The Experts below are selected from a list of 132 Experts worldwide ranked by ideXlab platform
Yutaka Kirino - One of the best experts on this subject based on the ideXlab platform.
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A calcium channel from the presynaptic nerve terminal of the Narke japonica Electric organ contains a non-N-type α2δ subunit
Journal of Neurochemistry, 2002Co-Authors: Hiroshi Tokumaru, Hideo Saisu, Suzuyo Shojaku, Naohide Hirashima, Hiroaki Takehara, Yutaka KirinoAbstract:: A monoclonal antibody (MCC-1) that recognizes the alpha 2 delta subunit complex of L-type calcium channels from rabbit skeletal muscle membranes partially inhibited the evoked release of acetylcholine from synaptosomes isolated from the Electric organ of the marine Electric Ray, Narke japonica. Digitonin extracts of synaptosomal plasma membranes were subjected to immunoaffinity column chromatography on MCC-1-Sepharose. The purified fraction contained a 170-kDa protein that reacts with MCC-1 and dissociates into smaller polypeptides under reducing conditions. In addition, immunoblotting analysis revealed the existence of syntaxin in the purified fraction, suggesting that the calcium channel forms a complex with syntaxin. However, MCC-1 did not immunoprecipitate an omega-conotoxin GVIA-binding protein. These findings indicate that the 170-kDa protein may be the alpha 2 delta subunit of a calcium channel that is distinct from the omega-conotoxin GVIA-sensitive N-type calcium channel and partially responsible for the calcium influx that triggers the evoked release of acetylcholine.
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action and binding of omega conotoxin on the putative calcium channel of synaptosomal plasma membrane from Electric organ of japanese Electric Ray narke japonica
Neuroscience, 1993Co-Authors: Tomohiro Ohori, Hiroshi Tokumaru, Naohide Hirashima, Chenyueh Wang, L C Chen, Kenichi Hatanaka, Yutaka KirinoAbstract:Abstract Actions of ω-conotoxin GVIA on synaptosomes isolated from a Japanese Electric Ray, Narke japonica , were investigated. ω-Conotoxin inhibited, in a dose-dependent manner, both increases in free calcium concentration in, and acetylcholine release from synaptosomes depolarized with a high concentration of potassium ions. The concentrations of ω-conotoxin required for half-maximal inhibition ( ic 50 ) of increase in intrasynaptosomal Ca and acetylcholine release were 8 and 7 μM, respectively. Assay using radioiodinated toxin derivative revealed a specific binding site with a dissociation constant ( K D ) of 2.8 μM and a density ( B max ) of 45 pmol/mg protein of synaptosome. Binding assay with synaptosomal plasma membrane showed a K D = 7μ M and a B max = 200pmol/mg protein. Autoradiography with sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis after covalent cross-linking of the toxin, using disuccinimidyl suberate, revealed the 170,000 mol. wt peptide to be an ω-conotoxin receptor. The present study has directly and clearly shown that ω-conotoxin inhibits acetylcholine release by blocking Ca influx into nerve terminals. The 170,000 mol. wt peptide identified as a receptor of the toxin exists in high density in the plasma membrane of the presynaptic nerve terminal and is likely to be a component of a voltage-dependent Ca channel responsible for the neurotransmitter release.
Jemma L Geoghegan - One of the best experts on this subject based on the ideXlab platform.
