Cridland, Caitlin A.Gillaspy, Glenda E.2020-06-302020-06-302020-06-17Cridland, C.; Gillaspy, G. Inositol Pyrophosphate Pathways and Mechanisms: What Can We Learn from Plants?Molecules 2020, 25, 2789.http://hdl.handle.net/10919/99194The ability of an organism to maintain homeostasis in changing conditions is crucial for growth and survival. Eukaryotes have developed complex signaling pathways to adapt to a readily changing environment, including the inositol phosphate (InsP) signaling pathway. In plants and humans the pyrophosphorylated inositol molecules, inositol pyrophosphates (PP-InsPs), have been implicated in phosphate and energy sensing. PP-InsPs are synthesized from the phosphorylation of InsP₆, the most abundant InsP. The plant PP-InsP synthesis pathway is similar but distinct from that of the human, which may reflect differences in how molecules such as Ins(1,4,5)P₃ and InsP₆ function in plants vs. animals. In addition, PP-InsPs can potentially interact with several major signaling proteins in plants, suggesting PP-InsPs play unique signaling roles via binding to protein partners. In this review, we will compare the biosynthesis and role of PP-InsPs in animals and plants, focusing on three central themes: InsP₆ synthesis pathways, synthesis and regulation of the PP-InsPs, and function of a specific protein domain called the Syg1, Pho1, Xpr1 (SPX ) domain in binding PP-InsPs and regulating inorganic phosphate (P<i>i</i>) sensing. This review will provide novel insights into the biosynthetic pathway and bioactivity of these key signaling molecules in plant and human systems.application/pdfenCreative Commons Attribution 4.0 Internationalinositol phosphateinositol pyrophosphateinositolinositol phosphate signalingPPIP5KITPKArticle - Refereed2020-06-30https://doi.org/10.3390/molecules25122789