1
|
Tardito S, Matis S, Zocchi MR, Benelli R, Poggi A. Epidermal Growth Factor Receptor Targeting in Colorectal Carcinoma: Antibodies and Patient-Derived Organoids as a Smart Model to Study Therapy Resistance. Int J Mol Sci 2024; 25:7131. [PMID: 39000238 PMCID: PMC11241078 DOI: 10.3390/ijms25137131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 06/22/2024] [Accepted: 06/25/2024] [Indexed: 07/16/2024] Open
Abstract
Colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide. Therefore, the need for new therapeutic strategies is still a challenge. Surgery and chemotherapy represent the first-line interventions; nevertheless, the prognosis for metastatic CRC (mCRC) patients remains unacceptable. An important step towards targeted therapy came from the inhibition of the epidermal growth factor receptor (EGFR) pathway, by the anti-EGFR antibody, Cetuximab, or by specific tyrosine kinase inhibitors (TKI). Cetuximab, a mouse-human chimeric monoclonal antibody (mAb), binds to the extracellular domain of EGFR thus impairing EGFR-mediated signaling and reducing cell proliferation. TKI can affect the EGFR biochemical pathway at different steps along the signaling cascade. Apart from Cetuximab, other anti-EGFR mAbs have been developed, such as Panitumumab. Both antibodies have been approved for the treatment of KRAS-NRAS wild type mCRC, alone or in combination with chemotherapy. These antibodies display strong differences in activating the host immune system against CRC, due to their different immunoglobulin isotypes. Although anti-EGFR antibodies are efficient, drug resistance occurs with high frequency. Resistant tumor cell populations can either already be present before therapy or develop later by biochemical adaptations or new genomic mutations in the EGFR pathway. Numerous efforts have been made to improve the efficacy of the anti-EGFR mAbs or to find new agents that are able to block downstream EGFR signaling cascade molecules. Indeed, we examined the importance of analyzing the anti-EGFR antibody-drug conjugates (ADC) developed to overcome resistance and/or stimulate the tumor host's immunity against CRC growth. Also, patient-derived CRC organoid cultures represent a useful and feasible in vitro model to study tumor behavior and therapy response. Organoids can reflect tumor genetic heterogeneity found in the tissue of origin, representing a unique tool for personalized medicine. Thus, CRC-derived organoid cultures are a smart model for studying the tumor microenvironment and for the preclinical assay of anti-EGFR drugs.
Collapse
Affiliation(s)
- Samuele Tardito
- Center for Cancer and Immunology Research, Children’s National Hospital, Washington, DC 20010, USA;
| | - Serena Matis
- Molecular Oncology and Angiogenesis Unit, IRRCS Ospedale Policlinico San Martino, 16132 Genoa, Italy;
| | - Maria Raffaella Zocchi
- Department of Immunology, Transplant and Infectious Diseases, IRCCS Scientific Institute San Raffaele, 20132 Milan, Italy;
| | - Roberto Benelli
- Molecular Oncology and Angiogenesis Unit, IRRCS Ospedale Policlinico San Martino, 16132 Genoa, Italy;
| | - Alessandro Poggi
- Molecular Oncology and Angiogenesis Unit, IRRCS Ospedale Policlinico San Martino, 16132 Genoa, Italy;
| |
Collapse
|
2
|
Ma X, Wang C, Zhou B, Cheng Z, Mao Z, Tang TS, Guo C. DNA polymerase η promotes nonhomologous end joining upon etoposide exposure dependent on the scaffolding protein Kap1. J Biol Chem 2022; 298:101861. [PMID: 35339488 PMCID: PMC9046958 DOI: 10.1016/j.jbc.2022.101861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 11/25/2022] Open
Abstract
DNA polymerase eta (Pol η) is a eukaryotic member of the Y-family of DNA polymerase involved in translesion DNA synthesis and genome mutagenesis. Recently, several translesion DNA synthesis polymerases have been found to function in repair of DNA double-strand breaks (DSBs). However, the role of Pol η in promoting DSB repair remains to be well defined. Here, we demonstrated that Pol η could be targeted to etoposide (ETO)-induced DSBs and that depletion of Pol η in cells causes increased sensitivity to ETO. Intriguingly, depletion of Pol η also led to a nonhomologous end joining repair defect in a catalytic activity–independent manner. We further identified the scaffold protein Kap1 as a novel interacting partner of Pol η, the depletion of which resulted in impaired formation of Pol η and Rad18 foci after ETO treatment. Additionally, overexpression of Kap1 failed to restore Pol η focus formation in Rad18-deficient cells after ETO treatment. Interestingly, we also found that Kap1 bound to Rad18 in a Pol η-dependent manner, and moreover, depletion of Kap1 led to a significant reduction in Rad18–Pol η association, indicating that Kap1 forms a ternary complex with Rad18 and Pol η to stabilize Rad18–Pol η association. Our findings demonstrate that Kap1 could regulate the role of Pol η in ETO-induced DSB repair via facilitating Rad18 recruitment and stabilizing Rad18–Pol η association.
