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[PMID]:28468991
[Au] Autor:Cai Z; Neveu CL; Baxter DA; Byrne JH; Aazhang B
[Ad] Endereço:Department of Electrical and Computer Engineering, Rice University, Houston, Texas; and.
[Ti] Título:Inferring neuronal network functional connectivity with directed information.
[So] Source:J Neurophysiol;118(2):1055-1069, 2017 Aug 01.
[Is] ISSN:1522-1598
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:A major challenge in neuroscience is to develop effective tools that infer the circuit connectivity from large-scale recordings of neuronal activity patterns. In this study, context tree maximizing (CTM) was used to estimate directed information (DI), which measures causal influences among neural spike trains in order to infer putative synaptic connections. In contrast to existing methods, the method presented here is data driven and can readily identify both linear and nonlinear relations between neurons. This CTM-DI method reliably identified circuit structures underlying simulations of realistic conductance-based networks. It also inferred circuit properties from voltage-sensitive dye recordings of the buccal ganglion of This method can be applied to other large-scale recordings as well. It offers a systematic tool to map network connectivity and to track changes in network structure such as synaptic strengths as well as the degrees of connectivity of individual neurons, which in turn could provide insights into how modifications produced by learning are distributed in a neural network. This study brings together the techniques of voltage-sensitive dye recording and information theory to infer the functional connectome of the feeding central pattern generating network of In contrast to current statistical approaches, the inference method developed in this study is data driven and validated by conductance-based model circuits, can distinguish excitatory and inhibitory connections, is robust against synaptic plasticity, and is capable of detecting network structures that mediate motor patterns.
[Mh] Termos MeSH primário: Encéfalo/anatomia & histologia
Encéfalo/fisiologia
Conectoma/métodos
Neurônios/fisiologia
[Mh] Termos MeSH secundário: Potenciais de Ação
Animais
Aplysia
Teoria da Informação
Modelos Neurológicos
Redes Neurais (Computação)
Vias Neurais/fisiologia
Imagens com Corantes Sensíveis à Voltagem
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180205
[Lr] Data última revisão:
180205
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170505
[St] Status:MEDLINE
[do] DOI:10.1152/jn.00086.2017


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[PMID]:29053733
[Au] Autor:Hastings MH; Gong K; Freibauer A; Courchesne C; Fan X; Sossin WS
[Ad] Endereço:Department of Psychology Montreal Neurological Institute McGill University, Montreal, Quebec, Canada.
[Ti] Título:Novel calpain families and novel mechanisms for calpain regulation in Aplysia.
[So] Source:PLoS One;12(10):e0186646, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Calpains are a family of intracellular proteases defined by a conserved protease domain. In the marine mollusk Aplysia californica, calpains are important for the induction of long-term synaptic plasticity and memory, at least in part by cleaving protein kinase Cs (PKCs) into constitutively active kinases, termed protein kinase Ms (PKMs). We identify 14 genes encoding calpains in Aplysia using bioinformatics, including at least one member of each of the four major calpain families into which metazoan calpains are generally classified, as well as additional truncated and atypical calpains. Six classical calpains containing a penta-EF-hand (PEF) domain are present in Aplysia. Phylogenetic analysis determined that these six calpains come from three separate classical calpain families. One of the classical calpains in Aplysia, AplCCal1, has been implicated in plasticity. We identify three splice cassettes and an alternative transcriptional start site in AplCCal1. We characterize several of the possible isoforms of AplCCal1 in vitro, and demonstrate that AplCCal1 can cleave PKCs into PKMs in a calcium-dependent manner in vitro. We also find that AplCCal1 has a novel mechanism of auto-inactivation through N-terminal cleavage that is modulated through its alternative transcriptional start site.
[Mh] Termos MeSH primário: Aplysia/metabolismo
Calpaína/metabolismo
[Mh] Termos MeSH secundário: Animais
Aplysia/fisiologia
Plasticidade Neuronal
Filogenia
Transcrição Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
EC 3.4.22.- (Calpain)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171113
[Lr] Data última revisão:
171113
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171021
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0186646


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[PMID]:28820587
[Au] Autor:Onozaki Y; Horikoshi R; Ohno I; Kitsuda S; Durkin KA; Suzuki T; Asahara C; Hiroki N; Komabashiri R; Shimizu R; Furutani S; Ihara M; Matsuda K; Mitomi M; Kagabu S; Uomoto K; Tomizawa M
[Ad] Endereço:Agricultural and Veterinary Research Laboratories, Agricultural and Veterinary Division, Meiji Seika Pharma Co., Ltd. , Yokohama, Kanagawa 222-8567, Japan.
