Ried, M.K.; Wild, R.; Zhu, J.; Pipercevic, J.; Sturm, K. et al.: Inositol pyrophosphates promote the interaction of SPX domains with the coiled-coil motif of PHR transcription factors to regulate plant phosphate homeostasis. In: Nature Communications 12 (2021), Nr. 1, 384. DOI:
https://doi.org/10.1038/s41467-020-20681-4
| Abstract: |
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Phosphorus is an essential nutrient taken up by organisms in the form of inorganic phosphate (Pi). Eukaryotes have evolved sophisticated Pi sensing and signaling cascades, enabling them to stably maintain cellular Pi concentrations. Pi homeostasis is regulated by inositol pyrophosphate signaling molecules (PP-InsPs), which are sensed by SPX domain-containing proteins. In plants, PP-InsP-bound SPX receptors inactivate Myb coiled-coil (MYB-CC) Pi starvation response transcription factors (PHRs) by an unknown mechanism. Here we report that a InsP8–SPX complex targets the plant-unique CC domain of PHRs. Crystal structures of the CC domain reveal an unusual four-stranded anti-parallel arrangement. Interface mutations in the CC domain yield monomeric PHR1, which is no longer able to bind DNA with high affinity. Mutation of conserved basic residues located at the surface of the CC domain disrupt interaction with the SPX receptor in vitro and in planta, resulting in constitutive Pi starvation responses. Together, our findings suggest that InsP8 regulates plant Pi homeostasis by controlling the oligomeric state and hence the promoter binding capability of PHRs via their SPX receptors.
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| License of this version: |
CC BY 4.0 Unported - https://creativecommons.org/licenses/by/4.0/
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| Publication type: |
Article |
| Publishing status: |
publishedVersion |
| Publication date: |
2021 |
| Keywords english: |
binding protein, brassinosteroid, brassinosteroid receptor kinase bri1, inhibitor protein, inhibitor protein bki1, inositol phosphate, inositol pyrophosphate, Pi starvation response transcription factor, plant protein, receptor, spx domain containing protein, transcription factor, unclassified drug, Arabidopsis protein, inositol phosphate, nuclear protein, PHR1 protein, Arabidopsis, protein binding, pyrophosphoric acid derivative, recombinant protein, SPX1 protein, Arabidopsis, transcription factor, concentration (composition), DNA, eukaryote, homeostasis, inorganic phosphorus, mutation, phosphate, protein, starvation, Agrobacterium tumefaciens, Arabidopsis thaliana, Chaetomium thermophilum, comparative study, complex formation, controlled study, crystal structure, dimerization, dissociation constant, DNA binding, gene expression, gene interaction, gene mutation, gene rearrangement, in vitro study, isothermal titration calorimetry, metabolic regulation, molecular cloning, nonhuman, nuclear magnetic resonance spectroscopy, oligomerization, phosphate metabolism, point mutation, promoter region, protein domain, protein expression, protein motif, protein protein interaction, protein structure, quantitative analysis, seedling, site directed mutagenesis, starvation, stoichiometry, tetramerization, Arabidopsis, gene expression regulation, genetics, isolation and purification, metabolism, mutation, physiology, protein domain, protein motif, signal transduction, ultrastructure, X ray crystallography, Eukaryota, Amino Acid Motifs, Arabidopsis, Arabidopsis Proteins, Crystallography, X-Ray, Diphosphates, Gene Expression Regulation, Plant, Inositol Phosphates, Mutation, Nuclear Proteins, Protein Binding, Protein Domains, Recombinant Proteins, Signal Transduction, Transcription Factors
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| DDC: |
500 | Naturwissenschaften
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