The plant G box promoter sequence activates transcription in Saccharomyces cerevisiae and is bound in vitro by a yeast activity similar to GBF, the plant G box binding factor.
G box and I box sequences of the Arabidopsis thaliana ribulose-bisphosphate-1,5-carboxylase small subunit (RBCS) promoter are required for expression mediated by the Arabidopsis rbcS-1A promoter in transgenic tobacco plants and are bound in vitro by factors from plant nuclear extracts termed GBF and GA-1, respectively. We show here that a -390 to -60 rbcS-1A promoter fragment containing the G box and two I boxes activates transcription from a truncated iso-1-cytochrome c (CYC1) gene promoter in Saccharomyces cerevisiae. Mutagenesis of either the rbcS-1A G box or both I box sequences eliminated the expression mediated by this fragment. When polymerized, I box oligonucleotides were also capable of enhancing expression from the truncated CYC1 promoter. Single-copy G box sequences from the Arabidopsis rbcS-1A, Arabidopsis Adh and tomato rbcS-3A promoters were more potent activators and were used in mobility shift assays to identify a DNA binding activity in yeast functionally similar to GBF. In methylation interference experiments, the binding specificity of the yeast protein was indistinguishable from that obtained with plant nuclear extracts.
Donald
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RG
Department of Biology, University of Pennsylvania, Philadelphia 19104.
Schindler
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U
Batschauer
A
A
Cashmore
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AR
D001483:Base Sequence; D003574:Cytochrome c Group / Q000235:genetics; D045304:Cytochromes c; D004247:DNA / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D004742:Enhancer Elements, Genetic; D007763:Lac Operon; D008969:Molecular Sequence Data; D010944:Plants / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D014158:Transcription, Genetic
C014059:CYC1 protein, S cerevisiae; D003574:Cytochrome c Group; D004268:DNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D045304:Cytochromes c; D004247:DNA