Mitochondrial PARP1 Regulates NAD+-dependent Poly ADP-ribosylation on Mitochondrial Nucleoids
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE182533 | GEO | 2022/08/20
REPOSITORIES: GEO
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Project description:Formation of a repair enzyme complex is beneficial to DNA repair. Despite cellular studies showed that mitochondrial DNA polymerase (Pol ) and poly(ADP-ribose) polymerase 1 (PARP1) were found in the same complex along with other mitochondrial DNA repair enzymes and mitochondrial PARP1 level is correlated with mtDNA integrity, the molecular basis for the functional connection between Pol and PARP1 has not been illustrated, because cellular functions of PARP1 in DNA repair are intertwined with metabolism via NAD+ (nicotinamide adenosine dinucleotide), the substrate of PARP1 and a metabolic cofactor. To dissect the direct effect of PARP1 on mtDNA from the secondary perturbation metabolism, we report here biochemical studies that recapitulated Pol PARylation observed in cells, showed that PARP1 regulates Pol activity during DNA repair in a metabolic cofactor NAD+ (nicotinamide adenosine dinucleotide)-dependent manner. In the absence of NAD+, PARP1 completely inhibits Pol, while increasing NAD+ level to physiological concentration enables Pol to resume maximum repair activity. Because cellular NAD+ levels are linked to metabolism and to ATP production via oxidative phosphorylation, our results suggest that mtDNA damage repair is correlated with cellular metabolic state and integrity of the respiratory chain.
2020-12-16 | MSV000086606 | MassIVE
Project description:The macro domain of the histone variant macroH2A1.1 is an evolutionary conserved ADP ribose-binding module of unknown physiological function. We demonstrate that during myogenic differentiation alternative splicing switches the expression of macroH2A1 from the non-ADP ribose binding to the binding isoform. While differentiation commitment is normal in cells lacking macroH2A1.1, we observe two phenotypes: diminished cell fusion correlating with reduced expression of adhesion and migration genes and reduced mitochondrial capacity. While the integrity of the ADP ribose-binding pocket is dispensable for gene regulation and fusion, it is critical to sustain optimal mitochondrial fatty acid oxidation. Rescue experiments using a pharmacological PARP-1 inhibitor and metabolomics support the idea that loss of macroH2A1.1 leads to PARP-1 activation and accelerated NAD+ consumption. As a consequence, the level of nicotinamide mononucleotide, the key metabolite for mitochondrial NAD+ pool regeneration, is reduced and sirtuins fail to maintain mitochondrial proteins in their hypoacetylated and active form. Our results support the idea that chromatin states containing the histone variant macroH2A1.1 contribute to optimal mitochondrial oxidative capacity by channeling the consumption of NAD+ from the nucleus to mitochondria in a manner largely independent on transcriptional regulation.
2017-08-18 | GSE70015 | GEO
Project description:The macro domain of the histone variant macroH2A1.1 is an evolutionary conserved ADP ribose-binding module of unknown physiological function. We demonstrate that during myogenic differentiation alternative splicing switches the expression of macroH2A1 from the non-ADP ribose binding to the binding isoform. While differentiation commitment is normal in cells lacking macroH2A1.1, we observe two phenotypes: diminished cell fusion correlating with reduced expression of adhesion and migration genes and reduced mitochondrial capacity. While the integrity of the ADP ribose-binding pocket is dispensable for gene regulation and fusion, it is critical to sustain optimal mitochondrial fatty acid oxidation. Rescue experiments using a pharmacological PARP-1 inhibitor and metabolomics support the idea that loss of macroH2A1.1 leads to PARP-1 activation and accelerated NAD+ consumption. As a consequence, the level of nicotinamide mononucleotide, the key metabolite for mitochondrial NAD+ pool regeneration, is reduced and sirtuins fail to maintain mitochondrial proteins in their hypoacetylated and active form. Our results support the idea that chromatin states containing the histone variant macroH2A1.1 contribute to optimal mitochondrial oxidative capacity by channeling the consumption of NAD+ from the nucleus to mitochondria in a manner largely independent on transcriptional regulation.
2017-08-18 | GSE78256 | GEO
Project description:Non-small cell lung cancer (NSCLC) is often treated with cisplatin (CDDP). Here, we report that two distinct poly(ADP-ribose) polymerase (PARP) inhibitors exhibited a hyperadditive combination effect with CDDP to kill NSCLC cells. A majority of CDDP-resistant cell lines and clones exhibited constitutively increased PARP expression and enzymatic activity. Cells with hyperactivated PARP initiated a DNA damage response and the intrinsic pathway of apoptosis in response to pharmacological PARP inhibition or PARP1-targeting siRNAs. Transcriptome analysis depicted an unsupervised hierarchical clustering of NSCLC cells and CDDP resistant counterparts regarding to their response to PARP inhibitors. PARP-overexpressing tumors displayed elevated levels of intracellular poly(ADP-ribose) (PAR), which predicted the response to PARP inhibitors in vitro and in vivo more accurately than PARP expression itself. Thus, CDDP-resistant cancer cells develop a dependency to PARP, becoming susceptible to PARP inhibitor-induced apoptosis.
