Identification of a Soybean Protein That Interacts with GAGA Element Dinucleotide Repeat DNA

Abstract

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)nDNA. Soybean GBP was dissimilar from the GAGA factor ofDrosophila 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.

BASIC PENTACYSTEINE Proteins Mediate MADS Domain Complex Binding to the DNA for Tissue-Specific Expression of Target Genes in Arabidopsis

“…In fact, this GAGA binding protein was first described in soybean (Glycine max) (GAGA Binding Protein [GBP]; Sangwan and O'Brian, 2002) and subsequently also in barley (Hordeum vulgare) (B Recombinant barley [BBR]; Santi et al, 2003) and rice (Oryza sativa) (Meister et al, 2004). Conservation of their function in different plant species is further suggested by the observation that in the promoter of the STK ortholog in rice, MADS13 (Dreni et al, 2007), C-box sequences are also present.…”

Analyses of Expressed Sequence Tags from Apple

“…This could also account for why they are so common in transcribed sequences compared to other repeats. Factors that bind AG repeats in regulatory regions are known in both animals and plants (Epplen et al, 1996;Sangwan and O'Brian, 2002;Iglesias et al, 2004). Other potential ways SSRs affect regulation is by hypermethylation and/or secondary structure (Jacobsen et al, 2000).…”

The Arabidopsis GAGA-Binding Factor BASIC PENTACYSTEINE6 Recruits the POLYCOMB-REPRESSIVE COMPLEX1 Component LIKE HETEROCHROMATIN PROTEIN1 to GAGA DNA Motifs

“…Members of the plant-specific BARLEY B RECOM-BINANT (BBR)/BASIC PENTACYSTEINE (BPC) family have GAGA motif-binding properties and are involved in the control of homeotic genes (Sangwan and O'Brian, 2002;Santi et al, 2003;Kooiker et al, 2005;Brand et al, 2010;Berger et al, 2011;Simonini and Kater, 2014). Phylogenetic analysis disclosed three groups of plant BBR/BPC proteins and a high degree of conservation within these groups that is indicative of a strong positive selection throughout evolution (Meister et al, 2004;Lang et al, 2010;Wanke et al, 2011).…”