[Ti] Título:Flupyrimin: A Novel Insecticide Acting at the Nicotinic Acetylcholine Receptors.
[So] Source:J Agric Food Chem;65(36):7865-7873, 2017 Sep 13.
[Is] ISSN:1520-5118
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:A novel chemotype insecticide flupyrimin (FLP) [N-[(E)-1-(6-chloro-3-pyridinylmethyl)pyridin-2(1H)-ylidene]-2,2,2-trifluoroacetamide], discovered by Meiji Seika Pharma, has unique biological properties, including outstanding potency to imidacloprid (IMI)-resistant rice pests together with superior safety toward pollinators. Intriguingly, FLP acts as a nicotinic antagonist in American cockroach neurons, and [ H]FLP binds to the multiple high-affinity binding components in house fly nicotinic acetylcholine (ACh) receptor (nAChR) preparation. One of the [ H]FLP receptors is identical to the IMI receptor, and the alternative is IMI-insensitive subtype. Furthermore, FLP is favorably safe to rats as predicted by the very low affinity to the rat α4ß2 nAChR. Structure-activity relationships of FLP analogues in terms of receptor potency, featuring the pyridinylidene and trifluoroacetyl pharmacophores, were examined, thereby establishing the FLP molecular recognition at the Aplysia californica ACh-binding protein, a suitable structural surrogate of the insect nAChR. These FLP pharmacophores account for the excellent receptor affinity, accordingly revealing differences in its binding mechanism from IMI.
[Mh] Termos MeSH primário: Inseticidas/química
Inseticidas/farmacologia
Antagonistas Nicotínicos/química
Antagonistas Nicotínicos/farmacologia
Receptores Nicotínicos/química
[Mh] Termos MeSH secundário: Animais
Aplysia/efeitos dos fármacos
Aplysia/metabolismo
Sítios de Ligação
Proteínas de Insetos/química
Proteínas de Insetos/metabolismo
Cinética
Periplaneta/efeitos dos fármacos
Periplaneta/genética
Periplaneta/metabolismo
Ratos
Receptores Nicotínicos/metabolismo
Relação Estrutura-Atividade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Insect Proteins); 0 (Insecticides); 0 (Nicotinic Antagonists); 0 (Receptors, Nicotinic)
[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:170819
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jafc.7b02924


  4 / 3446 MEDLINE  
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[PMID]:28345161
[Au] Autor:McCamphill PK; Ferguson L; Sossin WS
[Ad] Endereço:Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
[Ti] Título:A decrease in eukaryotic elongation factor 2 phosphorylation is required for local translation of sensorin and long-term facilitation in Aplysia.
[So] Source:J Neurochem;142(2):246-259, 2017 Jul.
[Is] ISSN:1471-4159
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Mechanistic target of rapamycin complex 1 (mTORC1)-dependent protein synthesis is required for many forms of synaptic plasticity and memory, but the downstream pathways important for synaptic plasticity are poorly understood. Long-term facilitation (LTF) in Aplysia is a form of synaptic plasticity that is closely linked to behavioral memory and an attractive model system for examining the important downstream targets for mTORC1 in regulating synaptic plasticity. Although mTORC1-regulated protein synthesis has been strongly linked to translation initiation, translation elongation is also regulated by mTORC1 and LTF leads to an mTORC1-dependent decrease in eukaryotic elongation factor 2 (eEF2) phosphorylation. The purpose of this study is to test the hypothesis that the decrease in eEF2 phosphorylation is required for mTORC1-dependent translation and plasticity. We show that the LTF-induced decrease in eEF2 phosphorylation is blocked by expression of an eEF2 kinase (eEF2K) modified to be resistant to mTORC1 regulation. We found that expression of this modified kinase blocked LTF. LTF requires local protein synthesis of the neuropeptide sensorin and importantly, local sensorin synthesis can be measured using a dendra fluorescent protein containing the 5' and 3' untranslated regions (UTRs) of sensorin. Using this construct, we show that blocking eEF2 dephosphorylation also blocks the increase in local sensorin synthesis. These results identify decreases in eEF2 phosphorylation as a critical downstream effector of mTOR required for long-term plasticity and identify an important translational target regulated by decreases in eEF2 phosphorylation.
