1993 Fiscal Year Final Research Report Summary
Regulatory mechanisms of gene expression through the interactions of transcription factors in plants
| Project/Area Number |
04454013
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| 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
|
| Keywords | histone H3 gene / S phase gene expression / type I cis-element / transcription factor / HBP-1a subfamily / OBRF / HALF1 / protein-protein interaction |
|---|
| 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.
|
