensitive to proteases and that the DNA binding domain was separable from the dimerizing activity by the proteolytic cleavage at 20 kD from the COOH terminus of the molecule. Thus, CENP-B may organize a higher order structure in the centromere by juxtaposing two CENP-B boxes in the alphoid DNA repeat through both the DNA-protein and protein-protein interactions.


Assuntos
Autoantígenos , Centrômero/química , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Ligação a DNA/metabolismo , Conformação Proteica , Estrutura Secundária de Proteína , Sequência de Aminoácidos , Sequência de Bases , Proteína B de Centrômero , Proteínas Cromossômicas não Histona/efeitos dos fármacos , Reagentes de Ligações Cruzadas , DNA/metabolismo , Análise Mutacional de DNA , Proteínas de Ligação a DNA/efeitos dos fármacos , Endopeptidases/farmacologia , Escherichia coli/genética , Glutaral , Humanos , Substâncias Macromoleculares , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Fragmentos de Peptídeos/metabolismo , Proteínas Recombinantes/efeitos dos fármacos , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Relação Estrutura-Atividade
5.
J Cell Biol ; 113(2): 245-60, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2010462

RESUMO

The Saccharomyces cerevisiae mutant strains blocked in the protein secretion pathway are not able to induce sexual aggregation. We have utilized the defect of aggregation to concentrate the secretion-deficient cells and identified a new gene which functions in the process of intracellular protein transport. The new mutant, uso1, is temperature sensitive for growth and protein secretion. At the restrictive temperature (37 degrees C), uso1 mutant accumulated the core-glycosylated precursor form of the exported protein invertase in the cells. Ultrastructural study of the mutant fixed by the freeze-substitution method revealed expansion of the nuclear envelope lumen and accumulation of the ER at the restrictive temperature. Abnormally oriented bundles of microtubules were often found in the nucleus. The USO1 gene was cloned by complementation of the uso1 temperature-sensitive growth defect. DNA sequence analysis revealed a hydrophilic protein of 1790 amino acids with a COOH-terminal 1,100-amino acid-long alpha-helical structure characteristic of the coiled-coil rod region of the cytoskeleton-related proteins. These observations suggest that Uso1 protein plays a role as a cytoskeletal component in the protein transport from the ER to the later secretory compartments.


Assuntos
Proteínas de Transporte , Citoesqueleto/metabolismo , Proteínas Fúngicas/biossíntese , Genes Fúngicos , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Proteínas de Transporte Vesicular , Sequência de Aminoácidos , Sequência de Bases , Transporte Biológico Ativo/genética , Clonagem Molecular , DNA Fúngico , Eletroforese em Gel de Poliacrilamida , Retículo Endoplasmático/metabolismo , Proteínas Fúngicas/isolamento & purificação , Proteínas Fúngicas/metabolismo , Teste de Complementação Genética , Glicosídeo Hidrolases/metabolismo , Glicosilação , Complexo de Golgi/metabolismo , Cinética , Microscopia Eletrônica , Dados de Sequência Molecular , Mutação , Miosinas/genética , Mapeamento por Restrição , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/ultraestrutura , Homologia de Sequência do Ácido Nucleico , Temperatura , Vacúolos/ultraestrutura , beta-Frutofuranosidase
6.
J Cell Biol ; 116(3): 585-96, 1992 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1730770

RESUMO

We purified 15,000-fold from HeLa cell nuclear extract the centromere antigen that reacts specifically with the 17-bp sequence, designated previously as CENP-B box, in human centromeric alpha-satellite (alphoid) DNA by a two-step procedure including an oligonucleotide affinity column. The purified protein was identified as the centromere protein B (CENP-B) by its mobility on SDS-PAGE (80 kD), and reactivities to a monoclonal antibody raised to CENP-B (bacterial fusion protein) and to anticentromere sera from patients with autoimmune diseases. Direct binding by CENP-B of the CENP-B box sequence in the alphoid DNA has been proved using the purified CENP-B by DNA mobility-shift assay, Southwestern blotting, and DNase I protection analysis. The binding constant of the antigen to the CENP-B box sequence is 6 x 10(8) M-1. DNA mobility-shift assays indicated that the major complex formed between the CENP-B and the DNA contains two DNA molecules, suggesting the importance of the CENP-B/CENP-B box interaction in organization of higher ordered chromatin structures in the centromere and/or kinetochore. Location of DNA binding and dimerization domains in CENP-B was discussed based on the DNA mobility-shift assays performed with a protein fraction containing intact and partial cleavage products of CENP-B.


