Base de dados : MEDLINE
Pesquisa : B03.280.575 [Categoria DeCS]
Referências encontradas : 440 [refinar]
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[PMID]:28455341
[Au] Autor:Garby TJ; Matys ED; Ongley SE; Salih A; Larkum AWD; Walter MR; Summons RE; Neilan BA
[Ad] Endereço:Australian Centre for Astrobiology and School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, Australia.
[Ti] Título:Lack of Methylated Hopanoids Renders the Cyanobacterium Nostoc punctiforme Sensitive to Osmotic and pH Stress.
[So] Source:Appl Environ Microbiol;83(13), 2017 Jul 01.
[Is] ISSN:1098-5336
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:To investigate the function of 2-methylhopanoids in modern cyanobacteria, the gene coding for the radical -adenosyl methionine (SAM) methylase protein that acts on the C-2 position of hopanoids was deleted from the filamentous cyanobacterium ATCC 29133S. The resulting Δ mutant lacked all 2-methylhopanoids but was found to produce much higher levels of two bacteriohopanepentol isomers than the wild type. Growth rates of the Δ mutant cultures were not significantly different from those of the wild type under standard growth conditions. Akinete formation was also not impeded by the absence of 2-methylhopanoids. The relative abundances of the different hopanoid structures in akinete-dominated cultures of the wild-type and Δ mutant strains were similar to those of vegetative cell-dominated cultures. However, the Δ mutant was found to have decreased growth rates under both pH and osmotic stress, confirming a role for 2-methylhopanoids in stress tolerance. Evidence of elevated photosystem II yield and NAD(P)H-dependent oxidoreductase activity in the Δ mutant under stress conditions, compared to the wild type, suggested that the absence of 2-methylhopanoids increases cellular metabolic rates under stress conditions. As the first group of organisms to develop oxygenic photosynthesis, are central to the evolutionary history of life on Earth and the subsequent oxygenation of the atmosphere. To investigate the origin of cyanobacteria and the emergence of oxygenic photosynthesis, geobiologists use biomarkers, the remnants of lipids produced by different organisms that are found in geologic sediments. 2-Methylhopanes have been considered indicative of cyanobacteria in some environmental settings, with the parent lipids 2-methylhopanoids being present in many contemporary cyanobacteria. We have created a Δ mutant strain that does not produce 2-methylhopanoids to assess the influence of 2-methylhopanoids on stress tolerance. Increased metabolic activity in the mutant under stress indicates compensatory alterations in metabolism in the absence of 2-methylhopanoids.
[Mh] Termos MeSH primário: Nostoc/metabolismo
Triterpenos/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Concentração de Íons de Hidrogênio
Isomerismo
Metilação
Nostoc/química
Nostoc/genética
Nostoc/crescimento & desenvolvimento
Osmose
Triterpenos/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Triterpenes)
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171225
[Lr] Data última revisão:
171225
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170430
[St] Status:MEDLINE


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[PMID]:28868999
[Au] Autor:Bagchi SN; Dubey N; Singh P
[Ad] Endereço:1​Department of Biological Science, Rani Durgavati University, Jabalpur, Madhya Pradesh 482001, India.
[Ti] Título:Phylogenetically distant clade of Nostoc-like taxa with the description of Aliinostoc gen. nov. and Aliinostoc morphoplasticum sp. nov.
[So] Source:Int J Syst Evol Microbiol;67(9):3329-3338, 2017 Sep.
