1
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Liu Y, Yang H, Gan S, He L, Zeng R, Xiao T, Wu L. A novel mutation of DNA2 regulates neuronal cell membrane potential and epileptogenesis. Cell Death Discov 2024; 10:259. [PMID: 38802339 PMCID: PMC11130173 DOI: 10.1038/s41420-024-02029-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 04/28/2024] [Accepted: 05/14/2024] [Indexed: 05/29/2024] Open
Abstract
Mesial temporal lobe epilepsy (MTLE) is one of the most intractable epilepsies. Previously, we reported that mitochondrial DNA deletions were associated with epileptogenesis. While the underlying mechanism of mitochondrial DNA deletions during epileptogenesis remain unknown. In this study, a novel somatic mutation of DNA2 gene was identified in the hippocampal tissue of two MTLE patients carrying mitochondrial DNA deletions, and this mutation decreased the full-length expression of DNA2 protein significantly, aborting its normal functions. Then, we knocked down the DNA2 protein in zebrafish, and we demonstrated that zebrafish with DNA2 deficiency showed decreased expression of mitochondrial complex II-IV, and exhibited hallmarks of epileptic seizures, including abnormal development of the zebrafish and epileptiform discharge signals in brain, compared to the Cas9-control group. Moreover, our cell-based assays showed that DNA2 deletion resulted in accumulated mitochondrial DNA damage, abnormal oxidative phosphorylation and decreased ATP production in cells. Inadequate ATP generation in cells lead to declined Na+, K+-ATPase activity and change of cell membrane potential. Together, these disorders caused by DNA2 depletion increased cell apoptosis and inhibited the differentiation of SH-SY5Y into branched neuronal phenotype. In conclusion, DNA2 deficiency regulated the cell membrane potential via affecting ATP production by mitochondria and Na+, K+-ATPase activity, and also affected neuronal cell growth and differentiation. These disorders caused by DNA2 dysfunction are important causes of epilepsy. In summary, we are the first to report the pathogenic somatic mutation of DNA2 gene in the patients with MTLE disease, and we uncovered the mechanism of DNA2 regulating the epilepsy. This study provides new insight into the pathogenesis of epilepsy and underscore the value of DNA2 in epilepsy.
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Affiliation(s)
- Yuting Liu
- Pediatrics Research Institute, The Affiliated Children's Hospital of Xiangya School of Medicine, Hunan Children's Hospital, Central South University, Changsha, Hunan, China
| | - Haiyan Yang
- Department of Neurology, The Affiliated Children's Hospital of Xiangya School of Medicine, Hunan Children's Hospital, Central South University, Changsha, Hunan, China
| | - Siyi Gan
- Department of Neurology, The Affiliated Children's Hospital of Xiangya School of Medicine, Hunan Children's Hospital, Central South University, Changsha, Hunan, China
| | - Lu He
- Department of Neurology, The Affiliated Children's Hospital of Xiangya School of Medicine, Hunan Children's Hospital, Central South University, Changsha, Hunan, China
| | - Rongrong Zeng
- Department of Neurology, The Affiliated Children's Hospital of Xiangya School of Medicine, Hunan Children's Hospital, Central South University, Changsha, Hunan, China
| | - Ting Xiao
- Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Liwen Wu
- Department of Neurology, The Affiliated Children's Hospital of Xiangya School of Medicine, Hunan Children's Hospital, Central South University, Changsha, Hunan, China.
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2
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Sanyal S, Kouznetsova A, Ström L, Björkegren C. A system for inducible mitochondria-specific protein degradation in vivo. Nat Commun 2024; 15:1454. [PMID: 38365818 PMCID: PMC10873288 DOI: 10.1038/s41467-024-45819-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 02/05/2024] [Indexed: 02/18/2024] Open
Abstract
Targeted protein degradation systems developed for eukaryotes employ cytoplasmic machineries to perform proteolysis. This has prevented mitochondria-specific analysis of proteins that localize to multiple locations, for example, the mitochondria and the nucleus. Here, we present an inducible mitochondria-specific protein degradation system in Saccharomyces cerevisiae based on the Mesoplasma florum Lon (mf-Lon) protease and its corresponding ssrA tag (called PDT). We show that mitochondrially targeted mf-Lon protease efficiently and selectively degrades a PDT-tagged reporter protein localized to the mitochondrial matrix. The degradation can be induced by depleting adenine from the medium, and tuned by altering the promoter strength of the MF-LON gene. We furthermore demonstrate that mf-Lon specifically degrades endogenous, PDT-tagged mitochondrial proteins. Finally, we show that mf-Lon-dependent PDT degradation can also be achieved in human mitochondria. In summary, this system provides an efficient tool to selectively analyze the mitochondrial function of dually localized proteins.
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Affiliation(s)
- Swastika Sanyal
- Karolinska Institutet, Department of Biosciences and Nutrition, Neo, Hälsovägen 7c, 141 83, Huddinge, Sweden.
| | - Anna Kouznetsova
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77, Stockholm, Sweden
| | - Lena Ström
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77, Stockholm, Sweden
| | - Camilla Björkegren
- Karolinska Institutet, Department of Cell and Molecular Biology, Biomedicum, Tomtebodavägen 16, 171 77, Stockholm, Sweden.
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3
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Thongon N, Ma F, Baran N, Lockyer P, Liu J, Jackson C, Rose A, Furudate K, Wildeman B, Marchesini M, Marchica V, Storti P, Todaro G, Ganan-Gomez I, Adema V, Rodriguez-Sevilla JJ, Qing Y, Ha MJ, Fonseca R, Stein C, Class C, Tan L, Attanasio S, Garcia-Manero G, Giuliani N, Berrios Nolasco D, Santoni A, Cerchione C, Bueso-Ramos C, Konopleva M, Lorenzi P, Takahashi K, Manasanch E, Sammarelli G, Kanagal-Shamanna R, Viale A, Chesi M, Colla S. Targeting DNA2 overcomes metabolic reprogramming in multiple myeloma. Nat Commun 2024; 15:1203. [PMID: 38331987 PMCID: PMC10853245 DOI: 10.1038/s41467-024-45350-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 01/18/2024] [Indexed: 02/10/2024] Open
Abstract
DNA damage resistance is a major barrier to effective DNA-damaging therapy in multiple myeloma (MM). To discover mechanisms through which MM cells overcome DNA damage, we investigate how MM cells become resistant to antisense oligonucleotide (ASO) therapy targeting Interleukin enhancer binding factor 2 (ILF2), a DNA damage regulator that is overexpressed in 70% of MM patients whose disease has progressed after standard therapies have failed. Here, we show that MM cells undergo adaptive metabolic rewiring to restore energy balance and promote survival in response to DNA damage activation. Using a CRISPR/Cas9 screening strategy, we identify the mitochondrial DNA repair protein DNA2, whose loss of function suppresses MM cells' ability to overcome ILF2 ASO-induced DNA damage, as being essential to counteracting oxidative DNA damage. Our study reveals a mechanism of vulnerability of MM cells that have an increased demand for mitochondrial metabolism upon DNA damage activation.
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Affiliation(s)
- Natthakan Thongon
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Feiyang Ma
- Division of Rheumatology, Department of Internal Medicine, Michigan Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Natalia Baran
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Pamela Lockyer
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jintan Liu
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Christopher Jackson
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ashley Rose
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ken Furudate
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Bethany Wildeman
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Matteo Marchesini
- IRCCS Instituto Romagnolo per lo Studio dei Tumori (IRST) Dino Amadori, Meldola, Italy
| | | | - Paola Storti
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Giannalisa Todaro
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Irene Ganan-Gomez
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Vera Adema
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | | | - Yun Qing
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Min Jin Ha
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | | | - Caleb Stein
- Department of Medicine, Mayo Clinic, Scottsdale, AZ, USA
| | - Caleb Class
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Butler University, Indianapolis, IN, USA
| | - Lin Tan
- Metabolomics Core Facility, Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Sergio Attanasio
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | | | - Nicola Giuliani
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - David Berrios Nolasco
- Department of Lymphoma and Myeloma, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Andrea Santoni
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Claudio Cerchione
- IRCCS Instituto Romagnolo per lo Studio dei Tumori (IRST) Dino Amadori, Meldola, Italy
| | - Carlos Bueso-Ramos
- Department of Hemopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Marina Konopleva
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Philip Lorenzi
- Metabolomics Core Facility, Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Koichi Takahashi
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Elisabet Manasanch
- Department of Lymphoma and Myeloma, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | | | - Rashmi Kanagal-Shamanna
- Department of Hemopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Andrea Viale
- Department of Genomic Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Marta Chesi
- Department of Medicine, Mayo Clinic, Scottsdale, AZ, USA
| | - Simona Colla
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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4
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Mackay HL, Stone HR, Ellis K, Ronson GE, Walker AK, Starowicz K, Garvin AJ, van Eijk P, Vaitsiankova A, Vijayendran S, Beesley JF, Petermann E, Brown EJ, Densham RM, Reed SH, Dobbs F, Saponaro M, Morris JR. USP50 suppresses alternative RecQ helicase use and deleterious DNA2 activity during replication. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.10.574674. [PMID: 38260523 PMCID: PMC10802463 DOI: 10.1101/2024.01.10.574674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Mammalian DNA replication employs several RecQ DNA helicases to orchestrate the faithful duplication of genetic information. Helicase function is often coupled to the activity of specific nucleases, but how helicase and nuclease activities are co-directed is unclear. Here we identify the inactive ubiquitin-specific protease, USP50, as a ubiquitin-binding and chromatin-associated protein required for ongoing replication, fork restart, telomere maintenance and cellular survival during replicative stress. USP50 supports WRN:FEN1 at stalled replication forks, suppresses MUS81-dependent fork collapse and restricts double-strand DNA breaks at GC-rich sequences. Surprisingly we find that cells depleted for USP50 and recovering from a replication block exhibit increased DNA2 and RECQL4 foci and that the defects in ongoing replication, poor fork restart and increased fork collapse seen in these cells are mediated by DNA2, RECQL4 and RECQL5. These data define a novel ubiquitin-dependent pathway that promotes the balance of helicase: nuclease use at ongoing and stalled replication forks.
