Noncovalent pADPr Interaction with Proteins and Competition with RNA for Binding to Proteins

PARP1 can modify a variety of proteins through conserved domains in noncovalent manner. Since poly(ADP-ribose) is highly negatively charged and has a strong binding affinity for its target proteins, noncovalent binding by poly(ADP-ribose) modulates the protein activity during developmental processes. In this section, the methods including co-immunoprecipitation and dot-blot assay were illustrated for determining the specific interaction between poly(ADP-ribose) and proteins. Furthermore, the protocol for RNA EMSA was described to determine whether pADPr binding to hnRNPs can inhibit RNA-binding ability of human hnRNP A1.