Requirement of poly(ADP-ribose) polymerase in recovery from DNA damage in mice and in cells
08 Jul 1997-Proceedings of the National Academy of Sciences of the United States of America (National Academy of Sciences)-Vol. 94, Iss: 14, pp 7303-7307
TL;DR: Results demonstrate that PARP is a survival factor playing an essential and positive role during DNA damage recovery, and inactivated both alleles by gene targeting in mice.
Abstract: Poly(ADP-ribose) polymerase [PARP; NAD+ ADP-ribosyltransferase; NAD+: poly(adenosine-diphosphate-d-ribosyl)-acceptor ADP-d-ribosyltransferase, EC 2.4.2.30] is a zinc-finger DNA-binding protein that detects specifically DNA strand breaks generated by genotoxic agents. To determine its biological function, we have inactivated both alleles by gene targeting in mice. Treatment of PARP−/− mice either by the alkylating agent N-methyl-N-nitrosourea (MNU) or by γ-irradiation revealed an extreme sensitivity and a high genomic instability to both agents. Following whole body γ-irradiation (8 Gy) mutant mice died rapidly from acute radiation toxicity to the small intestine. Mice-derived PARP−/− cells displayed a high sensitivity to MNU exposure: a G2/M arrest in mouse embryonic fibroblasts and a rapid apoptotic response and a p53 accumulation were observed in splenocytes. Altogether these results demonstrate that PARP is a survival factor playing an essential and positive role during DNA damage recovery.
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TL;DR: It is proposed that, in the absence of PARP1, spontaneous single-strand breaks collapse replication forks and trigger homologous recombination for repair and exploited in order to kill BRCA2-deficient tumours by PARP inhibition alone.
Abstract: Poly(ADP-ribose) polymerase (PARP1) facilitates DNA repair by binding to DNA breaks and attracting DNA repair proteins to the site of damage. Nevertheless, PARP1-/- mice are viable, fertile and do not develop early onset tumours. Here, we show that PARP inhibitors trigger gamma-H2AX and RAD51 foci formation. We propose that, in the absence of PARP1, spontaneous single-strand breaks collapse replication forks and trigger homologous recombination for repair. Furthermore, we show that BRCA2-deficient cells, as a result of their deficiency in homologous recombination, are acutely sensitive to PARP inhibitors, presumably because resultant collapsed replication forks are no longer repaired. Thus, PARP1 activity is essential in homologous recombination-deficient BRCA2 mutant cells. We exploit this requirement in order to kill BRCA2-deficient tumours by PARP inhibition alone. Treatment with PARP inhibitors is likely to be highly tumour specific, because only the tumours (which are BRCA2-/-) in BRCA2+/- patients are defective in homologous recombination. The use of an inhibitor of a DNA repair enzyme alone to selectively kill a tumour, in the absence of an exogenous DNA-damaging agent, represents a new concept in cancer treatment.
4,262 citations
Cites background from "Requirement of poly(ADP-ribose) pol..."
...Despite its important role in the cellular response to genotoxic stress, PARP1 is not required for survival in the absence of such an insult, and PARP1 -/- mice are viable and fertil...
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01 Jan 2000
TL;DR: This annex is aimed at providing a sound basis for conclusions regarding the number of significant radiation accidents that have occurred, the corresponding levels of radiation exposures and numbers of deaths and injuries, and the general trends for various practices, in the context of the Committee's overall evaluations of the levels and effects of exposure to ionizing radiation.
Abstract: NOTE The report of the Committee without its annexes appears as Official Records of the General Assembly, Sixty-third Session, Supplement No. 46. The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. The country names used in this document are, in most cases, those that were in use at the time the data were collected or the text prepared. In other cases, however, the names have been updated, where this was possible and appropriate, to reflect political changes. Scientific Annexes Annex A. Medical radiation exposures Annex B. Exposures of the public and workers from various sources of radiation INTROdUCTION 1. In the course of the research and development for and the application of atomic energy and nuclear technologies, a number of radiation accidents have occurred. Some of these accidents have resulted in significant health effects and occasionally in fatal outcomes. The application of technologies that make use of radiation is increasingly widespread around the world. Millions of people have occupations related to the use of radiation, and hundreds of millions of individuals benefit from these uses. Facilities using intense radiation sources for energy production and for purposes such as radiotherapy, sterilization of products, preservation of foodstuffs and gamma radiography require special care in the design and operation of equipment to avoid radiation injury to workers or to the public. Experience has shown that such technology is generally used safely, but on occasion controls have been circumvented and serious radiation accidents have ensued. 2. Reviews of radiation exposures from accidents have been presented in previous UNSCEAR reports. The last report containing an exclusive chapter on exposures from accidents was the UNSCEAR 1993 Report [U6]. 3. This annex is aimed at providing a sound basis for conclusions regarding the number of significant radiation accidents that have occurred, the corresponding levels of radiation exposures and numbers of deaths and injuries, and the general trends for various practices. Its conclusions are to be seen in the context of the Committee's overall evaluations of the levels and effects of exposure to ionizing radiation. 4. The Committee's evaluations of public, occupational and medical diagnostic exposures are mostly concerned with chronic exposures of …
3,924 citations
TL;DR: The addition to proteins of the negatively charged polymer of ADP-ribose (PAR), which is synthesized by PAR polymerases (PARPs) from NAD+, is a unique post-translational modification that regulates not only cell survival and cell-death programmes, but also an increasing number of other biological functions with which novel members of the PARP family have been associated.
