Repressor of jasmonate (JA) responses. Targets MYC2, MYC3 and MYC4 that are JA-dependent transcription activators. Interacts with MYC2, MYB21, MYB24, AFPH2/NINJA, TIFY10A/JAZ1, TIFY10B/JAZ2, TIFY6B/JAZ3, TIFY6A/JAZ4, TIFY7/JAZ9 and TIFY9/JAZ10. A number of isoforms are produced. According to EST sequences. Up-regulated by wounding and herbivory. The jas domains (101-120) and (197-222) are required for interaction with COI1. Ubiquitinated. Targeted for degradation by the SCF(COI1) E3 ubiquitin ligase-proteasome pathway during jasmonate signaling. Belongs to the TIFY/JAZ family.