biostudies-literatureLu QChina Scholarship CouncilVlaams Instituut voor BiotechnologieFonds Wetenschappelijk OnderzoekAgentschap voor Innovatie door Wetenschap en Technologiee2118220119https://www.ebi.ac.uk/biostudies/studies/S-EPMC8931322biostudies-literatureUnknown119(11)SignificanceChemical genetics, which investigates biological processes using small molecules, is gaining interest in plant research. However, a major challenge is to uncover the mode of action of the small molecules. Here, we applied the cellular thermal shift assay coupled with mass spectrometry (CETSA MS) to intact <i>Arabidopsis</i> cells and showed that bikinin, the plant-specific glycogen synthase kinase 3 (GSK3) inhibitor, changed the thermal stability of some of its direct targets and putative GSK3-interacting proteins. In combination with phosphoproteomics, we also revealed that GSK3s phosphorylated the auxin carrier PIN-FORMED1 and regulated its polarity that is required for the vascular patterning in the leaf.Proceedings of the National Academy of Sciences of the United States of AmericaProteome-wide cellular thermal shift assay reveals unexpected cross-talk between brassinosteroid and auxin signaling.PMC8931322naG002121NG009018NMa QPauwels JHellner JDe Smet IDejonghe WFriml JGevaert KVan de Cotte BZhang YGiannini CMolina DMHan HImpens FRussinova EXu XLu QfalseProteome-wide cellular thermal shift assay reveals unexpected cross-talk between brassinosteroid and auxin signaling.SignificanceChemical genetics, which investigates biological processes using small molecules, is gaining interest in plant research. However, a major challenge is to uncover the mode of action of the small molecules. Here, we applied the cellular thermal shift assay coupled with mass spectrometry (CETSA MS) to intact <i>Arabidopsis</i> cells and showed that bikinin, the plant-specific glycogen synthase kinase 3 (GSK3) inhibitor, changed the thermal stability of some of its direct targets and putative GSK3-interacting proteins. In combination with phosphoproteomics, we also revealed that GSK3s phosphorylated the auxin carrier PIN-FORMED1 and regulated its polarity that is required for the vascular patterning in the leaf.2022-01-01T00:00:00Z2022 Mar2025-04-25T22:59:44.892Z2025-04-06T09:11:55.419ZS-EPMC89313223525491510.1073/pnas.2118220119