Collapse
Affiliation(s)
- Xiaolu Ma
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, China; State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
| | - Chen Wang
- Clinical and Translational Research Center of Shanghai First Maternity & Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Bo Zhou
- CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences/China National Center for Bioinformation, Beijing, China
| | - Zina Cheng
- College of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, China
| | - Zhiyong Mao
- Clinical and Translational Research Center of Shanghai First Maternity & Infant Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Tie-Shan Tang
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China; Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China; Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China.
| | - Caixia Guo
- CAS Key Laboratory of Genomics and Precision Medicine, Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences/China National Center for Bioinformation, Beijing, China.
| |
Collapse
|
3
|
Systematic Analysis of Targets of Pumilio-Mediated mRNA Decay Reveals that PUM1 Repression by DNA Damage Activates Translesion Synthesis. Cell Rep 2021; 31:107542. [PMID: 32375027 DOI: 10.1016/j.celrep.2020.107542] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 01/28/2020] [Accepted: 03/31/2020] [Indexed: 02/07/2023] Open
Abstract
RNA-binding proteins (RBPs) play a pivotal role in gene expression by modulating the stability of transcripts. However, the identification of degradation target mRNAs of RBPs remains difficult. By the combined analysis of transcriptome-wide mRNA stabilities and the binding of mRNAs to human Pumilio 1 (PUM1), we identify 48 mRNAs that both bind to PUM1 and exhibit PUM1-dependent degradation. Analysis of changes in the abundance of PUM1 and its degradation target mRNAs in RNA-seq data indicate that DNA-damaging agents negatively regulate PUM1-mediated mRNA decay. Cells exposed to cisplatin have reduced PUM1 abundance and increased PCNA and UBE2A mRNAs encoding proteins involved in DNA damage tolerance by translesion synthesis (TLS). Cells overexpressing PUM1 exhibit impaired DNA synthesis and TLS and increased sensitivity to the cytotoxic effect of cisplatin. Thus, our method identifies target mRNAs of PUM1-mediated decay and reveals that cells respond to DNA damage by inhibiting PUM1-mediated mRNA decay to activate TLS.
Collapse
|
4
|
Poveda A, Méndez MÁ, Armijos-Jaramillo V. Analysis of DNA Polymerases Reveals Specific Genes Expansion in Leishmania and Trypanosoma spp. Front Cell Infect Microbiol 2020; 10:570493. [PMID: 33117729 PMCID: PMC7576959 DOI: 10.3389/fcimb.2020.570493] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 09/02/2020] [Indexed: 01/01/2023] Open
Abstract
Leishmaniasis and trypanosomiasis are largely neglected diseases prevailing in tropical and subtropical conditions. These are an arthropod-borne zoonosis that affects humans and some animals and is caused by infection with protozoan of the genera Leishmania and Trypanosoma, respectively. These parasites present high genomic plasticity and are able to adapt themselves to adverse conditions like the attack of host cells or toxicity induced by drug exposure. Different mechanisms allow these adapting responses induced by stress, such as mutation, chromosomal rearrangements, establishment of mosaic ploidies, and gene expansion. Here we describe how a subset of genes encoding for DNA polymerases implied in repairing/translesion (TLS) synthesis are duplicated in some pathogenic species of the Trypanosomatida order and a free-living species from the Bodonida order. These enzymes are both able to repair DNA, but are also error-prone under certain situations. We discuss about the possibility that these enzymes can act as a source of genomic variation promoting adaptation in trypanosomatids.
