@Article{IPB-2565, author = {Jung, J.-Y. and Ried, M. K. and Hothorn, M. and Poirier, Y.}, title = {{Control of plant phosphate homeostasis by inositol pyrophosphates and the SPX domain}}, year = {2018}, pages = {156-162}, journal = {Curr Opin Biotech}, doi = {10.1016/j.copbio.2017.08.012}, url = {https://dx.doi.org/10.1016/j.copbio.2017.08.012}, volume = {49}, abstract = {Proteins containing a SPX domain are involved in phosphate (Pi) homeostasis, including Pi transport and adaptation to Pi deficiency. The SPX domain harbors a basic surface binding Pi at low affinity and inositol pyrophosphates (PP-InsPs) at high affinity. Genetic and biochemical studies revealed that PP-InsPs serve as ligands for the SPX domain. Residues in the PHO1 SPX domain involved in PP-InsPs binding are critical for its Pi export activity, and the interaction between SPX proteins and the PHR1 transcription factor, which results in PHR1 inactivation, is promoted by PP-InsPs. Changes in PP-InsPs levels in response to Pi deficiency may thus contribute to the adaptation of plants to stress via the modulation of the activity of SPX-containing proteins and their interactors. Modulating PP-InsP levels or the affinity/specificity of the SPX domain for PP-InsP could potentially be used to engineer crops to maintain high yield under reduced Pi fertilizer input.} }