The Involvement of ATP Produced via (ADP-Ribose)n in the Maintenance of DNA Replication Apparatus during DNA Repair

SummaryMutant pqr-216 from an Arabidopsis activation-tagged line showed a phenotype of increased tolerance to oxidative stress after treatment with 3 lM paraquat (PQ). Based on the phenotype of transgenic plants overexpressing the genes flanking the T-DNA insert, it was clear that enhanced expression of a Nudix (nucleoside diphosphates linked to some moiety X) hydrolase gene, AtNUDX2 (At5g47650), was responsible for the tolerance. It has been reported that the AtNUDX2 protein has pyrophosphatase activities towards both ADP-ribose and NADH (Ogawa et al., 2005). Interestingly, the pyrophosphatase activity toward ADP-ribose, but not NADH, was increased in pqr-216 and Pro 35S :AtNUDX2 plants compared with control plants. The amount of free ADP-ribose was lower in the Pro 35S :AtNUDX2 plants, while the level of NADH was similar to those in control plants under both normal conditions and oxidative stress. Depletion of NAD + and ATP resulting from activation of poly(ADP-ribosyl)ation under oxidative stress was observed in the control Arabidopsis plants. Such alterations in the levels of these molecules were significantly suppressed in the Pro 35S :AtNUDX2 plants.The results indicate that overexpression of AtNUDX2, encoding ADP-ribose pyrophosphatase, confers enhanced tolerance of oxidative stress on Arabidopsis plants, resulting from maintenance of NAD + and ATP levels by nucleotide recycling from free ADP-ribose molecules under stress conditions.

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“…Intracellular ADP‐ribose is mainly produced from metabolism of poly(ADP‐ribose) catalyzed by PARP and PARG (Maruta et al. , 2007).…”

Section: Discussionmentioning

confidence: 99%

Overexpression of an ADP‐ribose pyrophosphatase, AtNUDX2, confers enhanced tolerance to oxidative stress in Arabidopsis plants

et al. 2009

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“…Rossi et al (2002) have reported that the ADP-Rib produced from poly(ADP-Rib) is rapidly degraded to AMP and that the production of AMP might be an important pathway to reestablish utilizable energy units. In addition, it has been demonstrated that an important function of ATP is derived from poly(ADP-Rib) for the maintenance of the replication apparatus during DNA repair (Maruta et al, 2007). Furthermore, nicotinamide was released by the degradation of NAD + by PARP and returned to NAD + by the salvage pathway, which was accompanied by ATP consumption (Noctor et al, 2006).…”

Section: Maintenance Of Nad + and Atp Levels By Atnudx7 Under Oxidatimentioning

confidence: 99%

Modulation of the Poly(ADP-ribosyl)ation Reaction via the Arabidopsis ADP-Ribose/NADH Pyrophosphohydrolase, AtNUDX7, Is Involved in the Response to Oxidative Stress

et al. 2009

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Here, we assessed modulation of the poly(ADP-ribosyl)ation (PAR) reaction by an Arabidopsis (Arabidopsis thaliana) ADPribose (Rib)/NADH pyrophosphohydrolase, AtNUDX7 (for Arabidopsis Nudix hydrolase 7), in AtNUDX7-overexpressed (Pro 35S :AtNUDX7) or AtNUDX7-disrupted (KO-nudx7) plants under normal conditions and oxidative stress caused by paraquat treatment. Levels of NADH and ADP-Rib were decreased in the Pro 35S :AtNUDX7 plants but increased in the KOnudx7 plants under normal conditions and oxidative stress compared with the control plants, indicating that AtNUDX7 hydrolyzes both ADP-Rib and NADH as physiological substrates. The Pro 35S :AtNUDX7 and KO-nudx7 plants showed increased and decreased tolerance, respectively, to oxidative stress compared with the control plants. Levels of poly(ADP-Rib) in the Pro 35S :AtNUDX7 and KO-nudx7 plants were markedly higher and lower, respectively, than those in the control plants. Depletion of NAD + and ATP resulting from the activation of the PAR reaction under oxidative stress was completely suppressed in the Pro 35S :AtNUDX7 plants. Accumulation of NAD + and ATP was observed in the KO-nudx7-and 3-aminobenzamide-treated plants, in which the PAR reaction was suppressed. The expression levels of DNA repair factors, AtXRCC1 and AtXRCC2 (for x-ray repair cross-complementing factors 1 and 2), paralleled that of AtNUDX7 under both normal conditions and oxidative stress, although an inverse correlation was observed between the levels of AtXRCC3, AtRAD51 (for Escherichia coli RecA homolog), AtDMC1 (for disrupted meiotic cDNA), and AtMND1 (for meiotic nuclear divisions) and AtNUDX7. These findings suggest that AtNUDX7 controls the balance between NADH and NAD + by NADH turnover under normal conditions. Under oxidative stress, AtNUDX7 serves to maintain NAD + levels by supplying ATP via nucleotide recycling from free ADP-Rib molecules and thus regulates the defense mechanisms against oxidative DNA damage via modulation of the PAR reaction.

