Project/Area Number |
04454013
|
Research Category |
Grant-in-Aid for General Scientific Research (B)
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Allocation Type | Single-year Grants |
Research Field |
植物生理学
|
Research Institution | KYOTO UNIVERSITY |
Principal Investigator |
IWABUCHI Masaki Kyoto Univ.Botany Professor, 理学部, 教授 (30000839)
|
Co-Investigator(Kenkyū-buntansha) |
MESHI Tetsuo Kyoto Univ.Botany Assoc.Professor, 理学部, 助教授 (40157813)
|
Project Period (FY) |
1992 – 1993
|
Project Status |
Completed (Fiscal Year 1993)
|
Budget Amount *help |
¥6,600,000 (Direct Cost: ¥6,600,000)
Fiscal Year 1993: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1992: ¥4,500,000 (Direct Cost: ¥4,500,000)
|
Keywords | histone H3 gene / S phase gene expression / type I cis-element / transcription factor / HBP-1a subfamily / OBRF / HALF1 / protein-protein interaction / ヘキサマーシス・エレメント / オクタマーシス・エレメント / トランス転写因子 / 形質転換細胞 / 単鎖DNA結合因子 / タンパク質-タンパク質相互作用 |
Research Abstract |
Focusing on the transcription factors, HBP-1a and HBP-1b, that bind to the hexamer sequence in the type I element which defines the S phase-specific transcription of a wheat histone H3 gene (TH012), we investigated the structures and functions of the members of the HBP-1 transcription factor family and other transcription factors that interact with these members. Within a research term, we obtained the following results. 1. The members of the HBP-1 family differ in their ability of the dimer formation and their affinity for DNA-binding. This finding suggests a possibility that the HBP-1 family members would control the gene expression by changing the partners of the members to from homo- or hetero-dimers through the bZIP domain. 2. A DNA-binding protein (OBRF) was identified which specifically interacts with an octamer sequence, another cis-sequence within the type I element, by the DNA mobility shift assay of the nuclear extract from wheat cultured cells. Although OBRF was labile, its DNA-binding activity was the highest at the S phase of cell cycle and parallel with the level of the histone H3 gene expression through the cell cycle. 3. A cDNA clone encoding the protein, termed HALF1, was isolated which associates with HBP-1a(17) through the protein-protein interactions by the West-western screening method. Sequence analysis of the cDNA clone revealed that an overall structure of HALF1 resembles that of the HBP-1a subfamily. The DNA-binding experiments showed that HALF1 can not bind to DNA (hexamer sequence) as a homodimer but interact with DNA as a heterodimer containing HBP-1a(17). The results suggest that HALF1 may be involved in the H3 gene regulation through the interaction with the members of the HBP-1a subfamily.
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