Phalloidin-induced accumulation of myosin in rat hepatocytes is caused by suppression of autolysosome formation
| العنوان: | Phalloidin-induced accumulation of myosin in rat hepatocytes is caused by suppression of autolysosome formation |
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| المؤلفون: | Takashi Ueno, Eiki Kominami, Sumio Watanabe, Miyoko Hirose, Toshihiko Namihisa |
| المصدر: | European Journal of Biochemistry. 190:63-69 |
| بيانات النشر: | Wiley, 1990. |
| سنة النشر: | 1990 |
| مصطلحات موضوعية: | Leupeptins, Phalloidine, Phalloidin, Acid Phosphatase, Pyruvate Kinase, macromolecular substances, Myosins, Protein degradation, Biochemistry, Immunoenzyme Techniques, chemistry.chemical_compound, Fructose-Bisphosphate Aldolase, Myosin, Animals, Cathepsin, chemistry.chemical_classification, L-Lactate Dehydrogenase, biology, Leupeptin, Rats, Inbred Strains, Cathepsins, Actins, Enzyme assay, Rats, Cell biology, Microscopy, Electron, Enzyme, Liver, chemistry, biology.protein, Female, Lysosomes, Oligopeptides, Pyruvate kinase |
| الوصف: | Administration of phalloidin in vivo to rats causes marked changes in the distribution of actin and myosin in hepatocytes, which accompanies reduced bile flow. We have found that in hepatocytes treated with phalloidin for 3 and 7 days, cellular myosin content increased about 1.5-fold and 4.7-fold, respectively. In addition, total cell protein content and several marker enzyme activities were also elevated by 30-120% depending on the duration of phalloidin treatment. These observations allow us to speculate that phalloidin somehow elicits inhibition of cellular protein degradation, which results in the increase of these protein levels. To examine this possibility further, we analyzed leupeptin-induced density shift of phagolysosomes. In normal liver, the injection of leupeptin/E64c caused an increase in the density of both heterolysosomes and autolysosomes, due to retarded digestion of sequestered proteins as a result of the inhibition of lysosomal cathepsins. Accumulation, in these denser autolysosomes, of lactic dehydrogenase, pyruvate kinase, aldolase, and myosin was demonstrated by enzyme assays and immunoblot analysis. In the phalloidin-treated liver, the increase in the density of autolysosomes and the accumulation of above cytoplasmic enzymes were markedly inhibited. However, phalloidin did not affect the shift in the density of heterolysosomes. From these data, we concluded that autolysosome formation was specifically hindered in phalloidin-treated rat hepatocytes, which results in the reduction of autophagic protein degradation and eventual increase in intracellular protein levels. |
| تدمد: | 1432-1033 0014-2956 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::90c2688d38d98b43bf9f95d641fe55b9Test https://doi.org/10.1111/j.1432-1033.1990.tb15546.xTest |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....90c2688d38d98b43bf9f95d641fe55b9 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 14321033 00142956 |
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