Jasmonate perception by inositol-phosphate-potentiated COI1.pdfVIP

ARTICLE doi:10.1038/nature09430 Jasmonate perception by inositol-phosphate-potentiated COI1–JAZ co-receptor 1 1 1 2,3 4 1 5 Laura B. Sheard *, Xu Tan *{, Haibin Mao *, John Withers , Gili Ben-Nissan , Thomas R. Hinds , Yuichi Kobayashi , Fong-Fu Hsu6 4 7 2,3 8 2,9 1,10 , Michal Sharon , John Browse , Sheng Yang He , Josep Rizo , Gregg A. Howe Ning Zheng Jasmonates are a family of plant hormones that regulate plant growth, development and responses to stress. The F-box protein CORONATINE INSENSITIVE 1 (COI1) mediates jasmonate signalling by promoting hormone-dependent ubiquitylation and degradation of transcriptional repressor JAZ proteins. Despite its importance, the mechanism of jasmonate perception remains unclear. Here we present structural and pharmacological data to show that the true Arabidopsis jasmonate receptor is a complex of both COI1 and JAZ. COI1 contains an open pocket that recognizes the bioactive hormone (3R,7S)-jasmonoyl-L -isoleucine (JA-Ile) with high specificity. High-affinity hormone binding requires a bipartite JAZ degron sequence consisting of a conserved a-helix for COI1 docking and a loop region to trap the hormone in its binding pocket. In addition, we identify a third critical component of the jasmonate co-receptor complex, inositol pentakisphosphate, which interacts with both COI1 and JAZ adjacent to the ligand. Our results unravel the mechanism of jasmonate perception and highlight