The study investigates the mechanism of jasmonate (JA) perception in plants, focusing on the role of the COI1 protein and the JAZ transcriptional repressors. The authors present structural and pharmacological data to show that the true JA receptor is a complex of COI1 and JAZ proteins. COI1 contains a specific binding pocket that recognizes the bioactive hormone, (3R,7S)-jasmonoyl-L-isoleucine (JA-Ile), with high specificity. The high-affinity hormone binding requires a bipartite JAZ degron sequence, which consists of a conserved α-helix for COI1 docking and a loop region to trap the hormone in its binding pocket. Additionally, the study identifies inositol pentakisphosphate (InsP5) as a critical third component of the JA co-receptor complex, interacting with both COI1 and JAZ proteins. The results provide insights into the mechanism of JA perception and highlight the ability of F-box proteins to evolve as multi-component signaling hubs.The study investigates the mechanism of jasmonate (JA) perception in plants, focusing on the role of the COI1 protein and the JAZ transcriptional repressors. The authors present structural and pharmacological data to show that the true JA receptor is a complex of COI1 and JAZ proteins. COI1 contains a specific binding pocket that recognizes the bioactive hormone, (3R,7S)-jasmonoyl-L-isoleucine (JA-Ile), with high specificity. The high-affinity hormone binding requires a bipartite JAZ degron sequence, which consists of a conserved α-helix for COI1 docking and a loop region to trap the hormone in its binding pocket. Additionally, the study identifies inositol pentakisphosphate (InsP5) as a critical third component of the JA co-receptor complex, interacting with both COI1 and JAZ proteins. The results provide insights into the mechanism of JA perception and highlight the ability of F-box proteins to evolve as multi-component signaling hubs.