The Role of PARPs in DNA Strand Break Repair

Abstract

ADP-ribosylation is a post-translational modification in which a target protein becomes modified with monomeric, short chains, or long branching chains of ADP-ribose (ADPR). The process can be carried out by a number of ADP-ribosyltransferases and polymerases (ADP-RTs and PARPs) and the consequences of ribosylation are as diverse and heterogeneous as the products that are formed. In mammalian cells, only three PARPs bind to DNA, and their activity is stimulated by DNA ends. A number of roles for these three PARPs have been characterised, including several functions in DNA repair. The known repertoire of ADPR-binding proteins is vastly expanding, meaning that ribosylation increases the rate and complexity of ways in which DNA is repaired by a number of different ways.

Non‐homologous end joining: Common interaction sites and exchange of multiple factors in the DNA repair process

“…The poly(ADP‐ribose) polymerases represent another class of DNA‐damage sensors. PARP1, 2 and 2 contain N‐terminal DNA‐binding domains and C‐terminal catalytic domains, which form post‐translational mono‐ or poly‐ADP‐ribose modifications (MAR and PAR, respectively) on target proteins following DNA damage (reviewed in ). ADP‐ribosylation can act as a recruitment signal for a number of DNA damage response factors, including Ku70, which has a PAR binding motif between its vWA and core domain and APLF, which contains a PAR‐binding zinc finger (PBZ) .…”