[Is] ISSN:1466-5034
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Nostoc is a complex and tough genus to differentiate, and its morphological plasticity makes it taxonomically complicated. Its cryptic diversity and almost no distinguishable morphological characteristics make this genus incredibly heterogeneous to evaluate on taxonomic scales. The strain NOS, isolated from a eutrophic water body, is being described as a new genus Aliinostoc with the strain showing motile hormogonia with gas vesicles as an atypical feature, which is currently considered as the diacritical feature of the genus but should be subjected to critical evaluation in the near future. The phylogenetic placement of Aliinostoc along with some other related sequences of Nostoc clearly separated this clade from Nostoc sensu stricto with high bootstrap support and robust topology in all the methods tested, thus providing strong proof of the taxa being representative of a new genus which morphologically appears to be Nostoc-like. Subsequent phylogenetic assessment using the rbcL, psbA, rpoC1 and tufA genes was done with the aim of facilitating future multi-locus studies on the proposed genus for better taxonomic clarity and resolution. Folding of the 16S-23S internal transcribed spacer region and subsequent comparisons with members of the genera Nostoc, Anabaena, Aulosira, Cylindrospermum, Sphaerospermopsis, Raphidiopsis, Desmonostoc and Mojavia gave entirely new secondary structures for the D1-D1' and box-B helix. Clear and separate clustering from Nostoc sensu stricto supports the establishment of Aliinostoc gen. nov. with the type species being Aliinostoc morphoplasticum sp. nov. in accordance with the International Code of Nomenclature for algae, fungi and plants.
[Mh] Termos MeSH primário: Nostoc/classificação
Filogenia
Microbiologia da Água
[Mh] Termos MeSH secundário: Técnicas de Tipagem Bacteriana
Composição de Bases
DNA Bacteriano/genética
Genes Bacterianos
Índia
Conformação de Ácido Nucleico
RNA Ribossômico 16S/genética
Análise de Sequência de DNA
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Bacterial); 0 (RNA, Ribosomal, 16S)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170920
[Lr] Data última revisão:
170920
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170905
[St] Status:MEDLINE
[do] DOI:10.1099/ijsem.0.002112


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[PMID]:28544967
[Au] Autor:Ishihara K; Watanabe R; Uchida H; Suzuki T; Yamashita M; Takenaka H; Nazifi E; Matsugo S; Yamaba M; Sakamoto T
[Ad] Endereço:Marine Biochemistry Division, National Research Institute of Fisheries Science, Yokohama 236-8648, Japan. Electronic address: hplc@affrc.go.jp.
[Ti] Título:Novel glycosylated mycosporine-like amino acid, 13-O-(ß-galactosyl)-porphyra-334, from the edible cyanobacterium Nostoc sphaericum-protective activity on human keratinocytes from UV light.
[So] Source:J Photochem Photobiol B;172:102-108, 2017 Jul.
[Is] ISSN:1873-2682
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:A UV-absorbing compound was purified and identified as a novel glycosylated mycosporine-like amino acid (MAA), 13-O-ß-galactosyl-porphyra-334 (ß-Gal-P334) from the edible cyanobacterium Nostoc sphaericum, known as "ge xian mi" in China and "cushuro" in Peru. Occurrence of the hexosylated derivative of shinorine (hexosyl-shinorine) was also supported by LC-MS/MS analysis. ß-Gal-P334 accounted for about 86.5% of total MAA in N. sphaericum, followed by hexosyl-shinorine (13.2%) and porphyra-334 (0.2%). ß-Gal-P334 had an absorption maximum at 334nm and molecular absorption coefficient was 46,700 at 334nm. Protection activity of ß-Gal-P334 from UVB and UVA+8-methoxypsoralen induced cell damage on human keratinocytes (HaCaT) was assayed in comparison with other MAA (porphyra-334, shinorine, palythine and mycosporine-glycine). The UVB protection activity was highest in mycosporine-glycine, followed by palythine, ß-Gal-P334, porphyra-334 and shinorine in order. ß-Gal-P334 had highest protection activity from UVA+8-methoxypsoralen induced cell damage followed by porphyra-334, shinorine, mycosporine-glycine and palythine. We also found an antioxidant (radical-scavenging) activity of ß-Gal-P334 by colorimetric and ESR methods. From these findings, ß-Gal-P334 was suggested to play important roles in stress tolerant mechanisms such as UV and oxidative stress in N. sphaericum as a major MAA. We also consider that the newly identified MAA, ß-Gal-P334 has a potential for use as an ingredient of cosmetics and toiletries.
