Localization and conditional redundancy of regulatory elements in rbcS-3A, a pea gene encoding the small subunit of ribulose-bisphosphate carboxylase
| Autor: | Maria Cuozzo, Kathy Ward, C Kuhlemeier, Pamela J. Green, Nam-Hai Chua, Elisabeth Goyvaerts |
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| Rok vydání: | 1988 |
| Předmět: |
Genetics
Multidisciplinary Plants Medicinal biology Base Sequence Light Protein subunit Ribulose-Bisphosphate Carboxylase RuBisCO Molecular Sequence Data food and beverages Fabaceae Regulatory Sequences Nucleic Acid Conserved sequence Genes Regulatory sequence Transcription (biology) Organ Specificity biology.protein Transversion Enhancer Gene Plant Proteins Research Article |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America. 85(13) |
| ISSN: | 0027-8424 |
| Popis: | Expression of the pea rbcS-3A gene, one of a family of genes encoding the small subunit of ribulose-bisphosphate carboxylase [EC 4.1.1.39], is regulated by light and is restricted to chloroplast-containing cells. We analyzed the effects of light and development on rbcS-3A expression in transgenic plants. Two highly conserved sequences ("boxes" II and III) around nucleotide position -150 (relative to the transcription initiation site, +1) are required for rbcS-3A expression. The so-defined positive elements overlap with previously identified negative light-regulatory elements. In the case of box II, which has sequence similarity to the core enhancer motif of simian virus 40, a GG----CC transversion is sufficient to abolish expression. The effect of mutations in boxes II and III can only be measured when sequences upstream of -170 are removed, and because sequences both 5' and 3' of -170 can direct light-regulated and organ-specific expression. This implies that there is a redundancy of cis-acting elements in the 5' noncoding region of rbcS-3A. However, we show that the sequences upstream of -170 are dispensable only in the mature leaves of a green plant. In contrast, in the young, expanding leaves at the top of a green plant, as well as in seedlings, the distal elements are required for high-level expression. Therefore, redundancy is not absolute, and the requirements for rbcS-3A expression change during plant development. |
| Databáze: | OpenAIRE |
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