| Project/Area Number |
12680630
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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 |
Functional biochemistry
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| Research Institution | Kanazawa University |
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Principal Investigator |
NAKANISHI Yoshinobu Graduate School of Medical Science, Kanazawa University ; Professor, 医学系研究科, 教授 (40172358)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 2001: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2000: ¥2,300,000 (Direct Cost: ¥2,300,000)
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| Keywords | Apoptosis / Phagocytosis / Phosphatidylserine / Golgi apparatus / Monoclonal antibody / Ribosome / 細胞貪食 / 精巣 / セルトリ細胞 / マクロファージ |
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| Research Abstract |
Mechanism of phosphatidylserine externalization in apoptotic cells
In order to elucidate the mechanism by which the membrane phospholipid phosphatidylserine (PS) translocates from the inner to the outer leaflet of the membrane bilayer and serves as a phagocytosis marker, we examined changes in the amount and activity of candidate enzymes responsible for the localization of PS in apoptotic cells. We have cloned a gene coding for presumed amino phospholipid translocase and obtained other candidate enzymes, but all of them turned out to be unrelated to the aimed enzymes. We thus gave up this project.
Analysis of candidate novel phagocytosis marker
We generated a monoclonal antibody named PH2 that inhibits macrophage phagocytosis of apoptotic cells. The antigen recognized by PH2 was thus considered to be a novel phagocytosis marker. We then characterized the PH2 antigen and found that it consists of protein and is localized to the membranous structures in normal cells. Furthermore, some fractions of the antigen was detectable in trans-Golgi. These results suggest that the PH2 antigen undergoes membrane vesicle transport and is exposed to cell surface upon apoptosis induction.
Externalization of ribosomal proteins in apoptotic calls
We determined structural change of ribosomes during apoptosis. When 28 out of 79 kinds of human ribosomal proteins were analyzed, 3 proteins were found to be degraded and released from ribosomes in apoptotic cells. In addition, 6 ribosomal proteins became detectable on cell surface upon apoptosis. These results suggest that some ribosomal proteins move from the ribosome to cell surface during apoptosis and serve as phagocytosis markers.
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