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5
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Polêto MD, Lemkul JA. Differences in Conformational Sampling and Intrinsic Electric Fields Drive Ion Binding in Telomeric and TERRA G-Quadruplexes. J Chem Inf Model 2023; 63:6851-6862. [PMID: 37847037 PMCID: PMC10841373 DOI: 10.1021/acs.jcim.3c01305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
The formation of G-quadruplexes (GQs) occurs in guanine-rich sequences of DNA and RNA, producing highly stable and structurally diverse noncanonical nucleic acid structures. GQs play crucial roles in regulating transcription, translation, and replication and maintaining the genome, among others; thus, changes to their structures can lead to diseases such as cancer. Previous studies using polarizable molecular dynamics simulations have shown differences in ion binding properties between telomeric and telomeric repeat-containing RNA GQs despite architectural similarities. Here, we used volume-based metadynamics and repulsive potential simulations in conjunction with polarizable force fields to quantify the impact of ion binding on the GQ dynamics and ion binding free energies. Furthermore, we describe how GQs exert electric fields on their surroundings to link dynamics with variations in the electronic structure. Our findings provide new insights into the energetic, physical, and conformational properties of GQs and expose subtle but important differences between DNA and RNA GQs with the same fold.
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Affiliation(s)
- Marcelo D Polêto
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Justin A Lemkul
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States
- Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
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6
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Czarny P, Ziółkowska S, Kołodziej Ł, Watała C, Wigner-Jeziorska P, Bliźniewska-Kowalska K, Wachowska K, Gałecka M, Synowiec E, Gałecki P, Bijak M, Szemraj J, Śliwiński T. Single-Nucleotide Polymorphisms in Genes Maintaining the Stability of Mitochondrial DNA Affect the Occurrence, Onset, Severity and Treatment of Major Depressive Disorder. Int J Mol Sci 2023; 24:14752. [PMID: 37834200 PMCID: PMC10573273 DOI: 10.3390/ijms241914752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 09/26/2023] [Accepted: 09/27/2023] [Indexed: 10/15/2023] Open
Abstract
One of the key features of major depressive disorder (MDD, depression) is increased oxidative stress manifested by elevated levels of mtROS, a hallmark of mitochondrial dysfunction, which can arise from mitochondrial DNA (mtDNA) damage. Thus, the current study explores possibility that the single-nucleotide polymorphisms (SNPs) of genes encoding the three enzymes that are thought to be implicated in the replication, repair or degradation of mtDNA, i.e., POLG, ENDOG and EXOG, have an impact on the occurrence, onset, severity and treatment of MDD. Five SNPs were selected: EXOG c.-188T > G (rs9838614), EXOG c.*627G > A (rs1065800), POLG c.-1370T > A (rs1054875), ENDOG c.-394T > C (rs2977998) and ENDOG c.-220C > T (rs2997922), while genotyping was performed on 538 DNA samples (277 cases and 261 controls) using TaqMan probes. All SNPs of EXOG and ENDOG modulated the risk of depression, but the strongest effect was observed for rs1065800, while rs9838614 and rs2977998 indicate that they might influence the severity of symptoms, and, to a lesser extent, treatment effectiveness. Although the SNP located in POLG did not affect occurrence of the disease, the result suggests that it may influence the onset and treatment outcome. These findings further support the hypothesis that mtDNA damage and impairment in its metabolism play a crucial role not only in the development, but also in the treatment of depression.
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Affiliation(s)
- Piotr Czarny
- Department of Medical Biochemistry, Medical University of Lodz, 92-215 Lodz, Poland; (S.Z.); (J.S.)
| | - Sylwia Ziółkowska
- Department of Medical Biochemistry, Medical University of Lodz, 92-215 Lodz, Poland; (S.Z.); (J.S.)
| | - Łukasz Kołodziej
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 92-215 Lodz, Poland; (Ł.K.)
| | - Cezary Watała
- Department of Haemostatic Disorders, Medical University of Lodz, 92-215 Lodz, Poland;
| | - Paulina Wigner-Jeziorska
- Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, 90-136 Lodz, Poland;
| | | | - Katarzyna Wachowska
- Department of Adult Psychiatry, Medical University of Lodz, 91-229 Lodz, Poland; (K.B.-K.); (K.W.); (P.G.)
| | - Małgorzata Gałecka
- Department of Psychotherapy, Medical University of Lodz, 91-229 Lodz, Poland;
| | - Ewelina Synowiec
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 92-215 Lodz, Poland; (Ł.K.)
| | - Piotr Gałecki
- Department of Adult Psychiatry, Medical University of Lodz, 91-229 Lodz, Poland; (K.B.-K.); (K.W.); (P.G.)
| | - Michał Bijak
- Biohazard Prevention Centre, Faculty of Biology and Environmental Protection, University of Lodz, 90-136 Lodz, Poland;
| | - Janusz Szemraj
- Department of Medical Biochemistry, Medical University of Lodz, 92-215 Lodz, Poland; (S.Z.); (J.S.)
| | - Tomasz Śliwiński
- Laboratory of Medical Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 92-215 Lodz, Poland; (Ł.K.)
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7
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Polêto MD, Lemkul JA. Differences in Conformational Sampling and Intrinsic Electric Fields Drive Ion Binding in Telomeric and TERRA G-Quadruplexes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.10.552810. [PMID: 37645825 PMCID: PMC10461924 DOI: 10.1101/2023.08.10.552810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
The formation of G-quadruplexes (GQs) occurs in guanine-rich sequences of DNA and RNA, producing highly stable and structurally diverse noncanonical nucleic acid structures. GQs play crucial roles in regulating transcription, translation, and replication; and maintaining the genome, among others, thus changes to their structures can lead to diseases such as cancer. Previous studies using polarizable molecular dynamics simulations have shown differences in ion binding properties between telomeric and TERRA GQs despite architectural similarities. Here, we used volume-based metadynamics and repulsive potential simulations in conjunction with polarizable force fields to quantify the impact of ion binding on GQ dynamics and ion binding free energies. Furthermore, we describe how GQs exert electric fields on their surroundings to link dynamics with variations in electronic structure. Our findings provide new insights into the energetic, physical, and conformational properties of GQs and expose subtle, but important, differences between DNA and RNA GQs with the same fold.
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Affiliation(s)
- Marcelo D Polêto
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, United States
| | - Justin A Lemkul
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, United States
- Center for Drug Discovery, Virginia Tech, Blacksburg, VA 24061, United States
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8
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Farcy S, Hachour H, Bahi-Buisson N, Passemard S. Genetic Primary Microcephalies: When Centrosome Dysfunction Dictates Brain and Body Size. Cells 2023; 12:1807. [PMID: 37443841 PMCID: PMC10340463 DOI: 10.3390/cells12131807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 06/04/2023] [Accepted: 06/13/2023] [Indexed: 07/15/2023] Open
Abstract
Primary microcephalies (PMs) are defects in brain growth that are detectable at or before birth and are responsible for neurodevelopmental disorders. Most are caused by biallelic or, more rarely, dominant mutations in one of the likely hundreds of genes encoding PM proteins, i.e., ubiquitous centrosome or microtubule-associated proteins required for the division of neural progenitor cells in the embryonic brain. Here, we provide an overview of the different types of PMs, i.e., isolated PMs with or without malformations of cortical development and PMs associated with short stature (microcephalic dwarfism) or sensorineural disorders. We present an overview of the genetic, developmental, neurological, and cognitive aspects characterizing the most representative PMs. The analysis of phenotypic similarities and differences among patients has led scientists to elucidate the roles of these PM proteins in humans. Phenotypic similarities indicate possible redundant functions of a few of these proteins, such as ASPM and WDR62, which play roles only in determining brain size and structure. However, the protein pericentrin (PCNT) is equally required for determining brain and body size. Other PM proteins perform both functions, albeit to different degrees. Finally, by comparing phenotypes, we considered the interrelationships among these proteins.
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Affiliation(s)
- Sarah Farcy
- UMR144, Institut Curie, 75005 Paris, France;
- Inserm UMR-S 1163, Institut Imagine, 75015 Paris, France
| | - Hassina Hachour
- Service de Neurologie Pédiatrique, DMU INOV-RDB, APHP, Hôpital Robert Debré, 75019 Paris, France;
| | - Nadia Bahi-Buisson
- Service de Neurologie Pédiatrique, DMU MICADO, APHP, Hôpital Necker Enfants Malades, 75015 Paris, France;
- Université Paris Cité, Inserm UMR-S 1163, Institut Imagine, 75015 Paris, France
| | - Sandrine Passemard
- Service de Neurologie Pédiatrique, DMU INOV-RDB, APHP, Hôpital Robert Debré, 75019 Paris, France;
- Université Paris Cité, Inserm UMR 1141, NeuroDiderot, 75019 Paris, France
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9
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Thongon N, Ma F, Lockyer P, Baran N, Liu J, Jackson C, Rose A, Wildeman B, Marchesini M, Marchica V, Storti P, Giuliani N, Ganan-Gomez I, Adema V, Qing Y, Ha M, Fonseca R, Class C, Tan L, Kanagal-Shamanna R, Nolasco DB, Cerchione C, Montalban-Bravo G, Santoni A, Bueso-Ramos C, Konopleva M, Lorenzi P, Garcia-Manero G, Manasanch E, Viale A, Chesi M, Colla S. Targeting DNA2 Overcomes Metabolic Reprogramming in Multiple Myeloma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.22.529457. [PMID: 36865225 PMCID: PMC9980056 DOI: 10.1101/2023.02.22.529457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
DNA damage resistance is a major barrier to effective DNA-damaging therapy in multiple myeloma (MM). To discover novel mechanisms through which MM cells overcome DNA damage, we investigated how MM cells become resistant to antisense oligonucleotide (ASO) therapy targeting ILF2, a DNA damage regulator that is overexpressed in 70% of MM patients whose disease has progressed after standard therapies have failed. Here, we show that MM cells undergo an adaptive metabolic rewiring and rely on oxidative phosphorylation to restore energy balance and promote survival in response to DNA damage activation. Using a CRISPR/Cas9 screening strategy, we identified the mitochondrial DNA repair protein DNA2, whose loss of function suppresses MM cells' ability to overcome ILF2 ASO-induced DNA damage, as being essential to counteracting oxidative DNA damage and maintaining mitochondrial respiration. Our study revealed a novel vulnerability of MM cells that have an increased demand for mitochondrial metabolism upon DNA damage activation. STATEMENT OF SIGNIFICANCE Metabolic reprogramming is a mechanism through which cancer cells maintain survival and become resistant to DNA-damaging therapy. Here, we show that targeting DNA2 is synthetically lethal in myeloma cells that undergo metabolic adaptation and rely on oxidative phosphorylation to maintain survival after DNA damage activation.
