Abstract
We show here that the EAR-motif repression domain (SRDX) can covert a transcriptional complex into a repressor by transrepression activity through protein-protein interaction. We propose here that this transrepression activity can be used for detection of protein-protein interactions in plants. We demonstrated transrepression in combination of FOS and JUN, and PI and AP3, which are known to form a heterodimer, respectively, in our transient studies. Furthermore, we showed that transgenic Arabidopsis that expressed TTG1-SRDX, which is a WD40 protein and does not has DNA binding activity, resulted in the phenotype similar to ttg1 mutants possibly due to suppression of expression of genes that are regulated by protein complex including TTG1, as similar manner in the transient study. These results indicate that the transrepressive activity by SRDX can be used to detect and confirm protein-protein interaction in plants.
