CUL3 E3 ubiquitin ligases regulate MYC2, MYC3, and MYC4 stability and JA responses.
Fiche publication
Date publication
mars 2020
Journal
Proceedings of the National Academy of Sciences of the United States of America
Auteurs
Membres identifiés du Cancéropôle Est :
Mr HAMMANN Philippe
Tous les auteurs :
Chico JM, Lechner E, Fernandez-Barbero G, Canibano E, García-Casado G, Franco-Zorrilla JM, Hammann P, Zamarreño AM, García-Mina JM, Rubio V, Genschik P, Solano R
Lien Pubmed
Résumé
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 CUL3 in lines, triple mutants, and 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 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 CUL3-mediated degradation of MYC transcription factors.
Mots clés
Cullin ring ligases, MYC2, jasmonate signaling, phytohormone, proteasome
Référence
Proc. Natl. Acad. Sci. U.S.A.. 2020 Mar 2;: