634 / 2019-04-28 04:55:55

Chemical proteomic identification of PARP targets reveals a role for poly(ADP-ribosyl)ation in plant immunity

plant immuntiy,PARP,PARG,poly(ADP-ribosyl)ation,DNA damage

全体主题 > Biotic Stress

Poly(ADP-ribosyl)ation is a posttranslational modification catalyzed by poly(ADP-ribose) polymerase (PARP) using NAD+ as a substrate, and plays a key role in multiple cellular processes, including DNA damage repair, transcription, translation, and cell death. This posttranslational modification is reversible and the covalently attached poly(ADP-ribose) can be cleaved from target proteins by poly(ADP-ribose) glycohydrolases (PARGs). The Arabidopsis genome encodes three PARPs and two PARGs proteins. A number of approaches have been developed to identify the targets of poly(ADP-ribosyl)ation, however, these techniques lack specificity for individual PARP family members. Here we adapted a robust NAD+ analog-sensitive approach to identify PARP-specific substrates that is suitable for subsequent copper-catalyzed azid-alkyne cycloaddition reaction. Using this approach, we identified a PARP target, GIP1, which can also physically interact with PARP1/2 and PARG1/2. Intriguingly, flg22 promotes these interactions and also enhances poly(ADP-ribosyl)ation of GIP1. Moreover, the gip1 mutant exhibited enhanced susceptibility to bacterial pathogens and is defective in systemic acquired resistance, suggesting that poly(ADP-risobyl)ation plays an important role in plant immunity. Our data suggested that this analog-sensitive approach has the potential to illuminate the poly(ADP-ribosyl)ated proteome and the molecular mechanisms used by individual PARPs to modulate diverse cellular processes.