[Mh] Termos MeSH primário: Quinase do Fator 2 de Elongação/metabolismo
Eucariotos/metabolismo
Potenciação de Longa Duração/fisiologia
Fator 2 de Elongação de Peptídeos/metabolismo
[Mh] Termos MeSH secundário: Animais
Aplysia
Células Cultivadas
Quinase do Fator 2 de Elongação/genética
Neuropeptídeos/metabolismo
Fosforilação
Transdução de Sinais/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Neuropeptides); 0 (Peptide Elongation Factor 2); EC 2.7.11.20 (Elongation Factor 2 Kinase)
[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:170328
[St] Status:MEDLINE
[do] DOI:10.1111/jnc.14030


  5 / 3446 MEDLINE  
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[PMID]:28197555
[Au] Autor:Zhang Y; Smolen P; Baxter DA; Byrne JH
[Ad] Endereço:Department of Neurobiology and Anatomy, W.M. Keck Center for the Neurobiology of Learning and Memory, McGovern Medical School, University of Texas Health Science Center at Houston , Houston, TX 77030.
[Ti] Título:Biphasic Regulation of p38 MAPK by Serotonin Contributes to the Efficacy of Stimulus Protocols That Induce Long-Term Synaptic Facilitation.
[So] Source:eNeuro;4(1), 2017 Jan-Feb.
[Is] ISSN:2373-2822
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The MAPK isoforms ERK and p38 MAPK are believed to play opposing roles in long-term synaptic facilitation (LTF) induced by serotonin (5-HT) in . To fully understand their roles, however, it is necessary to consider the dynamics of ERK and p38 MAPK activation. Previous studies determined that activation of ERK occurred ∼45 min after a 5-min pulse of 5-HT treatment. The dynamics of p38 MAPK activation following 5-HT are yet to be elucidated. Here, the activity of p38 MAPK was examined at different times after 5-HT, and the interaction between the ERK and p38 MAPK pathways was investigated. A 5-min pulse of 5-HT induced a transient inhibition of p38 MAPK, followed by a delayed activation between 25 and 45 min. This activation was blocked by a MAPK kinase inhibitor, suggesting that similar pathways are involved in activation of ERK and p38 MAPK. ERK activity decreased shortly after the activation of p38 MAPK. A p38 MAPK inhibitor blocked this decrease in ERK activity, suggesting a causal relationship. The p38 MAPK activity ∼45 min after different stimulus protocols was also characterized. These data were incorporated into a computational model for the induction of LTF. Simulations and empirical data suggest that p38 MAPK, together with ERK, contributes to the efficacy of spaced stimulus protocols to induce LTF, a correlate of long-term memory (LTM). For example, decreased p38 MAPK activity ∼45 min after the first of two sensitizing stimuli might be an important determinant of an optimal interstimulus interval (ISI) for LTF induction.
[Mh] Termos MeSH primário: Potenciação de Longa Duração/fisiologia
Serotonina/metabolismo
Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
[Mh] Termos MeSH secundário: Animais
Aplysia
Células Cultivadas
Simulação por Computador
MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores
MAP Quinases Reguladas por Sinal Extracelular/metabolismo
Imunofluorescência
Potenciação de Longa Duração/efeitos dos fármacos
Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo
Modelos Neurológicos
Fosforilação/fisiologia
Inibidores de Proteínas Quinases/farmacologia
Células Receptoras Sensoriais/efeitos dos fármacos
Células Receptoras Sensoriais/enzimologia
Fatores de Tempo
Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Protein Kinase Inhibitors); 333DO1RDJY (Serotonin); EC 2.7.11.24 (Extracellular Signal-Regulated MAP Kinases); EC 2.7.11.24 (p38 Mitogen-Activated Protein Kinases); EC 2.7.12.2 (Mitogen-Activated Protein Kinase Kinases)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171030
[Lr] Data última revisão:
171030
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170216
[St] Status:MEDLINE


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[PMID]:28179558
[Au] Autor:Hu J; Adler K; Farah CA; Hastings MH; Sossin WS; Schacher S
[Ad] Endereço:Department of Neuroscience, Columbia University Medical Center, New York State Psychiatric Institute, New York, New York 10032, jh2004@cumc.columbia.edu.
[Ti] Título:Cell-Specific PKM Isoforms Contribute to the Maintenance of Different Forms of Persistent Long-Term Synaptic Plasticity.