[Mh] Termos MeSH primário: Cicloexanonas/química
Glicina/análogos & derivados
Nostoc/química
Estresse Oxidativo/efeitos dos fármacos
Substâncias Protetoras/farmacologia
Raios Ultravioleta
[Mh] Termos MeSH secundário: Aminoácidos/química
Antioxidantes/química
Antioxidantes/isolamento & purificação
Antioxidantes/farmacologia
Linhagem Celular
Sobrevivência Celular/efeitos dos fármacos
Sobrevivência Celular/efeitos da radiação
Cromatografia Líquida de Alta Pressão
Cicloexanonas/isolamento & purificação
Cicloexanonas/farmacologia
Cicloexilaminas/química
Glicina/química
Glicina/isolamento & purificação
Glicina/farmacologia
Glicosilação
Seres Humanos
Queratinócitos/citologia
Queratinócitos/efeitos dos fármacos
Queratinócitos/efeitos da radiação
Conformação Molecular
Nostoc/metabolismo
Estresse Oxidativo/efeitos da radiação
Substâncias Protetoras/química
Substâncias Protetoras/isolamento & purificação
Espectrometria de Massas em Tandem
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Amino Acids); 0 (Antioxidants); 0 (Cyclohexanones); 0 (Cyclohexylamines); 0 (Protective Agents); 0 (porphyra-334); 0 (shinorine); TE7660XO1C (Glycine)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170925
[Lr] Data última revisão:
170925
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170526
[St] Status:MEDLINE


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[PMID]:28527322
[Au] Autor:Xue XM; Yan Y; Xiong C; Raber G; Francesconi K; Pan T; Ye J; Zhu YG
[Ad] Endereço:Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
[Ti] Título:Arsenic biotransformation by a cyanobacterium Nostoc sp. PCC 7120.
[So] Source:Environ Pollut;228:111-117, 2017 Sep.
[Is] ISSN:1873-6424
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Nostoc sp. PCC 7120 (Nostoc), a typical filamentous cyanobacterium ubiquitous in aquatic system, is recognized as a model organism to study prokaryotic cell differentiation and nitrogen fixation. In this study, Nostoc cells incubated with arsenite (As(III)) for two weeks were extracted with dichloromethane/methanol (DCM/MeOH) and the extract was partitioned between water and DCM. Arsenic species in aqueous and DCM layers were determined using high performance liquid chromatography - inductively coupled plasma mass spectrometer/electrospray tandem mass spectrometry (HPLC-ICPMS/ESIMSMS). In addition to inorganic arsenic (iAs), the aqueous layer also contained monomethylarsonate (MAs(V)), dimethylarsinate (DMAs(V)), and the two arsenosugars, namely a glycerol arsenosugar (Oxo-Gly) and a phosphate arsenosugar (Oxo-PO4). Two major arsenosugar phospholipids (AsSugPL982 and AsSugPL984) were detected in DCM fraction. Arsenic in the growth medium was also investigated by HPLC/ICPMS and shown to be present mainly as the inorganic forms As(III) and As(V) accounting for 29%-38% and 29%-57% of the total arsenic respectively. The total arsenic of methylated arsenic, arsenosugars, and arsenosugar phospholipids in Nostoc cells with increasing As(III) exposure were not markedly different, indicating that the transformation to organoarsenic in Nostoc was not dependent on As(III) concentration in the medium. Our results provide new insights into the role of cyanobacteria in the biogeochemical cycling of arsenic.
[Mh] Termos MeSH primário: Arsênico/metabolismo
Biotransformação
Nostoc/metabolismo
Poluentes Químicos da Água/toxicidade
[Mh] Termos MeSH secundário: Arseniatos/metabolismo
Arsênico/análise
Arsenitos/metabolismo
Ácido Cacodílico/metabolismo
Cromatografia Líquida de Alta Pressão/métodos
Espectrometria de Massas
Monossacarídeos/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Arsenates); 0 (Arsenites); 0 (Monosaccharides); 0 (Water Pollutants, Chemical); 0 (arsenosugar); AJ2HL7EU8K (Cacodylic Acid); N5509X556J (arsenite); N712M78A8G (Arsenic)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170810
[Lr] Data última revisão:
170810
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170521
[St] Status:MEDLINE


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[PMID]:28282402
[Au] Autor:Bell SM; Wendt DJ; Zhang Y; Taylor TW; Long S; Tsuruda L; Zhao B; Laipis P; Fitzpatrick PA
[Ad] Endereço:BioMarin Pharmaceutical, Novato, California, United States of America.
