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Pesquisa : D12.776.543.750.695.700.150 [Categoria DeCS]
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  1 / 1071 MEDLINE  
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[PMID]:27258043
[Au] Autor:Haycocks JR; Grainger DC
[Ad] Endereço:Institute of Microbiology and Infection, School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.
[Ti] Título:Unusually Situated Binding Sites for Bacterial Transcription Factors Can Have Hidden Functionality.
[So] Source:PLoS One;11(6):e0157016, 2016.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:A commonly accepted paradigm of molecular biology is that transcription factors control gene expression by binding sites at the 5' end of a gene. However, there is growing evidence that transcription factor targets can occur within genes or between convergent genes. In this work, we have investigated one such target for the cyclic AMP receptor protein (CRP) of enterotoxigenic Escherichia coli. We show that CRP binds between two convergent genes. When bound, CRP regulates transcription of a small open reading frame, which we term aatS, embedded within one of the adjacent genes. Our work demonstrates that non-canonical sites of transcription factor binding can have hidden functionality.
[Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo
Fatores de Transcrição/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Sítios de Ligação/genética
Proteínas de Ligação a DNA/genética
Proteínas de Ligação a DNA/metabolismo
Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/metabolismo
Regulação Bacteriana da Expressão Gênica/genética
Regiões Promotoras Genéticas/genética
Ligação Proteica/genética
Receptores de AMP Cíclico/genética
Receptores de AMP Cíclico/metabolismo
Fatores de Transcrição/genética
Transcrição Genética/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (DNA-Binding Proteins); 0 (Escherichia coli Proteins); 0 (Receptors, Cyclic AMP); 0 (Transcription Factors); 0 (cyclic AMP receptor protein, E coli)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170818
[Lr] Data última revisão:
170818
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160604
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0157016


  2 / 1071 MEDLINE  
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[PMID]:26276689
[Au] Autor:Krishnamurthy S; Tulsian NK; Chandramohan A; Anand GS
[Ad] Endereço:Department of Biological Sciences, National University of Singapore, Singapore.
[Ti] Título:Parallel Allostery by cAMP and PDE Coordinates Activation and Termination Phases in cAMP Signaling.
[So] Source:Biophys J;109(6):1251-63, 2015 Sep 15.
[Is] ISSN:1542-0086
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The second messenger molecule cAMP regulates the activation phase of the cAMP signaling pathway through high-affinity interactions with the cytosolic cAMP receptor, the protein kinase A regulatory subunit (PKAR). Phosphodiesterases (PDEs) are enzymes responsible for catalyzing hydrolysis of cAMP to 5' AMP. It was recently shown that PDEs interact with PKAR to initiate the termination phase of the cAMP signaling pathway. While the steps in the activation phase are well understood, steps in the termination pathway are unknown. Specifically, the binding and allosteric networks that regulate the dynamic interplay between PKAR, PDE, and cAMP are unclear. In this study, PKAR and PDE from Dictyostelium discoideum (RD and RegA, respectively) were used as a model system to monitor complex formation in the presence and absence of cAMP. Amide hydrogen/deuterium exchange mass spectrometry was used to monitor slow conformational transitions in RD, using disordered regions as conformational probes. Our results reveal that RD regulates its interactions with cAMP and RegA at distinct loci by undergoing slow conformational transitions between two metastable states. In the presence of cAMP, RD and RegA form a stable ternary complex, while in the absence of cAMP they maintain transient interactions. RegA and cAMP each bind at orthogonal sites on RD with resultant contrasting effects on its dynamics through parallel allosteric relays at multiple important loci. RD thus serves as an integrative node in cAMP termination by coordinating multiple allosteric relays and governing the output signal response.