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10
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Sahayasheela VJ, Yu Z, Hidaka T, Pandian GN, Sugiyama H. Mitochondria and G-quadruplex evolution: an intertwined relationship. Trends Genet 2023; 39:15-30. [PMID: 36414480 PMCID: PMC9772288 DOI: 10.1016/j.tig.2022.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/27/2022] [Accepted: 10/27/2022] [Indexed: 11/21/2022]
Abstract
G-quadruplexes (G4s) are non-canonical structures formed in guanine (G)-rich sequences through stacked G tetrads by Hoogsteen hydrogen bonding. Several studies have demonstrated the existence of G4s in the genome of various organisms, including humans, and have proposed that G4s have a regulatory role in various cellular functions. However, little is known regarding the dissemination of G4s in mitochondria. In this review, we report the observation that the number of potential G4-forming sequences in the mitochondrial genome increases with the evolutionary complexity of different species, suggesting that G4s have a beneficial role in higher-order organisms. We also discuss the possible function of G4s in mitochondrial (mt)DNA and long noncoding (lnc)RNA and their role in various biological processes.
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Affiliation(s)
- Vinodh J Sahayasheela
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | - Zutao Yu
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | - Takuya Hidaka
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | - Ganesh N Pandian
- Institute for Integrated Cell-Material Science (WPI-iCeMS), Kyoto University, Sakyo, Kyoto 606-8501, Japan
| | - Hiroshi Sugiyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan; Institute for Integrated Cell-Material Science (WPI-iCeMS), Kyoto University, Sakyo, Kyoto 606-8501, Japan.
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11
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Saleem B, Farooq U, Rehman OU, Aqeel M, Farooq MS, Naeem MK, Inam S, Ajmal W, Rahim AA, Chen M, Kalsoom R, Uzair M, Fiaz S, Attia K, Alafari HA, Khan MR, Yu G. Genome-wide and molecular characterization of the DNA replication helicase 2 ( DNA2) gene family in rice under drought and salt stress. Front Genet 2022; 13:1039548. [PMID: 36506305 PMCID: PMC9728955 DOI: 10.3389/fgene.2022.1039548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 10/31/2022] [Indexed: 11/23/2022] Open
Abstract
Rice plants experience various biotic (such as insect and pest attack) and abiotic (such as drought, salt, heat, and cold etc.) stresses during the growing season, resulting in DNA damage and the subsequent losses in rice production. DNA Replication Helicase/Nuclease2 (DNA2) is known to be involved in DNA replication and repair. In animals and yeast DNA2 are well characterized because it has the abilities of both helicase and nuclease, it plays a crucial role in DNA replication in the nucleus and mitochondrial genomes. However; they are not fully examined in plants due to less focused on plants damage repair. To fill this research gap, the current study focused on the genome-wide identification and characterization of OsDNA2 genes, along with analyses of their transcriptional expression, duplication, and phylogeny in rice. Overall, 17 OsDNA2 members were reported to be found on eight different chromosomes (2, 3, 4, 6, 7, 9, 10, and 11). Among these chromosomes (Chr), Chr4 contained a maximum of six OsDNA2 genes. Based on phylogenetic analysis, the OsDNA2 gene members were clustered into three different groups. Furthermore, the conserved domains, gene structures, and cis-regulatory elements were systematically investigated. Gene duplication analysis revealed that OsDNA2_2 had an evolutionary relationship with OsDNA2_14, OsDNA2_5 with OsDNA2_6, and OsDNA2_1 with OsDNA2_8. Moreover, results showed that the conserved domain (AAA_11 superfamily) were present in the OsDNA2 genes, which belongs to the DEAD-like helicase superfamily. In addition, to understand the post-transcriptional modification of OsDNA2 genes, miRNAs were predicted, where 653 miRNAs were reported to target 17 OsDNA2 genes. The results indicated that at the maximum, OsDNA2_1 and OsDNA2_4 were targeted by 74 miRNAs each, and OsDNA2_9 was less targeted (20 miRNAs). The three-dimensional (3D) structures of 17 OsDNA2 proteins were also predicted. Expression of OsDNA2 members was also carried out under drought and salt stresses, and conclusively their induction indicated the possible involvement of OsDNA2 in DNA repair under stress when compared with the control. Further studies are recommended to confirm where this study will offer valuable basic data on the functioning of DNA2 genes in rice and other crop plants.
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Affiliation(s)
- Bilal Saleem
- National Institute for Genomics and Advanced Biotechnology, National Agricultural Research Centre, Islamabad, Pakistan
| | - Umer Farooq
- National Institute for Genomics and Advanced Biotechnology, National Agricultural Research Centre, Islamabad, Pakistan
| | - Obaid Ur Rehman
- National Institute for Genomics and Advanced Biotechnology, National Agricultural Research Centre, Islamabad, Pakistan,Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Muhammad Aqeel
- National Institute for Genomics and Advanced Biotechnology, National Agricultural Research Centre, Islamabad, Pakistan
| | - Muhammad Shahbaz Farooq
- National Institute for Genomics and Advanced Biotechnology, National Agricultural Research Centre, Islamabad, Pakistan
| | - Muhammad Kashif Naeem
- National Institute for Genomics and Advanced Biotechnology, National Agricultural Research Centre, Islamabad, Pakistan
| | - Safeena Inam
- National Institute for Genomics and Advanced Biotechnology, National Agricultural Research Centre, Islamabad, Pakistan
| | - Wajya Ajmal
- National Institute for Genomics and Advanced Biotechnology, National Agricultural Research Centre, Islamabad, Pakistan
| | - Amna Abdul Rahim
- National Institute for Genomics and Advanced Biotechnology, National Agricultural Research Centre, Islamabad, Pakistan
| | - Ming Chen
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Rabia Kalsoom
- School of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Muhammad Uzair
- National Institute for Genomics and Advanced Biotechnology, National Agricultural Research Centre, Islamabad, Pakistan,National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China,*Correspondence: Muhammad Uzair, ; Muhammad Ramzan Khan, ; Guoping Yu,
| | - Sajid Fiaz
- Department of Plant Breeding and Genetics, The University of Haripur, Haripur, Pakistan
| | - Kotb Attia
- Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Hayat Ali Alafari
- Department of Biology, College of Science, Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Muhammad Ramzan Khan
- National Institute for Genomics and Advanced Biotechnology, National Agricultural Research Centre, Islamabad, Pakistan,*Correspondence: Muhammad Uzair, ; Muhammad Ramzan Khan, ; Guoping Yu,
| | - Guoping Yu
- National Nanfan Research Institute, Chinese Academy of Agricultural Sciences, Sanya, China,China National Rice Research Institute, Hangzhou, China,Hainan Yazhou Bay Seed Lab, Sanya, China,*Correspondence: Muhammad Uzair, ; Muhammad Ramzan Khan, ; Guoping Yu,
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12
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DNA2 mutation causing multisystemic disorder with impaired mitochondrial DNA maintenance. J Hum Genet 2022; 67:691-699. [PMID: 36064591 DOI: 10.1038/s10038-022-01075-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 08/10/2022] [Accepted: 08/14/2022] [Indexed: 11/09/2022]
Abstract
PURPOSE To describe a novel DNA2 variant contributing to defects in mtDNA maintenance and mtDNA depletion syndrome (MDS), and the clinical and histological findings associated with this variation. METHODS Herein, we describe the case of a patient who presented with hearing loss and myopathy, given the family history of similar findings in the father, was evaluated by sequencing of the deafness gene panel, mitochondrial genome, and the exome. Furthermore, tissue staining, mtDNA copy number detection, mtDNA sequencing, and long-range polymerase chain reaction tests were also conducted on the muscle biopsy specimen. In vitro experiments, including analyses of the mtDNA copy number; levels of ATP, ATPase, and reactive oxygen species (ROS); and the membrane potential, were performed. RESULTS The DNA2 heterozygous truncating variant c. 2368C > T (p.Q790X) was identified and verified as the cause of an mtDNA copy number decrement in both functional experiments and muscle tissue analyses. These changes were accompanied by reductions in ATP, ATPase, and ROS levels. CONCLUSION The DNA2 variant was a likely cause of MDS in this patient. These findings expand the mutational spectrum of MDS and improve our understanding of the functions of DNA2 by revealing its novel role in mtDNA maintenance.
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13
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Karlowicz A, Dubiel AB, Czerwinska J, Bledea A, Purzycki P, Grzelewska M, McAuley RJ, Szczesny RJ, Brzuska G, Krol E, Szczesny B, Szymanski MR. In vitro reconstitution reveals a key role of human mitochondrial EXOG in RNA primer processing. Nucleic Acids Res 2022; 50:7991-8007. [PMID: 35819194 PMCID: PMC9371904 DOI: 10.1093/nar/gkac581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 06/01/2022] [Accepted: 06/24/2022] [Indexed: 11/12/2022] Open
Abstract
The removal of RNA primers is essential for mitochondrial DNA (mtDNA) replication. Several nucleases have been implicated in RNA primer removal in human mitochondria, however, no conclusive mechanism has been elucidated. Here, we reconstituted minimal in vitro system capable of processing RNA primers into ligatable DNA ends. We show that human 5'-3' exonuclease, EXOG, plays a fundamental role in removal of the RNA primer. EXOG cleaves short and long RNA-containing flaps but also in cooperation with RNase H1, processes non-flap RNA-containing intermediates. Our data indicate that the enzymatic activity of both enzymes is necessary to process non-flap RNA-containing intermediates and that regardless of the pathway, EXOG-mediated RNA cleavage is necessary prior to ligation by DNA Ligase III. We also show that upregulation of EXOG levels in mitochondria increases ligation efficiency of RNA-containing substrates and discover physical interactions, both in vitro and in cellulo, between RNase H1 and EXOG, Pol γA, Pol γB and Lig III but not FEN1, which we demonstrate to be absent from mitochondria of human lung epithelial cells. Together, using human mtDNA replication enzymes, we reconstitute for the first time RNA primer removal reaction and propose a novel model for RNA primer processing in human mitochondria.