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a novel rubi like virus in the pacific Electric Ray tetronarce californica reveals the complex evolutionary history of the matonaviridae
Viruses, 2021Co-Authors: Rebecca M Grimwood, Edward C Holmes, Jemma L GeogheganAbstract:Rubella virus (RuV) is the causative agent of rubella (“German measles”) and remains a global health concern. Until recently, RuV was the only known member of the genus Rubivirus and the only virus species classified within the Matonaviridae family of positive-sense RNA viruses. Recently, two new rubella-like matonaviruses, Rustrela virus and Ruhugu virus, have been identified in several mammalian species, along with more divergent viruses in fish and reptiles. To screen for the presence of additional novel rubella-like viruses, we mined published transcriptome data using genome sequences from Rubella, Rustrela, and Ruhugu viruses as baits. From this, we identified a novel rubella-like virus in a transcriptome of Tetronarce californica—order Torpediniformes (Pacific Electric Ray)—that is more closely related to mammalian Rustrela virus than to the divergent fish matonavirus and indicative of a complex pattern of cross-species virus transmission. Analysis of host reads confirmed that the sample analysed was indeed from a Pacific Electric Ray, and two other viruses identified in this animal, from the Arenaviridae and Reoviridae, grouped with other fish viruses. These findings indicate that the evolutionary history of the Matonaviridae is more complex than previously thought and highlights the vast number of viruses that remain undiscovered.
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a novel rubi like virus in the pacific Electric Ray tetronarce californica reveals the complex evolutionary history of the matonaviridae
bioRxiv, 2021Co-Authors: Rebecca M Grimwood, Edward C Holmes, Jemma L GeogheganAbstract:Abstract Rubella virus (RuV) is the causative agent of rubella (“German measles”) and remains a global health concern. Until recently, RuV was the only known member of the genus Rubivirus and the only virus species classified within the Matonaviridae family of positive-sense RNA viruses. Other matonaviruses, including two new rubella-like viruses, Rustrela virus and Ruhugu virus, have been identified in several mammalian species, along with more divergent viruses in fish and reptiles. To screen for the presence of additional novel rubella-like viruses we mined published transcriptome data using genome sequences from Rubella, Rustrela, and Ruhugu viruses as baits. From this, we identified a novel rubella-like virus in a transcriptome of Tetronarce californica (Pacific Electric Ray) that is more closely related to mammalian Rustrela virus than to the divergent fish matonavirus and indicative of a complex pattern of cross-species virus transmission. Analysis of host reads confirmed that the sample analysed was indeed from a Pacific Electric Ray, and two other viruses identified in this animal, from the Arenaviridae and Reoviridae, grouped with other fish viruses. These findings indicate that the evolutionary history of the Matonaviridae is more complex than previously thought and highlights the vast number of viruses still to be discovered.
Robert H Edwards - One of the best experts on this subject based on the ideXlab platform.
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molecular cloning of a putative vesicular transporter for acetylcholine
Proceedings of the National Academy of Sciences of the United States of America, 1994Co-Authors: Ali Roghani, Arshia Shirzadi, Sirus A Kohan, Jonathan Feldman, Cameron B Gundersen, Nicholas C Brecha, Robert H EdwardsAbstract:Abstract Classical neurotransmitters such as acetylcholine (ACh) require transport into synaptic vesicles for regulated exocytotic release. The Caenorhabditis elegans gene unc-17 encodes a protein with homology to mammalian transporters that concentrate monoamine neurotransmitters into synaptic vesicles. Mutations in unc-17 protect against organophosphorus toxicity, indicating a role in cholinergic neurotransmission. Using the relationship of unc-17 to the vesicular amine transporters, we first isolated a related sequence from the Electric Ray Torpedo californica [Torpedo vesicular ACh transporter (TorVAChT)] that is expressed by the Electric lobe but not by peripheral tissues. Using the relationship of the Torpedo sequence to unc-17, we then isolated the cDNA for a rat homologue (rVAChT). Northern blot analysis shows expression of these sequences in the basal forebrain, basal ganglia, and spinal cord but not cerebellum or peripheral tissues. In situ hybridization shows expression of rVAChT mRNA in all cholinergic cell groups, including those in the basal forebrain, brainstem, and spinal cord that previously have been shown to express choline acetyltransferase mRNA. The human VAChT gene also localizes to chromosome 10 near the gene for choline acetyltransferase. Taken together, these observations support a role for rVAChT in vesicular ACh transport and indicate its potential as a novel marker for cholinergic neurons.
