The Experts below are selected from a list of 105 Experts worldwide ranked by ideXlab platform
Masahiro Fujishima - One of the best experts on this subject based on the ideXlab platform.
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Symbiotic Chlorella vulgaris of the ciliate Paramecium bursaria plays an important role in maintaining periAlgal vacuole membrane functions.
Protist, 2010Co-Authors: Yuuki Kodama, Isao Inouye, Masahiro FujishimaAbstract:Treatment of symbiotic alga-bearing Paramecium bursaria cells with a protein synthesis inhibitor, cycloheximide, induces synchronous swelling of all periAlgal vacuoles at about 24 h after treatment under a constant light condition. Subsequently, the vacuoles detach from the host cell cortex. The algae in the vacuoles are digested by the host's lysosomal fusion to the vacuoles. To elucidate the timing of Algal degeneration, P. bursaria cells were treated with cycloheximide under a constant light condition. Then the cells were observed using transmission electron microscopy. Results show that Algal chloroplasts and nuclei degenerated within 9 h after treatment, but before the synchronous swelling of the periAlgal vacuole and appearance of acid phosphatase activity in the periAlgal vacuole by lysosomal fusion. Treatment with cycloheximide under a constant dark condition and treatment with chloramphenicol under a constant light condition induced neither synchronous swelling of the vacuoles nor digestion of the algae inside the vacuoles. These results demonstrate that Algal Proteins synthesized during photosynthesis are necessary to maintain chloroplastic and nuclear structures, and that inhibition of protein synthesis induces rapid lysis of these organelles, after which synchronous swelling of the periAlgal vacuole and fusion occur with the host lysosomes.
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Cycloheximide induces synchronous swelling of periAlgal vacuoles enclosing symbiotic Chlorella vulgaris and digestion of the algae in the ciliate Paramecium bursaria.
Protist, 2008Co-Authors: Yuuki Kodama, Masahiro FujishimaAbstract:Cycloheximide is known to inhibit preferentially protein synthesis of symbiotic Chlorella of the ciliate Paramecium bursaria, but to hardly host protein synthesis. Treatment of algae-bearing Paramecium cells with cycloheximide induces synchronous swelling of all periAlgal vacuoles that are localized immediately beneath the host's cell membrane. In this study, the space between the symbiotic Algal cell wall and the periAlgal vacuole membrane widened to about 25 times its normal width 24 h after treatment with cycloheximide. Then, the vacuoles detached from beneath the host's cell membrane, were condensed and stained with Gomori's solution, and the algae in the vacuoles were digested. Although this phenomenon is induced only under a fluorescent light condition, and not under a constant dark condition, this phenomenon was not induced in paramecia treated with cycloheximide in the light in the presence of the photosynthesis inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea. These results indicate that Algal Proteins synthesized in the presence of Algal photosynthesis serve some important function to prevent expansion of the periAlgal vacuole and to maintain the ability of the periAlgal vacuole membrane to protect itself from host lysosomal fusion.
Yuuki Kodama - One of the best experts on this subject based on the ideXlab platform.
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Symbiotic Chlorella vulgaris of the ciliate Paramecium bursaria plays an important role in maintaining periAlgal vacuole membrane functions.
Protist, 2010Co-Authors: Yuuki Kodama, Isao Inouye, Masahiro FujishimaAbstract:Treatment of symbiotic alga-bearing Paramecium bursaria cells with a protein synthesis inhibitor, cycloheximide, induces synchronous swelling of all periAlgal vacuoles at about 24 h after treatment under a constant light condition. Subsequently, the vacuoles detach from the host cell cortex. The algae in the vacuoles are digested by the host's lysosomal fusion to the vacuoles. To elucidate the timing of Algal degeneration, P. bursaria cells were treated with cycloheximide under a constant light condition. Then the cells were observed using transmission electron microscopy. Results show that Algal chloroplasts and nuclei degenerated within 9 h after treatment, but before the synchronous swelling of the periAlgal vacuole and appearance of acid phosphatase activity in the periAlgal vacuole by lysosomal fusion. Treatment with cycloheximide under a constant dark condition and treatment with chloramphenicol under a constant light condition induced neither synchronous swelling of the vacuoles nor digestion of the algae inside the vacuoles. These results demonstrate that Algal Proteins synthesized during photosynthesis are necessary to maintain chloroplastic and nuclear structures, and that inhibition of protein synthesis induces rapid lysis of these organelles, after which synchronous swelling of the periAlgal vacuole and fusion occur with the host lysosomes.
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Cycloheximide induces synchronous swelling of periAlgal vacuoles enclosing symbiotic Chlorella vulgaris and digestion of the algae in the ciliate Paramecium bursaria.
