Poly(ADP-ribose) Glycohydrolase (PARG) (多聚ADP核糖水解酶)

Poly (ADP-ribose) glycohydrolase (PARG) is the primary hydrolase involved in the degradation of poly(ADP-ribose) (PAR). PARG possesses both endo-glycohydrolase and exo-glycohydrolase activity, preferentially performing the latter by binding to the two most distal ADP-ribose residues within the PAR chain. These different modes of catalysis produce free PAR and mono ADP-ribose moieties, respectively. The free mono ADP-ribose is then metabolized into AMP and ribose 5′ phosphate by ADP-ribose pyrophosphohydrolases such as the NUDIX family. AMP is utilized in ATP reformation and different metabolic and cell signaling pathways while ribose 5′ phosphate is a precursor to many biomolecules including DNA, RNA and ATP. Endo-glycohydrolase activity is considered to occur primarily during hyper-PARP activation, the resulting free PAR chains produced are then implicated in apoptosis acting as a death signal.