Abstract: The addition to proteins of the negatively charged polymer of ADP-ribose (PAR), which is synthesized by PAR polymerases (PARPs) from NAD(+), is a unique post-translational modification. It regulates not only cell survival and cell-death programmes, but also an increasing number of other biological functions with which novel members of the PARP family have been associated. These functions include transcriptional regulation, telomere cohesion and mitotic spindle formation during cell division, intracellular trafficking and energy metabolism.
1,820 citations
Cites background from "Requirement of poly(ADP-ribose) pol..."
...Studies with chemical inhibitors of PARP activity and Parp-1 -knockout mice showed that the role of PARP-1 is as a survival factor that functions in the surveillance and maintenance of genome integrit...
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TL;DR: The total dependence of poly(ADP-ribose) synthesis on DNA strand breaks strongly suggests that this post-translational modification is involved in the metabolism of nucleic acids, and the presence of PARP in these multiprotein complexes clearly supports an important role for poly(ADE-ribosyl)ation reactions in DNA transactions.
Abstract: Poly(ADP-ribosyl)ation is a post-translational modification of proteins. During this process, molecules of ADP-ribose are added successively on to acceptor proteins to form branched polymers. This modification is transient but very extensive in vivo, as polymer chains can reach more than 200 units on protein acceptors. The existence of the poly(ADP-ribose) polymer was first reported nearly 40 years ago. Since then, the importance of poly(ADP-ribose) synthesis has been established in many cellular processes. However, a clear and unified picture of the physiological role of poly(ADP-ribosyl)ation still remains to be established. The total dependence of poly(ADP-ribose) synthesis on DNA strand breaks strongly suggests that this post-translational modification is involved in the metabolism of nucleic acids. This view is also supported by the identification of direct protein-protein interactions involving poly(ADP-ribose) polymerase (113 kDa PARP), an enzyme catalysing the formation of poly(ADP-ribose), and key effectors of DNA repair, replication and transcription reactions. The presence of PARP in these multiprotein complexes, in addition to the actual poly(ADP-ribosyl)ation of some components of these complexes, clearly supports an important role for poly(ADP-ribosyl)ation reactions in DNA transactions. Accordingly, inhibition of poly(ADP-ribose) synthesis by any of several approaches and the analysis of PARP-deficient cells has revealed that the absence of poly(ADP-ribosyl)ation strongly affects DNA metabolism, most notably DNA repair. The recent identification of new poly(ADP-ribosyl)ating enzymes with distinct (non-standard) structures in eukaryotes and archaea has revealed a novel level of complexity in the regulation of poly(ADP-ribose) metabolism.
1,797 citations
TL;DR: The double-edged sword roles of PARP in DNA damage signaling and cell death are reviewed and the underlying mechanisms of the anti-inflammatory effects ofPARP inhibitors are summarized.
Abstract: Poly(ADP-ribose) polymerase-1 (PARP-1) is a member of the PARP enzyme family consisting of PARP-1 and several recently identified novel poly(ADP-ribosylating) enzymes. PARP-1 is an abundant nuclear protein functioning as a DNA nick-sensor enzyme. Upon binding to DNA breaks, activated PARP cleaves NAD(+) into nicotinamide and ADP-ribose and polymerizes the latter onto nuclear acceptor proteins including histones, transcription factors, and PARP itself. Poly(ADP-ribosylation) contributes to DNA repair and to the maintenance of genomic stability. On the other hand, oxidative stress-induced overactivation of PARP consumes NAD(+) and consequently ATP, culminating in cell dysfunction or necrosis. This cellular suicide mechanism has been implicated in the pathomechanism of stroke, myocardial ischemia, diabetes, diabetes-associated cardiovascular dysfunction, shock, traumatic central nervous system injury, arthritis, colitis, allergic encephalomyelitis, and various other forms of inflammation. PARP has also been shown to associate with and regulate the function of several transcription factors. Of special interest is the enhancement by PARP of nuclear factor kappa B-mediated transcription, which plays a central role in the expression of inflammatory cytokines, chemokines, adhesion molecules, and inflammatory mediators. Herein we review the double-edged sword roles of PARP in DNA damage signaling and cell death and summarize the underlying mechanisms of the anti-inflammatory effects of PARP inhibitors. Moreover, we discuss the potential use of PARP inhibitors as anticancer agents, radiosensitizers, and antiviral agents.
1,410 citations
Cites background from "Requirement of poly(ADP-ribose) pol..."
...High levels of ionizing radiation and alkylating agents elicit higher lethality in PARP-1deficient mice when compared with wild-type ones (de Murcia et al., 1997)....
