This enzyme, a mono-ADP-ribosyltransferase, plays a vital role in DNA damage response by catalyzing mono-ADP-ribosylation on specific residues—glutamate, aspartate, or lysine—of target proteins. Unlike PARP1 and PARP2, it exclusively mediates mono-ADP-ribosylation, targeting key proteins involved in DNA repair and chromatin structure, including histone H2B, XRCC5, and XRCC6. Following DNA damage, this modification initiates a critical detection and signaling pathway to facilitate DNA repair, specifically by catalyzing mono-ADP-ribosylation at nicked DNA sites within nucleosomes. Through cooperation with the XRCC5-XRCC6 (Ku80-Ku70) complex, the enzyme limits DNA end resection, enhancing the fidelity of non-homologous end-joining (NHEJ).
Additionally, it prevents the formation of G-quadruplex structures under DNA damage conditions and interacts with multiple DNA repair factors to support the cellular response to DNA strand breaks. In partnership with APLF, it aids in retaining the LIG4-XRCC4 complex on chromatin, accelerating DNA ligation during NHEJ. This enzyme may also link DNA damage response to mitotic checkpoint fidelity and acts as a negative regulator of immunoglobulin class switch recombination by controlling AICDA/AID levels on chromatin.
Notably, it also has the unique ability to ADP-ribosylate DNA itself, adding a single ADP-ribose unit to the 5′ or 3′ terminal phosphate of DNA strand break termini, particularly in DNA with multiple strand breaks. This function underscores its integral role in the DNA damage surveillance and repair network.
| Product Name | Recombinant Human PARP3 Protein (His & GST Tag) |
| Accession | Q9Y6F1 |
| Host Species | Human |
| Gene | PARP3 |
| Source | Baculovirus insect cells |
