CUL3BPM E3 ubiquitin ligases regulate MYC2, MYC3, and MYC4 stability and JA responses

The jasmonate (JA)-pathway regulators MYC2, MYC3, and MYC4 are central nodes in plant signaling networks integrating environmental and developmental signals to fine-tune JA defenses and plant growth. Continuous activation of MYC activity is potentially lethal. Hence, MYCs need to be tightly regulate...

Full description

Saved in:
Bibliographic Details
Published in:Proceedings of the National Academy of Sciences - PNAS 2020-03, Vol.117 (11), p.6205-6215
Main Authors: Chico, Jose Manuel, Lechner, Esther, Fernandez-Barbero, Gemma, Canibano, Esther, García-Casado, Gloria, Franco-Zorrilla, Jose Manuel, Hammann, Philippe, Zamarreño, Angel M., García-Mina, Jose M., Rubio, Vicente, Genschik, Pascal, Solano, Roberto
Format: Article
Language:English
Subjects:
Adapters
Adaptor proteins
Biological Sciences
Gene expression
Jasmonic acid
Mutants
Myc protein
Negative feedback
Plant growth
Proteins
Regulators
Regulatory mechanisms (biology)
Stability
Substrates
Transcription factors
Ubiquitin
Ubiquitin-protein ligase
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The jasmonate (JA)-pathway regulators MYC2, MYC3, and MYC4 are central nodes in plant signaling networks integrating environmental and developmental signals to fine-tune JA defenses and plant growth. Continuous activation of MYC activity is potentially lethal. Hence, MYCs need to be tightly regulated in order to optimize plant fitness. Among the increasing number of mechanisms regulating MYC activity, protein stability is arising as a major player. However, how the levels of MYC proteins are modulated is still poorly understood. Here, we report that MYC2, MYC3, and MYC4 are targets of BPM(BTB/POZ-MATH) proteins, which act as substrate adaptors of CUL3-based E3 ubiquitin ligases. Reduction of function of CUL3BPM in amiR-bpm lines, bpm235 triple mutants, and cul3ab double mutants enhances MYC2 and MYC3 stability and accumulation and potentiates plant responses to JA such as root-growth inhibition and MYC-regulated gene expression. Moreover, MYC3 polyubiquitination levels are reduced in amiR-bpm lines. BPM3 protein is stabilized by JA, suggesting a negative feedback regulatory mechanism to control MYC activity, avoiding harmful runaway responses. Our results uncover a layer for JA-pathway regulation by CUL3BPM-mediated degradation of MYC transcription factors.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.1912199117