[So] Source:J Neurosci;37(10):2746-2763, 2017 Mar 08.
[Is] ISSN:1529-2401
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Multiple kinase activations contribute to long-term synaptic plasticity, a cellular mechanism mediating long-term memory. The sensorimotor synapse of expresses different forms of long-term facilitation (LTF)-nonassociative and associative LTF-that require the timely activation of kinases, including protein kinase C (PKC). It is not known which PKC isoforms in the sensory neuron or motor neuron L7 are required to sustain each form of LTF. We show that different PKMs, the constitutively active isoforms of PKCs generated by calpain cleavage, in the sensory neuron and L7 are required to maintain each form of LTF. Different PKMs or calpain isoforms were blocked by overexpressing specific dominant-negative constructs in either presynaptic or postsynaptic neurons. Blocking either PKM Apl I in L7, or PKM Apl II or PKM Apl III in the sensory neuron 2 d after 5-hydroxytryptamine (5-HT) treatment reversed persistent nonassociative LTF. In contrast, blocking either PKM Apl II or PKM Apl III in L7, or PKM Apl II in the sensory neuron 2 d after paired stimuli reversed persistent associative LTF. Blocking either classical calpain or atypical small optic lobe (SOL) calpain 2 d after 5-HT treatment or paired stimuli did not disrupt the maintenance of persistent LTF. Soon after 5-HT treatment or paired stimuli, however, blocking classical calpain inhibited the expression of persistent associative LTF, while blocking SOL calpain inhibited the expression of persistent nonassociative LTF. Our data suggest that different stimuli activate different calpains that generate specific sets of PKMs in each neuron whose constitutive activities sustain long-term synaptic plasticity. Persistent synaptic plasticity contributes to the maintenance of long-term memory. Although various kinases such as protein kinase C (PKC) contribute to the expression of long-term plasticity, little is known about how constitutive activation of specific kinase isoforms sustains long-term plasticity. This study provides evidence that the cell-specific activities of different PKM isoforms generated from PKCs by calpain-mediated cleavage maintain two forms of persistent synaptic plasticity, which are the cellular analogs of two forms of long-term memory. Moreover, we found that the activation of specific calpains depends on the features of the stimuli evoking the different forms of synaptic plasticity. Given the recent controversy over the role of PKMζ maintaining memory, these findings are significant in identifying roles of multiple PKMs in the retention of memory.
[Mh] Termos MeSH primário: Calpaína/metabolismo
Plasticidade Neuronal/fisiologia
Neurônios/classificação
Neurônios/fisiologia
Proteína Quinase C/metabolismo
Transmissão Sináptica/fisiologia
[Mh] Termos MeSH secundário: Animais
Aplysia
Células Cultivadas
Potenciação de Longa Duração
Depressão Sináptica de Longo Prazo
Memória de Longo Prazo/fisiologia
Isoformas de Proteínas
Sinapses/classificação
Sinapses/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Protein Isoforms); EC 2.7.11.13 (Protein Kinase C); EC 3.4.22.- (Calpain)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170909
[Lr] Data última revisão:
170909
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170210
[St] Status:MEDLINE
[do] DOI:10.1523/JNEUROSCI.2805-16.2017


  7 / 3446 MEDLINE  
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[PMID]:28150103
[Au] Autor:Carneiro RF; Torres RC; Chaves RP; de Vasconcelos MA; de Sousa BL; Goveia AC; Arruda FV; Matos MN; Matthews-Cascon H; Freire VN; Teixeira EH; Nagano CS; Sampaio AH
[Ad] Endereço:Laboratório de Biotecnologia Marinha - BioMar-Lab, Departamento de Engenharia de Pesca, Universidade Federal do Ceará, Campus do Pici s/n, bloco 871, Av. Mister Hull, Box 6043, Fortaleza, Ceará, 60440-970, Brazil.
[Ti] Título:Purification, Biochemical Characterization, and Amino Acid Sequence of a Novel Type of Lectin from Aplysia dactylomela Eggs with Antibacterial/Antibiofilm Potential.
[So] Source:Mar Biotechnol (NY);19(1):49-64, 2017 Feb.
