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.