Screening and Identification of Proteins Interacting with ERF Transcription Factor W17 in Wheat

Abstract

Ethylene responsive factors (ERFs) regulate a variety of biotic- and abiotic-stress responses. Transcription factor W17 is an ERF isolated from wheat (Triticum aestivum L.), which participates in stress responses. To provide data for exploring the functional mechanism of ERF proteins, we constructed a wheat cDNA library and screened proteins interacting with W17 by yeast two-hybrid system. The mixture of recombinant plasmid pGBKT7-W77, pGADT7, and wheat cDNA library was introduced into yeast cell AH109. Transformed cells were incubated on SD/-Trp/-Leu/-His/-Ade plate for 3-5 d at 30°C before selection of clones with diameter larger than 2 mm, and further incubated on SD/Raf/Gal/X-gal for screening blue clones. Four types of proteins that interacted with W17 were obtained, namely stress-related functional protein, post-translational modification protein, ribulose-1,5-bisphosphate carboxylase/oxygenase, and unknown protein. The protein-protein interaction was retested using the co-transformation yeast system of pGBKT7-W17 and candidates of interaction protein carried by pGADT7. The result showed that HSP90 and PPR proteins interacted with W17 in vivo. Most of candidate proteins involved in signal transduction and immune process, such as Tir cytoskeleton coupling protein (TCCP), 26S proteasome subunit, RNA binding protein, WD40, PPR, HSP90, and cysteine proteinase inhibitor. This result suggests that W17 possibly plays significant roles in stress signal transduction, transcription regulation of downstream genes, and translation process in stress environments.