JPOST Repositoryapplication/xmlhttps://storage.jpostdb.org/JPST003145/files/L1_20230825_AR_02_185_cytoMg_IP8_rep2.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_001_nuclMg_InsP6_rep2.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_001_nuclMg_IP8_rep3.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_001_nuclMg_1IP7_rep1.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_002_nuclEDTA_1IP7_rep1.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_001_nuclMg_1IP7_rep2.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_001_nuclMg_IP8_rep1.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_002_nuclEDTA_1IP7_rep3.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_001_nuclMg_5IP7_rep1.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_001_nuclMg_InsP6_rep3.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230825_AR_02_185_cytoMg_IP8_rep1.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230825_AR_02_185_cytoMg_IP8_rep3.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_001_nuclMg_5IP7_rep3.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_001_nuclMg_IP8_rep2.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_002_nuclEDTA_5IP7_rep1.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_001_nuclMg_5IP7_rep2.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_002_nuclEDTA_1IP7_rep2.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_001_nuclMg_1IP7_rep3.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_002_nuclEDTA_5IP7_rep1_rerun.rawhttps://storage.jpostdb.org/JPST003145/files/L1_20230901_AR_03_001_nuclMg_InsP6_rep1.rawprimaryOK200ProteomicsDorothea FiedlerHomo Sapiens (human)https://repository.jpostdb.org/entry/JPST003145Leibniz FMPjPOSTfalseProteome-wide quantification of inositol pyrophosphate-protein interactionsInositol polyphosphates (InsPs) and inositol pyrophosphates (PP-InsPs) constitute a group of highly phosphorylated molecules that are involved in many cellular signaling processes. To characterize discrete signaling events of these structurally closely related molecules, a mass spectrometry approach was developed to derive apparent binding constants for these ligands on a proteome-wide scale. The method employed a series of chemically synthesized, biotinylated affinity reagents for inositol hexakisphosphate (InsP6), and the inositol pyrophosphates 1PP-InsP5, 5PP-InsP5 and 1,5(PP)2-InsP4 (also termed InsP8). Application of these affinity reagents at different concentrations, in combination with tandem mass tag (TMT) labeling, provided binding data for thousands of proteins from a mammalian cell lysate. Investigation of different enrichment conditions, where Mg2+ ions were either available or not, showcased a strong influence of Mg2+ on the protein binding capacities of PP-InsPs. Gene ontology analysis closely linked PP-InsPs-interacting proteins to transcriptional processes in the nucleus. Subsequent data analysis enabled a targeted search for protein pyrophosphorylation among PP-InsP interactors, and identified four new targets . The data presented here constitute a valuable resource for the community, and application of the method reported here to other biological contexts will enable the exploration of PP-InsP dependent signaling pathways across species. Mon Apr 27 00:00:00 BST 2026PXD0526829606