Collapse
Affiliation(s)
- Ana Poveda
- DNA Replication and Genome Instability Unit, Grupo de Investigación en Biodiversidad, Zoonosis y Salud Pública (GIBCIZ), Instituto de Investigación en Salud Pública y Zoonosis-CIZ, Facultad de Ciencias Químicas, Universidad Central del Ecuador, Quito, Ecuador.,Departamento de Bioquímica y Biología Molecular, Universidad de Valencia, Burjassot, Spain
| | - Miguel Ángel Méndez
- Grupo de Química Computacional y Teórica, Universidad San Francisco de Quito, Quito, Ecuador
| | - Vinicio Armijos-Jaramillo
- Grupo de Bio-Quimioinformática, Carrera de Ingeniería en Biotecnología, Facultad de Ingeniería y Ciencias Aplicadas, Universidad de Las Américas, Quito, Ecuador
| |
Collapse
|
5
|
Phi KK, Smith MC, Tokarsky EJ, Suo Z. Kinetic Investigation of Translesion Synthesis across a 3-Nitrobenzanthrone-Derived DNA Lesion Catalyzed by Human DNA Polymerase Kappa. Chem Res Toxicol 2019; 32:1699-1706. [PMID: 31286773 DOI: 10.1021/acs.chemrestox.9b00219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
3-Nitrobenzanthrone (3-NBA) is a byproduct of diesel exhaust and is highly present in industrial and populated areas. Inhalation of 3-NBA results in formation of N-(2'-deoxyguanosin-8-yl)-3-aminobenzanthrone (dGC8-N-ABA), a bulky DNA lesion that is of concern due to its mutagenic and carcinogenic potential. If dGC8-N-ABA is not bypassed during genomic replication, the lesion can stall cellular DNA replication machinery, leading to senescence or apoptosis. We have previously used running start assays to demonstrate that human DNA polymerases eta (hPolη) and kappa (hPolκ) are able to catalyze translesion DNA synthesis (TLS) across a site-specifically placed dGC8-N-ABA in a DNA template. Consistently, gene knockdown of hPolη and hPolκ in HEK293T cells reduces the efficiency of TLS across dGC8-N-ABA by ∼25 and ∼30%, respectively. Here, we kinetically investigated why hPolκ paused when bypassing and extending from dGC8-N-ABA. Our kinetic data show that correct dCTP incorporation efficiency of hPolκ dropped by 116-fold when opposite dGC8-N-ABA relative to undamaged dG, leading to hPolκ pausing at the lesion site observed in the running start assays. The already low nucleotide incorporation fidelity of hPolκ was further decreased by 10-fold during lesion bypass, and thus, incorrect nucleotides, especially dATP, were incorporated opposite dGC8-N-ABA with comparable efficiencies as correct dCTP. With regard to the dGC8-N-ABA bypass product extension step, hPolκ incorporated correct dGTP onto the damaged DNA substrate with a 786-fold lower efficiency than onto the corresponding undamaged DNA substrate, which resulted in hPolκ pausing at the site in the running start assays. Furthermore, hPolκ extended the primer-terminal matched base pair dC:dGC8-N-ABA with a 100-1000-fold lower fidelity than it extended the undamaged dC:dG base pair. Together, our kinetic results strongly indicate that hPolκ was error-prone during TLS of dGC8-N-ABA.
Collapse
Affiliation(s)
| | | | | | - Zucai Suo
- Department of Biomedical Sciences , Florida State University College of Medicine , Tallahassee , Florida 32306 , United States
| |
Collapse
|
6
|
Gallo D, Brown GW. Post-replication repair: Rad5/HLTF regulation, activity on undamaged templates, and relationship to cancer. Crit Rev Biochem Mol Biol 2019; 54:301-332. [PMID: 31429594 DOI: 10.1080/10409238.2019.1651817] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 07/12/2019] [Accepted: 07/31/2019] [Indexed: 12/18/2022]
Abstract
The eukaryotic post-replication repair (PRR) pathway allows completion of DNA replication when replication forks encounter lesions on the DNA template and are mediated by post-translational ubiquitination of the DNA sliding clamp proliferating cell nuclear antigen (PCNA). Monoubiquitinated PCNA recruits translesion synthesis (TLS) polymerases to replicate past DNA lesions in an error-prone manner while addition of K63-linked polyubiquitin chains signals for error-free template switching to the sister chromatid. Central to both branches is the E3 ubiquitin ligase and DNA helicase Rad5/helicase-like transcription factor (HLTF). Mutations in PRR pathway components lead to genomic rearrangements, cancer predisposition, and cancer progression. Recent studies have challenged the notion that the PRR pathway is involved only in DNA lesion tolerance and have shed new light on its roles in cancer progression. Molecular details of Rad5/HLTF recruitment and function at replication forks have emerged. Mounting evidence indicates that PRR is required during lesion-less replication stress, leading to TLS polymerase activity on undamaged templates. Analysis of PRR mutation status in human cancers and PRR function in cancer models indicates that down regulation of PRR activity is a viable strategy to inhibit cancer cell growth and reduce chemoresistance. Here, we review these findings, discuss how they change our views of current PRR models, and look forward to targeting the PRR pathway in the clinic.