Assuntos
Autoantígenos , Centrômero/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , DNA Satélite/metabolismo , Proteínas de Ligação a DNA , Sequência de Bases , Proteína B de Centrômero , Proteínas Cromossômicas não Histona/isolamento & purificação , DNA Satélite/química , Células HeLa , Humanos , Dados de Sequência Molecular
7.
Mol Cell Biol ; 4(8): 1591-6, 1984 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-6436687

RESUMO

To investigate the precise structure of eucaryotic primer RNA made in vivo, short DNA chains isolated from nuclei of Drosophila melanogaster embryos were analyzed. Post-labeling of 5' ends of short DNA chains with polynucleotide kinase and [gamma-32P]ATP revealed that 7% of the DNA fragments were covalently linked with mono- to octaribonucleotide primers at their 5' ends. Octaribonucleotides, the major component (ca. 30%), formed the cap structure in the reaction with vaccinia guanylyltransferase and [alpha-32P]GTP, indicating that they were the intact primer RNA with tri- (or di-) phosphate termini, and the shorter ribooligomers were degradation intermediates. The intact primers started with purine (A/G ratio, 4:1), and the starting few ribonucleotide residues were rich in A.


Assuntos
Replicação do DNA , Drosophila melanogaster/metabolismo , Oligonucleotídeos/metabolismo , Oligorribonucleotídeos/metabolismo , Animais , Desoxirribonucleases , Drosophila melanogaster/embriologia , Capuzes de RNA/metabolismo , Ribonucleotídeos/análise
8.
Mol Cell Biol ; 16(9): 5169-77, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8756674

RESUMO

Centromere protein B (CENP-B) is a centromeric DNA-binding protein which recognizes a 17-bp sequence (CENP-B box) in human and mouse centromeric satellite DNA. The African green monkey (AGM) is phylogenetically closer to humans than mice and is known to contain large amounts of alpha-satellite DNA, but there has been no report of CENP-B boxes or CENP-B in the centromere domains of its chromosomes. To elucidate the AGM CENP-B-CENP-B box interaction, we have analyzed the gene structure, expression, biochemical properties, and centromeric localization of its CENP-B. The amino acid sequence deduced from the cloned AGM CENP-B gene was established to be highly homologous to that of human and mouse CENP-B. In particular, the DNA binding and homodimer formation domains demonstrated 100% identity to their human and mouse counterparts. Immunoblotting and DNA mobility shift analyses revealed CENP-B to be expressed in AGM cell lines. As predicted from the gene structure, the AGM CENP-B in the cell extracts exhibited the same DNA binding specificity and homodimer forming activity as human CENP-B. By indirect immunofluorescent staining of AGM mitotic cells with anti-CENP-B antibodies, a centromere-specific localization of AGM CENP-B could be demonstrated. We also isolated AGM alpha-satellite DNA with a CENP-B box-like sequence with CENP-B affinity. These results not only prove that CENP-B functionally persists in AGM cells but also suggest that the AGM genome contains the recognition sequences for CENP-B (CENP-B boxes with the core recognition sequence or CENP-B box variants) in centromeric satellite DNA.


Assuntos
Autoantígenos , Centrômero/metabolismo , Chlorocebus aethiops/genética , Proteínas Cromossômicas não Histona/genética , Proteínas de Ligação a DNA , Genes , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular , Proteína B de Centrômero , Proteínas Cromossômicas não Histona/metabolismo , DNA Satélite/metabolismo , Regulação da Expressão Gênica , Células HeLa , Humanos , Mamíferos/genética , Metáfase , Camundongos , Mitose , Dados de Sequência Molecular , Muridae/genética , Sequências Reguladoras de Ácido Nucleico , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Especificidade da Espécie
9.
Cancer Res ; 35(9): 2494-9, 1975 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-167961