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Affiliation(s)
- Anna Karlowicz
- Structural Biology Laboratory, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, ul. Abrahama 58, 80-307 Gdansk, Poland
| | - Andrzej B Dubiel
- Structural Biology Laboratory, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, ul. Abrahama 58, 80-307 Gdansk, Poland
| | - Jolanta Czerwinska
- Institute of Biochemistry and Biophysics Polish Academy of Sciences, ul. Pawinskiego 5A, 02-106 Warsaw, Poland.,Faculty of Biology, Institute of Genetics and Biotechnology, University of Warsaw, Warsaw 02-106, Poland
| | - Adela Bledea
- Structural Biology Laboratory, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, ul. Abrahama 58, 80-307 Gdansk, Poland
| | - Piotr Purzycki
- Structural Biology Laboratory, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, ul. Abrahama 58, 80-307 Gdansk, Poland
| | - Marta Grzelewska
- Structural Biology Laboratory, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, ul. Abrahama 58, 80-307 Gdansk, Poland
| | - Ryan J McAuley
- Department of Ophthalmology and Visual Sciences, The University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA
| | - Roman J Szczesny
- Institute of Biochemistry and Biophysics Polish Academy of Sciences, ul. Pawinskiego 5A, 02-106 Warsaw, Poland
| | - Gabriela Brzuska
- Laboratory of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, ul. Abrahama 58, 80-307 Gdansk, Poland
| | - Ewelina Krol
- Laboratory of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, ul. Abrahama 58, 80-307 Gdansk, Poland
| | - Bartosz Szczesny
- Department of Ophthalmology and Visual Sciences, The University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555, USA
| | - Michal R Szymanski
- Structural Biology Laboratory, Intercollegiate Faculty of Biotechnology of University of Gdansk and Medical University of Gdansk, University of Gdansk, ul. Abrahama 58, 80-307 Gdansk, Poland
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14
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Roy A, Kandettu A, Ray S, Chakrabarty S. Mitochondrial DNA replication and repair defects: Clinical phenotypes and therapeutic interventions. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148554. [PMID: 35341749 DOI: 10.1016/j.bbabio.2022.148554] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 03/06/2022] [Accepted: 03/16/2022] [Indexed: 12/15/2022]
Abstract
Mitochondria is a unique cellular organelle involved in multiple cellular processes and is critical for maintaining cellular homeostasis. This semi-autonomous organelle contains its circular genome - mtDNA (mitochondrial DNA), that undergoes continuous cycles of replication and repair to maintain the mitochondrial genome integrity. The majority of the mitochondrial genes, including mitochondrial replisome and repair genes, are nuclear-encoded. Although the repair machinery of mitochondria is quite efficient, the mitochondrial genome is highly susceptible to oxidative damage and other types of exogenous and endogenous agent-induced DNA damage, due to the absence of protective histones and their proximity to the main ROS production sites. Mutations in replication and repair genes of mitochondria can result in mtDNA depletion and deletions subsequently leading to mitochondrial genome instability. The combined action of mutations and deletions can result in compromised mitochondrial genome maintenance and lead to various mitochondrial disorders. Here, we review the mechanism of mitochondrial DNA replication and repair process, key proteins involved, and their altered function in mitochondrial disorders. The focus of this review will be on the key genes of mitochondrial DNA replication and repair machinery and the clinical phenotypes associated with mutations in these genes.
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Affiliation(s)
- Abhipsa Roy
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Amoolya Kandettu
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Swagat Ray
- Department of Life Sciences, School of Life and Environmental Sciences, University of Lincoln, Lincoln LN6 7TS, United Kingdom
| | - Sanjiban Chakrabarty
- Department of Cell and Molecular Biology, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India.
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15
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Mitchell C, Becker V, DeLoach J, Nestore E, Bolterstein E, Kohl KP. The Drosophila Mutagen-Sensitivity Gene mus109 Encodes DmDNA2. Genes (Basel) 2022; 13:genes13020312. [PMID: 35205357 PMCID: PMC8872385 DOI: 10.3390/genes13020312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 02/02/2022] [Accepted: 02/04/2022] [Indexed: 02/05/2023] Open
Abstract
The identification of mutants through forward genetic screens is the backbone of Drosophila genetics research, yet many mutants identified through these screens have yet to be mapped to the Drosophila genome. This is especially true of mutants that have been identified as mutagen-sensitive (mus), but have not yet been mapped to their associated molecular locus. Our study addressed the need for additional mus gene identification by determining the locus and exploring the function of the X-linked mutagen-sensitive gene mus109 using three available mutant alleles: mus109D1, mus109D2, and mus109lS. After first confirming that all three mus109 alleles were sensitive to methyl methanesulfonate (MMS) using complementation analysis, we used deletion mapping to narrow the candidate genes for mus109. Through DNA sequencing, we were able to determine that mus109 is the uncharacterized gene CG2990, which encodes the Drosophila ortholog of the highly conserved DNA2 protein that is important for DNA replication and repair. We further used the sequence and structure of DNA2 to predict the impact of the mus109 allele mutations on the final gene product. Together, these results provide a tool for researchers to further investigate the role of DNA2 in DNA repair processes in Drosophila.
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Affiliation(s)
- Chandani Mitchell
- Biology Department, Winthrop University, Rock Hill, SC 29733, USA; (C.M.); (J.D.); (E.N.)
| | - Vada Becker
- Biology Department, Northeastern Illinois University, Chicago, IL 60625, USA; (V.B.); (E.B.)
| | - Jordan DeLoach
- Biology Department, Winthrop University, Rock Hill, SC 29733, USA; (C.M.); (J.D.); (E.N.)
| | - Erica Nestore
- Biology Department, Winthrop University, Rock Hill, SC 29733, USA; (C.M.); (J.D.); (E.N.)
| | - Elyse Bolterstein
- Biology Department, Northeastern Illinois University, Chicago, IL 60625, USA; (V.B.); (E.B.)
| | - Kathryn P. Kohl
- Biology Department, Winthrop University, Rock Hill, SC 29733, USA; (C.M.); (J.D.); (E.N.)
- Correspondence:
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16
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Gong X, Cheng J, Zhang K, Wang Y, Li S, Luo Y. Transcriptome sequencing reveals Gastrodia elata Blume could increase the cell viability of eNPCs under hypoxic condition by improving DNA damage repair ability. JOURNAL OF ETHNOPHARMACOLOGY 2022; 282:114646. [PMID: 34530095 DOI: 10.1016/j.jep.2021.114646] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 09/09/2021] [Accepted: 09/13/2021] [Indexed: 06/13/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Gastrodia elata Blume (GEB), known as Tianma in China, is a traditional medicinal herb that has been reported to have various pharmacological effects and neuroprotection, has long been used for treating dizziness, epilepsy, stroke. However, explanation of its underlying mechanisms remains a great challenge. AIM OF THE STUDY The neuroprotective mechanism of GEB on hypoxia-induced neuronal injury in cultured mouse embryonic neural progenitor cells (eNPCs) was investigated, with emphasis on the eNPCs proliferation and DNA damage repair. MATERIALS AND METHODS In this study, hypoxia was focused, which may be caused by stroke or acute cerebral ischemia and is considered as one of the important factors contributing to the Central Nervous System diseases. CoCl2 was adopted to construct a hypoxic/ischemic condition in eNPCs. eNPCs proliferation analysis validated GEB neuroprotective effect under hypoxic/ischemic condition. Transcriptome and weighted gene co-expression network analysis (WGCNA) screened the special gene-network module correlated with what appeared to have significant positive correlation with GEB. Then, Gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were performed to explore the biological functions of selected genes in the modules that had high correlation with GEB. RESULTS GEB has neuroprotective effect and could rescue eNPCs proliferation under hypoxic/ischemic condition induced by CoCl2. Transcriptome and WGCNA unveil the neuroprotective mechanism of GEB on improving DNA damage repair ability by increasing the expression of genes associated with DNA repair and replication. Western blotting and qPCR showed that GEB could improve DNA damage repair ability by increasing the expression of Mcm2, Mcm6, Pold2, Pole, Pole2, Rfc1, Pole4, Dna2 and Rpa2, which were associated with DNA damage and replication. CONCLUSION Through transcriptome and WGCNA, this study unveiled Gastrodia elata Blume could increase the cell viability of eNPCs under hypoxic condition by improving DNA damage repair ability.
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Affiliation(s)
- Xi Gong
- Human Aging Research Institute and School of Life Science, Nanchang University, and Jiangxi Key Laboratory of Human Aging, Nanchang, 999 Xuefu Rd., Honggutan New District, Nanchang, Jiangxi, 330031, China
| | - Jing Cheng
- Human Aging Research Institute and School of Life Science, Nanchang University, and Jiangxi Key Laboratory of Human Aging, Nanchang, 999 Xuefu Rd., Honggutan New District, Nanchang, Jiangxi, 330031, China
| | - Kunshan Zhang
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopedic Department of Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China
| | - Yanlu Wang
- Human Aging Research Institute and School of Life Science, Nanchang University, and Jiangxi Key Laboratory of Human Aging, Nanchang, 999 Xuefu Rd., Honggutan New District, Nanchang, Jiangxi, 330031, China
| | - Siguang Li
- Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopedic Department of Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China.
| | - Yuping Luo
- Human Aging Research Institute and School of Life Science, Nanchang University, and Jiangxi Key Laboratory of Human Aging, Nanchang, 999 Xuefu Rd., Honggutan New District, Nanchang, Jiangxi, 330031, China; Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopedic Department of Tongji Hospital, Tongji University School of Medicine, Shanghai, 200065, China.
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17
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So M, Stiban J, Ciesielski GL, Hovde SL, Kaguni LS. Implications of Membrane Binding by the Fe-S Cluster-Containing N-Terminal Domain in the Drosophila Mitochondrial Replicative DNA Helicase. Front Genet 2021; 12:790521. [PMID: 34950192 PMCID: PMC8688847 DOI: 10.3389/fgene.2021.790521] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 11/15/2021] [Indexed: 11/13/2022] Open
Abstract
Recent evidence suggests that iron-sulfur clusters (ISCs) in DNA replicative proteins sense DNA-mediated charge transfer to modulate nuclear DNA replication. In the mitochondrial DNA replisome, only the replicative DNA helicase (mtDNA helicase) from Drosophila melanogaster (Dm) has been shown to contain an ISC in its N-terminal, primase-like domain (NTD). In this report, we confirm the presence of the ISC and demonstrate the importance of a metal cofactor in the structural stability of the Dm mtDNA helicase. Further, we show that the NTD also serves a role in membrane binding. We demonstrate that the NTD binds to asolectin liposomes, which mimic phospholipid membranes, through electrostatic interactions. Notably, membrane binding is more specific with increasing cardiolipin content, which is characteristically high in the mitochondrial inner membrane (MIM). We suggest that the N-terminal domain of the mtDNA helicase interacts with the MIM to recruit mtDNA and initiate mtDNA replication. Furthermore, Dm NUBPL, the known ISC donor for respiratory complex I and a putative donor for Dm mtDNA helicase, was identified as a peripheral membrane protein that is likely to execute membrane-mediated ISC delivery to its target proteins.
