| Project/Area Number |
10680518
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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 |
環境影響評価(含放射線生物学)
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| Research Institution | NAGASAKI UNIVERSITY |
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Principal Investigator |
SUZUKI Keiji NAGASAKI UNIVERSITY, PHARMACEUTICAL SCIENCES, RESEARCH ASSOCIATE, 薬学部, 助手 (00196809)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Masami NAGASAKI UNIVERSITY, PHARMACEUTICAL SCIENCES, PROFESSOR, 薬学部, 教授 (20111768)
KODAMA Seiji NAGASAKI UNIVERSITY, PHARMACEUTICAL SCIENCES, ASSISTANT PROFESSOR, 薬学部, 助教授 (00195744)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 1999: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1998: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | IONIZING RADIATION / PHOSPHORYLATION / P53 / ATM / SIGNAL TRANSDUCTION / MDM2 / 分子生物学 / 放射線生物学 |
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| Research Abstract |
(1) P53 ACCUMULATION IN X-IRRADIATED NORMAL HUMAN EMBRYONIC CELLS.
THE KINETICS OF P53 ACCUMULATION IN NORMAL HUMAN EMBRYO CELLS IRRADIATED WITH VARIOUS DOSES OF X-RAYS WAS EXAMINED. THE INCREASE OF THE P53 LEVEL WAS DETECTED 1 HOUR AFTER IRRADIATION, AND THE ACCUMULATION WAS BI-PHASIC WITH DOSES MORE THAN 4 GY, WHEREAS THE ACCUMULATION WAS MONO-PHASIC WITH DOSES LESS THAN 2 GY. WE OBSERVED THAT P53 WAS ACCUMULATED WITH RESTRICTION ENZYME PVU II INTRODUCED INTO CELLS BY THE AID OF STREPTLYSIN-O. THESE RESULTS INDICATE THAT DNA DOUBLE STRAND BREAKS ARE THE TRIGGER FOR ACCUMULATION OF P53 PROTEIN.
(2) SITE-SPECIFIC PHOSPHORYLATION OF P53 BY ATM
BECAUSE P53 PROTEIN DOES NOT ACCUMULATED SIGNIFICANTLY IN AT CELLS, ATM PROTEIN IS SUGGESTED TO BE INVOLVED IN P53 PHOSPHORYLATION IN RESPONSE TO IOZING RADIATION. HERE WE HAVE USED POLYCLONAL ANTIBODY AGINST PHOSPHORYLATED P53 AT SERINE 15, AND FOUND THAT PHSOPHORYLATION OF P53 AT SERINE 15 WAS DEFICIENT IN AT CELLS. USING DNA-CELLULOSE PULL-DOWN ASSAY, WE SHOWED THAT ATM PROTEIN WAS RECRUITED TO DNA DOUBLE STRAND BREAKS.
(3) SITE-SPECIFIC PHOSPHORYALTION AND REGULATION OF P53 STABILITY
TREATMENT OF CELLS WITH THE PROTEASOME INHIBITOR, ALLN, REVEALED THAT P53 WAS UBIQUITINATED UNDER THE CONTROL STATE. WE FOUND THAT P53 WAS PHOSPHORYLATED AT SERINE 15 INRESPONSE TO X-RAYS, HOWEVER, PHOSPHORYLATED P53 WAS ALSO UBIQUITINATED, SUGGESTING THAT PHOSPHORYLATION OF P53 AT SERINE 15 SUPPRESSED P53 DEGRADATION THROUGH AN INHIBITION OF PROTEASOME RECOGNITION.
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