RESUMO

A culture line of mouse glioblastoma cells changed morphologically to differentiated astrocyte-like cells when cultured in medium with dibutyryl cyclic adenosine monophosphate and theophylline. Morphological alteration occurred within only 5 hr when 3 mM dibutyryl cyclic adenosine monophosphate and 1 mM theophylline were used, and in 1 day when 1 mM theophylline were used. Cells showing this morphological change reverted completely to immature cells when they were transferred to medium without these two chemicals. Addition of 1 or 3 mM dibutyryl cyclic guanosine monophosphate with 1 mM theophylline to the medium also induced development of cytoplasmic processes from these cells and the cells became stellate, although the cytoplasmic processes were not as long or as numerous as those induced by dibutyryl cyclic adenosine monophosphate, and the altered cells could not be referred to as differentiated glia cells. Sodium butyrate induced morphological alterations similar to those induced by dibutyryl cyclic guanosine monophosphate, but fewer cells showed these alterations. Addition of cyclic adenosine monophosphate or cyclic guanosine monophosphate in the presence of theophylline or addition of theophylline alone did not induce morphological changes of the cells.


Assuntos
Bucladesina/farmacologia , Diferenciação Celular/efeitos dos fármacos , Glioma/patologia , Animais , Butiratos/farmacologia , Linhagem Celular , Células Cultivadas , GMP Cíclico/farmacologia , DNA de Neoplasias/biossíntese , Relação Dose-Resposta a Droga , Glioma/metabolismo , Camundongos , Neoplasias Experimentais/patologia , Neuroglia/patologia , Teofilina/farmacologia , Timidina/metabolismo , Fatores de Tempo
10.
Biochim Biophys Acta ; 521(2): 677-88, 1978 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-367440

RESUMO

Rat liver chromatin was fractionated into DNA, histones and non-histone chromosomal proteins and each component was modified with N-methyl-l-N'-nitro-N-nitrosoguanidine of N-ethyl-N'-nitrosoguanidine. The radioactivity of 14C-labeled alkyl or guanidino moieties of both compounds bound significantly to both histones and non-histone chromosomal proteins and the binding of N-methyl-N'-nitro-N-nitrosoguanidine was higher than N-ethyl-N'-nitro-N-nitrosoguanidine. However the binding of both compounds to DNA was very low and its significance was hard to evaluate. All of the three components, one of which was modified, were reconstituted into chromatin, then, [3H]UMP incorporation into acid insoluble material using Escherichia coli RNA polymerase (EC 2.7.7.6) was measured. Only with the reconstituted chromatin containing histones modified either by N-methyl-N'-nitro-N-nitrosoguanidine or N-ethyl-N'-nitro-N-nitrosoguanidine, the template activity increased drastically; i.e., about 10 or 5 times higher than that with the unmodified reconstituted chromatin, respectively. However, any remarkable alteration in the electrophoretic pattern of protein fraction of the reconstituted chromatin could not be found. The results obtained in this study are discussed in the context that the modified histones could give rise to change in the mutual interaction of chromosomal components during the reconstitution of chromatin accompanied with the increase of chromatine template activity.


Assuntos
Cromatina/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , Escherichia coli/enzimologia , Fígado/metabolismo , Metilnitronitrosoguanidina/análogos & derivados , Metilnitronitrosoguanidina/farmacologia , RNA/biossíntese , Animais , Cromatina/efeitos dos fármacos , Cinética , Masculino , Ratos , Moldes Genéticos , Transcrição Gênica/efeitos dos fármacos
11.
Biochim Biophys Acta ; 1009(2): 194-7, 1989 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-2804080

RESUMO

We have isolated several gamma-actin-related genes from a mouse genomic library. One of these has been shown to be a gamma-actin processed pseudogene (Tokunga, K., Yoda, K. and Sakiyama, S. (1985) Nucleic Acids Res. 13, 3031-3042). Here, we report the structure of another pseudogene (pMA131). pMA131 contained the sequences corresponding to the carboxyl half of a cytoskeletal actin in which random point mutations as well as insertion and deletion events took place. This region was flanked at its 5' end by the sequences related to mouse repetitive sequences, including the MIF-1 family, and was interrupted by the sequence homologous to the R family which is also a mouse repetitive sequence. The coding region was followed by the sequence corresponding to 3' untranslated region of gamma-actin mRNA.