[Is] ISSN:1436-2236
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:A new lectin from Aplysia dactylomela eggs (ADEL) was isolated by affinity chromatography on HCl-activated Sepharose™ media. Hemagglutination caused by ADEL was inhibited by several galactosides, mainly galacturonic acid (Ka = 6.05 × 10 M ). The primary structure of ADEL consists of 217 residues, including 11 half-cystines involved in five intrachain and one interchain disulfide bond, resulting in a molecular mass of 57,228 ± 2 Da, as determined by matrix-assisted laser desorption/ionization time of flight mass spectrometry. ADEL showed high similarity with lectins isolated from Aplysia eggs, but not with other known lectins, indicating that these lectins could be grouped into a new family of animal lectins. Three glycosylation sites were found in its polypeptide backbone. Data from peptide-N-glycosidase F digestion and MS suggest that all oligosaccharides attached to ADEL are high in mannose. The secondary structure of ADEL is predominantly ß-sheet, and its tertiary structure is sensitive to the presence of ligands, as observed by CD. A 3D structure model of ADEL was created and shows two domains connected by a short loop. Domain A is composed of a flat three-stranded and a curved five-stranded ß-sheet, while domain B presents a flat three-stranded and a curved four-stranded ß-sheet. Molecular docking revealed favorable binding energies for interactions between lectin and galacturonic acid, lactose, galactosamine, and galactose. Moreover, ADEL was able to agglutinate and inhibit biofilm formation of Staphylococcus aureus, suggesting that this lectin may be a potential alternative to conventional use of antimicrobial agents in the treatment of infections caused by Staphylococcal biofilms.
[Mh] Termos MeSH primário: Antibacterianos/química
Aplysia/química
Biofilmes/efeitos dos fármacos
Lectinas/química
Staphylococcus aureus/efeitos dos fármacos
Zigoto/química
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Animais
Antibacterianos/isolamento & purificação
Antibacterianos/metabolismo
Antibacterianos/farmacologia
Aplysia/genética
Aplysia/metabolismo
Biofilmes/crescimento & desenvolvimento
Escherichia coli/genética
Escherichia coli/metabolismo
Galactosídeos/farmacologia
Expressão Gênica
Testes de Inibição da Hemaglutinação
Ácidos Hexurônicos/farmacologia
Lectinas/genética
Lectinas/isolamento & purificação
Lectinas/farmacologia
Simulação de Acoplamento Molecular
Domínios Proteicos
Estrutura Secundária de Proteína
Proteínas Recombinantes/química
Proteínas Recombinantes/genética
Proteínas Recombinantes/isolamento & purificação
Proteínas Recombinantes/farmacologia
Alinhamento de Sequência
Staphylococcus aureus/crescimento & desenvolvimento
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Galactosides); 0 (Hexuronic Acids); 0 (Lectins); 0 (Recombinant Proteins); 4JK6RN80GF (galacturonic acid)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:171013
[Lr] Data última revisão:
171013
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170203
[St] Status:MEDLINE
[do] DOI:10.1007/s10126-017-9728-x


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[PMID]:28129373
[Au] Autor:Tsuji A; Kuwamura S; Shirai A; Yuasa K
[Ad] Endereço:Department of Biomolecular function and Technology, Graduate School of Bioscience and Bioindustry, Tokushima University, 2-1 Minamijosanjima, Tokushima, Japan.
[Ti] Título:Identification and Characterization of a 25 kDa Protein That Is Indispensable for the Efficient Saccharification of Eisenia bicyclis in the Digestive Fluid of Aplysia kurodai.
[So] Source:PLoS One;12(1):e0170669, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The digestive fluid of the sea hare Aplysia kurodai can liberate approximately 2.5 mg of glucose from 10 mg of dried Eisenia bicyclis powder. Although laminaran, a major storage polysaccharide in E. bicyclis, is easily digested to glucose by the synergistic action of the 110 and 210 kDa A. kurodai ß-glucosidases (BGLs), glucose is not liberated from E. bicyclis by direct incubation with these BGLs. To clarify this discrepancy, we searched for an Eisenia hydrolysis enhancing protein (EHEP) in the digestive fluid of A. kurodai. A novel 25 kDa protein that enhances E. bicyclis saccharification by ß-glucosidases was purified to a homogeneous state from the digestive fluid of A. kurodai, and its cDNA was cloned from total cDNAs reverse-transcribed from hepatopancreas total RNA. The E. bicyclis extract strongly inhibited BGLs, suggesting some compound within this brown alga functioned as a feeding deterrent. However, when E. bicyclis was incubated with BGLs in the presence of EHEP, glucose production was markedly increased. As E. bicyclis is rich in phlorotannin, which are only found in brown algae, our study suggested that these compounds are the main BGL inhibitors in E. bicyclis extract. EHEP protects BGLs from phlorotannin inhibition by binding to phlorotannins and forming an insoluble complex with phloroglucinol and phlorotannins. These findings indicated that EHEP plays a key role in the saccharification of brown seaweeds containing phlorotannins in the digestive fluid of A. kurodai. This is the first report of EHEP as a phlorotannin-binding protein that protects BGLs from inhibition.
