The Experts below are selected from a list of 50643 Experts worldwide ranked by ideXlab platform
Vitaly Citovsky - One of the best experts on this subject based on the ideXlab platform.
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ank a host Cytoplasmic Receptor for the tobacco mosaic virus cell to cell movement protein facilitates intercellular transport through plasmodesmata
PLOS Pathogens, 2010Co-Authors: Shoko Ueki, Roman Spektor, Danielle M. Natale, Vitaly CitovskyAbstract:Plasmodesma (PD) is a channel structure that spans the cell wall and provides symplastic connection between adjacent cells. Various macromolecules are known to be transported through PD in a highly regulated manner, and plant viruses utilize their movement proteins (MPs) to gate the PD to spread cell-to-cell. The mechanism by which MP modifies PD to enable intercelluar traffic remains obscure, due to the lack of knowledge about the host factors that mediate the process. Here, we describe the functional interaction between Tobacco mosaic virus (TMV) MP and a plant factor, an ankyrin repeat containing protein (ANK), during the viral cell-to-cell movement. We utilized a reverse genetics approach to gain insight into the possible involvement of ANK in viral movement. To this end, ANK overexpressor and suppressor lines were generated, and the movement of MP was tested. MP movement was facilitated in the ANK-overexpressing plants, and reduced in the ANK-suppressing plants, demonstrating that ANK is a host factor that facilitates MP cell-to-cell movement. Also, the TMV local infection was largely delayed in the ANK-suppressing lines, while enhanced in the ANK-overexpressing lines, showing that ANK is crucially involved in the infection process. Importantly, MP interacted with ANK at PD. Finally, simultaneous expression of MP and ANK markedly decreased the PD levels of callose, b-1,3-glucan, which is known to act as a molecular sphincter for PD. Thus, the MP-ANK interaction results in the downregulation of callose and increased cell-to-cell movement of the viral protein. These findings suggest that ANK represents a host cellular Receptor exploited by MP to aid viral movement by gating PD through relaxation of their callose sphincters.
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ANK, a host Cytoplasmic Receptor for the tobacco mosaic virus cellto-cell movement protein, facilitates intercellular transport through plasmodesmata
2010Co-Authors: Shoko Ueki, Roman Spektor, Danielle M. Natale, Vitaly CitovskyAbstract:Plasmodesma (PD) is a channel structure that spans the cell wall and provides symplastic connection between adjacent cells. Various macromolecules are known to be transported through PD in a highly regulated manner, and plant viruses utilize their movement proteins (MPs) to gate the PD to spread cell-to-cell. The mechanism by which MP modifies PD to enable intercelluar traffic remains obscure, due to the lack of knowledge about the host factors that mediate the process. Here, we describe the functional interaction between Tobacco mosaic virus (TMV) MP and a plant factor, an ankyrin repeat containing protein (ANK), during the viral cell-to-cell movement. We utilized a reverse genetics approach to gain insight into the possible involvement of ANK in viral movement. To this end, ANK overexpressor and suppressor lines were generated, and the movement of MP was tested. MP movement was facilitated in the ANK-overexpressing plants, and reduced in the ANK-suppressing plants, demonstrating that ANK is a host factor that facilitates MP cell-to-cell movement. Also, the TMV local infection was largely delayed in the ANK-suppressing lines, while enhanced in the ANK-overexpressing lines, showing that ANK is crucially involved in the infection process. Importantly, MP interacted with ANK at PD. Finally, simultaneous expression of MP and ANK markedly decreased the PD levels of callose, b-1,3-glucan, which is known to act as a molecular sphincter for PD. Thus, the MP-ANK interaction results in the downregulation of callose and increased cell-to-cell movement of the viral protein. These findings suggest that ANK represents a host cellular Receptor exploited by MP to aid vira
Shoko Ueki - One of the best experts on this subject based on the ideXlab platform.
