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The purine‐rich DNA‐binding protein OsPur α participates in the regulation of the rice sucrose synthase 1 gene expression
Author(s) -
Chang JuiChe,
Liao YiChun,
Yang ChienChih,
Wang AiYu
Publication year - 2011
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.2011.01501.x
Subject(s) - cauliflower mosaic virus , biology , gene , microbiology and biotechnology , sucrose , biochemistry , transcription (linguistics) , gene expression , dna , reporter gene , recombinant dna , transgene , genetically modified crops , linguistics , philosophy
The rice sucrose synthase 1 ( RSus1 ) gene is transcriptionally induced by sucrose, and a region within its promoter, at −1117 to −958 upstream of the transcription initiation site, was found to be essential for enhancing the sucrose‐induced expression. Further dissection of this region revealed that a group of nuclear proteins interact with a 39‐bp fragment named A‐3‐2 (−1045 to −1007). A protein that specifically and directly interacted with A‐3‐2 was isolated from the suspension‐cultured cells of rice and was subsequently identified as a purine‐rich DNA‐binding protein. The amino acid sequence of this protein, OsPur α , exhibited 73% identity with the Arabidopsis Pur α ‐1 protein, and its modeled structure resembled the structure of Pur‐ α in Drosophila . Recombinant OsPur α expressed and purified from Escherichia coli was demonstrated to have DNA‐binding activity and to interact with A‐3‐2 specifically. Moreover, OsPur α was able to enhance sucrose‐induced expression of the β ‐glucuronidase ( GUS ) reporter gene, which was transcriptionally fused to two copies of a DNA fragment containing A‐3‐2 and the cauliflower mosaic virus 35S minimal promoter, in vivo . The level of OsPur α bound to A‐3‐2 was higher in cells cultured in the presence of sucrose; however, the level of OsPurα mRNA in cells was not affected by sucrose. The results of this study demonstrate that OsPur α participates in the regulation of RSus1 expression in response to sucrose; nevertheless, it may require other partner proteins for full function.