title: Tannins elevate the level of poly(ADP-ribose) in HeLa cell extracts.
abstract: Phenolic phytochemicals such as tannins, which are natural constituents of green tea, red wine, and other plant products, are considered to have cancer-preventive properties. An important endogenous mediator of tumorigenesis is the nuclear enzyme poly(ADP-ribose) polymerase 1 (PARP-1). PARP-1 synthesizes polymers of ADP-ribose (PAR), which, in turn, are degraded by the catabolic enzyme poly(ADP-ribose) glycohydrolase (PARG). In the present study, we investigated the effects of tannins on the level of PAR in HeLa nuclear extracts. The addition of tannins to nuclear extracts led to a 40-fold elevation of PAR-levels. The observed increased PAR-levels resulted from inhibition of the catalytic activity of PARG. Additionally, the human PARG cDNA was cloned and the recombinant enzyme was overexpressed and isolated. Recombinant PARG was immobilized using an affinity column composed of tannins covalently linked to Sepharose beads. Finally, an interaction between immobilized PARG and endogenous PARP-1 from HeLa cell extracts is demonstrated.
authors.affiliation: Institut für Biochemie, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Keil
authors.forename: Eva
authors.initials: E
authors.lastname: Petermann
authors.forename: Shiao Li
authors.initials: SL
authors.lastname: Oei
mesh_terms: D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D006026:Glycoside Hydrolases / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D047348:Hydrolyzable Tannins / Q000494:pharmacology*; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism*; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism
chemical_list: D047348:Hydrolyzable Tannins; D011064:Poly Adenosine Diphosphate Ribose; D011065:Poly(ADP-ribose) Polymerases; D006026:Glycoside Hydrolases; C022407:poly ADP-ribose glycohydrolase