Assuntos
Actinas/genética , Pseudogenes , Animais , Sequência de Bases , Clonagem Molecular , Camundongos , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Sequências Repetitivas de Ácido Nucleico , Homologia de Sequência do Ácido Nucleico
12.
J Mol Biol ; 184(1): 45-52, 1985 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-2411935

RESUMO

Intact primer RNA for discontinuous DNA replication of Escherichia coli has been detected by specific labeling in vitro of its 5'-terminal tri- (or di-) phosphate group with vaccinia guanylyltransferase and [alpha-32P]GTP. A mutant defective either in RNase H or in both RNase H and DNA polymerase I accumulated about 10 or 30 times more intact primer RNA, respectively, than wild-type cells. The primers started with purine in an A to G ratio of 5 and the most abundant 5'-terminal dinucleotide sequence was (p)ppA-Pu. The chain length of the intact primer RNA was approximately 10 to 12 nucleotide residues. The structural properties of the E. coli primer RNa resemble those of the eukaryotic primer RNA.


Assuntos
Replicação do DNA , DNA Bacteriano/genética , RNA Bacteriano/genética , RNA/genética , Sequência de Bases , Eletroforese em Gel de Poliacrilamida , Escherichia coli/genética , Purinas
13.
Benef Microbes ; 6(4): 441-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25653155

RESUMO

This double-blind, placebo-controlled clinical trial was conducted to test whether Lactobacillus gasseri TMC0356 (TMC0356) can modify the immune response in the elderly. Heat-killed TMC0356 or placebo was orally administered to 28 healthy subjects aged 50-70 years old for 4 weeks at a dosage of 1.0×10(9) cfu/day. Peripheral blood mononuclear cells (PBMCs) were collected from the subjects before and after the study completion, together with general health and blood examination records. Isolated PBMCs were examined for the number of T cells, CD8(+)CD28(+) cells, native T cells, B cells, natural killer (NK) cells and the ratios of CD4/CD8 T cells and native/memory T cells. NK cell activation and concanavalin A-induced lymphocyte transformation of the isolated PBMCs were also examined. The number of CD8(+) T cells significantly increased in the subjects after TMC0356 oral administration (P<0.05). Furthermore, the population of CD8(+)CD28(+) T cells and the amount of lymphocyte transformation both significantly decreased in PBMCs from the placebo group (P<0.05). However, such changes were not observed in the subjects exposed to TMC0356. These results suggest that TMC0356 can increase the number of CD8(+) T cells and reduce CD28 expression loss in CD8(+) T cells of the elderly. The effect of TMC0356 on immune responses in the elderly may enhance their natural defence mechanisms against pathogenic infections.


Assuntos
Fatores Imunológicos/administração & dosagem , Lactobacillus/imunologia , Leucócitos Mononucleares/imunologia , Probióticos/administração & dosagem , Administração Oral , Idoso , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Concanavalina A/metabolismo , Método Duplo-Cego , Temperatura Alta , Humanos , Fatores Imunológicos/efeitos da radiação , Lactobacillus/efeitos da radiação , Contagem de Leucócitos , Masculino , Viabilidade Microbiana/efeitos da radiação , Pessoa de Meia-Idade , Placebos/administração & dosagem , Probióticos/efeitos da radiação , Resultado do Tratamento
14.
FEBS Lett ; 458(3): 309-12, 1999 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-10570930

RESUMO

Saccharomyces cerevisiae Vig4/Vrg4 protein is a Golgi membrane protein which has multiple transmembrane domains and is essential for transport of GDP-mannose across the Golgi membrane. By immunoprecipitation of detergent-solubilized tagged protein, we found that this protein exists as oligomer. Two mutants vig4-1 and vig4-2 had amino acid substitutions in the C-terminal region, Ala286Val and Ser278Cys, respectively. In accord with these mutations, trimming of the C-terminal hydrophobic part close to the region impaired the function and traffic of the proteins from the endoplasmic reticulum to the Golgi compartments.