2013-10-31 | E-MTAB-1353 | biostudies-arrayexpress
Project description:Epstein Barr Virus (EBV) is a potentially oncogenic gammaherpesvirus that establishes a chronic, latent infection in memory B cells. The EBV genome persists in infected host cells as a chromatinized episome and is subject to chromatin-mediated regulation. Binding of the host insulator protein CTCF to the EBV genome has an established role in maintaining viral latency type. CTCF is post-translationally modified by the host enzyme PARP1. PARP1, or Poly(ADP-ribose) polymerase 1, catalyzes the transfer of a poly(ADP-ribose) (PAR) moiety from NAD+ onto acceptor proteins including itself, histone proteins, and CTCF. PARylation of CTCF by PARP1 can affect CTCF’s insulator activity, DNA binding capacity, and ability to form chromatin loops. Both PARP1 and CTCF have been implicated in the regulation of EBV latency and lytic reactivation. Thus, we predicted that pharmacological inhibition with PARP1 inhibitors would affect EBV latency type through a chromatin-specific mechanism. Here, we show that PARP1 and CTCF colocalize at specific sites throughout the EBV genome, and provide evidence to suggest that PARP1 acts to stabilize CTCF binding and maintain the open chromatin landscape at the active Cp promoter during type III latency. Further, PARP1 activity is important in maintaining latency type-specific viral gene expression. The data presented here provide a rationale for the use of PARP inhibitors in the treatment of EBV-associated cancers exhibiting type III latency, and could ultimately contribute to an EBV-specific treatment strategy for AIDS-related or post-transplant lymphomas.
2018-06-27 | GSE115829 | GEO
Project description:Poly(ADP-ribose) polymerase 1 (PARP1) critically facilitates DNA damage response (DDR) that suppresses genomic instability. However, the physiological function of PARP1 in regulating genomic integrity is unclear. We investigated the Ewing’s sarcoma breakpoint region 1 (EWS) and found that it regulated the physiological function of PARP1. EWS was indispensable to dissociation of PARP1 from damaged DNA, promoting DDR and regulating DDR protein expression. Abnormal PARP1 accumulation due to EWS expression silencing, induced hyper-PARylation, which exhausted cellular NAD+ levels and caused cell death in in vitro and in vivo. Positively charged EWS arginine-glycine-glycine (Arg-Gly-Gly, RGG) domains directly interact with poly ADP-ribose (PAR) chains produced by PARP1 and are essential to dissociate PARP1 from damaged DNA. Consistently, Ewing’s sarcoma cells with defective EWS function accumulated PARP1 on chromatin and tissues from Ewing’s sarcoma patients, exhibiting high PARylation levels. Taken together, loss of EWS causes defects in PARP1 dissociation and results in genomic instability.
2020-11-03 | PXD016145 | Pride
Project description:Cockayne syndrome (CS) is an accelerated aging disorder, caused by mutations in the CSA or CSB genes. In CSB-deficient cells, poly (ADP ribose) polymerase (PARP) is persistently activated by unrepaired DNA damage and PARP consumes and depletes cellular nicotinamide adenine dinucleotide (NAD), which leads to mitochondrial dysfunction. Here, the distribution of poly (ADP ribose) (PAR) was determined in CSB-deficient cells using ADPr-ChAP (ADP ribose-chromatin affinity purification), and the results show striking enrichment of PAR at transcription start sites (TSS), depletion of heterochromatin, and downregulation of H3K9me3-specific methyltransferases SUV39H1 and SETDB1. Induced-expression of SETDB1 in CSB-deficient cells downregulated PAR and normalized mitochondrial function. The results suggest that defects in CSB are strongly associated with loss of heterochromatin, downregulation of SETDB1, increased PAR in highly-transcribed regions, and mitochondrial dysfunction.
