Chemical Reporter for Malonylated Proteins

Protein lysine malonylation is a newly identified posttranslational modification (PTM), but its cellular functions and regulatory mechanisms remain largely unknown. To facilitate the study on this new PTM, we have developed a chemical probe (MalAM-yne) for detection and identification of alonylated proteins. Here we demonstrate that this alkynefunctionalized chemical probe can be metabolically incorporated into protein substrates of malonylation. The subsequent bioorthogonal conjugation with azide-fluorescent dyes or affinity purification tags enables the robust in-gel fluorescence visualization of malonylation dynamics and rapid profiling of malonylated proteins. We also used this probe to examine protein malonylation patterns in different types of cells ranging from bacteria to various human cells. Our finding indicates that protein lysine malonylation is a dynamic, abundant and
evolutionarily conserved posttranslational modification.