[Mh] Termos MeSH primário: Aplysia/genética
Digestão/genética
Glucose/metabolismo
Proteínas/genética
Taninos/metabolismo
[Mh] Termos MeSH secundário: Animais
Aplysia/metabolismo
Celulases/genética
Celulases/metabolismo
Clonagem Molecular
DNA Complementar
Glucanos/metabolismo
Hidrólise
Feófitas/química
Feófitas/metabolismo
Polissacarídeos/metabolismo
Ligação Proteica
Alinhamento de Sequência
Análise de Sequência de Proteína
Taninos/química
Taninos/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Complementary); 0 (Glucans); 0 (Polysaccharides); 0 (Proteins); 0 (Tannins); 9008-22-4 (laminaran); EC 3.2.1.- (Cellulases); IY9XDZ35W2 (Glucose)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170814
[Lr] Data última revisão:
170814
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170128
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0170669


  9 / 3446 MEDLINE  
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[PMID]:28119399
[Au] Autor:Zhang Y; Ni W; Horwich AL; Kaczmarek LK
[Ad] Endereço:Departments of Pharmacology.
[Ti] Título:An ALS-Associated Mutant SOD1 Rapidly Suppresses KCNT1 (Slack) Na -Activated K Channels in Neurons.
[So] Source:J Neurosci;37(8):2258-2265, 2017 Feb 22.
[Is] ISSN:1529-2401
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Mutations that alter levels of Slack (KCNT1) Na -activated K current produce devastating effects on neuronal development and neuronal function. We now find that Slack currents are rapidly suppressed by oligomers of mutant human Cu/Zn superoxide dismutase 1 (SOD1), which are associated with motor neuron toxicity in an inherited form of amyotrophic lateral sclerosis (ALS). We recorded from bag cell neurons of , a model system to study neuronal excitability. We found that injection of fluorescent wild-type SOD1 (wt SOD1YFP) or monomeric mutant G85R SOD1YFP had no effect on net ionic currents measured under voltage clamp. In contrast, outward potassium currents were significantly reduced by microinjection of mutant G85R SOD1YFP that had been preincubated at 37°C or of cross-linked dimers of G85R SOD1YFP. Reduction of potassium current was also seen with multimeric G85R SOD1YFP of ∼300 kDa or >300 kDa that had been cross-linked. In current clamp recordings, microinjection of cross-linked 300 kDa increased excitability by depolarizing the resting membrane potential, and decreasing the latency of action potentials triggered by depolarization. The effect of cross-linked 300 kDa on potassium current was reduced by removing Na from the bath solution, or by knocking down levels of Slack using siRNA. It was also prevented by pharmacological inhibition of ASK1 (apoptosis signal-regulating kinase 1) or of c-Jun N-terminal kinase, but not by an inhibitor of p38 mitogen-activated protein kinase. These results suggest that soluble mutant SOD1 oligomers rapidly trigger a kinase pathway that regulates the activity of Na -activated K channels in neurons. Slack Na -activated K channels (KCNT1, K 1.1) regulate neuronal excitability but are also linked to cytoplasmic signaling pathways that control neuronal protein translation. Mutations that alter the amplitude of these currents have devastating effects on neuronal development and function. We find that injection of oligomers of mutant superoxide dismutase 1 (SOD1) into the cytoplasm of invertebrate neurons rapidly suppresses these Na -activated K currents and that this effect is mediated by a MAP kinase cascade, including ASK1 and c-Jun N-terminal kinase. Because amyotrophic lateral sclerosis is a fatal adult-onset neurodegenerative disease produced by mutations in SOD1 that cause the enzyme to form toxic oligomers, our findings suggest that suppression of Slack channels may be an early step in the progression of the disease.
