Inositol pyrophosphates promote the interaction of SPX domains with the coiled-coil motif of PHR transcription factors to regulate plant phosphate homeostasis

Article Article scientifique Article Inositol pyrophosphates promote the interaction of SPX domains with the coiled-coil motif of PHR transcription factors to regulate plant phosphate homeostasis eng 2021 author Ried Martina 868007 author Wild Rebekka 824346 author Zhu Jinsheng 841635 author Pipercevic Joka author Sturm Kristina 938444 author Broger Larissa 95643 author Harmel Robert K author Abriata Luciano A author Hothorn Ludwig A author Fiedler Dorothea author Hiller Sebastian author Hothorn Michael 826130 10.1038/s41467-020-20681-4 2041-1723 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. Amino Acid Motifs Arabidopsis/physiology Arabidopsis Proteins/genetics/isolation & purification/metabolism/ultrastructure Crystallography X-Ray Diphosphates/metabolism Gene Expression Regulation Plant Inositol Phosphates/metabolism Mutation Nuclear Proteins/genetics/metabolism Protein Binding/genetics Protein Domains/genetics Recombinant Proteins/genetics/isolation & purification/metabolism/ultrastructure Signal Transduction/genetics Transcription Factors/genetics/isolation & purification/metabolism/ultrastructure Dewey 580 Swiss National Science Foundation Discovery and mechanistic dissection of novel signaling pathways controlling phosphate homeostasis in eukaryotes CRSII5_170925 CH Programmes European Commission CoG 818696 - INSPIRE EU H2020 45 Département des sciences végétales 163 false Nature Communications 12 384 dd43bed6-5b13-45a7-afe7-fe111dc4e05d Article (Published version) Public s41467-020-20681-4.pdf 3242453 application/pdf CC BY openAccess Faculté des sciences / Section de biologie / Département des sciences végétales

Title	Published in	Year	Views	Downloads

Inositol pyrophosphates promote the interaction of SPX domains with the coiled-coil motif of PHR transcription factors to regulate plant phosphate homeostasis	Nature Communications	2021	357	325
Control of plant phosphate homeostasis by inositol pyrophosphates and the SPX domain	Current Opinion in Biotechnology	2018	548	2

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Ried, Martina