[Ti] Título:Formulation and PEGylation optimization of the therapeutic PEGylated phenylalanine ammonia lyase for the treatment of phenylketonuria.
[So] Source:PLoS One;12(3):e0173269, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Phenylketonuria (PKU) is a genetic metabolic disease in which the decrease or loss of phenylalanine hydroxylase (PAH) activity results in elevated, neurotoxic levels of phenylalanine (Phe). Due to many obstacles, PAH enzyme replacement therapy is not currently an option. Treatment of PKU with an alternative enzyme, phenylalanine ammonia lyase (PAL), was first proposed in the 1970s. However, issues regarding immunogenicity, enzyme production and mode of delivery needed to be overcome. Through the evaluation of PAL enzymes from multiple species, three potential PAL enzymes from yeast and cyanobacteria were chosen for evaluation of their therapeutic potential. The addition of polyethylene glycol (PEG, MW = 20,000), at a particular ratio to modify the protein surface, attenuated immunogenicity in an animal model of PKU. All three PEGylated PAL candidates showed efficacy in a mouse model of PKU (BTBR Pahenu2) upon subcutaneous injection. However, only PEGylated Anabaena variabilis (Av) PAL-treated mice demonstrated sustained low Phe levels with weekly injection and was the only PAL evaluated that maintained full enzymatic activity upon PEGylation. A PEGylated recombinant double mutant version of AvPAL (Cys503Ser/Cys565Ser), rAvPAL-PEG, was selected for drug development based on its positive pharmacodynamic profile and favorable expression titers. PEGylation was shown to be critical for rAvPAL-PEG efficacy as under PEGylated rAvPAL had a lower pharmacodynamic effect. rAvPAL and rAvPAL-PEG had poor stability at 4°C. L-Phe and trans-cinnamate were identified as activity stabilizing excipients. rAvPAL-PEG is currently in Phase 3 clinical trials to assess efficacy in PKU patients.
[Mh] Termos MeSH primário: Fenilalanina Amônia-Liase/uso terapêutico
Fenilcetonúrias/tratamento farmacológico
Polietilenoglicóis/química
[Mh] Termos MeSH secundário: Anabaena/enzimologia
Animais
Anticorpos/sangue
Modelos Animais de Doenças
Composição de Medicamentos
Terapia de Reposição de Enzimas
Ensaio de Imunoadsorção Enzimática
Camundongos
Nostoc/enzimologia
Petroselinum/enzimologia
Fenilalanina Amônia-Liase/química
Fenilalanina Amônia-Liase/imunologia
Fenilalanina Amônia-Liase/isolamento & purificação
Fenilcetonúrias/patologia
Proteínas Recombinantes/biossíntese
Proteínas Recombinantes/química
Proteínas Recombinantes/isolamento & purificação
Proteínas Recombinantes/uso terapêutico
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antibodies); 0 (Recombinant Proteins); 30IQX730WE (Polyethylene Glycols); EC 4.3.1.24 (Phenylalanine Ammonia-Lyase)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170829
[Lr] Data última revisão:
170829
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170311
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0173269


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[PMID]:28252962
[Au] Autor:May DS; Chen WL; Lantvit DD; Zhang X; Krunic A; Burdette JE; Eustaquio A; Orjala J
[Ad] Endereço:Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago , Chicago, Illinois 60612, United States.
[Ti] Título:Merocyclophanes C and D from the Cultured Freshwater Cyanobacterium Nostoc sp. (UIC 10110).
[So] Source:J Nat Prod;80(4):1073-1080, 2017 Apr 28.
[Is] ISSN:1520-6025
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Merocyclophanes C and D (1 and 2) were isolated from the cell extract of the cultured cyanobacterium UIC 10110. The structures were determined by one-dimensional nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry and confirmed by 2D NMR techniques. The absolute configurations were determined using electronic circular dichroism spectroscopy. Merocyclophanes C and D represent the first known analogues of the merocyclophane core structure, a recently discovered scaffold of [7,7] paracyclophanes characterized by an α-branched methyl at C-1/C-14; 1 and 2 showed antiproliferative activity against the MDA-MB-435 cell line with IC values of 1.6 and 0.9 µM, respectively. Partial 16S analysis determined UIC 10110 to be a Nostoc sp., and it was found to clade with UIC 10062 Nostoc sp., the only other strain known to produce merocyclophanes. The genome of UIC 10110 was sequenced, and a biosynthetic gene cluster was identified that is proposed to encode type I and type III polyketide synthases that are potentially responsible for production of the merocyclophanes; however, further experiments will be required to verify the true function of the gene cluster. The gene cluster provides a genetic basis for the observed structural differences of the [7,7] paracyclophane core structures.
