Chemical genetics and proteome-wide site mapping reveal cysteine MARylation by PARP-7 on immune-relevant protein targets

ABSTRACT: Poly (ADP-ribose) polymerase 7 (PARP-7) has emerged as a critically important member of a large enzyme family that catalyze ADP-ribosylation in mammalian cells. PARP-7 is a critical regulator of the innate immune response. What remains unclear is the mechanism by which PARP-7 regulates this process, namely because the protein targets of PARP-7 mono-ADP-ribosylation (MARylation) are largely unknown. Here, we combine chemical genetics, proximity labeling, and proteome-wide amino acid ADP- ribosylation site profiling for identifying the direct targets and sites of PARP-7-mediated MARylation in a cellular context. We found that the inactive PARP family member, PARP13 (a critical regulator of the antiviral innate immune response) is a major target of PARP-7. PARP-13 is preferentially MARylated on cysteine residues in its RNA binding zinc finger domain. Proteome-wide ADP-ribosylation analysis reveals cysteine as a major MARylation acceptor of PARP-7. This study provides insight into PARP-7 targeting and MARylation site preference.

INSTRUMENT(S): Orbitrap Fusion

ORGANISM(S): Homo Sapiens (human)

SUBMITTER: Phillip Wilmarth  

LAB HEAD: Dr. Michael S. Cohen

PROVIDER: PXD020323 | Pride | 2021-07-21

REPOSITORIES: Pride