Assuntos
Proteínas Fúngicas/química , Guanosina Difosfato Manose/metabolismo , Proteínas de Membrana Transportadoras , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Sequência de Aminoácidos , Transporte Biológico , Proteínas de Transporte/química , Proteínas de Transporte/genética , Retículo Endoplasmático/metabolismo , Escherichia coli , Imunofluorescência , Proteínas Fúngicas/genética , Complexo de Golgi/metabolismo , Proteínas de Membrana/química , Proteínas de Membrana/genética , Dados de Sequência Molecular , Mutação , Conformação Proteica , Transformação Genética
15.
FEBS Lett ; 469(2-3): 151-4, 2000 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-10713261

RESUMO

The yeast tSNARE Sed5p is considered to mainly reside in the early Golgi compartment at the steady state of its intracellular cycling. To better understand this compartment, we immunoisolated a membrane subfraction having Sed5p on the surface (the Sed5 vesicles). Immunoblot studies showed that considerable portions (20-30%) of the Golgi mannosyltransferases (Mnt1p, Van1p, and Mnn9p) were simultaneously recovered while the late Golgi (Kex2p) or endoplasmic reticulum (Sec71p) proteins were almost excluded. The N-terminal sequences of the polypeptides detectable by Coomassie blue staining indicated that the prominent components of the Sed5 vesicles include Anp1p, Emp24p, Erv25p, Erp1p, Ypt52p, and a putative membrane protein of unknown function (Yml067c).


Assuntos
Proteínas Fúngicas/metabolismo , Complexo de Golgi/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Proteínas de Transporte Vesicular , Proteínas rab5 de Ligação ao GTP , Proteínas de Transporte/análise , Proteínas de Transporte/metabolismo , Eletroforese em Gel de Poliacrilamida , Proteínas Fúngicas/análise , Immunoblotting , Manosiltransferases/análise , Manosiltransferases/metabolismo , Proteínas de Membrana/análise , Proteínas Qa-SNARE , Saccharomyces cerevisiae/ultraestrutura , Análise de Sequência de Proteína , Proteínas rab de Ligação ao GTP/análise , Proteínas rab de Ligação ao GTP/metabolismo
16.
J Biochem ; 79(5): 1119-22, 1976 May.
Artigo em Inglês | MEDLINE | ID: mdl-821940

RESUMO

A fifth and new DFP-sensitive alkaline proteinase E, with strong esterase activity toward Ac-(Ala)3-OMe was found in pronase, a protease mixture from St. griseus K-1. Proteinase E was shown to be different from the elastase [EC 3.4.21.11]-like enzyme or subtilisin [EC 3.4.21.14]like enzyme, and alkaline proteinase A, B, and C in pronase. Proteinase E was purified to a state appearing homogeneous on polyacrylamide gel electrophoresis. Its molecular weight was estimated as 26,600 by gel filtration. It was unstable below pH 5.6. Studies on its actions on acyl-amino acid esters showed that it hydrolyzed the ester bonds of esters of tryptophan, tyrosine, phenylalanine, leucine, and alanine in decreasing order of ease.


Assuntos
Peptídeo Hidrolases/metabolismo , Streptomyces griseus/enzimologia , Estabilidade de Medicamentos , Cinética , Peso Molecular , Elastase Pancreática/metabolismo , Streptomyces griseus/isolamento & purificação , Relação Estrutura-Atividade , Subtilisinas/metabolismo
17.
J Biochem ; 81(3): 587-97, 1977 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16870

RESUMO

Two DFP-sensitive alkaline proteinases with strong esterase activity toward Ac-(Ala)3-OMe, designated as alkaline serine proteinases D and E, were purified pronase, a protease mixture from St. griseus K-1. Each was shown to be homogeneous by acrylamide disc gel electrophoresis. The molecular weights of these enzymes were estimated to be about 27,000 be gel filtration. Studies on their actions on acyl-tl-amino acid methyl or ethyl esters indicated that proteinases D and E both exhibited a broad substrate specificity and hydrolyzed the ester bonds of esters containing Trp, Tyr, Phe, Leu, and Ala. The esterase activities of both enzymes toward Ac-(Ala)3-OMe were the highest among proteinases so far isolated from various sources. Proteinases D and E also lacked cystine residues in their molecules, being entirely different from alkaline serine proteinases A, B, and C in pronase. Some differences were , however, observed between them as regards pH stability, behavior on CM-cellulose, mobility on polyacrylamide electrophoresis, and amidase activity toward Suc-(Ala)3-pNA.


