Identification of a soybean protein that interacts with GAGA element dinucleotide repeat DNA.
Dinucleotide repeat DNA with the pattern (GA)(n)/(TC)(n), so-called GAGA elements, control gene expression in animals, and are recognized by a specific regulatory protein. Here, a yeast one-hybrid screen was used to isolate soybean (Glycine max) cDNA encoding a GAGA-binding protein (GBP) that binds to (GA)(n)/(CT)(n) DNA. Soybean GBP was dissimilar from the GAGA factor of Drosophila melanogaster. Recombinant GBP protein did not bind to dinucleotide repeat sequences other than (GA)(n)/(CT)(n). GBP bound to the promoter of the heme and chlorophyll synthesis gene Gsa1, which contains a GAGA element. Removal of that GAGA element abrogated binding of GBP to the promoter. Furthermore, insertion of the GAGA element to a nonspecific DNA conferred GBP-binding activity on that DNA. Thus, the GAGA element of the Gsa1 promoter is both necessary and sufficient for GBP binding. Gbp mRNA was expressed in leaves and was induced in symbiotic root nodules elicited by the bacterium Bradyrhizobium japonicum. In addition, Gbp transcripts were much higher in leaves of dark-treated etiolated plantlets than in those exposed to light for 24 h. Homologs of GBP were found in other dicots and in the monocot rice (Oryza sativa), as well. We suggest that interaction between GAGA elements and GBP-like proteins is a regulatory feature in plants.
Sangwan
Indu
I
Department of Biochemistry, State University of New York, Buffalo, New York 14214, USA. mrobrian@buffalo.edu
O'Brian
Mark R
MR
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D020369:Bradyrhizobium / Q000254:growth & development; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018900:Dinucleotide Repeats / Q000235:genetics*; D029721:Drosophila Proteins; D018506:Gene Expression Regulation, Plant; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D019751:Intramolecular Transferases / Q000096:biosynthesis / Q000235:genetics; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins; D030262:Soybean Proteins / Q000378:metabolism*; D013025:Glycine max / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D013559:Symbiosis; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D002352:Carrier Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D010750:Phosphoproteins; D010940:Plant Proteins; D030262:Soybean Proteins; D014157:Transcription Factors; C063460:Trl protein, Drosophila; C099131:gibberellin-binding phosphoprotein, plant; D019751:Intramolecular Transferases; C061049:glutamate-1-semialdehyde 2,1-aminomutase