Proteome-wide microarray-based screening of PAR-binding proteins

Poly (ADP-ribose) (PAR) plays a crucial role in intracellular signaling and scaffolding through covalent modification or non-covalent binding to target proteins. The non-covalent PAR binding proteome (PARylome) has not been extensively characterized. Here, we performed a PAR-binding screen using a human protein microarray that covers most of the human proteome to characterize the non-covalent binding PARylome. A total of 356 PAR-binding proteins were identified. The PAR-binding PARylome suggests that PAR binding regulates a variety of biological processes beyond DNA damage signaling and DNA repair. Proteins that may be reprogrammed by PAR binding include signaling molecules, transcription factors, nucleic acid-binding proteins, calcium-binding proteins, ligases, oxidoreductases, enzymes, transferases, hydrolases, and receptors. The global database of PAR-binding proteins that we established will be a valuable tool for further in-depth analysis of the role of PARylation in a wide range of biological contexts.