info:eu-repo/semantics/article
TcPARP: A DNA damage-dependent poly(ADP-ribose) polymerase from Trypanosoma cruzi
Fecha
2008-03Registro en:
Fernandez Villamil, Silvia Hebe; Baltanas, Rodrigo; Alonso, Guillermo Daniel; Vilchez Larrea, Salomé Catalina; Torres, Hector Norberto; et al.; TcPARP: A DNA damage-dependent poly(ADP-ribose) polymerase from Trypanosoma cruzi; Elsevier; International Journal for Parasitology; 38; 3-4; 3-2008; 277-287
0020-7519
CONICET Digital
CONICET
Autor
Fernandez Villamil, Silvia Hebe
Baltanas, Rodrigo
Alonso, Guillermo Daniel
Vilchez Larrea, Salomé Catalina
Torres, Hector Norberto
Flawia, Mirtha Maria
Resumen
Poly(ADP-ribose) polymerase (PARP) is a nuclear enzyme present in most eukaryotes and has been involved in processes such as DNA repair and gene expression. The poly(ADP-ribose) polymer (PAR) is mainly catabolised by poly(ADP-ribose) glycohydrolase. Here, we describe the cloning and characterisation of a PARP from Trypanosoma cruzi (TcPARP). The recombinant enzyme (Mr = 65) required DNA for catalytic activity and it was strongly enhanced by nicked DNA. Histones purified from T. cruzi increased TcPARP activity and the covalent attachment of [32P]ADP-ribose moieties to histones was demonstrated. TcPARP required no magnesium or any other metal ion cofactor for its activity. The enzyme was inhibited by 3-aminobenzamide, nicotinamide, theophylline and thymidine but not by menadione. We demonstrated an automodification reaction of TcPARP, and that the removal of attached PAR from this protein resulted in an increase of its activity. The enzyme was expressed in all parasite stages (amastigotes, epimastigotes and trypomastigotes). When T. cruzi epimastigotes were exposed to DNA-damaging agents such as hydrogen peroxide or β-lapachone, PAR drastically increased in the nucleus, thus confirming PAR synthesis in vivo and suggesting a physiological role for PARP in trypanosomatid DNA repair signalling.