[Mh] Termos MeSH primário: Potenciais da Membrana/genética
Mutação/genética
Proteínas do Tecido Nervoso/metabolismo
Neurônios/fisiologia
Canais de Potássio/metabolismo
Superóxido Dismutase-1/genética
[Mh] Termos MeSH secundário: Animais
Aplysia/citologia
Biofísica
Células Cultivadas
Estimulação Elétrica
Inibidores Enzimáticos/farmacologia
Gânglios dos Invertebrados/citologia
Seres Humanos
Proteínas Luminescentes/genética
Proteínas Luminescentes/metabolismo
Potenciais da Membrana/efeitos dos fármacos
Microinjeções
Morfolinos/farmacologia
Neurônios/efeitos dos fármacos
Técnicas de Patch-Clamp
RNA Interferente Pequeno/genética
RNA Interferente Pequeno/metabolismo
Sódio/farmacologia
Superóxido Dismutase-1/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzyme Inhibitors); 0 (KCNT1 protein, human); 0 (Luminescent Proteins); 0 (Morpholinos); 0 (Nerve Tissue Proteins); 0 (Potassium Channels); 0 (RNA, Small Interfering); 9NEZ333N27 (Sodium); EC 1.15.1.1 (Superoxide Dismutase-1)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170822
[Lr] Data última revisão:
170822
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170126
[St] Status:MEDLINE
[do] DOI:10.1523/JNEUROSCI.3102-16.2017


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[PMID]:28077092
[Au] Autor:Greer JB; Khuri S; Fieber LA
[Ad] Endereço:Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Cswy, Miami, FL, 33149, USA. jgreer@rsmas.miami.edu.
[Ti] Título:Phylogenetic analysis of ionotropic L-glutamate receptor genes in the Bilateria, with special notes on Aplysia californica.
[So] Source:BMC Evol Biol;17(1):11, 2017 Jan 11.
[Is] ISSN:1471-2148
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: The neurotransmitter L-Glutamate (L-Glu) acting at ionotropic L-Glu receptors (iGluR) conveys fast excitatory signal transmission in the nervous systems of all animals. iGluR-dependent neurotransmission is a key component of the synaptic plasticity that underlies learning and memory. During learning, two subtypes of iGluR, α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPAR) and N-methyl-D-aspartate receptors (NMDAR), are dynamically regulated postsynaptically in vertebrates. Invertebrate organisms such as Aplysia californica (Aplysia) are well-studied models for iGluR-mediated function, yet no studies to date have analyzed the evolutionary relationships between iGluR genes in these species and those in vertebrates, to identify genes that may mediate plasticity. We conducted a thorough phylogenetic analysis spanning Bilateria to elucidate these relationships. The expression status of iGluR genes in the Aplysia nervous system was also examined. RESULTS: Our analysis shows that ancestral genes for both NMDAR and AMPAR subtypes were present in the common bilaterian ancestor. NMDAR genes show very high conservation in motifs responsible for forming the conductance pore of the ion channel. The number of NMDAR subunits is greater in vertebrates due to an increased number of splice variants and an increased number of genes, likely due to gene duplication events. AMPAR subunits form an orthologous group, and there is high variability in the number of AMPAR genes in each species due to extensive taxon specific gene gain and loss. qPCR results show that all 12 Aplysia iGluR subunits are expressed in all nervous system ganglia. CONCLUSIONS: Orthologous NMDAR subunits in all species studied suggests conserved function across Bilateria, and potentially a conserved mechanism of neuroplasticity and learning. Vertebrates display an increased number of NMDAR genes and splice variants, which may play a role in their greater diversity of physiological responses. Extensive gene gain and loss of AMPAR genes may result in different physiological properties that are taxon specific. Our results suggest a significant role for L-Glu mediated responses throughout the Aplysia nervous system, consistent with L-Glu's role as the primary excitatory neurotransmitter.
[Mh] Termos MeSH primário: Aplysia/genética
Filogenia
Receptores Ionotrópicos de Glutamato/genética
[Mh] Termos MeSH secundário: Animais
Sequência Conservada
Evolução Molecular
Invertebrados/genética
Domínios Proteicos
Receptores Ionotrópicos de Glutamato/química
Alinhamento de Sequência
Análise de Sequência de Proteína
Transmissão Sináptica/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Receptors, Ionotropic Glutamate)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170815
[Lr] Data última revisão:
170815
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170113
[St] Status:MEDLINE
[do] DOI:10.1186/s12862-016-0871-1



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