Role of Multiple HLR1 Sequences in the Regulation of the Dual Promoters of the psaAB Genes in Synechocystis sp. PCC 6803▿
| Autor: | Yukako Hihara, Masayuki Muramatsu, Tomoko Takahashi, Nanako Nakai |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: |
Regulation of gene expression
Genetics DNA Bacterial biology Base Sequence Light Synechocystis Promoter Gene Expression Regulation Bacterial biology.organism_classification Microbiology Response regulator chemistry.chemical_compound chemistry Bacterial Proteins Gene expression Gene Regulation Promoter Regions Genetic Molecular Biology Gene Psychological repression DNA |
| Popis: | Previously, we analyzed the promoter architecture of the psaAB genes encoding reaction center subunits of photosystem I (PSI) in the cyanobacterium Synechocystis sp. PCC 6803. There exist two promoters, P1 and P2, both of which show typical high-light (HL) response of PSI genes; their activities are high under low-light (LL) conditions but rapidly downregulated upon the shift to HL conditions. In this study, it was suggested that a response regulator RpaB binds to multiple high-light regulatory 1 (HLR1) sequences in the upstream region of the psaAB genes. We explored the regulatory role of cis -elements, including these HLR1 sequences on the individual activity of P1 and P2. Under LL conditions, the most influential cis -element is HLR1C (−62 to −45, relative to the transcriptional starting point of P1) working for positive regulation of P1. The other HLR1 sequences also affect the promoter activity under LL conditions; HLR1A (−255 to −238) is involved in repression of P1, whereas HLR1B (−153 to −126) works for activation of P2. Upon the shift to HL conditions, regulation via HNE2 located within the region from −271 to −177 becomes active in order to downregulate both P1 and P2 activities. A positive effect of HLR1B on P2 may persist under HL. These results suggest that cis -elements, including multiple HLR1 sequences, differently regulate the activities of dual promoters of the psaAB genes to achieve the fine-tuning of the gene expression. |
| Databáze: | OpenAIRE |
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