1993 Fiscal Year Final Research Report Summary
Regulation of DNA replication by microtubule-associated proteins
| Project/Area Number |
04833005
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
分子細胞生物学
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| Research Institution | University of Tokyo |
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Principal Investigator |
SHIODA Masaki University of Tokyo, Faculty of Medicine, Assistant, 医学部(医), 助手 (80134526)
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| Project Period (FY) |
1992 – 1993
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| Keywords | microtubule-associated protein / DNA replication / DNA polymerase alpha / nuclear matrix / enzyme kinetics / phosphorylation / cytoplasm / nucleus |
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| Research Abstract |
Stimulation of DNA synthesis by microtubule-associated protein (MAP) was examined in the isolated nuclear matrix and DNA polymerase alpha. The results showed that MAP stimulates DNA synthesis by stimulating DNA polymerase alpha activity, that the stimulation is caused by a decrease of the Km value of DNA replication machinery for deoxyribonucleotide triphosphates, and that the decrease of the Km value corresponds to the alternation of the machinery from the latent-type one to the active-type one. Thus, it is suggested that MAP has an ability to modulate the machenry "on". Phosphorylation of MAP revealed that phosphorylation of microtubule-assembly-promoting sites and adjacent proline-rich regions is required for the stimulation of DNA synthesis by MAP.It was also found that a part of MAP is localized in the nucleus in proliferating cells. All the above results taken together, it is proposed that DNA replication is regulated by MAP which is released from cytoplasm to the nucleus by phosphorylation.
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