[Mh] Termos MeSH primário: 3´,5´-AMP Cíclico Fosfodiesterases/metabolismo
AMP Cíclico/metabolismo
Proteínas de Protozoários/metabolismo
[Mh] Termos MeSH secundário: 3',5'-AMP Cíclico Fosfodiesterases/química
Regulação Alostérica
Sítios de Ligação
Calorimetria
AMP Cíclico/química
Dictyostelium
Escherichia coli
Cinética
Espectrometria de Massas
Conformação Proteica
Desdobramento de Proteína
Proteínas de Protozoários/química
Receptores de AMP Cíclico/química
Receptores de AMP Cíclico/metabolismo
Transdução de Sinais
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Protozoan Proteins); 0 (Receptors, Cyclic AMP); E0399OZS9N (Cyclic AMP); EC 3.1.4.17 (3',5'-Cyclic-AMP Phosphodiesterases); EC 3.1.4.17 (regA protein, Dictyostelium)
[Em] Mês de entrada:1606
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150816
[St] Status:MEDLINE


  3 / 1071 MEDLINE  
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[PMID]:26243616
[Au] Autor:Bai J; Zhu X; Wang Q; Zhang J; Chen H; Dong G; Zhu L; Zheng H; Xie Q; Nian J; Chen F; Fu Y; Qian Q; Zuo J
[Ad] Endereço:State Key Laboratory of Plant Genomics and National Plant Gene Research Center (J.B., Q.W., J.Zh., H.Z., Q.X., J.N., J.Zu.) and State Key Laboratory of Molecular Developmental Biology and National Plant Gene Research Center (F.C.), Institute of Genetics and Developmental Biology, Chinese Academy of
[Ti] Título:Rice TUTOU1 Encodes a Suppressor of cAMP Receptor-Like Protein That Is Important for Actin Organization and Panicle Development.
[So] Source:Plant Physiol;169(2):1179-91, 2015 Oct.
[Is] ISSN:1532-2548
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Panicle development, a key event in rice (Oryza sativa) reproduction and a critical determinant of grain yield, forms a branched structure containing multiple spikelets. Genetic and environmental factors can perturb panicle development, causing panicles to degenerate and producing characteristic whitish, small spikelets with severely reduced fertility and yield; however, little is known about the molecular basis of the formation of degenerating panicles in rice. Here, we report the identification and characterization of the rice panicle degenerative mutant tutou1 (tut1), which shows severe defects in panicle development. The tut1 also shows a pleiotropic phenotype, characterized by short roots, reduced plant height, and abnormal development of anthers and pollen grains. Molecular genetic studies revealed that TUT1 encodes a suppressor of cAMP receptor/Wiskott-Aldrich syndrome protein family verprolin-homologous (SCAR/WAVE)-like protein. We found that TUT1 contains conserved functional domains found in eukaryotic SCAR/WAVE proteins, and was able to activate Actin-related protein2/3 to promote actin nucleation and polymerization in vitro. Consistently, tut1 mutants show defects in the arrangement of actin filaments in trichome. These results indicate that TUT1 is a functional SCAR/WAVE protein and plays an important role in panicle development.
[Mh] Termos MeSH primário: Actinas/metabolismo
Topos Floridos/crescimento & desenvolvimento
Oryza/crescimento & desenvolvimento
Proteínas de Plantas/metabolismo
[Mh] Termos MeSH secundário: Complexo 2-3 de Proteínas Relacionadas à Actina/genética
Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo
Proteínas de Arabidopsis/genética
Clonagem Molecular
Topos Floridos/fisiologia
Flores/citologia
Flores/genética
Flores/crescimento & desenvolvimento
Regulação da Expressão Gênica de Plantas
Mutação
Oryza/fisiologia
Proteínas de Plantas/genética
Plantas Geneticamente Modificadas
Pólen/citologia
Pólen/genética
Pólen/crescimento & desenvolvimento
Receptores de AMP Cíclico/genética
Receptores de AMP Cíclico/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Actin-Related Protein 2-3 Complex); 0 (Actins); 0 (Arabidopsis Proteins); 0 (DIS3 protein, Arabidopsis); 0 (Plant Proteins); 0 (Receptors, Cyclic AMP)
[Em] Mês de entrada:1607
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150806
[St] Status:MEDLINE
[do] DOI:10.1104/pp.15.00229


  4 / 1071 MEDLINE  
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[PMID]:25541491
[Au] Autor:Saha A; Mukhopadhyay J; Datta AB; Parrack P
[Ad] Endereço:Department of Biochemistry, Bose Institute, P-1/12, C.I.T. Scheme VIIM, Kolkata 700054, India.
