JAZ repressor proteins are targets of the SCF(COI1) complex during jasmonate signalling.
Jasmonate and related signalling compounds have a crucial role in both host immunity and development in plants, but the molecular details of the signalling mechanism are poorly understood. Here we identify members of the jasmonate ZIM-domain (JAZ) protein family as key regulators of jasmonate signalling. JAZ1 protein acts to repress transcription of jasmonate-responsive genes. Jasmonate treatment causes JAZ1 degradation and this degradation is dependent on activities of the SCF(COI1) ubiquitin ligase and the 26S proteasome. Furthermore, the jasmonoyl-isoleucine (JA-Ile) conjugate, but not other jasmonate-derivatives such as jasmonate, 12-oxo-phytodienoic acid, or methyl-jasmonate, promotes physical interaction between COI1 and JAZ1 proteins in the absence of other plant proteins. Our results suggest a model in which jasmonate ligands promote the binding of the SCF(COI1) ubiquitin ligase to and subsequent degradation of the JAZ1 repressor protein, and implicate the SCF(COI1)-JAZ1 protein complex as a site of perception of the plant hormone JA-Ile.
Thines
Bryan
B
Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164-6340, USA.
Katsir
Leron
L
Melotto
Maeli
M
Niu
Yajie
Y
Mandaokar
Ajin
A
Liu
Guanghui
G
Nomura
Kinya
K
He
Sheng Yang
SY
Howe
Gregg A
GA
Browse
John
J
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002474:Cell-Free System; D003517:Cyclopentanes / Q000494:pharmacology*; D017343:Genes, Plant / Q000235:genetics; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D007532:Isoleucine / Q000031:analogs & derivatives* / Q000494:pharmacology; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D054883:Oxylipins; D010641:Phenotype; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D044843:SKP Cullin F-Box Protein Ligases / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D013379:Substrate Specificity
D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D054883:Oxylipins; D012097:Repressor Proteins; C532883:jasmonoyl-isoleucine; D007532:Isoleucine; C011006:jasmonic acid; D044843:SKP Cullin F-Box Protein Ligases; D005966:Glucuronidase