Zhao, YiHerrera, Pierre A. MirandaChang, DaluHamelin, RomainLong, Marcus J. C.Aye, Yimon2022-04-252022-04-252022-04-252022-02-0110.1073/pnas.2120687119https://infoscience.epfl.ch/handle/20.500.14299/187363WOS:000776483700009Enzyme-assisted posttranslational modifications (PTMs) constitute a major means of signaling across different cellular compartments. However, how nonenzymatic PTMs-despite their direct relevance to covalent drug development-impinge on crosscompartment signaling remains inaccessible as current targetidentification (target-ID) technologies offer limited spatiotemporal resolution, and proximity mapping tools are also not guided by specific, biologically-relevant, ligand chemotypes. Here we establish a quantitative and direct profiling platform (Localis-rex) that ranks responsivity of compartmentalized subproteomes to nonenzymatic PTMs. In a setup that contrasts nucleus- vs. cytoplasm-specific responsivity to reactive-metabolite modification (hydroxynonenylation), similar to 40% of the top-enriched protein sensors investigated respond in compartments of nonprimary origin or where the canonical activity of the protein sensor is inoperative. CDK9-a primarily nuclear-localized kinase-was hydroxy nonenylated only in the cytoplasm. Site-specific CDK9 hydroxynonenylation-which we identified in untreated cells-drives its nuclear translocation, downregulating RNA-polymerase-II activity, through a mechanism distinct from that of commonly used CDK9 inhibitors. Taken together, this work documents an unmet approach to quantitatively profile and decode localized and context-specific signaling/signal-propagation programs orchestrated by reactive covalent ligands.Multidisciplinary SciencesScience & Technology - Other Topicsreactive metabolitesfunction-guided proximity mappingelectrophile signalingcdk9/cyclin t1tyrannosaurus-rexcdk9targetredoxstressFunction-guided proximity mapping unveils electrophilic-metabolite sensing by proteins not present in their canonical localestext::journal::journal article::research article