[Ti] Título:Revisiting the mechanism of activation of cyclic AMP receptor protein (CRP) by cAMP in Escherichia coli: lessons from a subunit-crosslinked form of CRP.
[So] Source:FEBS Lett;589(3):358-63, 2015 Jan 30.
[Is] ISSN:1873-3468
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Cyclic AMP receptor protein (CRP), the global transcription regulator in prokaryotes, is active only as a cAMP-CRP complex. Binding of cAMP changes the conformation of CRP, transforming it from a transcriptionally 'inactive' to an 'active' molecule. These conformers are also characterized by distinct biochemical properties including the ability to form an S-S crosslink between the C178 residues of its two monomeric subunits. We studied a CRP variant (CRP(cl)), in which the subunits are crosslinked. We demonstrate that CRP(cl) can activate transcription even in the absence of cAMP. Implications of these results for the crystallographically-determined structure of cAMP-CRP are discussed.
[Mh] Termos MeSH primário: AMP Cíclico/química
Proteínas de Ligação a DNA/química
Proteínas de Escherichia coli/química
Receptores de AMP Cíclico/química
Ativação Transcricional/genética
[Mh] Termos MeSH secundário: Sítios de Ligação
Cristalografia por Raios X
AMP Cíclico/genética
Proteínas de Ligação a DNA/genética
Proteínas de Ligação a DNA/ultraestrutura
Escherichia coli
Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/ultraestrutura
Ligação Proteica
Conformação Proteica
Subunidades Proteicas/química
Subunidades Proteicas/metabolismo
Receptores de AMP Cíclico/genética
Receptores de AMP Cíclico/ultraestrutura
Relação Estrutura-Atividade
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (DNA-Binding Proteins); 0 (Escherichia coli Proteins); 0 (Protein Subunits); 0 (Receptors, Cyclic AMP); 0 (cyclic AMP receptor protein, E coli); E0399OZS9N (Cyclic AMP)
[Em] Mês de entrada:1504
[Cu] Atualização por classe:150126
[Lr] Data última revisão:
150126
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:141227
[St] Status:MEDLINE


  5 / 1071 MEDLINE  
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[PMID]:25446527
[Au] Autor:Singh SP; Dhakshinamoorthy R; Jaiswal P; Schmidt S; Thewes S; Baskar R
[Ad] Endereço:Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology-Madras, Chennai 600036, India.
[Ti] Título:The thyroxine inactivating gene, type III deiodinase, suppresses multiple signaling centers in Dictyostelium discoideum.
[So] Source:Dev Biol;396(2):256-68, 2014 Dec 15.
[Is] ISSN:1095-564X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Thyroxine deiodinases, the enzymes that regulate thyroxine metabolism, are essential for vertebrate growth and development. In the genome of Dictyostelium discoideum, a single intronless gene (dio3) encoding type III thyroxine 5' deiodinase is present. The amino acid sequence of D. discoideum Dio3 shares 37% identity with human T4 deiodinase and is a member of the thioredoxin reductase superfamily. dio3 is expressed throughout growth and development and by generating a knockout of dio3, we have examined the role of thyroxine 5' deiodinase in D. discoideum. dio3(-) had multiple defects that affected growth, timing of development, aggregate size, cell streaming, and cell-type differentiation. A prominent phenotype of dio3(-) was the breaking of late aggregates into small signaling centers, each forming a fruiting body of its own. cAMP levels, its relay, photo- and chemo-taxis were also defective in dio3(-). Quantitative RT-PCR analyses suggested that expression levels of genes encoding adenylyl cyclase A (acaA), cAMP-receptor A (carA) and cAMP-phosphodiesterases were reduced. There was a significant reduction in the expression of CadA and CsaA, which are involved in cell-cell adhesion. The dio3(-) slugs had prestalk identity, with pronounced prestalk marker ecmA expression. Thus, Dio3 seems to have roles in mediating cAMP synthesis/relay, cell-cell adhesion and slug patterning. The phenotype of dio3(-) suggests that Dio3 may prevent the formation of multiple signaling centers during D. discoideum development. This is the first report of a gene involved in thyroxine metabolism that is also involved in growth and development in a lower eukaryote.
