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Descripción
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| Direct intercellular communication via gap junction channels among oligodendrotrocytes and astrocytes themselves and between each other is essential to maintain the functionality and integrity of central myelin. In that regards, oligodendrocyte gap junction connexin-47 (Cx47) constitutes a key element since Cx47 mutations in humans cause severe defects of myelination and demyelination. Cx47 is the principal component of intercellular channels that account for the weak coupling among oligodentrocytes and, by forming heterotypic channels with astrocyte connexin-43 (Cx43), of heterologous oligodendrocyte-astrocyte junctions that act as a diffusion barrier to the movement of molecules between oligodentrocytes and astrocytes. The determinants of pore channel structure responsible for the permeability characteristics of coupling interoligodendrocytes and that generate ?oligodentrocyte-astrocyte rectifier? were investigated. We found that the restrictive permeability of Cx47 channels are due to the presence of three extra residues (Met-Thr-Asn) at 5¿ extreme of aminoterminal domain of full-length Cx47 and, therefore, to the strong electrostatic interaction of Met1 with the pore exposed residue Glu44 located at the narrower constriction site of pore tunnel. In turn, the asymmetrical ionic rectification with the transjunctional voltage polarity of Cx47-Cx43 channels and the unidirectional passage of negatively but not of positively, charged dyes from Cx47 side to Cx43 cell are generated on the basis of the more restrictive permeability of Cx47 hemichannel. Interestingly, a disease-related mutation of Cx47, the P90S, abolished the restrictive properties of permeability of Cx47 channels and the directionality of Cx47-Cx43 channels, suggesting that they may be of physiological relevance. | |
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Internacional
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Si |
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Nombre congreso
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5th Spanish Ion Channel Network Meeting (RECI): Present and Future Research in Ion Channel Research |
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Tipo de participación
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970 |
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Lugar del congreso
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BARCELONA |
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Revisores
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Si |
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ISBN o ISSN
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0000-0000-00 |
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DOI
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Fecha inicio congreso
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04/10/2015 |
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Fecha fin congreso
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06/10/2015 |
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Desde la página
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60 |
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Hasta la página
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60 |
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Título de las actas
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ABSTRACTS BOOK RECI |