Hemerythrin E3 Ubiquitin Ligases as Negative Regulators of Iron Homeostasis in Plants

Autor: Jorge Rodríguez-Celma, Hsuan Chou, Takanori Kobayashi, Terri A. Long, Janneke Balk
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Frontiers in Plant Science, Vol 10 (2019)
Druh dokumentu: article
ISSN: 1664-462X
DOI: 10.3389/fpls.2019.00098
Popis: Iron (Fe) is an essential nutrient for plants, but at the same time its redox properties can make it a dangerous toxin inside living cells. Homeostasis between uptake, use and storage of Fe must be maintained at all times. A small family of unique hemerythrin E3 ubiquitin ligases found in green algae and plants play an important role in avoiding toxic Fe overload, acting as negative regulators of Fe homeostasis. Protein interaction data showed that they target specific transcription factors for degradation by the 26S proteasome. It is thought that the activity of the E3 ubiquitin ligases is controlled by Fe binding to the N-terminal hemerythrin motifs. Here, we discuss what we have learned so far from studies on the HRZ (Hemerythrin RING Zinc finger) proteins in rice, the homologous BTS (BRUTUS) and root-specific BTSL (BRUTUS-LIKE) in Arabidopsis. A mechanistic model is proposed to help focus future research questions towards a full understanding of the regulatory role of these proteins in Fe homeostasis in plants.
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