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Affiliation(s)
- Minyoung So
- Department of Biochemistry and Molecular Biology and Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI, United States
| | - Johnny Stiban
- Department of Biochemistry and Molecular Biology and Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI, United States.,Department of Biology and Biochemistry, Birzeit University, Birzeit, Palestine
| | - Grzegorz L Ciesielski
- Department of Biochemistry and Molecular Biology and Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI, United States.,Institute of Biosciences and Medical Technology, University of Tampere, Tampere, Finland.,Department of Chemistry, Auburn University at Montgomery, Montgomery, AL, United States
| | - Stacy L Hovde
- Department of Biochemistry and Molecular Biology and Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI, United States
| | - Laurie S Kaguni
- Department of Biochemistry and Molecular Biology and Center for Mitochondrial Science and Medicine, Michigan State University, East Lansing, MI, United States.,Institute of Biosciences and Medical Technology, University of Tampere, Tampere, Finland
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18
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Rong Z, Tu P, Xu P, Sun Y, Yu F, Tu N, Guo L, Yang Y. The Mitochondrial Response to DNA Damage. Front Cell Dev Biol 2021; 9:669379. [PMID: 34055802 PMCID: PMC8149749 DOI: 10.3389/fcell.2021.669379] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 04/20/2021] [Indexed: 01/08/2023] Open
Abstract
Mitochondria are double membrane organelles in eukaryotic cells that provide energy by generating adenosine triphosphate (ATP) through oxidative phosphorylation. They are crucial to many aspects of cellular metabolism. Mitochondria contain their own DNA that encodes for essential proteins involved in the execution of normal mitochondrial functions. Compared with nuclear DNA, the mitochondrial DNA (mtDNA) is more prone to be affected by DNA damaging agents, and accumulated DNA damages may cause mitochondrial dysfunction and drive the pathogenesis of a variety of human diseases, including neurodegenerative disorders and cancer. Therefore, understanding better how mtDNA damages are repaired will facilitate developing therapeutic strategies. In this review, we focus on our current understanding of the mtDNA repair system. We also discuss other mitochondrial events promoted by excessive DNA damages and inefficient DNA repair, such as mitochondrial fusion, fission, and mitophagy, which serve as quality control events for clearing damaged mtDNA.
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Affiliation(s)
- Ziye Rong
- Department of Immunology, School of Basic Medical Science, Anhui Medical University, Hefei, China
| | - Peipei Tu
- Department of Microbiology and Bioengineering, School of Life Sciences, Anhui Medical University, Hefei, China
| | - Peiqi Xu
- Department of Immunology, School of Basic Medical Science, Anhui Medical University, Hefei, China
| | - Yan Sun
- Department of Immunology, School of Basic Medical Science, Anhui Medical University, Hefei, China
| | - Fangfang Yu
- Department of Immunology, School of Basic Medical Science, Anhui Medical University, Hefei, China
| | - Na Tu
- Department of Immunology, School of Basic Medical Science, Anhui Medical University, Hefei, China
| | - Lixia Guo
- Division of Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN, United States
| | - Yanan Yang
- Department of Immunology, School of Basic Medical Science, Anhui Medical University, Hefei, China
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19
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DNA2 in Chromosome Stability and Cell Survival-Is It All about Replication Forks? Int J Mol Sci 2021; 22:ijms22083984. [PMID: 33924313 PMCID: PMC8069077 DOI: 10.3390/ijms22083984] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/08/2021] [Accepted: 04/10/2021] [Indexed: 01/16/2023] Open
Abstract
The conserved nuclease-helicase DNA2 has been linked to mitochondrial myopathy, Seckel syndrome, and cancer. Across species, the protein is indispensable for cell proliferation. On the molecular level, DNA2 has been implicated in DNA double-strand break (DSB) repair, checkpoint activation, Okazaki fragment processing (OFP), and telomere homeostasis. More recently, a critical contribution of DNA2 to the replication stress response and recovery of stalled DNA replication forks (RFs) has emerged. Here, we review the available functional and phenotypic data and propose that the major cellular defects associated with DNA2 dysfunction, and the links that exist with human disease, can be rationalized through the fundamental importance of DNA2-dependent RF recovery to genome duplication. Being a crucial player at stalled RFs, DNA2 is a promising target for anti-cancer therapy aimed at eliminating cancer cells by replication-stress overload.
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20
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Mitochondrial genome stability in human: understanding the role of DNA repair pathways. Biochem J 2021; 478:1179-1197. [DOI: 10.1042/bcj20200920] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/15/2021] [Accepted: 02/17/2021] [Indexed: 11/17/2022]
Abstract
Mitochondria are semiautonomous organelles in eukaryotic cells and possess their own genome that replicates independently. Mitochondria play a major role in oxidative phosphorylation due to which its genome is frequently exposed to oxidative stress. Factors including ionizing radiation, radiomimetic drugs and replication fork stalling can also result in different types of mutations in mitochondrial DNA (mtDNA) leading to genome fragility. Mitochondria from myopathies, dystonia, cancer patient samples show frequent mtDNA mutations such as point mutations, insertions and large-scale deletions that could account for mitochondria-associated disease pathogenesis. The mechanism by which such mutations arise following exposure to various DNA-damaging agents is not well understood. One of the well-studied repair pathways in mitochondria is base excision repair. Other repair pathways such as mismatch repair, homologous recombination and microhomology-mediated end joining have also been reported. Interestingly, nucleotide excision repair and classical nonhomologous DNA end joining are not detected in mitochondria. In this review, we summarize the potential causes of mitochondrial genome fragility, their implications as well as various DNA repair pathways that operate in mitochondria.
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21
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Yan X, Stuurman N, Ribeiro SA, Tanenbaum ME, Horlbeck MA, Liem CR, Jost M, Weissman JS, Vale RD. High-content imaging-based pooled CRISPR screens in mammalian cells. J Cell Biol 2021; 220:211696. [PMID: 33465779 PMCID: PMC7821101 DOI: 10.1083/jcb.202008158] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 11/17/2020] [Accepted: 12/02/2020] [Indexed: 12/11/2022] Open
Abstract
CRISPR (clustered regularly interspaced short palindromic repeats)-based gene inactivation provides a powerful means for linking genes to particular cellular phenotypes. CRISPR-based screening typically uses large genomic pools of single guide RNAs (sgRNAs). However, this approach is limited to phenotypes that can be enriched by chemical selection or FACS sorting. Here, we developed a microscopy-based approach, which we name optical enrichment, to select cells displaying a particular CRISPR-induced phenotype by automated imaging-based computation, mark them by photoactivation of an expressed photoactivatable fluorescent protein, and then isolate the fluorescent cells using fluorescence-activated cell sorting (FACS). A plugin was developed for the open source software μManager to automate the phenotypic identification and photoactivation of cells, allowing ∼1.5 million individual cells to be screened in 8 h. We used this approach to screen 6,092 sgRNAs targeting 544 genes for their effects on nuclear size regulation and identified 14 bona fide hits. These results present a scalable approach to facilitate imaging-based pooled CRISPR screens.
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Affiliation(s)
- Xiaowei Yan
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA
| | - Nico Stuurman
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA
| | - Susana A. Ribeiro
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA,Cairn Biosciences, Inc., San Francisco, CA
| | - Marvin E. Tanenbaum
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA,Oncode Institute, Hubrecht Institute-KNAW and University Medical Center Utrecht, Utrecht, Netherlands
| | - Max A. Horlbeck
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA,Boston Children's Hospital, Boston, MA
| | - Christina R. Liem
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA,University of California, San Diego, San Diego, CA
| | - Marco Jost
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA
| | - Jonathan S. Weissman
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA,Whitehead Institute and Department of Biology, MIT, Cambridge, MA
| | - Ronald D. Vale
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA,Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA,Correspondence to Ronald D. Vale:
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22
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Ratnasinghe BD, Salsbury AM, Lemkul JA. Ion Binding Properties and Dynamics of the bcl-2 G-Quadruplex Using a Polarizable Force Field. J Chem Inf Model 2020; 60:6476-6488. [PMID: 33264004 DOI: 10.1021/acs.jcim.0c01064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
G-quadruplexes (GQs) are topologically diverse, highly thermostable noncanonical nucleic acid structures that form in guanine-rich sequences in DNA and RNA. GQs are implicated in transcriptional and translational regulation and genome maintenance, and deleterious alterations to their structures contribute to diseases such as cancer. The expression of the B-cell lymphoma 2 (Bcl-2) antiapoptotic protein, for example, is under transcriptional control of a GQ in the promoter of the bcl-2 gene. Modulation of the bcl-2 GQ by small molecules is of interest for chemotherapeutic development but doing so requires knowledge of the factors driving GQ folding and stabilization. To develop a greater understanding of the electrostatic properties of the bcl-2 promoter GQ, we performed molecular dynamics simulations using the Drude-2017 polarizable force field and compared relevant outcomes to the nonpolarizable CHARMM36 force field. Our simulation outcomes highlight the importance of dipole-dipole interactions in the bcl-2 GQ, particularly during the recruitment of a bulk K+ ion to the solvent-exposed face of the tetrad stem. We also predict and characterize an "electronegative pocket" at the tetrad-long loop junction that induces local backbone conformational change and may induce local conformational changes at cellular concentrations of K+. These outcomes suggest that moieties within the bcl-2 GQ can be targeted by small molecules to modulate bcl-2 GQ stability.