[Mh] Termos MeSH primário: Compostos Macrocíclicos/isolamento & purificação
Nostoc/química
[Mh] Termos MeSH secundário: Animais
Antibacterianos/química
Colorado
Água Doce/microbiologia
Concentração Inibidora 50
Compostos Macrocíclicos/química
Camundongos
Estrutura Molecular
Nostoc/genética
Ressonância Magnética Nuclear Biomolecular
Espectrometria de Massas por Ionização por Electrospray
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Macrocyclic Compounds); 0 (merocyclophane C); 0 (merocyclophane D)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170726
[Lr] Data última revisão:
170726
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170303
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jnatprod.6b01175


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[PMID]:28242721
[Au] Autor:Khayatan B; Bains DK; Cheng MH; Cho YW; Huynh J; Kim R; Omoruyi OH; Pantoja AP; Park JS; Peng JK; Splitt SD; Tian MY; Risser DD
[Ad] Endereço:Department of Biology, University of the Pacific, Stockton, California, USA.
[Ti] Título:A Putative O-Linked ß- -Acetylglucosamine Transferase Is Essential for Hormogonium Development and Motility in the Filamentous Cyanobacterium Nostoc punctiforme.
[So] Source:J Bacteriol;199(9), 2017 May 01.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Most species of filamentous cyanobacteria are capable of gliding motility, likely via a conserved type IV pilus-like system that may also secrete a motility-associated polysaccharide. In a subset of these organisms, motility is achieved only after the transient differentiation of hormogonia, which are specialized filaments that enter a nongrowth state dedicated to motility. Despite the fundamental importance of hormogonia to the life cycles of many filamentous cyanobacteria, the molecular regulation of hormogonium development is largely undefined. To systematically identify genes essential for hormogonium development and motility in the model heterocyst-forming filamentous cyanobacterium , a forward genetic screen was employed. The first gene identified using this screen, designated , encodes a putative O-linked ß- -acetylglucosamine transferase (OGT). The deletion of abolished motility, while ectopic expression of induced hormogonium development even under hormogonium-repressing conditions. Transcription of is rapidly upregulated (1 h) following hormogonium induction, and an OgtA-GFPuv fusion protein localized to the cytoplasm. In developing hormogonia, accumulation of PilA but not HmpD is dependent on Reverse transcription-quantitative PCR (RT-qPCR) analysis indicated equivalent levels of transcript in the wild-type and Δ mutant strains, while a reporter construct consisting of the intergenic region in the 5' direction of fused to produced lower levels of fluorescence in the Δ mutant strain than in the wild type. The production of hormogonium polysaccharide in the Δ mutant strain is reduced compared to that in the wild type but comparable to that in a deletion strain. Collectively, these results imply that -GlcNAc protein modification regulates the accumulation of PilA via a posttranscriptional mechanism in developing hormogonia. Filamentous cyanobacteria are among the most developmentally complex prokaryotes. Species such as develop an array of cell types, including nitrogen-fixing heterocysts, spore-like akinetes, and motile hormogonia, that function in dispersal as well as the establishment of nitrogen-fixing symbioses with plants and fungi. These symbioses are major contributors to global nitrogen fixation. Despite the fundamental importance of hormogonia to the life cycle of filamentous cyanobacteria and the establishment of symbioses, the molecular regulation of hormogonium development is largely undefined. We employed a genetic screen to identify genes essential for hormogonium development and motility in The first gene identified using this screen encodes a eukaryotic-like O-linked ß- -acetylglucosamine transferase that is required for accumulation of PilA in hormogonia.
[Mh] Termos MeSH primário: N-Acetilglucosaminiltransferases/metabolismo
Nostoc/enzimologia
Nostoc/crescimento & desenvolvimento
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Fímbrias Bacterianas/genética
Fímbrias Bacterianas/fisiologia
Perfilação da Expressão Gênica
Regulação Bacteriana da Expressão Gênica
Movimento
Mutação
N-Acetilglucosaminiltransferases/genética
Nostoc/genética
Simbiose
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); EC 2.4.1.- (N-Acetylglucosaminyltransferases)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:171011
[Lr] Data última revisão:
171011
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170301
[St] Status:MEDLINE


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[PMID]:28154339
[Au] Autor:Hori M; Oka S; Sugie Y; Ohtsuka H; Aiba H
[Ad] Endereço:Laboratory of Molecular Microbiology, Department of Basic Medicinal Sciences, Graduate School of Pharmaceutical Sciences, Nagoya University.
[Ti] Título:Construction of a photo-responsive chimeric histidine kinase in Escherichia coli.
[So] Source:J Gen Appl Microbiol;63(1):44-50, 2017 Mar 17.
[Is] ISSN:1349-8037
[Cp] País de publicação:Japan
[La] Idioma:eng
[Ab] Resumo:Two-component signal transduction systems (TCS), that are also referred to as His to Asp phosphorelay systems, are involved in widespread cellular responses to diverse signals from bacteria to plants. Previously, we succeeded in reconstructing a cyanobacterial photo-perception system in Escherichia coli by employing a CcaS-CcaR two-component system from Nostoc punctiforme. In this study, we have added a photo-responsive ability to ArcB-ArcA (anoxic redox control) TCS of E. coli by fusing a cyanobacterial photoreceptor domain of CcaS with an intracellular histidine kinase (HK) domain of ArcB. For this, we constructed several chimeric HKs between CcaS and ArcB and found that one chimeric HK, named ArcaS9, has a photo-responsive ability. When ArcaS9 was expressed with an ArcA response regulator in E. coli expressing phycocyanobilin (PCB)-producing enzymes, the expression of sdh, a target gene of ArcB-ArcA TCS was regulated in a light-color-dependent manner. Thus we succeeded in endowing E. coli HK with a photo-responsive ability. This provides an insight into how the sensing ability of HK can be manipulated by a chimeric construct.
[Mh] Termos MeSH primário: Escherichia coli/enzimologia
Regulação Bacteriana da Expressão Gênica/efeitos da radiação
Histidina Quinase/metabolismo
Nostoc/enzimologia
Fotorreceptores Microbianos/metabolismo
Proteínas Recombinantes/metabolismo
[Mh] Termos MeSH secundário: Escherichia coli/genética
Escherichia coli/efeitos da radiação
Histidina Quinase/genética
Luz
Nostoc/genética
Fotorreceptores Microbianos/genética
Proteínas Recombinantes/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Photoreceptors, Microbial); 0 (Recombinant Proteins); EC 2.7.13.1 (Histidine Kinase)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170417
[Lr] Data última revisão:
170417
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170204
[St] Status:MEDLINE
[do] DOI:10.2323/jgam.2016.07.005


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[PMID]:28150026
[Au] Autor:Hudek L; Torriero AAJ; Michalczyk AA; Neilan BA; Ackland ML; Bräu L
[Ad] Endereço:Centre for Regional and Rural Futures, Deakin University, Burwood, VIC, 3125, Australia.
[Ti] Título:Peroxide reduction by a metal-dependent catalase in Nostoc punctiforme (cyanobacteria).
[So] Source:Appl Microbiol Biotechnol;101(9):3781-3800, 2017 May.