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ank a host Cytoplasmic Receptor for the tobacco mosaic virus cell to cell movement protein facilitates intercellular transport through plasmodesmata
PLOS Pathogens, 2010Co-Authors: Shoko Ueki, Roman Spektor, Danielle M. Natale, Vitaly CitovskyAbstract:Plasmodesma (PD) is a channel structure that spans the cell wall and provides symplastic connection between adjacent cells. Various macromolecules are known to be transported through PD in a highly regulated manner, and plant viruses utilize their movement proteins (MPs) to gate the PD to spread cell-to-cell. The mechanism by which MP modifies PD to enable intercelluar traffic remains obscure, due to the lack of knowledge about the host factors that mediate the process. Here, we describe the functional interaction between Tobacco mosaic virus (TMV) MP and a plant factor, an ankyrin repeat containing protein (ANK), during the viral cell-to-cell movement. We utilized a reverse genetics approach to gain insight into the possible involvement of ANK in viral movement. To this end, ANK overexpressor and suppressor lines were generated, and the movement of MP was tested. MP movement was facilitated in the ANK-overexpressing plants, and reduced in the ANK-suppressing plants, demonstrating that ANK is a host factor that facilitates MP cell-to-cell movement. Also, the TMV local infection was largely delayed in the ANK-suppressing lines, while enhanced in the ANK-overexpressing lines, showing that ANK is crucially involved in the infection process. Importantly, MP interacted with ANK at PD. Finally, simultaneous expression of MP and ANK markedly decreased the PD levels of callose, b-1,3-glucan, which is known to act as a molecular sphincter for PD. Thus, the MP-ANK interaction results in the downregulation of callose and increased cell-to-cell movement of the viral protein. These findings suggest that ANK represents a host cellular Receptor exploited by MP to aid viral movement by gating PD through relaxation of their callose sphincters.
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ANK, a host Cytoplasmic Receptor for the tobacco mosaic virus cellto-cell movement protein, facilitates intercellular transport through plasmodesmata
2010Co-Authors: Shoko Ueki, Roman Spektor, Danielle M. Natale, Vitaly CitovskyAbstract:Plasmodesma (PD) is a channel structure that spans the cell wall and provides symplastic connection between adjacent cells. Various macromolecules are known to be transported through PD in a highly regulated manner, and plant viruses utilize their movement proteins (MPs) to gate the PD to spread cell-to-cell. The mechanism by which MP modifies PD to enable intercelluar traffic remains obscure, due to the lack of knowledge about the host factors that mediate the process. Here, we describe the functional interaction between Tobacco mosaic virus (TMV) MP and a plant factor, an ankyrin repeat containing protein (ANK), during the viral cell-to-cell movement. We utilized a reverse genetics approach to gain insight into the possible involvement of ANK in viral movement. To this end, ANK overexpressor and suppressor lines were generated, and the movement of MP was tested. MP movement was facilitated in the ANK-overexpressing plants, and reduced in the ANK-suppressing plants, demonstrating that ANK is a host factor that facilitates MP cell-to-cell movement. Also, the TMV local infection was largely delayed in the ANK-suppressing lines, while enhanced in the ANK-overexpressing lines, showing that ANK is crucially involved in the infection process. Importantly, MP interacted with ANK at PD. Finally, simultaneous expression of MP and ANK markedly decreased the PD levels of callose, b-1,3-glucan, which is known to act as a molecular sphincter for PD. Thus, the MP-ANK interaction results in the downregulation of callose and increased cell-to-cell movement of the viral protein. These findings suggest that ANK represents a host cellular Receptor exploited by MP to aid vira
Barbara Valent - One of the best experts on this subject based on the ideXlab platform.
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ta single amino acid difference distinguishes resistant and susceptible alleles of the rice blast resistance gene pi ta
The Plant Cell, 2000Co-Authors: Gregory T Bryan, Yulin Jia, Sean A Mcadams, Howard P Hershey, Leonard Farrall, Kristina N Faulk, Gail K Donaldson, Renato Tarchini, Barbara ValentAbstract:The rice blast resistance ( R ) gene Pi-ta mediates gene-for-gene resistance against strains of the fungus Magnaporthe grisea that express avirulent alleles of AVR-Pita . Using a map-based cloning strategy, we cloned Pi-ta , which is linked to the centromere of chromosome 12. Pi-ta encodes a predicted 928‐amino acid Cytoplasmic Receptor with a centrally localized nucleotide binding site. A single-copy gene, Pi-ta shows low constitutive expression in both resistant and susceptible rice. Susceptible rice varieties contain pi-ta ‐ alleles encoding predicted proteins that share a single amino acid difference relative to the Pi-ta resistance protein: serine instead of alanine at position 918. Transient expression in rice cells of a Pi-ta 1 R gene together with AVR-Pita 1 induces a resistance response. No resistance response is induced in transient assays that use a naturally occurring pi-ta ‐ allele differing only by the serine at position 918. Rice varieties reported to have the linked Pi-ta 2 gene contain Pi-ta plus at least one other R gene, potentially explaining the broadened resistance spectrum of Pi-ta 2 relative to Pi-ta . Molecular cloning of the AVR-Pita and Pi-ta genes will aid in deployment of R genes for effective genetic control of rice blast disease.
