1987 Fiscal Year Final Research Report Summary
Role of Ca^<2+> on c-fos expression during differentiation of leukemia cells.
| Project/Area Number |
61571044
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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 |
Biological pharmacy
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| Research Institution | Institute of Medical Science, University of Tokyo |
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Principal Investigator |
NOSE Kiyoshi Associate Professor, Institute of Medical Science, University of Tokyo, 医科学研究所, 助教授 (70012747)
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| Project Period (FY) |
1986 – 1987
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| Keywords | c-fos / TPA / C-kinase / 〓〓酵素 |
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| Research Abstract |
We analyzed mechanism of transcriptional induction of c-fos in U937 cells. Transcription of c-fos was induced by phorbol esters (TPA) and this induction required activation of protein kinase C. One of the factors which control gene expression is chromatin structure. Chromatin higher order structure was examined with induced and uninduced cells by comparing sensitivity of c-fos gene to nucleases. Four distinct sites which showed high sensitivity to DNase I were detected in a 5' upstream region of c-fos gene, but these sites and the sensitivity did not change after induction.
The induction of c-fos was found to be inhibited by inhibitors of topoisomerases, and specific cutting sites were found on 5'-upstream region of cellular c-fos gene, but these sites were not changed by inducers. From above results it was concluded that c-fos gene had active conformation even before transcriptional activation.
From competition experiments with CAT gene which had c-fos transcriptional promoter, existence of some factors was suggested which control c-fos expression negatively.
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