Arabidopsis BRUTUS-LIKE E3 ligases negatively regulate iron uptake by targeting transcription factor FIT for recycling

Jorge Rodríguez-Celma, James M. Connorton, Inga Kruse, Robert T. Green, Marina Franceschetti, Yi-Tze Chen, Yan Cui, Hong-Qing Ling, Kuo-Chen Yeh, Janneke Balk

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Organisms need to balance sufficient uptake of iron (Fe) with possible toxicity. In plant roots, a regulon of uptake genes is transcriptionally activated under Fe deficiency, but it is unknown how this response is inactivated when Fe becomes available. Here we describe the function of 2 partially redundant E3 ubiquitin ligases, BRUTUS-LIKE1 (BTSL1) and BTSL2, in Arabidopsis thaliana and provide evidence that they target the transcription factor FIT, a key regulator of Fe uptake, for degradation. The btsl double mutant failed to effectively down-regulate the transcription of genes controlled by FIT, and accumulated toxic levels of Fe in roots and leaves. The C-terminal domains of BTSL1 and BTSL2 exhibited E3 ligase activity, and interacted with FIT but not its dimeric partner bHLH39. The BTSL proteins were able to poly-ubiquitinate FIT in vitro and promote FIT degradation in vivo. Thus, posttranslational control of FIT is critical to prevent excess Fe uptake.

LanguageEnglish
Pages17584-17591
Number of pages8
JournalProceedings of the National Academy of Sciences of the United States of America
Volume116
Issue number35
Early online date14 Aug 2019
DOIs
Publication statusPublished - 27 Aug 2019

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Ubiquitin-Protein Ligases
Recycling
Arabidopsis
Transcription Factors
Iron
Regulon
Plant Roots
Poisons
Genes
Down-Regulation
Proteins
In Vitro Techniques

Keywords

  • BHLH transcription factor
  • dicotyledon
  • iron
  • micronutrient
  • ubiquitin

Cite this

Rodríguez-Celma, Jorge ; Connorton, James M. ; Kruse, Inga ; Green, Robert T. ; Franceschetti, Marina ; Chen, Yi-Tze ; Cui, Yan ; Ling, Hong-Qing ; Yeh, Kuo-Chen ; Balk, Janneke. / Arabidopsis BRUTUS-LIKE E3 ligases negatively regulate iron uptake by targeting transcription factor FIT for recycling. In: Proceedings of the National Academy of Sciences of the United States of America. 2019 ; Vol. 116, No. 35. pp. 17584-17591.
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Arabidopsis BRUTUS-LIKE E3 ligases negatively regulate iron uptake by targeting transcription factor FIT for recycling. / Rodríguez-Celma, Jorge; Connorton, James M.; Kruse, Inga; Green, Robert T.; Franceschetti, Marina; Chen, Yi-Tze; Cui, Yan; Ling, Hong-Qing; Yeh, Kuo-Chen; Balk, Janneke.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 116, No. 35, 27.08.2019, p. 17584-17591.

Research output: Contribution to journalArticle

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AU - Rodríguez-Celma, Jorge

AU - Connorton, James M.

AU - Kruse, Inga

AU - Green, Robert T.

AU - Franceschetti, Marina

AU - Chen, Yi-Tze

AU - Cui, Yan

AU - Ling, Hong-Qing

AU - Yeh, Kuo-Chen

AU - Balk, Janneke

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