[Is] ISSN:1432-0614
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:This study investigated the role of a novel metal-dependent catalase (Npun_R4582) that reduces hydrogen peroxide in the cyanobacterium Nostoc punctiforme. Quantitative real-time PCR showed that npun_R4582 relative mRNA levels were upregulated by over 16-fold in cells treated with either 2 µM added Co, 0.5 µM added Cu, 500 µM Mn, 1 µM Ni, or 18 µM Zn. For cells treated with 60 µM H O , no significant alteration in Npun_R4582 relative mRNA levels was detected, while in cells treated with Co, Cu, Mn, Ni, or Zn and 60 µM peroxide, relative mRNA levels were generally above control or peroxide only treated cells. Disruption or overexpression of npun_R4582 altered sensitivity to cells exposed to 60 µM H O and metals for treatments beyond the highest viable concentrations, or in a mixed metal solution for Npun_R4582 cells. Moreover, overexpression of npun_R4582 increased cellular peroxidase activity in comparison with wild-type and Npun_R4582 cells, and reduced peroxide levels by over 50%. The addition of cobalt, manganese, nickel, and zinc increased the capacity of Npun_R4582 to reduce the rate or total levels of peroxide produced by cells growing under photooxidative conditions. The work presented confirms the function of NpunR4582 as a catalase and provides insights as to how cells reduce potentially lethal peroxide levels produced by photosynthesis. The findings also show how trace elements play crucial roles as enzymatic cofactors and how the role of Npun_R4582 in hydrogen peroxide breakdown is dependent on the type of metal and the level available to cells.
[Mh] Termos MeSH primário: Catalase/metabolismo
Coenzimas/metabolismo
Metais/metabolismo
Nostoc/enzimologia
Nostoc/metabolismo
Peróxidos/metabolismo
[Mh] Termos MeSH secundário: Catalase/genética
Deleção de Genes
Expressão Gênica
Perfilação da Expressão Gênica
Peróxidos/toxicidade
Reação em Cadeia da Polimerase em Tempo Real
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Coenzymes); 0 (Metals); 0 (Peroxides); EC 1.11.1.6 (Catalase)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170428
[Lr] Data última revisão:
170428
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170203
[St] Status:MEDLINE
[do] DOI:10.1007/s00253-017-8130-y


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[PMID]:28109209
[Au] Autor:Suradkar A; Villanueva C; Gaysina LA; Casamatta DA; Saraf A; Dighe G; Mergu R; Singh P
[Ad] Endereço:1​Microbial Culture Collection (MCC), National Centre for Cell Science (NCCS), Pune, India.
[Ti] Título:Nostoc thermotolerans sp. nov., a soil-dwelling species of Nostoc (Cyanobacteria).
[So] Source:Int J Syst Evol Microbiol;67(5):1296-1305, 2017 May.
[Is] ISSN:1466-5034
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:A filamentous, soil-dwelling cyanobacterial strain (9C-PST) was isolated from Mandsaur, Madhya Pradesh, India, and is described as a new species of the genus Nostoc. Extensive morphological and molecular characterization along with a thorough assessment of ecology was performed. The style of filament orientation, type and nature of the sheath (e.g. distribution and visibility across the trichome), and vegetative and heterocyte cell dimensions and shape were assessed for over one year using both the laboratory grown culture and the naturally occurring samples. Sequencing of the 16S rRNA gene showed 94 % similarity with Nostocpiscinale CENA21 while analyses of the secondary structures of the 16S-23S ITS region showed unique folding patterns that differentiated this strain from other species of Nostoc. The level of rbcl and rpoC1 gene sequence similarity was 91 and 94 % to Nostocsp. PCC 7524 and Nostocpiscinale CENA21, respectively, while the nifD gene sequence similarity was found to be 99 % with Nostocpiscinale CENA21. The phenotypic, ecological, genetic and phylogenetic observations indicate that the strain 9C-PST represents a novel species of the genus Nostoc with the name proposed being Nostoc thermotolerans sp. nov. according to the International Code of Nomenclature for Algae, Fungi, and Plants.
[Mh] Termos MeSH primário: Nostoc/classificação
Filogenia
Microbiologia do Solo
[Mh] Termos MeSH secundário: Técnicas de Tipagem Bacteriana
Composição de Bases
DNA Bacteriano/genética
Genes Bacterianos
Índia
Nostoc/genética
Nostoc/isolamento & purificação
RNA Ribossômico 16S/genética
Análise de Sequência de DNA
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Bacterial); 0 (RNA, Ribosomal, 16S)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170825
[Lr] Data última revisão:
170825
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170122
[St] Status:MEDLINE
[do] DOI:10.1099/ijsem.0.001800



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