Protist, 2008Co-Authors: Yuuki Kodama, Masahiro FujishimaAbstract:Cycloheximide is known to inhibit preferentially protein synthesis of symbiotic Chlorella of the ciliate Paramecium bursaria, but to hardly host protein synthesis. Treatment of algae-bearing Paramecium cells with cycloheximide induces synchronous swelling of all periAlgal vacuoles that are localized immediately beneath the host's cell membrane. In this study, the space between the symbiotic Algal cell wall and the periAlgal vacuole membrane widened to about 25 times its normal width 24 h after treatment with cycloheximide. Then, the vacuoles detached from beneath the host's cell membrane, were condensed and stained with Gomori's solution, and the algae in the vacuoles were digested. Although this phenomenon is induced only under a fluorescent light condition, and not under a constant dark condition, this phenomenon was not induced in paramecia treated with cycloheximide in the light in the presence of the photosynthesis inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea. These results indicate that Algal Proteins synthesized in the presence of Algal photosynthesis serve some important function to prevent expansion of the periAlgal vacuole and to maintain the ability of the periAlgal vacuole membrane to protect itself from host lysosomal fusion.
Joël Fleurence - One of the best experts on this subject based on the ideXlab platform.
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Seaweed Proteins: biochemical, nutritional aspects and potential uses
Trends in Food Science & Technology, 1999Co-Authors: Joël FleurenceAbstract:Seaweeds are traditionally used in human and animal nutrition. Their protein contents differ according to the species and seasonal conditions. Little information is available on the nutritional value of Algal Proteins and, especially, on the compounds that decrease their digestibility. This paper is a short review of the biochemical and nutritional aspects associated with seaweed Proteins. Some perspectives on the potential uses of Algal Proteins for the development of new foods or additives for human or animal consumption are also discussed.
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The enzymatic degradation of Algal cell walls: a useful approach for improving protein accessibility?
Journal of Applied Phycology, 1999Co-Authors: Joël FleurenceAbstract:With protein contents higher than 20% (dry weight), some red or green seaweeds are potential sources of commercially useful plant Proteins. However, the presence of anionic or neutral polysaccharides in large quantities in the cell wall strongly hinders the solubilization of Proteins during the application of classical extraction procedures. A present this limits the study and industrial use of seaweed Proteins. This short paper is a discussion about the use of enzymes degrading the cell wall polysaccharides as an alternative method to improve the extraction and the solubilization of Algal Proteins.
Isao Inouye - One of the best experts on this subject based on the ideXlab platform.
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Symbiotic Chlorella vulgaris of the ciliate Paramecium bursaria plays an important role in maintaining periAlgal vacuole membrane functions.
Protist, 2010Co-Authors: Yuuki Kodama, Isao Inouye, Masahiro FujishimaAbstract:Treatment of symbiotic alga-bearing Paramecium bursaria cells with a protein synthesis inhibitor, cycloheximide, induces synchronous swelling of all periAlgal vacuoles at about 24 h after treatment under a constant light condition. Subsequently, the vacuoles detach from the host cell cortex. The algae in the vacuoles are digested by the host's lysosomal fusion to the vacuoles. To elucidate the timing of Algal degeneration, P. bursaria cells were treated with cycloheximide under a constant light condition. Then the cells were observed using transmission electron microscopy. Results show that Algal chloroplasts and nuclei degenerated within 9 h after treatment, but before the synchronous swelling of the periAlgal vacuole and appearance of acid phosphatase activity in the periAlgal vacuole by lysosomal fusion. Treatment with cycloheximide under a constant dark condition and treatment with chloramphenicol under a constant light condition induced neither synchronous swelling of the vacuoles nor digestion of the algae inside the vacuoles. These results demonstrate that Algal Proteins synthesized during photosynthesis are necessary to maintain chloroplastic and nuclear structures, and that inhibition of protein synthesis induces rapid lysis of these organelles, after which synchronous swelling of the periAlgal vacuole and fusion occur with the host lysosomes.
Diego González-halphen - One of the best experts on this subject based on the ideXlab platform.
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What limits the allotopic expression of nucleus-encoded mitochondrial genes? The case of the chimeric Cox3 and Atp6 genes.
Mitochondrion, 2010Co-Authors: Francisco Figueroa-martínez, Miriam Vázquez-acevedo, Paulina Cortés-hernández, José J. García-trejo, Edgar Davidson, Michael P. King, Diego González-halphenAbstract:Allotopic expression is potentially a gene therapy for mtDNA-related diseases. Some OXPHOS Proteins like ATP6 (subunit a of complex V) and COX3 (subunit III of complex IV) that are typically mtDNA-encoded, are naturally nucleus-encoded in the alga Chlamydomonas reinhardtii. The mitochondrial Proteins whose genes have been relocated to the nucleus exhibit long mitochondrial targeting sequences ranging from 100 to 140 residues and a diminished overall mean hydrophobicity when compared with their mtDNA-encoded counterparts. We explored the allotopic expression of the human gene products COX3 and ATP6 that were re-designed for mitochondrial import by emulating the structural properties of the corresponding Algal Proteins. In vivo and in vitro data in homoplasmic human mutant cells carrying either a T8993G mutation in the mitochondrial atp6 gene or a 15bp deletion in the mtDNA-encoded cox3 gene suggest that these human mitochondrial Proteins re-designed for nuclear expression are targeted to the mitochondria, but fail to functionally integrate into their corresponding OXPHOS complexes.