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Affiliation(s)
- Brian D Ratnasinghe
- Department of Biochemistry, Virginia Tech, 303 Engel Hall, 340 West Campus Dr., Blacksburg, Virginia 24061, United States
| | - Alexa M Salsbury
- Department of Biochemistry, Virginia Tech, 303 Engel Hall, 340 West Campus Dr., Blacksburg, Virginia 24061, United States
| | - Justin A Lemkul
- Department of Biochemistry and Center for Drug Discovery, Virginia Tech, 303 Engel Hall, 340 West Campus Dr., Blacksburg, Virginia 24061, United States
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23
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Fontana GA, Gahlon HL. Mechanisms of replication and repair in mitochondrial DNA deletion formation. Nucleic Acids Res 2020; 48:11244-11258. [PMID: 33021629 PMCID: PMC7672454 DOI: 10.1093/nar/gkaa804] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 09/07/2020] [Accepted: 09/25/2020] [Indexed: 02/06/2023] Open
Abstract
Deletions in mitochondrial DNA (mtDNA) are associated with diverse human pathologies including cancer, aging and mitochondrial disorders. Large-scale deletions span kilobases in length and the loss of these associated genes contributes to crippled oxidative phosphorylation and overall decline in mitochondrial fitness. There is not a united view for how mtDNA deletions are generated and the molecular mechanisms underlying this process are poorly understood. This review discusses the role of replication and repair in mtDNA deletion formation as well as nucleic acid motifs such as repeats, secondary structures, and DNA damage associated with deletion formation in the mitochondrial genome. We propose that while erroneous replication and repair can separately contribute to deletion formation, crosstalk between these pathways is also involved in generating deletions.
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Affiliation(s)
- Gabriele A Fontana
- Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland
| | - Hailey L Gahlon
- To whom correspondence should be addressed. Tel: +41 44 632 3731;
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24
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Drake KD, Lemoine C, Aquino GS, Vaeth AM, Kanadia RN. Loss of U11 small nuclear RNA in the developing mouse limb results in micromelia. Development 2020; 147:dev.190967. [PMID: 32665241 DOI: 10.1242/dev.190967] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 07/02/2020] [Indexed: 01/23/2023]
Abstract
Disruption of the minor spliceosome due to mutations in RNU4ATAC is linked to primordial dwarfism in microcephalic osteodysplastic primordial dwarfism type 1, Roifman syndrome, and Lowry-Wood syndrome. Similarly, primordial dwarfism in domesticated animals is linked to positive selection in minor spliceosome components. Despite being vital for limb development and size regulation, its role remains unexplored. Here, we disrupt minor spliceosome function in the developing mouse limb by ablating one of its essential components, U11 small nuclear RNA, which resulted in micromelia. Notably, earlier loss of U11 corresponded to increased severity. We find that limb size is reduced owing to elevated minor intron retention in minor intron-containing genes that regulate cell cycle. As a result, limb progenitor cells experience delayed prometaphase-to-metaphase transition and prolonged S-phase. Moreover, we observed death of rapidly dividing, distally located progenitors. Despite cell cycle defects and cell death, the spatial expression of key limb patterning genes was maintained. Overall, we show that the minor spliceosome is required for limb development via size control potentially shared in disease and domestication.
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Affiliation(s)
- Kyle D Drake
- Physiology and Neurobiology Department, University of Connecticut, Storrs, CT 06269, USA
| | - Christopher Lemoine
- Physiology and Neurobiology Department, University of Connecticut, Storrs, CT 06269, USA.,Department of Surgery, School of Medicine, University of Connecticut, Farmington, CT 06030, USA
| | - Gabriela S Aquino
- Physiology and Neurobiology Department, University of Connecticut, Storrs, CT 06269, USA
| | - Anna M Vaeth
- Physiology and Neurobiology Department, University of Connecticut, Storrs, CT 06269, USA.,Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Rahul N Kanadia
- Physiology and Neurobiology Department, University of Connecticut, Storrs, CT 06269, USA .,Institute for System Genomics, University of Connecticut, Storrs, CT 06269, USA
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25
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Mariotti L, Wild S, Brunoldi G, Piceni A, Ceppi I, Kummer S, Lutz RE, Cejka P, Gari K. The iron-sulphur cluster in human DNA2 is required for all biochemical activities of DNA2. Commun Biol 2020; 3:322. [PMID: 32576938 PMCID: PMC7311471 DOI: 10.1038/s42003-020-1048-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 06/03/2020] [Indexed: 11/25/2022] Open
Abstract
The nuclease/helicase DNA2 plays important roles in DNA replication, repair and processing of stalled replication forks. DNA2 contains an iron-sulphur (FeS) cluster, conserved in eukaryotes and in a related bacterial nuclease. FeS clusters in DNA maintenance proteins are required for structural integrity and/or act as redox-sensors. Here, we demonstrate that loss of the FeS cluster affects binding of human DNA2 to specific DNA substrates, likely through a conformational change that distorts the central DNA binding tunnel. Moreover, we show that the FeS cluster is required for DNA2’s nuclease, helicase and ATPase activities. Our data also establish that oxidation of DNA2 impairs DNA binding in vitro, an effect that is reversible upon reduction. Unexpectedly, though, this redox-regulation is independent of the presence of the FeS cluster. Together, our study establishes an important structural role for the FeS cluster in human DNA2 and discovers a redox-regulatory mechanism to control DNA binding. Mariotti et al. show that the iron-sulphur cluster in human DNA2 is required for its nuclease, helicase and ATPase activities. This study highlights the structural importance of the iron-sulphur cluster in human DNA2 and presents a separate redox-regulatory mechanism that controls DNA binding.
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Affiliation(s)
- Laura Mariotti
- Institute of Molecular Cancer Research, University of Zurich, 8057, Zurich, Switzerland.
| | - Sebastian Wild
- Institute of Molecular Cancer Research, University of Zurich, 8057, Zurich, Switzerland
| | - Giulia Brunoldi
- Institute of Molecular Cancer Research, University of Zurich, 8057, Zurich, Switzerland
| | - Alessandra Piceni
- Institute of Molecular Cancer Research, University of Zurich, 8057, Zurich, Switzerland
| | - Ilaria Ceppi
- Institute for Research in Biomedicine, Faculty of Biomedical Sciences, Università della Svizzera italiana, 6500, Bellinzona, Switzerland.,Department of Biology, Institute of Biochemistry, ETH Zurich, 8092, Zurich, Switzerland
| | - Sandra Kummer
- Institute of Molecular Cancer Research, University of Zurich, 8057, Zurich, Switzerland
| | - Richard E Lutz
- Institute of Molecular Cancer Research, University of Zurich, 8057, Zurich, Switzerland
| | - Petr Cejka
- Institute for Research in Biomedicine, Faculty of Biomedical Sciences, Università della Svizzera italiana, 6500, Bellinzona, Switzerland.,Department of Biology, Institute of Biochemistry, ETH Zurich, 8092, Zurich, Switzerland
| | - Kerstin Gari
- Institute of Molecular Cancer Research, University of Zurich, 8057, Zurich, Switzerland.
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26
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Peter B, Falkenberg M. TWINKLE and Other Human Mitochondrial DNA Helicases: Structure, Function and Disease. Genes (Basel) 2020; 11:genes11040408. [PMID: 32283748 PMCID: PMC7231222 DOI: 10.3390/genes11040408] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 04/06/2020] [Accepted: 04/07/2020] [Indexed: 12/30/2022] Open
Abstract
Mammalian mitochondria contain a circular genome (mtDNA) which encodes subunits of the oxidative phosphorylation machinery. The replication and maintenance of mtDNA is carried out by a set of nuclear-encoded factors—of which, helicases form an important group. The TWINKLE helicase is the main helicase in mitochondria and is the only helicase required for mtDNA replication. Mutations in TWINKLE cause a number of human disorders associated with mitochondrial dysfunction, neurodegeneration and premature ageing. In addition, a number of other helicases with a putative role in mitochondria have been identified. In this review, we discuss our current knowledge of TWINKLE structure and function and its role in diseases of mtDNA maintenance. We also briefly discuss other potential mitochondrial helicases and postulate on their role(s) in mitochondria.
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27
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Li Y, Liu X, Guo Y, Xie J, Wang L, Chen Q, Wang G, Wang Z, Gao H. Secondary Mutation-Induced Alternative Splicing Suppresses RNA Splicing Defect of the jhs1 Mutant. PLANT PHYSIOLOGY 2020; 182:2025-2034. [PMID: 32054782 PMCID: PMC7140918 DOI: 10.1104/pp.19.01571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 02/01/2020] [Indexed: 06/10/2023]
Abstract
jing he sheng1 (jhs1) is a mutant of the DNA2 homolog in Arabidopsis (Arabidopsis thaliana), which was previously identified as being involved in DNA damage repair, cell cycle regulation, and meristem maintenance. A mutation at the 3' intron splice site of the 11th intron causes alternative splicing of this intron at two other sites, which results in frame shifts and premature stop codons. Here, we screened suppressors of jhs1 to further study the function and regulatory networks of JHS1 Three suppressors with wild-type-like phenotypes were obtained. Sequencing analysis results showed that each of the suppressors has a second mutation in jhs1 that causes further alternative splicing of the intron and corrects the shifted reading frame with small insertions. Precursor mRNA sequence analysis and intron splice site evaluation results suggested that intron splicing was disturbed in the suppressors, and this switched the splice site, resulting in small insertions in the coding regions of JHS1. Structural analysis of JHS1 suggested that the insertions are in a disordered loop region of the DNA2 domain and do not seem to have much deleterious effect on the function of the protein. This work not only has implications for the evolution of protein sequences at exon junctions but also provides a strategy to study the mechanism of precursor mRNA splicing.
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Affiliation(s)
- Yiqiong Li
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Xiaomin Liu
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Yuxuan Guo
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China
| | - Jianbo Xie
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China
| | - Lulu Wang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China
| | - Qiankuo Chen
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China
| | - Guangshuai Wang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China
| | - Zefeng Wang
- Chinese Academy of Sciences and the German Max Planck Society, Partner Institute for Computational Biology, Shanghai 20031, China
| | - Hongbo Gao
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
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28
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Lemkul JA. Same fold, different properties: polarizable molecular dynamics simulations of telomeric and TERRA G-quadruplexes. Nucleic Acids Res 2020; 48:561-575. [PMID: 31807754 PMCID: PMC6954416 DOI: 10.1093/nar/gkz1154] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 11/21/2019] [Accepted: 11/26/2019] [Indexed: 12/12/2022] Open
Abstract
DNA and RNA sequences rich in guanine can fold into noncanonical structures called G-quadruplexes (GQs), which exhibit a common stem structure of Hoogsteen hydrogen-bonded guanine tetrads and diverse loop structures. GQ sequence motifs are overrepresented in promoters, origins of replication, telomeres, and untranslated regions in mRNA, suggesting roles in modulating gene expression and preserving genomic integrity. Given these roles and unique aspects of different structures, GQs are attractive targets for drug design, but greater insight into GQ folding pathways and the interactions stabilizing them is required. Here, we performed molecular dynamics simulations to study two bimolecular GQs, a telomeric DNA GQ and the analogous telomeric repeat-containing RNA (TERRA) GQ. We applied the Drude polarizable force field, which we show outperforms the additive CHARMM36 force field in both ion retention and maintenance of the GQ folds. The polarizable simulations reveal that the GQs bind bulk K+ ions differently, and that the TERRA GQ accumulates more K+ ions, suggesting different ion interactions stabilize these structures. Nucleobase dipole moments vary as a function of position and also contribute to ion binding. Finally, we show that the TERRA GQ is more sensitive than the telomeric DNA GQ to water-mediated modulation of ion-induced dipole-dipole interactions.