[Mh] Termos MeSH primário: Dictyostelium/crescimento & desenvolvimento
Regulação da Expressão Gênica no Desenvolvimento/fisiologia
Iodeto Peroxidase/genética
Iodeto Peroxidase/metabolismo
Transdução de Sinais/fisiologia
[Mh] Termos MeSH secundário: Adenosina Trifosfatases/metabolismo
Adenilil Ciclases/metabolismo
Sequência de Aminoácidos
Sequência de Bases
Western Blotting
Adesão Celular/fisiologia
Dictyostelium/metabolismo
Regulação da Expressão Gênica no Desenvolvimento/genética
Técnicas de Inativação de Genes
Seres Humanos
Iodeto Peroxidase/farmacologia
Microscopia de Fluorescência
Dados de Sequência Molecular
Reação em Cadeia da Polimerase em Tempo Real
Receptores de AMP Cíclico/metabolismo
Reação em Cadeia da Polimerase Via Transcriptase Reversa
Análise de Sequência de DNA
Homologia de Sequência
Transdução de Sinais/efeitos dos fármacos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Receptors, Cyclic AMP); EC 1.11.1.- (iodothyronine deiodinase type III); EC 1.11.1.8 (Iodide Peroxidase); EC 3.6.1.- (Adenosine Triphosphatases); EC 3.6.1.- (cadmium translocating ATPase); EC 4.6.1.1 (Adenylyl Cyclases)
[Em] Mês de entrada:1502
[Cu] Atualização por classe:151119
[Lr] Data última revisão:
151119
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:141203
[St] Status:MEDLINE


  6 / 1071 MEDLINE  
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[PMID]:25300796
[Au] Autor:Gerhardt M; Walz M; Beta C
[Ad] Endereço:Institute of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Strasse 24/25, 14476 Potsdam, Germany.
[Ti] Título:Signaling in chemotactic amoebae remains spatially confined to stimulated membrane regions.
[So] Source:J Cell Sci;127(Pt 23):5115-25, 2014 Dec 01.
[Is] ISSN:1477-9137
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Recent work has demonstrated that the receptor-mediated signaling system in chemotactic amoeboid cells shows typical properties of an excitable system. Here, we delivered spatially confined stimuli of the chemoattractant cAMP to the membrane of differentiated Dictyostelium discoideum cells to investigate whether localized receptor stimuli can induce the spreading of excitable waves in the G-protein-dependent signal transduction system. By imaging the spatiotemporal dynamics of fluorescent markers for phosphatidylinositol (3,4,5)-trisphosphate (PIP3), PTEN and filamentous actin, we observed that the activity of the signaling pathway remained spatially confined to the stimulated membrane region. Neighboring parts of the membrane were not excited and no receptor-initiated spatial spreading of excitation waves was observed. To generate localized cAMP stimuli, either particles that carried covalently bound cAMP molecules on their surface were brought into contact with the cell or a patch of the cell membrane was aspirated into a glass micropipette to shield this patch against freely diffusing cAMP molecules in the surrounding medium. Additionally, the binding site of the cAMP receptor was probed with different surface-immobilized cAMP molecules, confirming results from earlier ligand-binding studies.