Collapse
Affiliation(s)
- David Gallo
- Department of Biochemistry and Donnelly Centre, University of Toronto , Toronto , Canada
| | - Grant W Brown
- Department of Biochemistry and Donnelly Centre, University of Toronto , Toronto , Canada
| |
Collapse
|
7
|
Kurashima K, Sekimoto T, Oda T, Kawabata T, Hanaoka F, Yamashita T. Polη, a Y-family translesion synthesis polymerase, promotes cellular tolerance of Myc-induced replication stress. J Cell Sci 2018; 131:jcs.212183. [PMID: 29777036 DOI: 10.1242/jcs.212183] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 05/10/2018] [Indexed: 12/30/2022] Open
Abstract
Growth of precancerous and cancer cells relies on their tolerance of oncogene-induced replication stress (RS). Translesion synthesis (TLS) plays an essential role in the cellular tolerance of various types of RS and bypasses replication barriers by employing specialized polymerases. However, limited information is available about the role of TLS polymerases in oncogene-induced RS. Here, we report that Polη, a Y-family TLS polymerase, promotes cellular tolerance of Myc-induced RS. Polη was recruited to Myc-induced RS sites, and Polη depletion enhanced the Myc-induced slowing and stalling of replication forks and the subsequent generation of double-strand breaks (DSBs). Overexpression of a catalytically dead Polη also promoted Myc-induced DSB formation. In the absence of Polη, Myc-induced DSB formation depended on MUS81-EME2 (the S-phase-specific endonuclease complex), and concomitant depletion of MUS81-EME2 and Polη enhanced RS and cell death in a synergistic manner. Collectively, these results indicate that Polη facilitates fork progression during Myc-induced RS, thereby helping cells tolerate the resultant deleterious effects. Additionally, the present study highlights the possibility of a synthetic sickness or lethality between Polη and MUS81-EME2 in cells experiencing Myc-induced RS.
Collapse
Affiliation(s)
- Kiminori Kurashima
- Laboratory of Molecular Genetics, Institute for Molecular and Cellular Regulation, Gunma University, 371-8512 Gunma, Japan
| | - Takayuki Sekimoto
- Laboratory of Molecular Genetics, Institute for Molecular and Cellular Regulation, Gunma University, 371-8512 Gunma, Japan
| | - Tsukasa Oda
- Laboratory of Molecular Genetics, Institute for Molecular and Cellular Regulation, Gunma University, 371-8512 Gunma, Japan
| | - Tsuyoshi Kawabata
- Department of Stem Cell Biology, Atomic Bomb Disease Institute, Nagasaki University, 852-8523 Nagasaki, Japan
| | - Fumio Hanaoka
- Department of Life Science, Faculty of Science, Gakushuin University, 171-8588 Tokyo, Japan
| | - Takayuki Yamashita
- Laboratory of Molecular Genetics, Institute for Molecular and Cellular Regulation, Gunma University, 371-8512 Gunma, Japan
| |
Collapse
|
8
|
A neomorphic cancer cell-specific role of MAGE-A4 in trans-lesion synthesis. Nat Commun 2016; 7:12105. [PMID: 27377895 PMCID: PMC4935975 DOI: 10.1038/ncomms12105] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 05/31/2016] [Indexed: 12/11/2022] Open
Abstract
Trans-lesion synthesis (TLS) is an important DNA-damage tolerance mechanism that permits ongoing DNA synthesis in cells harbouring damaged genomes. The E3 ubiquitin ligase RAD18 activates TLS by promoting recruitment of Y-family DNA polymerases to sites of DNA-damage-induced replication fork stalling. Here we identify the cancer/testes antigen melanoma antigen-A4 (MAGE-A4) as a tumour cell-specific RAD18-binding partner and an activator of TLS. MAGE-A4 depletion from MAGE-A4-expressing cancer cells destabilizes RAD18. Conversely, ectopic expression of MAGE-A4 (in cell lines lacking endogenous MAGE-A4) promotes RAD18 stability. DNA-damage-induced mono-ubiquitination of the RAD18 substrate PCNA is attenuated by MAGE-A4 silencing. MAGE-A4-depleted cells fail to resume DNA synthesis normally following ultraviolet irradiation and accumulate γH2AX, thereby recapitulating major hallmarks of TLS deficiency. Taken together, these results demonstrate a mechanism by which reprogramming of ubiquitin signalling in cancer cells can influence DNA damage tolerance and probably contribute to an altered genomic landscape. RAD18 is an important protein in trans-lesion synthesis, an error-prone damage-tolerant mode of DNA replication. Here the authors show that MAGE-A4 stabilizes RAD18 and allows cancer cells to maintain on-going DNA synthesis in the face of genotoxic injury.
