JAZ repressors set the rhythm in jasmonate signaling.
Jasmonates (JAs) are essential hormones for plant defense and development. In spite of their importance, the molecular details of their signaling pathways remain largely unknown. A new family of regulators of JA signaling named JAZ, jasmonate ZIM-domain proteins, has recently been described. JAZ proteins repress of JA signaling and are targeted by the E3-ubiquitin ligase SCF(COI1) for proteasome degradation in response to JA. Hormone binding depends on a functional COI1 protein suggesting that COI1 is the JA receptor. MYC2, a positive regulator of JA-dependent responses, has been identified as a target of JAZ repressors. Interestingly, MYC2 and JAZ proteins are involved in a negative regulatory feedback loop, suggesting a model to explain how transcriptional reprogramming is turned on and off in response to JA. The discovery of JAZ repressors provides a new framework to understand JA-signaling pathways from hormonal perception to transcriptional activation.
Chico
Jose M
JM
Departamento de Genética Molecular de Plantas, Centro Nacional de Biotecnología-CSIC, Campus Universidad Autónoma, 28049 Madrid, Spain.
Chini
Andrea
A
Fonseca
Sandra
S
Solano
Roberto
R
D020816:Amino Acid Motifs; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism*; D025461:Feedback, Physiological; D008954:Models, Biological; D005810:Multigene Family; D054883:Oxylipins / Q000378:metabolism*; D010802:Phylogeny; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D044843:SKP Cullin F-Box Protein Ligases / Q000378:metabolism / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*
D029681:Arabidopsis Proteins; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; C112279:COI1 protein, Arabidopsis; D003517:Cyclopentanes; C473611:MYC2 protein, Arabidopsis; D054883:Oxylipins; D012097:Repressor Proteins; C011006:jasmonic acid; D044843:SKP Cullin F-Box Protein Ligases; D046988:Proteasome Endopeptidase Complex