[Mh] Termos MeSH primário: Membrana Celular/efeitos dos fármacos
Quimiotaxia/efeitos dos fármacos
AMP Cíclico/farmacologia
Dictyostelium/efeitos dos fármacos
Receptores de AMP Cíclico/agonistas
Transdução de Sinais/efeitos dos fármacos
[Mh] Termos MeSH secundário: Citoesqueleto de Actina/metabolismo
Linhagem Celular
Membrana Celular/metabolismo
Dictyostelium/metabolismo
Ligantes
Potenciais da Membrana
Microscopia de Fluorescência
PTEN Fosfo-Hidrolase/metabolismo
Técnicas de Patch-Clamp
Fosfatidilinositol 3-Quinase/metabolismo
Fosfatos de Fosfatidilinositol/metabolismo
Receptores de AMP Cíclico/metabolismo
Fatores de Tempo
Transfecção
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; VIDEO-AUDIO MEDIA
[Nm] Nome de substância:
0 (Ligands); 0 (Phosphatidylinositol Phosphates); 0 (Receptors, Cyclic AMP); 0 (phosphatidylinositol 3,4,5-triphosphate); E0399OZS9N (Cyclic AMP); EC 2.7.1.137 (Phosphatidylinositol 3-Kinase); EC 3.1.3.67 (PTEN Phosphohydrolase)
[Em] Mês de entrada:1507
[Cu] Atualização por classe:151021
[Lr] Data última revisão:
151021
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:141011
[St] Status:MEDLINE
[do] DOI:10.1242/jcs.161133


  7 / 1071 MEDLINE  
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[PMID]:25143405
[Au] Autor:Cao X; Yan J; Shu S; Brzostowski JA; Jin T
[Ad] Endereço:Shanghai Institute of Immunology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
[Ti] Título:Arrestins function in cAR1 GPCR-mediated signaling and cAR1 internalization in the development of Dictyostelium discoideum.
[So] Source:Mol Biol Cell;25(20):3210-21, 2014 Oct 15.
[Is] ISSN:1939-4586
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Oscillation of chemical signals is a common biological phenomenon, but its regulation is poorly understood. At the aggregation stage of Dictyostelium discoideum development, the chemoattractant cAMP is synthesized and released at 6-min intervals, directing cell migration. Although the G protein-coupled cAMP receptor cAR1 and ERK2 are both implicated in regulating the oscillation, the signaling circuit remains unknown. Here we report that D. discoideum arrestins regulate the frequency of cAMP oscillation and may link cAR1 signaling to oscillatory ERK2 activity. Cells lacking arrestins (adcB(-)C(-)) display cAMP oscillations during the aggregation stage that are twice as frequent as for wild- type cells. The adcB(-)C(-) cells also have a shorter period of transient ERK2 activity and precociously reactivate ERK2 in response to cAMP stimulation. We show that arrestin domain-containing protein C (AdcC) associates with ERK2 and that activation of cAR1 promotes the transient membrane recruitment of AdcC and interaction with cAR1, indicating that arrestins function in cAR1-controlled periodic ERK2 activation and oscillatory cAMP signaling in the aggregation stage of D. discoideum development. In addition, ligand-induced cAR1 internalization is compromised in adcB(-)C(-) cells, suggesting that arrestins are involved in elimination of high-affinity cAR1 receptors from cell surface after the aggregation stage of multicellular development.
[Mh] Termos MeSH primário: Arrestinas/metabolismo
Dictyostelium/crescimento & desenvolvimento
Receptores de AMP Cíclico/metabolismo
Receptores Acoplados a Proteínas-G/metabolismo
Transdução de Sinais/fisiologia
[Mh] Termos MeSH secundário: Dictyostelium/metabolismo
Proteína Quinase 1 Ativada por Mitógeno/metabolismo
Fosforilação
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., INTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Arrestins); 0 (Receptors, Cyclic AMP); 0 (Receptors, G-Protein-Coupled); EC 2.7.11.24 (Mitogen-Activated Protein Kinase 1)
[Em] Mês de entrada:1506
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140822
[St] Status:MEDLINE
[do] DOI:10.1091/mbc.E14-03-0834


  8 / 1071 MEDLINE  
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[PMID]:24509317
[Au] Autor:Uppal S; Shetty DM; Jawali N
[Ad] Endereço:Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India.
[Ti] Título:Cyclic AMP receptor protein regulates cspD, a bacterial toxin gene, in Escherichia coli.