Rebecca M Grimwood - One of the best experts on this subject based on the ideXlab platform.
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a novel rubi like virus in the pacific Electric Ray tetronarce californica reveals the complex evolutionary history of the matonaviridae
Viruses, 2021Co-Authors: Rebecca M Grimwood, Edward C Holmes, Jemma L GeogheganAbstract:Rubella virus (RuV) is the causative agent of rubella (“German measles”) and remains a global health concern. Until recently, RuV was the only known member of the genus Rubivirus and the only virus species classified within the Matonaviridae family of positive-sense RNA viruses. Recently, two new rubella-like matonaviruses, Rustrela virus and Ruhugu virus, have been identified in several mammalian species, along with more divergent viruses in fish and reptiles. To screen for the presence of additional novel rubella-like viruses, we mined published transcriptome data using genome sequences from Rubella, Rustrela, and Ruhugu viruses as baits. From this, we identified a novel rubella-like virus in a transcriptome of Tetronarce californica—order Torpediniformes (Pacific Electric Ray)—that is more closely related to mammalian Rustrela virus than to the divergent fish matonavirus and indicative of a complex pattern of cross-species virus transmission. Analysis of host reads confirmed that the sample analysed was indeed from a Pacific Electric Ray, and two other viruses identified in this animal, from the Arenaviridae and Reoviridae, grouped with other fish viruses. These findings indicate that the evolutionary history of the Matonaviridae is more complex than previously thought and highlights the vast number of viruses that remain undiscovered.
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a novel rubi like virus in the pacific Electric Ray tetronarce californica reveals the complex evolutionary history of the matonaviridae
bioRxiv, 2021Co-Authors: Rebecca M Grimwood, Edward C Holmes, Jemma L GeogheganAbstract:Abstract Rubella virus (RuV) is the causative agent of rubella (“German measles”) and remains a global health concern. Until recently, RuV was the only known member of the genus Rubivirus and the only virus species classified within the Matonaviridae family of positive-sense RNA viruses. Other matonaviruses, including two new rubella-like viruses, Rustrela virus and Ruhugu virus, have been identified in several mammalian species, along with more divergent viruses in fish and reptiles. To screen for the presence of additional novel rubella-like viruses we mined published transcriptome data using genome sequences from Rubella, Rustrela, and Ruhugu viruses as baits. From this, we identified a novel rubella-like virus in a transcriptome of Tetronarce californica (Pacific Electric Ray) that is more closely related to mammalian Rustrela virus than to the divergent fish matonavirus and indicative of a complex pattern of cross-species virus transmission. Analysis of host reads confirmed that the sample analysed was indeed from a Pacific Electric Ray, and two other viruses identified in this animal, from the Arenaviridae and Reoviridae, grouped with other fish viruses. These findings indicate that the evolutionary history of the Matonaviridae is more complex than previously thought and highlights the vast number of viruses still to be discovered.
G. O. Marcotrigiano - One of the best experts on this subject based on the ideXlab platform.
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Total and methylmercury residues in cartilaginous fish from Mediterranean Sea.
Marine pollution bulletin, 2002Co-Authors: Maria Maddalena Storelli, R. Giacominelli-stuffler, G. O. MarcotrigianoAbstract:Concentrations of mercury and methylmercury residues were determined in the muscle tissue of three cartilaginous fishes Chimaera monstrosa (ghostshark), Torpedo nobiliana (Electric Ray) and Myliobatis aquila (eagle Ray) from the Mediterranean Sea. The highest mean levels of total mercury were detected in ghostshark (3.14 mg/kg wet weight), followed by Electric Ray (2.42 mg/kg wet weight), and eagle Ray (0.83 mg/kg wet weight). Such a variability is influenced by quite a number of factors, among which size, fish ecology and feeding habits. The percentages of the methylated form to total mercury ranged from a minimum of 72% in eagle Ray to a maximum of 83% in ghostshark. Relationship between specimen size and mercury and methylmercury concentrations were found in ghostshark species.