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Affiliation(s)
- Justin A Lemkul
- Department of Biochemistry and Center for Drug Discovery, Virginia Tech, Blacksburg, VA 24061, USA
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29
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Jamroskovic J, Doimo M, Chand K, Obi I, Kumar R, Brännström K, Hedenström M, Nath Das R, Akhunzianov A, Deiana M, Kasho K, Sulis Sato S, Pourbozorgi PL, Mason JE, Medini P, Öhlund D, Wanrooij S, Chorell E, Sabouri N. Quinazoline Ligands Induce Cancer Cell Death through Selective STAT3 Inhibition and G-Quadruplex Stabilization. J Am Chem Soc 2020; 142:2876-2888. [PMID: 31990532 PMCID: PMC7307907 DOI: 10.1021/jacs.9b11232] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
![]()
The signal transducer
and activator of transcription 3 (STAT3)
protein is a master regulator of most key hallmarks and enablers of
cancer, including cell proliferation and the response to DNA damage.
G-Quadruplex (G4) structures are four-stranded noncanonical DNA structures
enriched at telomeres and oncogenes’ promoters. In cancer cells,
stabilization of G4 DNAs leads to replication stress and DNA damage
accumulation and is therefore considered a promising target for oncotherapy.
Here, we designed and synthesized novel quinazoline-based compounds
that simultaneously and selectively affect these two well-recognized
cancer targets, G4 DNA structures and the STAT3 protein. Using a combination
of in vitro assays, NMR, and molecular dynamics simulations, we show
that these small, uncharged compounds not only bind to the STAT3 protein
but also stabilize G4 structures. In human cultured cells, the compounds
inhibit phosphorylation-dependent activation of STAT3 without affecting
the antiapoptotic factor STAT1 and cause increased formation of G4
structures, as revealed by the use of a G4 DNA-specific antibody.
As a result, treated cells show slower DNA replication, DNA damage
checkpoint activation, and an increased apoptotic rate. Importantly,
cancer cells are more sensitive to these molecules compared to noncancerous
cell lines. This is the first report of a promising class of compounds
that not only targets the DNA damage cancer response machinery but
also simultaneously inhibits the STAT3-induced cancer cell proliferation,
demonstrating a novel approach in cancer therapy.
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Affiliation(s)
- Jan Jamroskovic
- Department of Medical Biochemistry and Biophysics , Umeå University , Umeå 90736 , Sweden
| | - Mara Doimo
- Department of Medical Biochemistry and Biophysics , Umeå University , Umeå 90736 , Sweden
| | - Karam Chand
- Department of Chemistry , Umeå University , Umeå 90736 , Sweden
| | - Ikenna Obi
- Department of Medical Biochemistry and Biophysics , Umeå University , Umeå 90736 , Sweden
| | - Rajendra Kumar
- Department of Chemistry , Umeå University , Umeå 90736 , Sweden
| | - Kristoffer Brännström
- Department of Medical Biochemistry and Biophysics , Umeå University , Umeå 90736 , Sweden
| | | | | | - Almaz Akhunzianov
- Department of Medical Biochemistry and Biophysics , Umeå University , Umeå 90736 , Sweden.,Institute of Fundamental Medicine and Biology , Kazan Federal University , Kazan 420008 , Russia
| | - Marco Deiana
- Department of Medical Biochemistry and Biophysics , Umeå University , Umeå 90736 , Sweden
| | - Kazutoshi Kasho
- Department of Medical Biochemistry and Biophysics , Umeå University , Umeå 90736 , Sweden
| | - Sebastian Sulis Sato
- Department of Integrative Medical Biology , Umeå University , Umeå 90736 , Sweden
| | - Parham L Pourbozorgi
- Department of Medical Biochemistry and Biophysics , Umeå University , Umeå 90736 , Sweden
| | - James E Mason
- Department of Radiation Sciences , Umeå University , Umeå 90736 , Sweden
| | - Paolo Medini
- Department of Integrative Medical Biology , Umeå University , Umeå 90736 , Sweden
| | - Daniel Öhlund
- Department of Radiation Sciences , Umeå University , Umeå 90736 , Sweden
| | - Sjoerd Wanrooij
- Department of Medical Biochemistry and Biophysics , Umeå University , Umeå 90736 , Sweden
| | - Erik Chorell
- Department of Chemistry , Umeå University , Umeå 90736 , Sweden
| | - Nasim Sabouri
- Department of Medical Biochemistry and Biophysics , Umeå University , Umeå 90736 , Sweden
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30
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Zheng L, Meng Y, Campbell JL, Shen B. Multiple roles of DNA2 nuclease/helicase in DNA metabolism, genome stability and human diseases. Nucleic Acids Res 2020; 48:16-35. [PMID: 31754720 PMCID: PMC6943134 DOI: 10.1093/nar/gkz1101] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 10/23/2019] [Accepted: 11/12/2019] [Indexed: 12/25/2022] Open
Abstract
DNA2 nuclease/helicase is a structure-specific nuclease, 5'-to-3' helicase, and DNA-dependent ATPase. It is involved in multiple DNA metabolic pathways, including Okazaki fragment maturation, replication of 'difficult-to-replicate' DNA regions, end resection, stalled replication fork processing, and mitochondrial genome maintenance. The participation of DNA2 in these different pathways is regulated by its interactions with distinct groups of DNA replication and repair proteins and by post-translational modifications. These regulatory mechanisms induce its recruitment to specific DNA replication or repair complexes, such as DNA replication and end resection machinery, and stimulate its efficient cleavage of various structures, for example, to remove RNA primers or to produce 3' overhangs at telomeres or double-strand breaks. Through these versatile activities at replication forks and DNA damage sites, DNA2 functions as both a tumor suppressor and promoter. In normal cells, it suppresses tumorigenesis by maintaining the genomic integrity. Thus, DNA2 mutations or functional deficiency may lead to cancer initiation. However, DNA2 may also function as a tumor promoter, supporting cancer cell survival by counteracting replication stress. Therefore, it may serve as an ideal target to sensitize advanced DNA2-overexpressing cancers to current chemo- and radiotherapy regimens.
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Affiliation(s)
- Li Zheng
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
| | - Yuan Meng
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
| | - Judith L Campbell
- Divisions of Chemistry and Chemical Engineering and Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Binghui Shen
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
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31
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Matkarimov BT, Saparbaev MK. DNA Repair and Mutagenesis in Vertebrate Mitochondria: Evidence for Asymmetric DNA Strand Inheritance. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1241:77-100. [DOI: 10.1007/978-3-030-41283-8_6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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32
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Meng Y, Liu C, Shen L, Zhou M, Liu W, Kowolik C, Campbell JL, Zheng L, Shen B. TRAF6 mediates human DNA2 polyubiquitination and nuclear localization to maintain nuclear genome integrity. Nucleic Acids Res 2019; 47:7564-7579. [PMID: 31216032 PMCID: PMC6698806 DOI: 10.1093/nar/gkz537] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 05/29/2019] [Accepted: 06/07/2019] [Indexed: 12/14/2022] Open
Abstract
The multifunctional human DNA2 (hDNA2) nuclease/helicase is required to process DNA ends for homology-directed recombination repair (HDR) and to counteract replication stress. To participate in these processes, hDNA2 must localize to the nucleus and be recruited to the replication or repair sites. However, because hDNA2 lacks the nuclear localization signal that is found in its yeast homolog, it is unclear how its migration into the nucleus is regulated during replication or in response to DNA damage. Here, we report that the E3 ligase TRAF6 binds to and mediates the K63-linked polyubiquitination of hDNA2, increasing the stability of hDNA2 and promoting its nuclear localization. Inhibiting TRAF6-mediated polyubiquitination abolishes the nuclear localization of hDNA2, consequently impairing DNA end resection and HDR. Thus, the current study reveals a mechanism for the regulation of hDNA2 localization and establishes that TRAF6-mediated hDNA2 ubiquitination activates DNA repair pathways to maintain nuclear genome integrity.
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Affiliation(s)
- Yuan Meng
- Colleges of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310027, China.,Department of Cancer Genetics and Epigenetics, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
| | - Changwei Liu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
| | - Lei Shen
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
| | - Mian Zhou
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
| | - Wenpeng Liu
- Colleges of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310027, China.,Department of Cancer Genetics and Epigenetics, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
| | - Claudia Kowolik
- Department of Molecular Medicine, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
| | - Judith L Campbell
- Division of Chemistry and Chemical Engineering, Braun Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
| | - Li Zheng
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
| | - Binghui Shen
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute of City of Hope, 1500 East Duarte Road, Duarte, CA 91010, USA
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33
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Billard P, Poncet DA. Replication Stress at Telomeric and Mitochondrial DNA: Common Origins and Consequences on Ageing. Int J Mol Sci 2019; 20:ijms20194959. [PMID: 31597307 PMCID: PMC6801922 DOI: 10.3390/ijms20194959] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/04/2019] [Accepted: 10/05/2019] [Indexed: 12/12/2022] Open
Abstract
Senescence is defined as a stress-induced durable cell cycle arrest. We herein revisit the origin of two of these stresses, namely mitochondrial metabolic compromise, associated with reactive oxygen species (ROS) production, and replicative senescence, activated by extreme telomere shortening. We discuss how replication stress-induced DNA damage of telomeric DNA (telDNA) and mitochondrial DNA (mtDNA) can be considered a common origin of senescence in vitro, with consequences on ageing in vivo. Unexpectedly, mtDNA and telDNA share common features indicative of a high degree of replicative stress, such as G-quadruplexes, D-loops, RNA:DNA heteroduplexes, epigenetic marks, or supercoiling. To avoid these stresses, both compartments use similar enzymatic strategies involving, for instance, endonucleases, topoisomerases, helicases, or primases. Surprisingly, many of these replication helpers are active at both telDNA and mtDNA (e.g., RNAse H1, FEN1, DNA2, RecQ helicases, Top2α, Top2β, TOP3A, DNMT1/3a/3b, SIRT1). In addition, specialized telomeric proteins, such as TERT (telomerase reverse transcriptase) and TERC (telomerase RNA component), or TIN2 (shelterin complex), shuttle from telomeres to mitochondria, and, by doing so, modulate mitochondrial metabolism and the production of ROS, in a feedback manner. Hence, mitochondria and telomeres use common weapons and cooperate to resist/prevent replication stresses, otherwise producing common consequences, namely senescence and ageing.