[So] Source:J Bacteriol;196(8):1569-77, 2014 Apr.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:cspD, a member of cspA family of cold shock genes in Escherichia coli, is not induced during cold shock. Its expression is induced during stationary phase. CspD inhibits DNA replication, and a high level of the protein is toxic to cells. Recently, CspD was proposed to be associated with persister cell formation in E. coli. Here, we show that cyclic AMP receptor protein (CRP) upregulates cspD transcription. Sequence analysis of the cspD upstream region revealed two tandem CRP target sites, CRP site-I (the proximal site centered at -83.5 with respect to the transcription start) and CRP site-II (the distal site centered at -112.5). The results from electrophoretic mobility shift assays showed that CRP indeed binds to these two target sites in PcspD. The promoter-proximal CRP target site was found to play a major role in PcspD activation by CRP, as studied by transcriptional fusions carrying mutations in the target sites. The results from in vitro transcription assays demonstrated that CRP activates PcspD transcription in the absence of additional factors other than RNA polymerase. The requirement for activating region 1 of CRP in PcspD activation, along with the involvement of the 287, 265, and 261 determinants of the α-CTD, suggest that CRP activates by a class I-type mechanism. However, only moderate activation in vitro was observed compared to high activation in vivo, suggesting there might be additional activators of PcspD. Overall, our findings show that CRP, a global metabolic regulator in E. coli, activates a gene potentially related to persistence.
[Mh] Termos MeSH primário: Toxinas Bacterianas/biossíntese
Proteínas de Ligação a DNA/metabolismo
Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/metabolismo
Escherichia coli/genética
Escherichia coli/metabolismo
Regulação Bacteriana da Expressão Gênica
Proteínas de Choque Térmico/genética
Receptores de AMP Cíclico/metabolismo
[Mh] Termos MeSH secundário: Sítios de Ligação
DNA Bacteriano/metabolismo
Ensaio de Desvio de Mobilidade Eletroforética
Ligação Proteica
Elementos Reguladores de Transcrição
Transcrição Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Toxins); 0 (DNA, Bacterial); 0 (DNA-Binding Proteins); 0 (Escherichia coli Proteins); 0 (Heat-Shock Proteins); 0 (Receptors, Cyclic AMP); 0 (cspH protein, E coli); 0 (cyclic AMP receptor protein, E coli)
[Em] Mês de entrada:1405
[Cu] Atualização por classe:150515
[Lr] Data última revisão:
150515
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140211
[St] Status:MEDLINE
[do] DOI:10.1128/JB.01476-13


  9 / 1071 MEDLINE  
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[PMID]:24387622
[Au] Autor:Lindemose S; Nielsen PE; Valentin-Hansen P; Møllegaard NE
[Ad] Endereço:Department of Cellular and Molecular Medicine, Panum Institute, University of Copenhagen , Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
[Ti] Título:A novel indirect sequence readout component in the E. coli cyclic AMP receptor protein operator.
[So] Source:ACS Chem Biol;9(3):752-60, 2014 Mar 21.
[Is] ISSN:1554-8937
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The cyclic AMP receptor protein (CRP) from Escherichia coli has been extensively studied for several decades. In particular, a detailed characterization of CRP interaction with DNA has been obtained. The CRP dimer recognizes a consensus sequence AANTGTGANNNNNNTCACANTT through direct amino acid nucleobase interactions in the major groove of the two operator half-sites. Crystal structure analyses have revealed that the interaction results in two strong kinks at the TG/CA steps closest to the 6-base-pair spacer (N6). This spacer exhibits high sequence variability among the more than 100 natural binding sites in the E. coli genome, but the exact role of the N6 region in CRP interaction has not previously been systematic examined. Here we employ an in vitro selection system based on a randomized N6 spacer region to demonstrate that CRP binding to the lacP1 site may be enhanced up to 14-fold or abolished by varying the N6 spacer sequences. Furthermore, on the basis of sequence analysis and uranyl (UO2(2+)) probing data, we propose that the underlying mechanism relies on N6 deformability.