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“…In addition, some authors have suggested that the concerted action of PARG and ADP-ribose pyrophosphorylase is capable of generating ATP from ADP-ribose units [11]. …”

Section: Introductionmentioning

confidence: 99%

Host Cell Poly(ADP-Ribose) Glycohydrolase Is Crucial for Trypanosoma cruzi Infection Cycle

et al. 2013

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Trypanosoma cruzi, etiological agent of Chagas’ disease, has a complex life cycle which involves the invasion of mammalian host cells, differentiation and intracellular replication. Here we report the first insights into the biological role of a poly(ADP-ribose) glycohydrolase in a trypanosomatid (TcPARG). In silico analysis of the TcPARG gene pointed out the conservation of key residues involved in the catalytic process and, by Western blot, we demonstrated that it is expressed in a life stage-dependant manner. Indirect immunofluorescence assays and electron microscopy using an anti-TcPARG antibody showed that this enzyme is localized in the nucleus independently of the presence of DNA damage or cell cycle stage. The addition of poly(ADP-ribose) glycohydrolase inhibitors ADP-HPD (adenosine diphosphate (hydroxymethyl) pyrrolidinediol) or DEA (6,9-diamino-2-ethoxyacridine lactate monohydrate) to the culture media, both at a 1 µM concentration, reduced in vitro epimastigote growth by 35% and 37% respectively, when compared to control cultures. We also showed that ADP-HPD 1 µM can lead to an alteration in the progression of the cell cycle in hydroxyurea synchronized cultures of T. cruzi epimastigotes. Outstandingly, here we demonstrate that the lack of poly(ADP-ribose) glycohydrolase activity in Vero and A549 host cells, achieved by chemical inhibition or iRNA, produces the reduction of the percentage of infected cells as well as the number of amastigotes per cell and trypomastigotes released, leading to a nearly complete abrogation of the infection process. We conclude that both, T. cruzi and the host, poly(ADP-ribose) glycohydrolase activities are important players in the life cycle of Trypanosoma cruzi, emerging as a promising therapeutic target for the treatment of Chagas’ disease.

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The Involvement of ATP Produced via (ADP-Ribose)n in the Maintenance of DNA Replication Apparatus during DNA Repair

Cited by 31 publications

References 35 publications

Overexpression of an ADP‐ribose pyrophosphatase, AtNUDX2, confers enhanced tolerance to oxidative stress in Arabidopsis plants

Overexpression of an ADP‐ribose pyrophosphatase, AtNUDX2, confers enhanced tolerance to oxidative stress in Arabidopsis plants

Modulation of the Poly(ADP-ribosyl)ation Reaction via the Arabidopsis ADP-Ribose/NADH Pyrophosphohydrolase, AtNUDX7, Is Involved in the Response to Oxidative Stress

Host Cell Poly(ADP-Ribose) Glycohydrolase Is Crucial for Trypanosoma cruzi Infection Cycle

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