Collapse
|
9
|
Gening LV, Lakhin AV, Makarova IV, Nenasheva VV, Andreeva LE, Tarantul VZ. Alterations in Synthesis and Repair of DNA during the Development of Loach Misgurnus fossilis. J Dev Biol 2016; 4:jdb4010006. [PMID: 29615575 PMCID: PMC5831811 DOI: 10.3390/jdb4010006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 01/18/2016] [Accepted: 01/20/2016] [Indexed: 01/01/2023] Open
Abstract
Using a modified radiolabeled primer extension method (we named this modification misGvA—“misincorporation of G versus A”) we have investigated the DNA synthesis and repair at early and late stages of development of loach Misgurnus fossilis. The misincorporation activity of DNA polymerase iota (Pol ι) in wild-type loach could not be detected by this method at any stage of loach development. In transgenic loach overexpressing human Pol ι we have shown that the bypassing of DNA synthesis arrest after incorporation of mismatched nucleotide by Pol ι (the T-stop) was not associated with this enzyme. Non-transgenic loach larvae are virtually lacking the capacity for error correction of DNA duplex containing a mismatched nucleotide. Such repair activity develops only in the adult fish. It appears that the initial stages of development are characterized by more intensive DNA synthesis, while in terminal stages the repair activities become more prominent. The misGvA approach clearly indicates substantial changes in the DNA synthesis intensity, although the role of particular replicative and repair DNA polymerases in this process requires further study.
Collapse
Affiliation(s)
- Leonid V Gening
- Institute of Molecular Genetics, Russian Academy of Sciences, 2 Kurchatov Square, 123182 Moscow, Russia.
| | - Andrei V Lakhin
- Institute of Molecular Genetics, Russian Academy of Sciences, 2 Kurchatov Square, 123182 Moscow, Russia.
| | - Irina V Makarova
- Institute of Molecular Genetics, Russian Academy of Sciences, 2 Kurchatov Square, 123182 Moscow, Russia.
| | - Valentina V Nenasheva
- Institute of Molecular Genetics, Russian Academy of Sciences, 2 Kurchatov Square, 123182 Moscow, Russia.
| | - Ludmila E Andreeva
- Institute of Molecular Genetics, Russian Academy of Sciences, 2 Kurchatov Square, 123182 Moscow, Russia.
| | - Vyacheslav Z Tarantul
- Institute of Molecular Genetics, Russian Academy of Sciences, 2 Kurchatov Square, 123182 Moscow, Russia.