[Mh] Termos MeSH primário: DNA Bacteriano/química
DNA Intergênico/química
Proteínas de Ligação a DNA/química
Proteínas de Escherichia coli/química
Receptores de AMP Cíclico/química
[Mh] Termos MeSH secundário: Sequência de Bases
Sítios de Ligação
Sequência Consenso
Pegada de DNA
DNA Bacteriano/genética
DNA Intergênico/genética
Proteínas de Ligação a DNA/genética
Proteínas de Escherichia coli/genética
Genoma Bacteriano
Óperon Lac/genética
Modelos Moleculares
Dados de Sequência Molecular
Ligação Proteica
Receptores de AMP Cíclico/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Bacterial); 0 (DNA, Intergenic); 0 (DNA-Binding Proteins); 0 (Escherichia coli Proteins); 0 (Receptors, Cyclic AMP); 0 (cyclic AMP receptor protein, E coli)
[Em] Mês de entrada:1411
[Cu] Atualização por classe:140321
[Lr] Data última revisão:
140321
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140107
[St] Status:MEDLINE
[do] DOI:10.1021/cb4008309


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[PMID]:24058516
[Au] Autor:Gonzales L; Ali ZB; Nygren E; Wang Z; Karlsson S; Zhu B; Quiding-Järbrink M; Sjöling Å
[Ad] Endereço:Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden ; Instituto de Biología Molecular y Biotecnología, Universidad Mayor de San Andrés, La Paz, Bolivia.
[Ti] Título:Alkaline pH Is a signal for optimal production and secretion of the heat labile toxin, LT in enterotoxigenic Escherichia coli (ETEC).
[So] Source:PLoS One;8(9):e74069, 2013.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Enterotoxigenic Escherichia coli (ETEC) cause secretory diarrhea in children and travelers to endemic areas. ETEC spreads through the fecal-oral route. After ingestion, ETEC passes through the stomach and duodenum before it colonizes the lower part of the small intestine, exposing bacteria to a wide range of pH and environmental conditions. This study aimed to determine the impact of external pH and activity of the Cyclic AMP receptor protein (CRP) on the regulation of production and secretion of heat labile (LT) enterotoxin. ETEC strain E2863wt and its isogenic mutant E2863ΔCRP were grown in LBK media buffered to pH 5, 7 and 9. GM1 ELISA, cDNA and cAMP analyses were carried out on bacterial pellet and supernatant samples derived from 3 and 5 hours growth and from overnight cultures. We confirm that CRP is a repressor of LT transcription and production as has been shown before but we show for the first time that CRP is a positive regulator of LT secretion both in vitro and in vivo. LT secretion increased at neutral to alkaline pH compared to acidic pH 5 where secretion was completely inhibited. At pH 9 secretion of LT was optimal resulting in 600 percent increase of secreted LT compared to unbuffered LBK media. This effect was not due to membrane leakage since the bacteria were viable at pH 9. The results indicate that the transition to the alkaline duodenum and/or exposure to high pH close to the epithelium as well as activation of the global transcription factor CRP are signals that induce secretion of the LT toxin in ETEC.
[Mh] Termos MeSH primário: Proteínas de Ligação a DNA/genética
Escherichia coli Enterotoxigênica/genética
Enterotoxinas/biossíntese
Proteínas de Escherichia coli/genética
Regulação Bacteriana da Expressão Gênica
Receptores de AMP Cíclico/genética
[Mh] Termos MeSH secundário: Meios de Cultura
Proteínas de Ligação a DNA/metabolismo
Escherichia coli Enterotoxigênica/metabolismo
Escherichia coli Enterotoxigênica/patogenicidade
Enterotoxinas/secreção
Proteínas de Escherichia coli/metabolismo
Temperatura Alta
Concentração de Íons de Hidrogênio
Receptores de AMP Cíclico/metabolismo
Transcrição Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Culture Media); 0 (DNA-Binding Proteins); 0 (Enterotoxins); 0 (Escherichia coli Proteins); 0 (Receptors, Cyclic AMP); 0 (cyclic AMP receptor protein, E coli)
[Em] Mês de entrada:1406
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:130924
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0074069



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