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...Furthermore, exposure to methylmethanesulfonate or N-methyl-N-nitrosourea of embryonic fibroblasts derived from PARP / mice but not from PARP / mice exhibited a reduced rate of proliferation because of their cell-cycle block in G2/M (de Murcia et al., 1997; Trucco et al., 1998)....
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...First, PARP-1 has been implicated in DNA repair and maintenance of genomic integrity (de Murcia and Menissier de Murcia, 1994; de Murcia et al., 1994,1997; Schreiber et al., 1995; Chatterjee et al., 1999b; Shall and de Murcia, 2000)....
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...PARP knockout mice generated in de Murcia’s laboratory were highly sensitive to death induced by ionizing radiation or monofunctional alkylating agents (de Murcia et al., 1997)....
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...This “guardian angel” function is indicated by delayed DNA base-excision repair and by a high frequency of sister chromatid exchange in PARP-1-deficient cells exposed to ionizing radiation or treated with alkylating agents (de Murcia et al., 1997)....
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References
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TL;DR: It is proposed that Yama may represent an effector component of the mammalian cell death pathway and suggest that CrmA blocks apoptosis by inhibiting Yama.
2,369 citations
TL;DR: Atm-disrupted mice recapitulate the ataxia telangiectasia phenotype in humans, providing a mammalian model in which to study the pathophysiology of this pleiotropic disorder.
1,467 citations
TL;DR: Nitric oxide stimulated ADP-ribosylation of PARS in rat brain and blocked N-methyl-D-aspartate- and NO-mediated neurotoxicity with relative potencies paralleling their ability to inhibit PARS.
Abstract: Poly(adenosine 5'-diphosphoribose) synthetase (PARS) is a nuclear enzyme which, when activated by DNA strand breaks, adds up to 100 adenosine 5'-diphosphoribose (ADP-ribose) units to nuclear proteins such as histones and PARS itself. This activation can lead to cell death through depletion of beta-nicotinamide adenine dinucleotide (the source of ADP-ribose) and adenosine triphosphate. Nitric oxide (NO) stimulated ADP-ribosylation of PARS in rat brain. Benzamide and other derivatives, which inhibit PARS, blocked N-methyl-D-aspartate- and NO-mediated neurotoxicity with relative potencies paralleling their ability to inhibit PARS. Thus, NO appeared to elicit neurotoxicity by activating PARS.
1,155 citations
TL;DR: The results indicate that unmodified polymerase molecules bind tightly to DNA strand breaks; auto-poly(ADP-ribosyl)ation of the protein then effects its release and allows access to lesions for DNA repair enzymes.
Abstract: THE abundant nuclear enzyme poly(ADP-ribose) polymerase catalyses the synthesis of poly(ADP-ribose) from nicotinamide adenine dinucleotide (NAD+)1–5. This protein has an N-terminal DNA-binding domain containing two zinc-fingers, which is linked to the C-terminal NAD+-binding domain by a short region containing several glutamic acid residues that are sites of auto-poly(ADP-ribosyl)ation6–8. The intracellular production of poly(ADP-ribose) is induced by agents that generate strand interruptions in DNA7. The branched homopolymer chains may attain a size of 200–300 residues9 but are rapidly degraded after synthesis. The function of poly(ADP-ribose) synthesis is not clear, although it seems to be required for DNA repair10,11. Here we describe a human cell-free system that enables the role of poly(ADP-ribose) synthesis in DNA repair to be characterized. The results indicate that unmodified polymerase molecules bind tightly to DNA strand breaks; auto-poly(ADP-ribosyl)ation of the protein then effects its release and allows access to lesions for DNA repair enzymes.
1,101 citations
TL;DR: The generation of viableADPRT-/-mice negates an essential role for this enzyme in normal chromatin function, but the impaired proliferation and the onset of skin lesions in older mice suggest a function for ADPRT in response to environmental stress.
Abstract: Poly(ADP-ribosyl)ation is catalyzed by NAD+: protein(ADP-ribosyl) transferase (ADPRT), a chromatin-associated enzyme which, in the presence of DNA breaks, transfers ADP-ribose from NAD+ to nuclear proteins. This post-translational modification has been implicated in many fundamental processes, like DNA repair, chromatin stability, cell proliferation, and cell death. To elucidate the biological function of ADPRT and poly(ADP-ribosyl)ation in vivo the gene was inactivated in the mouse germ line. Mice homozygous for the ADPRT mutation are healthy and fertile. Analysis of mutant tissues and fibroblasts isolated from mutant fetuses revealed the absence of ADPRT enzymatic activity and poly(ADP-ribose), implying that no poly(ADP-ribosyl)ated proteins are present. Mutant embryonic fibroblasts were able to efficiently repair DNA damaged by UV and alkylating agents. However, proliferation of mutant primary fibroblasts as well as thymocytes following gamma-radiation in vivo was impaired. Moreover, mutant mice are susceptible to the spontaneous development of skin disease as approximately 30% of older mice develop epidermal hyperplasia. The generation of viable ADPRT-/-mice negates an essential role for this enzyme in normal chromatin function, but the impaired proliferation and the onset of skin lesions in older mice suggest a function for ADPRT in response to environmental stress.
769 citations