Assuntos
Peptídeo Hidrolases , Streptomyces griseus/enzimologia , Concentração de Íons de Hidrogênio , Isoenzimas/isolamento & purificação , Isoenzimas/metabolismo , Cinética , Peso Molecular , Peptídeo Hidrolases/isolamento & purificação , Peptídeo Hidrolases/metabolismo , Serina , Relação Estrutura-Atividade
18.
J Biochem ; 82(2): 615-8, 1977 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-410802

RESUMO

A carboxypeptidase of St. griseus K-1 (CPase S) was found to possess the specificities of both mammalian pancreatic CPase A and B. Three adsorbents for affinity chromatography were prepared by coupling l-Leu, d-Leu, and d-Arg with CH-Sepharose 4B. d-Arg-CH-Sepharose and l-Leu-CH-Sepharose retained the purified CPase S but d-Leu-CH-Sepharose did not. The activities of CPase S toward CGL and BGA were eluted in the same position. CPase S migrated as a single band on polyacrylamide gel electrophoresis and the two activities were both extracted from this band on the gel.


Assuntos
Carboxipeptidases/isolamento & purificação , Streptomyces griseus/enzimologia , Carboxipeptidases/metabolismo , Especificidade por Substrato
19.
J Biochem ; 81(5): 1357-65, 1977 May.
Artigo em Inglês | MEDLINE | ID: mdl-330510

RESUMO

Large amounts of extra proteins, X (in the envelope fraction) and X' (in the cytoplasmic fraction) were detected by SDS-polyacrylamide gel electrophoresis when DNA of Escherichia coli was damaged. These two proteins had the same apparent molecular weight (appproximately 40,000) and were produced under identical conditions, including requirement for the recA" and lexA+ genotype. Sucrose density gradient centrifugation revealed that protein X' consisted of relatively large and heterogeneous aggregates in the cytoplasmic fraction; the distribution of protein X in the envelope was not determined. As proteins X and X' were shown to be equivalent, it is suggested that they are identical. Co-precipitation of the aggregates of protein X' with the envelope led to the appearance of protein X in the envelope fraction.


Assuntos
Proteínas de Bactérias/biossíntese , DNA Bacteriano/metabolismo , Escherichia coli/metabolismo , Proteínas de Membrana/biossíntese , Membrana Celular/metabolismo , Genótipo , Peso Molecular , Mutação , Especificidade da Espécie
20.
J Biochem ; 116(6): 1341-5, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7706227

RESUMO

We have previously shown that the Saccharomyces cerevisiae USO1 gene required in the protein transport from the endoplasmic reticulum (ER) to the Golgi apparatus encodes a 200-kDa protein (1,790 amino acids) which is present in a nonglobular high molecular mass complex. Antibodies against an N-terminal portion of Uso1 protein recognized a 100-kDa protein in Western blot of the temperature-sensitive uso1-1 mutant cell lysate. The nucleotide sequence of uso1-1 indicated the 951st codon was UAG (amber) in place of CAG (glutamine) in USO1. Deletion study of USO1 gene indicated that such truncated Uso1 polypeptides are sufficiently functional at 25 degrees C but not at 37 degrees C. Mutant Uso1-1 protein displayed an apparent molecular mass of 400-500 kDa in gel filtration while it cosedimented with a globular 6S marker protein, horseradish peroxidase (44 kDa), in sucrose density gradient centrifugation. These results indicated that truncated Uso1-1 protein is still present in a nonglobular high molecular mass complex, similar to the wild-type Uso1 protein.


Assuntos
Proteínas de Transporte , Retículo Endoplasmático/metabolismo , Proteínas Fúngicas/metabolismo , Complexo de Golgi/metabolismo , Estrutura Secundária de Proteína , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/ultraestrutura , Proteínas de Transporte Vesicular , Sequência de Aminoácidos , Transporte Biológico , Western Blotting , Cromatografia em Gel , Proteínas Fúngicas/genética , Genes Fúngicos , Dados de Sequência Molecular , Saccharomyces cerevisiae/genética , Relação Estrutura-Atividade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA