Structural basis of JAZ repression of MYC transcription factors in jasmonate signalling.

Zhang, Feng

Yao, Jian

Ke, Jiyuan

Zhang, Li

Lam, Vinh Q

Xin, Xiu-Fang

Zhou, X Edward

Chen, Jian

Brunzelle, Joseph

Griffin, Patrick R

Zhou, Mingguo

Xu, H Eric

Melcher, Karsten

He, Sheng Yang

2020-11-25T23:00:31Z

2020-11-25T23:00:31Z

2015-09

2020-11-25T23:00:28Z

The plant hormone jasmonate plays crucial roles in regulating plant responses to herbivorous insects and microbial pathogens and is an important regulator of plant growth and development. Key mediators of jasmonate signalling include MYC transcription factors, which are repressed by jasmonate ZIM-domain (JAZ) transcriptional repressors in the resting state. In the presence of active jasmonate, JAZ proteins function as jasmonate co-receptors by forming a hormone-dependent complex with COI1, the F-box subunit of an SCF-type ubiquitin E3 ligase. The hormone-dependent formation of the COI1-JAZ co-receptor complex leads to ubiquitination and proteasome-dependent degradation of JAZ repressors and release of MYC proteins from transcriptional repression. The mechanism by which JAZ proteins repress MYC transcription factors and how JAZ proteins switch between the repressor function in the absence of hormone and the co-receptor function in the presence of hormone remain enigmatic. Here we show that Arabidopsis MYC3 undergoes pronounced conformational changes when bound to the conserved Jas motif of the JAZ9 repressor. The Jas motif, previously shown to bind to hormone as a partly unwound helix, forms a complete α-helix that displaces the amino (N)-terminal helix of MYC3 and becomes an integral part of the MYC N-terminal fold. In this position, the Jas helix competitively inhibits MYC3 interaction with the MED25 subunit of the transcriptional Mediator complex. Our structural and functional studies elucidate a dynamic molecular switch mechanism that governs the repression and activation of a major plant hormone pathway.

nature14661

0028-0836

1476-4687

https://hdl.handle.net/10161/21722

eng

Springer Science and Business Media LLC

Nature

10.1038/nature14661

Arabidopsis

Cyclopentanes

Proteasome Endopeptidase Complex

Plant Growth Regulators

Apoproteins

Trans-Activators

Nuclear Proteins

Arabidopsis Proteins

Repressor Proteins

Crystallography, X-Ray

Signal Transduction

Binding, Competitive

Amino Acid Motifs

Protein Conformation

Protein Binding

Models, Molecular

Ubiquitination

Oxylipins

Structural basis of JAZ repression of MYC transcription factors in jasmonate signalling.

Journal article

He, Sheng Yang|0000-0003-1308-498X

269

273

7568

Trinity College of Arts & Sciences

Biology

Duke

Published

525