2019-06-22 | GSE133176 | GEO
Project description:Post-translational modifications, such as poly(ADP-ribosyl)ation (PARylation), regulate chromatin-modifying enzymes, ultimately affecting gene expression. This study explores the role of poly(ADP-ribose) polymerase (PARP) on global gene expression in a lymphoblastoid B cell line. We found that inhibition of PARP catalytic activity with olaparib resulted in global gene deregulation, affecting approximately 11% of genes expressed. Gene ontology analysis revealed that PARP could exert these effects through transcription factors and chromatin-remodeling enzymes, including the Polycomb Repressive Complex 2 (PRC2) member EZH2. EZH2 mediates the trimethylation of histone H3 at lysine 27 (H3K27me3), a modification associated with chromatin compaction and gene silencing. Both pharmacological inhibition of PARP and knockdown of PARP1 induced the expression of EZH2 that resulted in increased global H3K27me3. Chromatin immunoprecipitation confirmed that PARP1 inhibition led to H3K27me3 deposition at EZH2-target genes, which resulted in gene silencing. Moreover, increased EZH2 expression is attributed to occupancy loss of the transcription repressor E2F4 at the EZH2 promoter following PARP inhibition. Together, these data show that PARP plays an important role in global gene regulation and identifies for the first time a direct role of PARP1 in regulating the expression and function of EZH2.
2015-11-13 | GSE74974 | GEO
Project description:Latent membrane protein 1 (LMP1) is the major transforming protein of Epstein-Barr virus (EBV) and is critical for EBV-induced B-cell transformation in vitro. Poly(ADP-ribose) polymerase 1 (PARP1) regulates accessibility of chromatin, alters functions of transcriptional activators and repressors, and has been directly implicated in transcriptional activation. Previously we showed that LMP1 activates PARP1 and increases Poly(ADP-ribos)ylation (PARylation) through PARP1. Therefore, to identify targets of LMP1 that are regulated through PARP1, LMP1 was ectopically expressed in an EBV-negative Burkitt’s lymphoma cell line. These LMP1-expressing cells were then treated with the PARP inhibitor olaparib and prepared for RNA sequencing. The LMP1/PARP targets identified through this RNA-seq experiment are largely involved in metabolism and signaling. Interestingly, Ingenuity Pathway Analysis of RNA-seq data suggests that hypoxia-inducible factor 1-alpha (HIF-1α) is an LMP1 target mediated through PARP1. PARP1 is acting as a coactivator of HIF-1α-dependent gene expression in B cells, and this co-activation is enhanced by LMP1-mediated activation of PARP1. HIF-1α forms a PARylated complex with PARP1 and both HIF-1α and PARP1 are present at promoter regions of HIF-1α downstream targets, leading to accumulation of positive histone marks at these regions. Complex formation, PARylation and binding of PARP1 and HIF-1α at promoter regions of HIF-1α downstream targets can all be attenuated by PARP1 inhibition, subsequently leading to a buildup of repressive histone marks and loss of positive histone marks. In addition, LMP1 switches cells to a glycolytic ‘Warburg’ metabolism, preferentially using aerobic glycolysis over mitochondrial respiration. Finally, LMP1+ cells are more sensitive to PARP1 inhibition and, therefore, targeting PARP1 activity may be an effective treatment for LMP1+ EBV-associated malignancies.
2018-10-24 | GSE121476 | GEO
Project description:Nicotinamide adenine dinucleotide (NAD+) is a vital small molecule with important redox capacity in oxidative phosphorylation (OXPHOS) and a key co-factor in various enzymatic reactions. The recent identification of the mitochondrial NAD+ transporter SLC25A51 provides strong evidence for a direct regulation of the mitochondrial NAD+ pool. Though the effect of this transporter on glucose metabolism has been described, its contribution to other NAD+-dependent processes such as ADP-ribosylation remains elusive. Here, we report that knockdown of SLC25A51 decreased the NAD+ concentration in mitochondria but increased the NAD+ concentration in the cytoplasm and nucleus. The increase in nuclear and cytoplasmic NAD+ was not due to the upregulation of the salvage pathway, thus pointing towards an overall redistribution of NAD+ from the mitochondria towards the cyto/nuclear compartment. Furthermore, the NAD+ redistribution induced by knockdown or knockout of SLC25A51 resulted, as quantified by immunofluorescence or analyzed by mass-spectrometry, in a loss of mitochondrial ADP-ribosylation and an increase of PARP1-mediated nuclear ADP-ribosylation under basal conditions. Further, MMS/Olaparib induced PARP1 chromatin retention and the sensitivity of triple-negative MDA-MB-436 breast cancer cells to PARP inhibition were both reduced upon knockdown of SLC25A51. In addition, H2O2-induced PARP1-dependent nuclear ADP-ribosylation was prolonged while phosphorylation of H2AX was unexpectedly reduced. Together these results provide evidence that lack of SCL25A51 and subsequently altered NAD+ compartmentalization affects not only mitochondrial and nuclear ADP-ribosylation but also other chromatin associated events.
2023-10-24 | PXD031373 | Pride