| |
Collapse
|
10
|
Federico MB, Vallerga MB, Radl A, Paviolo NS, Bocco JL, Di Giorgio M, Soria G, Gottifredi V. Chromosomal Integrity after UV Irradiation Requires FANCD2-Mediated Repair of Double Strand Breaks. PLoS Genet 2016; 12:e1005792. [PMID: 26765540 PMCID: PMC4712966 DOI: 10.1371/journal.pgen.1005792] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 12/17/2015] [Indexed: 12/29/2022] Open
Abstract
Fanconi Anemia (FA) is a rare autosomal recessive disorder characterized by hypersensitivity to inter-strand crosslinks (ICLs). FANCD2, a central factor of the FA pathway, is essential for the repair of double strand breaks (DSBs) generated during fork collapse at ICLs. While lesions different from ICLs can also trigger fork collapse, the contribution of FANCD2 to the resolution of replication-coupled DSBs generated independently from ICLs is unknown. Intriguingly, FANCD2 is readily activated after UV irradiation, a DNA-damaging agent that generates predominantly intra-strand crosslinks but not ICLs. Hence, UV irradiation is an ideal tool to explore the contribution of FANCD2 to the DNA damage response triggered by DNA lesions other than ICL repair. Here we show that, in contrast to ICL-causing agents, UV radiation compromises cell survival independently from FANCD2. In agreement, FANCD2 depletion does not increase the amount of DSBs generated during the replication of UV-damaged DNA and is dispensable for UV-induced checkpoint activation. Remarkably however, FANCD2 protects UV-dependent, replication-coupled DSBs from aberrant processing by non-homologous end joining, preventing the accumulation of micronuclei and chromatid aberrations including non-homologous chromatid exchanges. Hence, while dispensable for cell survival, FANCD2 selectively safeguards chromosomal stability after UV-triggered replication stress.
Collapse
Affiliation(s)
- María Belén Federico
- Cell Cycle and Genomic Stability Laboratory, Fundación Instituto Leloir, IIBBA/ CONICET, Buenos Aires, Argentina
| | - María Belén Vallerga
- Cell Cycle and Genomic Stability Laboratory, Fundación Instituto Leloir, IIBBA/ CONICET, Buenos Aires, Argentina
| | - Analía Radl
- Laboratorio de Dosimetría Biológica, Autoridad Regulatoria Nuclear, Buenos Aires, Argentina
| | - Natalia Soledad Paviolo
- Cell Cycle and Genomic Stability Laboratory, Fundación Instituto Leloir, IIBBA/ CONICET, Buenos Aires, Argentina
| | - José Luis Bocco
- Centro de Investigaciones en Bioquímica Clínica e Inmunología/ CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Marina Di Giorgio
- Laboratorio de Dosimetría Biológica, Autoridad Regulatoria Nuclear, Buenos Aires, Argentina
| | - Gastón Soria
- Centro de Investigaciones en Bioquímica Clínica e Inmunología/ CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Vanesa Gottifredi
- Cell Cycle and Genomic Stability Laboratory, Fundación Instituto Leloir, IIBBA/ CONICET, Buenos Aires, Argentina
| |
Collapse
|
11
|
Richter KS, Götz M, Winter S, Jeske H. The contribution of translesion synthesis polymerases on geminiviral replication. Virology 2015; 488:137-48. [PMID: 26638018 DOI: 10.1016/j.virol.2015.10.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 10/26/2015] [Accepted: 10/28/2015] [Indexed: 12/25/2022]
Abstract
Geminiviruses multiply primarily in the plant phloem, but never in meristems. Their Rep protein can activate DNA synthesis in differentiated cells. However, when their single-stranded DNA is injected into the phloem by insects, no Rep is present for inducing initial complementary strand replication. Considering a contribution of translesion synthesis (TLS) polymerases in plants, four of them (Polη, Polζ, Polκ, Rev1) are highly and constitutively expressed in differentiated tissues like the phloem. Two geminiviruses (Euphorbia yellow mosaic virus, Cleome leaf crumple virus), inoculated either biolistically or by whiteflies, replicated in Arabidopsis thaliana mutant lines of these genes to the same extent as in wild type plants. Comparative deep sequencing of geminiviral DNAs, however, showed a high exchange rate (10(-4)-10(-3)) similar to the phylogenetic variation described before and a significant difference in nucleotide substation rates if Polη and Polζ were absent, with a differential response to the viral DNA components.
Collapse
Affiliation(s)
- Kathrin S Richter
- Institute of Biomaterials and Biomolecular Systems, Department of Molecular Biology and Plant Virology, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | - Monika Götz
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Messeweg 11-12, D-38104 Braunschweig, Germany
| | - Stephan Winter
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Messeweg 11-12, D-38104 Braunschweig, Germany
| | - Holger Jeske
- Institute of Biomaterials and Biomolecular Systems, Department of Molecular Biology and Plant Virology, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
| |
Collapse
|