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direct interaction of resistance gene and avirulence gene products confers rice blast resistance
The EMBO Journal, 2000Co-Authors: Yulin Jia, Sean A Mcadams, Gregory T Bryan, Howard P Hershey, Barbara ValentAbstract:Rice expressing the Pi-ta gene is resistant to strains of the rice blast fungus, Magnaporthe grisea, expressing AVR-Pita in a gene-for-gene relationship. Pi-ta encodes a putative Cytoplasmic Receptor with a centrally localized nucleotide-binding site and leucine-rich domain (LRD) at the C-terminus. AVR-Pita is predicted to encode a metalloprotease with an N-terminal secretory signal and pro-protein sequences. AVR-Pita176 lacks the secretory and pro-protein sequences. We report here that transient expression of AVR-Pita176 inside plant cells results in a Pi-ta-dependent resistance response. AVR-Pita176 protein is shown to bind specifically to the LRD of the Pi-ta protein, both in the yeast two-hybrid system and in an in vitro binding assay. Single amino acid substitutions in the Pi-ta LRD or in the AVR-Pita176 protease motif that result in loss of resistance in the plant also disrupt the physical interaction, both in yeast and in vitro. These data suggest that the AVR-Pita176 protein binds directly to the Pi-ta LRD region inside the plant cell to initiate a Pi-ta-mediated defense response.
Eicke Latz - One of the best experts on this subject based on the ideXlab platform.
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silica crystals and aluminum salts activate the nalp3 inflammasome through phagosomal destabilization
Nature Immunology, 2008Co-Authors: Veit Hornung, Franz Bauernfeind, Annett Halle, Eivind O Samstad, Hajime Kono, Kenneth L Rock, Katherine A Fitzgerald, Eicke LatzAbstract:Inhalation of silica crystals causes inflammation in the alveolar space. Prolonged exposure to silica can lead to the development of silicosis, an irreversible, fibrotic pulmonary disease. The mechanisms by which silica and other crystals activate immune cells are not well understood. Here we demonstrate that silica and aluminum salt crystals activated inflammasomes formed by the Cytoplasmic Receptor NALP3. NALP3 activation required phagocytosis of crystals, and this uptake subsequently led to lysosomal damage and rupture. 'Sterile' lysosomal damage (without crystals) also induced NALP3 activation, and inhibition of either phagosomal acidification or cathepsin B activity impaired NALP3 activation. Our results indicate that the NALP3 inflammasome senses lysosomal damage as an endogenous 'danger' signal.
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the nalp3 inflammasome is involved in the innate immune response to amyloid beta
Nature Immunology, 2008Co-Authors: Annett Halle, Veit Hornung, Katherine A Fitzgerald, Eicke Latz, Gabor C Petzold, Cameron R Stewart, Brian G Monks, Thomas Reinheckel, Kathryn J Moore, Douglas T GolenbockAbstract:The events leading to the inflammation and tissue damage associated with Alzheimer's disease are unclear. Golenbock and colleagues now show that amyloid-β activates the NALP3 inflammasome, which triggers the release of proinflammatory and neurotoxic factors. The fibrillar peptide amyloid-β (Aβ) has a chief function in the pathogenesis of Alzheimer's disease. Interleukin 1β (IL-1β) is a key cytokine in the inflammatory response to Aβ. Insoluble materials such as crystals activate the inflammasome formed by the Cytoplasmic Receptor NALP3, which results in the release of IL-1β. Here we identify the NALP3 inflammasome as a sensor of Aβ in a process involving the phagocytosis of Aβ and subsequent lysosomal damage and release of cathepsin B. Furthermore, the IL-1β pathway was essential for the microglial synthesis of proinflammatory and neurotoxic factors, and the inflammasome, caspase-1 and IL-1β were critical for the recruitment of microglia to exogenous Aβ in the brain. Our findings suggest that activation of the NALP3 inflammasome is important for inflammation and tissue damage in Alzheimer's disease.
