Figure 6. Identification of PARP-7-specific substrates using an NAD⁺ analog-sensitive PARP-7 approach.

(A) In-gel fluorescence of cytoplasmic extract from OVCAR4 cells conjugated to azido-TAMRA after labeling reactions with 8-Bu(3-yne)T-NAD⁺ in the presence of wild-type or S563G mutant PARP-7. Molecular weight markers in kDa are shown. Similar assays were performed with cytoplasmic extract from HeLa cells. The assay was performed twice in each cell line. (B) Venn diagram depicting the overlap of the protein substrates of PARP-7-mediated MARylation between OVCAR4 and HeLa cells identified using asPARP-7 and mass spectrometry. (C) Gene ontology terms enriched for the protein targets of PARP-7-mediated MARylation common between OVCAR4 and HeLa cells.