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Nature Cell Biology Apr 2022DNA damage shuts down genome-wide transcription to prevent transcriptional mutagenesis and to initiate repair signalling, but the mechanism to stall elongating RNA...
DNA damage shuts down genome-wide transcription to prevent transcriptional mutagenesis and to initiate repair signalling, but the mechanism to stall elongating RNA polymerase II (Pol II) is not fully understood. Central to the DNA damage response, poly(ADP-ribose) polymerase 1 (PARP1) initiates DNA repair by translocating to the lesions where it catalyses protein poly(ADP-ribosylation). Here we report that PARP1 inhibits Pol II elongation by inactivating the transcription elongation factor P-TEFb, a CDK9-cyclin T1 (CycT1) heterodimer. After sensing damage, the activated PARP1 binds to transcriptionally engaged P-TEFb and modifies CycT1 at multiple positions, including histidine residues that are rarely used as an acceptor site. This prevents CycT1 from undergoing liquid-liquid phase separation that is required for CDK9 to hyperphosphorylate Pol II and to stimulate elongation. Functionally, poly(ADP-ribosylation) of CycT1 promotes DNA repair and cell survival. Thus, the P-TEFb-PARP1 signalling plays a protective role in transcription quality control and genomic stability maintenance after DNA damage.
Topics: ADP-Ribosylation; Cyclin T; DNA Damage; Positive Transcriptional Elongation Factor B; RNA Polymerase II
PubMed: 35393539
DOI: 10.1038/s41556-022-00872-5 -
Viruses Jan 2023ADP-ribosylation (ADPRylation) is a versatile posttranslational modification in eukaryotic cells which is involved in the regulation of a wide range of key biological...
ADP-ribosylation (ADPRylation) is a versatile posttranslational modification in eukaryotic cells which is involved in the regulation of a wide range of key biological processes, including DNA repair, cell signalling, programmed cell death, growth and development and responses to biotic and abiotic stresses. Members of the poly(ADP-ribosyl) polymerase (PARP) family play a central role in the process of ADPRylation. Protein targets can be modified by adding either a single ADP-ribose moiety (mono(ADP-ribosyl)ation; MARylation), which is catalysed by mono(ADP-ribosyl) transferases (MARTs or PARP "monoenzymes"), or targets may be decorated with chains of multiple ADP-ribose moieties (PARylation), via the activities of PARP "polyenzymes". Studies have revealed crosstalk between PARylation (and to a lesser extent, MARylation) processes in plants and plant-virus interactions, suggesting that these tight links may represent a novel factor regulating plant antiviral immunity. From this perspective, we go through the literature linking PARylation-associated processes with other plant regulation pathways controlling virus resistance. Once unraveled, these links may serve as the basis of innovative strategies to improve crop resistance to viruses under challenging environmental conditions which could mitigate yield losses.
Topics: Poly(ADP-ribose) Polymerases; Poly Adenosine Diphosphate Ribose; Poly(ADP-ribose) Polymerase Inhibitors; ADP-Ribosylation; Adenosine Diphosphate Ribose; Antiviral Agents
PubMed: 36680280
DOI: 10.3390/v15010241 -
Biochemical Society Transactions Jun 2023ADP-ribosylation is a post-translational modification involved in DNA damage response (DDR). In higher organisms it is synthesised by PARP 1-3, DNA strand break sensors....
ADP-ribosylation is a post-translational modification involved in DNA damage response (DDR). In higher organisms it is synthesised by PARP 1-3, DNA strand break sensors. Recent advances have identified serine residues as the most common targets for ADP-ribosylation during DDR. To ADP-ribosylate serine, PARPs require an accessory factor, HPF1 which completes the catalytic domain. Through ADP-ribosylation, PARPs recruit a variety of factors to the break site and control their activities. However, the timely removal of ADP-ribosylation is also key for genome stability and is mostly performed by two hydrolases: PARG and ARH3. Here, we describe the key writers, readers and erasers of ADP-ribosylation and their contribution to the mounting of the DDR. We also discuss the use of PARP inhibitors in cancer therapy and the ways to tackle PARPi treatment resistance.
Topics: ADP-Ribosylation; DNA Damage; Protein Processing, Post-Translational; Hydrolases; Serine
PubMed: 37171085
DOI: 10.1042/BST20220749 -
ELife Aug 2017The modification of serines by molecules of ADP-ribose plays an important role in signaling that the DNA in a cell has been damaged and needs to be repaired.
The modification of serines by molecules of ADP-ribose plays an important role in signaling that the DNA in a cell has been damaged and needs to be repaired.
