Identification of a cis-regulatory element involved in phytochrome down-regulated expression of the pea small GTPase gene pra2.
The pra2 gene encodes a pea (Pisum sativum) small GTPase belonging to the YPT/rab family, and its expression is down-regulated by light, mediated by phytochrome. We have isolated and characterized a genomic clone of this gene and constructed a fusion DNA of its 5'-upstream region in front of the gene for firefly luciferase. Using this construct in a transient assay, we determined a pra2 cis-regulatory region sufficient to direct the light down-regulation of the luciferase reporter gene. Both 5'- and internal deletion analyses revealed that the 93-bp sequence between -734 and -642 from the transcriptional start site was important for phytochrome down-regulation. Gain-of-function analysis showed that this 93-bp region could confer light down-regulation when fused to the cauliflower mosaic virus 35S promoter. Furthermore, linker-scanning analysis showed that a 12-bp sequence within the 93-bp region mediated phytochrome down-regulation. Gel-retardation analysis showed the presence of a nuclear factor that was specifically bound to the 12-bp sequence in vitro. These results indicate that this element is a cis-regulatory element involved in phytochrome down-regulated expression.
Inaba
T
T
Laboratory of Plant Molecular Biology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.
Nagano
Y
Y
Sakakibara
T
T
Sasaki
Y
Y
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D018548:Cotyledon / Q000201:enzymology; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism; D015536:Down-Regulation / Q000528:radiation effects; D020558:GTP Phosphohydrolases / Q000235:genetics*; D019204:GTP-Binding Proteins / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects; D017343:Genes, Plant; D005809:Genes, Regulator; D017930:Genes, Reporter; D008027:Light; D008969:Molecular Sequence Data; D018532:Pisum sativum / Q000201:enzymology* / Q000235:genetics* / Q000528:radiation effects; D010834:Phytochrome / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D020691:rab GTP-Binding Proteins
D017931:DNA Primers; D004268:DNA-Binding Proteins; D010940:Plant Proteins; D010834:Phytochrome; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; C094510:PRA2 protein, Pisum sativum; D020691:rab GTP-Binding Proteins