Comprehensive analysis of protein interactions between JAZ proteins and BHLH transcription factors that negatively regulate jasmonate signaling

Abstract

Jasmonates have crucial roles in plant responses to biotic and abiotic stresses. Given the importance of transcriptional regulation in jasmonate-mediated stress responses, transcription factors are key regulators of jasmonate signaling. The transcription factors JASMONATE-ASSOCIATED MYC2-LIKE 1 (JAM1), JAM2, and JAM3 are negative regulators of jasmonate signaling, although the mechanisms that control the activities of these transcription factors remain unclear. To understand the regulatory mechanisms of JAMproteins, we used a yeast two-hybrid assay to screen for protein interaction partners of JAM1 and found that JAM1 interacted with JAZ proteins. As JAZ proteins interact with MYC2 and suppresses its transcriptional activity, we performed comprehensive interaction analysis between JAM1 through JAM3 and JAZ1 through JAZ12. We showed that JAM1 and JAM2 interacted with several of the JAZ proteins analyzed here. In contrast, JAM3 interacted with none of the tested JAZ proteins. These results suggest that JAZ proteins regulate JAM1 and JAM2 through protein-protein interactions in a manner similar to the repressive effects of JAZ proteins on the transcriptional activity of MYC2. © 2014 Landes Bioscience.