Topics: ADP-Ribosylation; Adenosine Diphosphate Ribose; Hydrolases; Serine; Signal Transduction
PubMed: 28796599
DOI: 10.7554/eLife.29942 -
Molecular Cell May 2023PARPs catalyze ADP-ribosylation-a post-translational modification that plays crucial roles in biological processes, including DNA repair, transcription, immune... (Review)
Review
PARPs catalyze ADP-ribosylation-a post-translational modification that plays crucial roles in biological processes, including DNA repair, transcription, immune regulation, and condensate formation. ADP-ribosylation can be added to a wide range of amino acids with varying lengths and chemical structures, making it a complex and diverse modification. Despite this complexity, significant progress has been made in developing chemical biology methods to analyze ADP-ribosylated molecules and their binding proteins on a proteome-wide scale. Additionally, high-throughput assays have been developed to measure the activity of enzymes that add or remove ADP-ribosylation, leading to the development of inhibitors and new avenues for therapy. Real-time monitoring of ADP-ribosylation dynamics can be achieved using genetically encoded reporters, and next-generation detection reagents have improved the precision of immunoassays for specific forms of ADP-ribosylation. Further development and refinement of these tools will continue to advance our understanding of the functions and mechanisms of ADP-ribosylation in health and disease.
Topics: Poly(ADP-ribose) Polymerases; ADP-Ribosylation; Protein Processing, Post-Translational; Adenosine Diphosphate Ribose
PubMed: 37119811
DOI: 10.1016/j.molcel.2023.04.009 -
Molecular Cell May 2023PARP1, an established anti-cancer target that regulates many cellular pathways, including DNA repair signaling, has been intensely studied for decades as a...
PARP1, an established anti-cancer target that regulates many cellular pathways, including DNA repair signaling, has been intensely studied for decades as a poly(ADP-ribosyl)transferase. Although recent studies have revealed the prevalence of mono-ADP-ribosylation upon DNA damage, it was unknown whether this signal plays an active role in the cell or is just a byproduct of poly-ADP-ribosylation. By engineering SpyTag-based modular antibodies for sensitive and flexible detection of mono-ADP-ribosylation, including fluorescence-based sensors for live-cell imaging, we demonstrate that serine mono-ADP-ribosylation constitutes a second wave of PARP1 signaling shaped by the cellular HPF1/PARP1 ratio. Multilevel chromatin proteomics reveals histone mono-ADP-ribosylation readers, including RNF114, a ubiquitin ligase recruited to DNA lesions through a zinc-finger domain, modulating the DNA damage response and telomere maintenance. Our work provides a technological framework for illuminating ADP-ribosylation in a wide range of applications and biological contexts and establishes mono-ADP-ribosylation by HPF1/PARP1 as an important information carrier for cell signaling.
Topics: Histones; Poly (ADP-Ribose) Polymerase-1; ADP-Ribosylation; Chromatin; DNA Damage; Antibodies; Signal Transduction
PubMed: 37116497
DOI: 10.1016/j.molcel.2023.03.027 -
Molecular Cell Jul 2022The efficiency of homologous recombination (HR) in the repair of DNA double-strand breaks (DSBs) is closely associated with genome stability and tumor response to...
The efficiency of homologous recombination (HR) in the repair of DNA double-strand breaks (DSBs) is closely associated with genome stability and tumor response to chemotherapy. While many factors have been functionally characterized in HR, such as TOPBP1, their precise regulation remains unclear. Here, we report that TOPBP1 interacts with the RNA-binding protein HTATSF1 in a cell-cycle- and phosphorylation-dependent manner. Mechanistically, CK2 phosphorylates HTATSF1 to facilitate binding to TOPBP1, which promotes S-phase-specific TOPBP1 recruitment to damaged chromatin and subsequent RPA/RAD51-dependent HR, genome integrity, and cancer-cell viability. The localization of HTATSF1-TOPBP1 to DSBs is potentially independent of the transcription-coupled RNA-binding and processing capacity of HTATSF1 but rather relies on the recognition of poly(ADP-ribosyl)ated RPA by HTATSF1, which can be blunted with PARP inhibitors. Together, our study provides a mechanistic insight into TOPBP1 loading at HR-prone DSB sites via HTATSF1 and reveals how RPA-RAD51 exchange is tuned by a PARylation-phosphorylation cascade.
Topics: DNA Breaks, Double-Stranded; DNA Repair; Homologous Recombination; Phosphorylation; Poly ADP Ribosylation; Rad51 Recombinase
PubMed: 35597237
DOI: 10.1016/j.molcel.2022.04.031 -
Molecular Cell Apr 2022Synthetic lethality through combinatorial targeting DNA damage response (DDR) pathways provides exciting anticancer therapeutic benefit. Currently, the long noncoding...