Roman Spektor - One of the best experts on this subject based on the ideXlab platform.
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ank a host Cytoplasmic Receptor for the tobacco mosaic virus cell to cell movement protein facilitates intercellular transport through plasmodesmata
PLOS Pathogens, 2010Co-Authors: Shoko Ueki, Roman Spektor, Danielle M. Natale, Vitaly CitovskyAbstract:Plasmodesma (PD) is a channel structure that spans the cell wall and provides symplastic connection between adjacent cells. Various macromolecules are known to be transported through PD in a highly regulated manner, and plant viruses utilize their movement proteins (MPs) to gate the PD to spread cell-to-cell. The mechanism by which MP modifies PD to enable intercelluar traffic remains obscure, due to the lack of knowledge about the host factors that mediate the process. Here, we describe the functional interaction between Tobacco mosaic virus (TMV) MP and a plant factor, an ankyrin repeat containing protein (ANK), during the viral cell-to-cell movement. We utilized a reverse genetics approach to gain insight into the possible involvement of ANK in viral movement. To this end, ANK overexpressor and suppressor lines were generated, and the movement of MP was tested. MP movement was facilitated in the ANK-overexpressing plants, and reduced in the ANK-suppressing plants, demonstrating that ANK is a host factor that facilitates MP cell-to-cell movement. Also, the TMV local infection was largely delayed in the ANK-suppressing lines, while enhanced in the ANK-overexpressing lines, showing that ANK is crucially involved in the infection process. Importantly, MP interacted with ANK at PD. Finally, simultaneous expression of MP and ANK markedly decreased the PD levels of callose, b-1,3-glucan, which is known to act as a molecular sphincter for PD. Thus, the MP-ANK interaction results in the downregulation of callose and increased cell-to-cell movement of the viral protein. These findings suggest that ANK represents a host cellular Receptor exploited by MP to aid viral movement by gating PD through relaxation of their callose sphincters.
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ANK, a host Cytoplasmic Receptor for the tobacco mosaic virus cellto-cell movement protein, facilitates intercellular transport through plasmodesmata
2010Co-Authors: Shoko Ueki, Roman Spektor, Danielle M. Natale, Vitaly CitovskyAbstract:Plasmodesma (PD) is a channel structure that spans the cell wall and provides symplastic connection between adjacent cells. Various macromolecules are known to be transported through PD in a highly regulated manner, and plant viruses utilize their movement proteins (MPs) to gate the PD to spread cell-to-cell. The mechanism by which MP modifies PD to enable intercelluar traffic remains obscure, due to the lack of knowledge about the host factors that mediate the process. Here, we describe the functional interaction between Tobacco mosaic virus (TMV) MP and a plant factor, an ankyrin repeat containing protein (ANK), during the viral cell-to-cell movement. We utilized a reverse genetics approach to gain insight into the possible involvement of ANK in viral movement. To this end, ANK overexpressor and suppressor lines were generated, and the movement of MP was tested. MP movement was facilitated in the ANK-overexpressing plants, and reduced in the ANK-suppressing plants, demonstrating that ANK is a host factor that facilitates MP cell-to-cell movement. Also, the TMV local infection was largely delayed in the ANK-suppressing lines, while enhanced in the ANK-overexpressing lines, showing that ANK is crucially involved in the infection process. Importantly, MP interacted with ANK at PD. Finally, simultaneous expression of MP and ANK markedly decreased the PD levels of callose, b-1,3-glucan, which is known to act as a molecular sphincter for PD. Thus, the MP-ANK interaction results in the downregulation of callose and increased cell-to-cell movement of the viral protein. These findings suggest that ANK represents a host cellular Receptor exploited by MP to aid vira
