Details
| Original language | English |
|---|---|
| Pages (from-to) | 23785-9 |
| Number of pages | 5 |
| Journal | Journal of Biological Chemistry |
| Volume | 276 |
| Issue number | 26 |
| Publication status | Published - 29 Jun 2001 |
Abstract
A single nucleotide exchange in a promoter region located immediately upstream of the CAAT box of the spinach photosynthesis gene AtpC (gene product is subunit gamma of the chloroplast ATP synthase) prevents the formation of a secondary structure and causes an unregulated, constitutive high level of expression (Kusnetsov, V., Landsberger, M., Oelmüller, R. (1999) J. Biol. Chem. 274, 36009-36014). We have isolated cDNAs for ATPC-2, a new polypeptide with homologies to pro- and eukaryotic helicases, which specifically binds to this promoter region. Binding of ATPC-2 competes strongly with that of a CAAT box binding factor (CBF), consistent with the idea that both complexes cannot be formed simultaneously because of sterical reasons. In gel mobility shift assays, high binding activities of ATPC-2 and low binding activities of CBF were observed with nuclear extracts from tissue with low AtpC expression levels, and the opposite was observed with extracts from tissues with high AtpC expression levels. Binding of ATPC-2 to the mutant sequence, which directs a constitutively high level expression in vivo and prevents the formation of a secondary structure in vitro, is significantly weaker than binding to the wild-type sequence. Again, the opposite results were obtained for the CBF. Thus, we conclude that the assembly of the CBF.DNA complex stimulates transcription of AtpC and that CBF binding is prevented if ATPC-2 is bound to the promoter region. The novel mechanism of gene regulation and the role of the helicase-like protein ATPC-2 as a potential transcriptional repressor is discussed in relation to its modular structure.
Keywords
- Amino Acid Sequence, Arabidopsis/genetics, CCAAT-Binding Factor/metabolism, Cloning, Molecular, DNA Helicases/genetics, DNA-Binding Proteins/genetics, Eukaryotic Cells/metabolism, Gene Expression Regulation, Plant, Macromolecular Substances, Molecular Sequence Data, Photosynthesis, Plant Proteins/genetics, Prokaryotic Cells/metabolism, Promoter Regions, Genetic, Proton-Translocating ATPases/genetics, Repressor Proteins/genetics, Response Elements, Sequence Homology, Amino Acid
Cite this
- Standard
- Harvard
- Apa
- Vancouver
- BibTeX
- RIS
In: Journal of Biological Chemistry, Vol. 276, No. 26, 29.06.2001, p. 23785-9.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - A repressor with similarities to prokaryotic and eukaryotic DNA helicases controls the assembly of the CAAT box binding complex at a photosynthesis gene promoter
AU - Bezhani, S
AU - Sherameti, I
AU - Pfannschmidt, T
AU - Oelmüller, R
PY - 2001/6/29
Y1 - 2001/6/29
N2 - A single nucleotide exchange in a promoter region located immediately upstream of the CAAT box of the spinach photosynthesis gene AtpC (gene product is subunit gamma of the chloroplast ATP synthase) prevents the formation of a secondary structure and causes an unregulated, constitutive high level of expression (Kusnetsov, V., Landsberger, M., Oelmüller, R. (1999) J. Biol. Chem. 274, 36009-36014). We have isolated cDNAs for ATPC-2, a new polypeptide with homologies to pro- and eukaryotic helicases, which specifically binds to this promoter region. Binding of ATPC-2 competes strongly with that of a CAAT box binding factor (CBF), consistent with the idea that both complexes cannot be formed simultaneously because of sterical reasons. In gel mobility shift assays, high binding activities of ATPC-2 and low binding activities of CBF were observed with nuclear extracts from tissue with low AtpC expression levels, and the opposite was observed with extracts from tissues with high AtpC expression levels. Binding of ATPC-2 to the mutant sequence, which directs a constitutively high level expression in vivo and prevents the formation of a secondary structure in vitro, is significantly weaker than binding to the wild-type sequence. Again, the opposite results were obtained for the CBF. Thus, we conclude that the assembly of the CBF.DNA complex stimulates transcription of AtpC and that CBF binding is prevented if ATPC-2 is bound to the promoter region. The novel mechanism of gene regulation and the role of the helicase-like protein ATPC-2 as a potential transcriptional repressor is discussed in relation to its modular structure.
AB - A single nucleotide exchange in a promoter region located immediately upstream of the CAAT box of the spinach photosynthesis gene AtpC (gene product is subunit gamma of the chloroplast ATP synthase) prevents the formation of a secondary structure and causes an unregulated, constitutive high level of expression (Kusnetsov, V., Landsberger, M., Oelmüller, R. (1999) J. Biol. Chem. 274, 36009-36014). We have isolated cDNAs for ATPC-2, a new polypeptide with homologies to pro- and eukaryotic helicases, which specifically binds to this promoter region. Binding of ATPC-2 competes strongly with that of a CAAT box binding factor (CBF), consistent with the idea that both complexes cannot be formed simultaneously because of sterical reasons. In gel mobility shift assays, high binding activities of ATPC-2 and low binding activities of CBF were observed with nuclear extracts from tissue with low AtpC expression levels, and the opposite was observed with extracts from tissues with high AtpC expression levels. Binding of ATPC-2 to the mutant sequence, which directs a constitutively high level expression in vivo and prevents the formation of a secondary structure in vitro, is significantly weaker than binding to the wild-type sequence. Again, the opposite results were obtained for the CBF. Thus, we conclude that the assembly of the CBF.DNA complex stimulates transcription of AtpC and that CBF binding is prevented if ATPC-2 is bound to the promoter region. The novel mechanism of gene regulation and the role of the helicase-like protein ATPC-2 as a potential transcriptional repressor is discussed in relation to its modular structure.
KW - Amino Acid Sequence
KW - Arabidopsis/genetics
KW - CCAAT-Binding Factor/metabolism
KW - Cloning, Molecular
KW - DNA Helicases/genetics
KW - DNA-Binding Proteins/genetics
KW - Eukaryotic Cells/metabolism
KW - Gene Expression Regulation, Plant
KW - Macromolecular Substances
KW - Molecular Sequence Data
KW - Photosynthesis
KW - Plant Proteins/genetics
KW - Prokaryotic Cells/metabolism
KW - Promoter Regions, Genetic
KW - Proton-Translocating ATPases/genetics
KW - Repressor Proteins/genetics
KW - Response Elements
KW - Sequence Homology, Amino Acid
U2 - 10.1074/jbc.M010945200
DO - 10.1074/jbc.M010945200
M3 - Article
C2 - 11274172
VL - 276
SP - 23785
EP - 23789
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 26
ER -