Synthetic lethality through combinatorial targeting DNA damage response (DDR) pathways provides exciting anticancer therapeutic benefit. Currently, the long noncoding RNAs (lncRNAs) have been implicated in tumor drug resistance; however, their potential significance in DDR is still largely unknown. Here, we report that a human lncRNA, CTD-2256P15.2, encodes a micropeptide, named PAR-amplifying and CtIP-maintaining micropeptide (PACMP), with a dual function to maintain CtIP abundance and promote poly(ADP-ribosyl)ation. PACMP not only prevents CtIP from ubiquitination through inhibiting the CtIP-KLHL15 association but also directly binds DNA damage-induced poly(ADP-ribose) chains to enhance PARP1-dependent poly(ADP-ribosyl)ation. Targeting PACMP alone inhibits tumor growth by causing a synthetic lethal interaction between CtIP and PARP inhibitions and confers sensitivity to PARP/ATR/CDK4/6 inhibitors, ionizing radiation, epirubicin, and camptothecin. Our findings reveal that a lncRNA-derived micropeptide regulates cancer progression and drug resistance by modulating DDR, whose inhibition could be employed to augment the existing anticancer therapeutic strategies.
Topics: DNA Repair; Endodeoxyribonucleases; Humans; Microfilament Proteins; Neoplasms; Peptides; Poly ADP Ribosylation; Poly Adenosine Diphosphate Ribose; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases; RNA, Long Noncoding
PubMed: 35219381
DOI: 10.1016/j.molcel.2022.01.020 -
Nature Mar 2020The anti-cancer drug target poly(ADP-ribose) polymerase 1 (PARP1) and its close homologue, PARP2, are early responders to DNA damage in human cells. After binding to...
The anti-cancer drug target poly(ADP-ribose) polymerase 1 (PARP1) and its close homologue, PARP2, are early responders to DNA damage in human cells. After binding to genomic lesions, these enzymes use NAD to modify numerous proteins with mono- and poly(ADP-ribose) signals that are important for the subsequent decompaction of chromatin and the recruitment of repair factors. These post-translational modifications are predominantly serine-linked and require the accessory factor HPF1, which is specific for the DNA damage response and switches the amino acid specificity of PARP1 and PARP2 from aspartate or glutamate to serine residues. Here we report a co-structure of HPF1 bound to the catalytic domain of PARP2 that, in combination with NMR and biochemical data, reveals a composite active site formed by residues from HPF1 and PARP1 or PARP2 . The assembly of this catalytic centre is essential for the addition of ADP-ribose moieties after DNA damage in human cells. In response to DNA damage and occupancy of the NAD-binding site, the interaction of HPF1 with PARP1 or PARP2 is enhanced by allosteric networks that operate within the PARP proteins, providing an additional level of regulation in the induction of the DNA damage response. As HPF1 forms a joint active site with PARP1 or PARP2, our data implicate HPF1 as an important determinant of the response to clinical PARP inhibitors.
Topics: ADP-Ribosylation; Allosteric Regulation; Amino Acid Motifs; Amino Acid Sequence; Animals; Biocatalysis; Carrier Proteins; Catalytic Domain; DNA Damage; HEK293 Cells; Humans; Models, Molecular; Mutation; NAD; Nuclear Magnetic Resonance, Biomolecular; Nuclear Proteins; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases; Sea Anemones
PubMed: 32028527
DOI: 10.1038/s41586-020-2013-6 -
Proceedings of the National Academy of... Dec 2023PARP7 was reported to promote tumor growth in a cell-autonomous manner and by repressing the antitumor immune response. Nevertheless, the molecular mechanism of how...
PARP7 was reported to promote tumor growth in a cell-autonomous manner and by repressing the antitumor immune response. Nevertheless, the molecular mechanism of how PARP7-mediated ADP-ribosylation exerts these effects in cancer cells remains elusive. Here, we identified PARP7 as a nuclear and cysteine-specific mono-ADP-ribosyltransferase that modifies targets critical for regulating transcription, including the AP-1 transcription factor FRA1. Loss of FRA1 ADP-ribosylation via PARP7 inhibition by RBN-2397 or mutation of the ADP-ribosylation site C97 increased FRA1 degradation by the proteasome via PSMC3. The reduction in FRA1 protein levels promoted IRF1- and IRF3-dependent cytokine as well as proapoptotic gene expression, culminating in CASP8-mediated apoptosis. Furthermore, high PARP7 expression was indicative of the PARP7 inhibitor response in FRA1-positive lung and breast cancer cells. Collectively, our findings highlight the connected roles of PARP7 and FRA1 and emphasize the clinical potential of PARP7 inhibitors for FRA1-driven cancers.
Topics: Humans; ADP Ribose Transferases; ADP-Ribosylation; Apoptosis; Cell Transformation, Neoplastic; Gene Expression Regulation; Interferon Regulatory Factor-1; Interferon Regulatory Factor-3; Neoplasms; Nucleoside Transport Proteins; Proto-Oncogene Proteins c-fos
PubMed: 38011562
DOI: 10.1073/pnas.2309047120