1997 Fiscal Year Final Research Report Summary
Studies on autophagy in tobacco cultured cells
| Project/Area Number |
07640867
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
植物生理
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| Research Institution | University of Shizuoka |
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Principal Investigator |
MORIYASU Yuji University of Shizuoka, School of Food and Nutiritional Sciences, Joshu, 食品栄養科学部, 助手 (20200454)
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| Project Period (FY) |
1995 – 1997
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| Keywords | autophagy / vacuole / lysosome / protease / autolysis / tobacco / cultured cells |
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| Research Abstract |
The plant central vacuole has been thought to be an organelle homologous to animal lysosomes ; it is acidic and contains various kinds of hydrolytic enzymes. However, we do not know if it functions as a proteolytic compartment as animal lysosomes do. To investigate this question, we have studied the mechanism of autophagy induced upon sucrose starvation, using heterotrophically growing tobacco suspension culture cells.
When the cells are incubated in sucrose-free culture medium, bulk degradation of intracellular protein is induced. This induction of protein degradation is inhibited by cysteine protease inhibitors such as E-64, which also cause accumulation of many membrane-bound vesicles in the perinuclear cytoplasm. These vesicles are 1 to 6 micrometers in diameter and have several osmiophilic particles within them. They are acidic compartments and contain acid phosphatase.
These results suggest that the vesicles are plant autolysosomes and that they contribute to cellular protein degradation which is induced by sucrose starvation. Thus plant cells are likely to possess a lytic organelle separate from the central vacuole.
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