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Affiliation(s)
- Pauline Billard
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de recherche en cancérologie de Lyon, 69008 Lyon, France.
- Institut de Biopathologie moléculaire, Centre de Bio-Pathologie Est, Groupement hospitalier Est, Hospices Civils de Lyon, 69500 Bron, France.
| | - Delphine A Poncet
- Univ Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de recherche en cancérologie de Lyon, 69008 Lyon, France.
- Institut de Biopathologie moléculaire, Centre de Bio-Pathologie Est, Groupement hospitalier Est, Hospices Civils de Lyon, 69500 Bron, France.
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González-Del Angel A, Bisciglia M, Vargas-Cañas S, Fernandez-Valverde F, Kazakova E, Escobar RE, Romero NB, Jardel C, Rucheton B, Stojkovic T, Malfatti E. Novel Phenotypes and Cardiac Involvement Associated With DNA2 Genetic Variants. Front Neurol 2019; 10:1049. [PMID: 31636600 PMCID: PMC6787284 DOI: 10.3389/fneur.2019.01049] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 09/16/2019] [Indexed: 12/17/2022] Open
Abstract
Objectives: To report two novel DNA2 gene mutations causing early onset myopathy with cardiac involvement and late onset mitochondriopathy with rhabdomyolysis. Methods: We performed detailed clinical, muscle histopathology and molecular studies including mitochondrial gene NGS analysis in two patients (Patient 1 and 2), a mother and her son, belonging to a Mexican family, and a third sporadic French patient. Results: Patient 1 and 2 presented with an early onset myopathy associated with ptosis, velopharyngeal weakness, and cardiac involvement. Patient 3 presented rhabdomyolysis unmasking a mitochondrial disease characterized by a sensorineural hearing loss, ptosis, and lipomas. Muscle biopsies performed in all patients showed variable mitochondrial alterations. Patient 3 had multiple mtDNA deletion in his muscle. Genetic studies revealed a novel heterozygous frameshift mutation in DNA2 gene (c.2346delT p.Phe782Leufs*3) in P1 and P2, and a novel heterozygous missense mutation in DNA2 gene (c.578T>C p.Leu193Ser) in the P3. Conclusions: To date only few AD cases presenting either missense or truncating DNA2 variants have been reported. None of them presented with a cardiac involvement or rhabdomyolysis. Here we enlarge the genetic and phenotypic spectrum of DNA2-related mitochondrial disorders.
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Affiliation(s)
- Ariadna González-Del Angel
- Laboratorio de Biología Molecular, Departamento de Genética Humana, Instituto Nacional de Pediatría, Mexico City, Mexico
| | - Michela Bisciglia
- AP-HP, GHU La Pitié-Salpêtrière, Institut de Myologie, Paris, France
| | - Steven Vargas-Cañas
- Instituto Nacional de Neurologia y Neurochirurgia, Mexico City, Mexico.,Laboratorio de Patología Experimental, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico
| | - Francisca Fernandez-Valverde
- Instituto Nacional de Neurologia y Neurochirurgia, Mexico City, Mexico.,Laboratorio de Patología Experimental, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico
| | - Ekaterina Kazakova
- Cedimemm: Centro de Diagnóstico en Metabolismo Energético y Medicina Mitocondrial, Mexico City, Mexico
| | - Rosa Elena Escobar
- Unit of Muscle Dystrophies, Instituto Nacional de Rehabilitacion (INR), Mexico City, Mexico
| | - Norma B Romero
- AP-HP, GHU La Pitié-Salpêtrière, Institut de Myologie, Paris, France.,Instituto Nacional de Neurologia y Neurochirurgia, Mexico City, Mexico.,Laboratorio de Patología Experimental, Instituto Nacional de Neurología y Neurocirugía, Mexico City, Mexico.,Cedimemm: Centro de Diagnóstico en Metabolismo Energético y Medicina Mitocondrial, Mexico City, Mexico.,Unit of Muscle Dystrophies, Instituto Nacional de Rehabilitacion (INR), Mexico City, Mexico.,Sorbonne Université, INSERM, Centre de Recherches, Centre de Référence des Maladies Neuromusculaires Nord/Est/Ile de France, GHU Pitié-Salpêtrière, Paris, France
| | - Claude Jardel
- AP-HP, GHU La Pitié-Salpêtrière, U.F. Cardiogénétique et Myogénétique, Service de Biochimie Métabolique, Paris, France
| | - Benoit Rucheton
- AP-HP, GHU La Pitié-Salpêtrière, U.F. Cardiogénétique et Myogénétique, Service de Biochimie Métabolique, Paris, France
| | - Tanya Stojkovic
- AP-HP, GHU La Pitié-Salpêtrière, Institut de Myologie, Paris, France
| | - Edoardo Malfatti
- Service Neurologie Médicale, Centre de Référence Maladies Neuromusculaire Paris-Nord, CHU Raymond-Poincaré, Garches, France.,U1179 UVSQ-INSERM Handicap Neuromusculaire: Physiologie, Biothérapie et Pharmacologie Appliquées, UFR des Sciences de la santé Simone Veil, Université Versailles-Saint-Quentin-en-Yvelines, France
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35
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Plant Organelle Genome Replication. PLANTS 2019; 8:plants8100358. [PMID: 31546578 PMCID: PMC6843274 DOI: 10.3390/plants8100358] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/14/2019] [Accepted: 09/18/2019] [Indexed: 12/21/2022]
Abstract
Mitochondria and chloroplasts perform essential functions in respiration, ATP production, and photosynthesis, and both organelles contain genomes that encode only some of the proteins that are required for these functions. The proteins and mechanisms for organelle DNA replication are very similar to bacterial or phage systems. The minimal replisome may consist of DNA polymerase, a primase/helicase, and a single-stranded DNA binding protein (SSB), similar to that found in bacteriophage T7. In Arabidopsis, there are two genes for organellar DNA polymerases and multiple potential genes for SSB, but there is only one known primase/helicase protein to date. Genome copy number varies widely between type and age of plant tissues. Replication mechanisms are only poorly understood at present, and may involve multiple processes, including recombination-dependent replication (RDR) in plant mitochondria and perhaps also in chloroplasts. There are still important questions remaining as to how the genomes are maintained in new organelles, and how genome copy number is determined. This review summarizes our current understanding of these processes.
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36
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Ronchi D, Liu C, Caporali L, Piga D, Li H, Tagliavini F, Valentino ML, Ferrò MT, Bini P, Zheng L, Carelli V, Shen B, Comi GP. Novel mutations in DNA2 associated with myopathy and mtDNA instability. Ann Clin Transl Neurol 2019; 6:1893-1899. [PMID: 31478350 PMCID: PMC6764641 DOI: 10.1002/acn3.50888] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 08/12/2019] [Accepted: 08/13/2019] [Indexed: 02/03/2023] Open
Abstract
The maintenance of mitochondrial DNA (mtDNA) relies on proteins encoded by nuclear genes. Mutations in their coding sequences result in heterogenous clinical presentations featuring mtDNA instability in affected tissues. DNA2 is a multi-catalytic protein involved in the removal of single strand DNA during mtDNA replication or Long Patch Base Excision Repair pathway. We have previously described DNA2 mutations in adult patients affected with familial and sporadic forms of mitochondrial myopathy. Here we describe four novel probands presenting with limb weakness associated with novel DNA2 molecular defects. Biochemical assays were established to investigate the functional effects of these variants.
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Affiliation(s)
- Dario Ronchi
- Neurology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.,Dino Ferrari Center, Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Changwei Liu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute City of Hope, Duarte, California
| | - Leonardo Caporali
- Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
| | - Daniela Piga
- Neurology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Hongzhi Li
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute City of Hope, Duarte, California
| | - Francesca Tagliavini
- Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
| | - Maria Lucia Valentino
- Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy.,Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM), Università di Bologna, Bologna, Italy
| | | | - Paola Bini
- IRCCS "C. Mondino" Foundation, National Neurological Institute, Pavia, Italy
| | - Li Zheng
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute City of Hope, Duarte, California
| | - Valerio Carelli
- Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy.,Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM), Università di Bologna, Bologna, Italy
| | - Binghui Shen
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute City of Hope, Duarte, California
| | - Giacomo Pietro Comi
- Dino Ferrari Center, Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.,Department of Neuroscience, Neuromuscular and Rare Diseases Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, 20122, Italy
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37
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Mitochondria in the signaling pathways that control longevity and health span. Ageing Res Rev 2019; 54:100940. [PMID: 31415807 PMCID: PMC7479635 DOI: 10.1016/j.arr.2019.100940] [Citation(s) in RCA: 106] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/09/2019] [Accepted: 08/06/2019] [Indexed: 12/26/2022]
Abstract
Genetic and pharmacological intervention studies have identified evolutionarily conserved and functionally interconnected networks of cellular energy homeostasis, nutrient-sensing, and genome damage response signaling pathways, as prominent regulators of longevity and health span in various species. Mitochondria are the primary sites of ATP production and are key players in several other important cellular processes. Mitochondrial dysfunction diminishes tissue and organ functional performance and is a commonly considered feature of the aging process. Here we review the evidence that through reciprocal and multilevel functional interactions, mitochondria are implicated in the lifespan modulation function of these pathways, which altogether constitute a highly dynamic and complex system that controls the aging process. An important characteristic of these pathways is their extensive crosstalk and apparent malleability to modification by non-invasive pharmacological, dietary, and lifestyle interventions, with promising effects on lifespan and health span in animal models and potentially also in humans.
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38
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Tarnauskaitė Ž, Bicknell LS, Marsh JA, Murray JE, Parry DA, Logan CV, Bober MB, de Silva DC, Duker AL, Sillence D, Wise C, Jackson AP, Murina O, Reijns MAM. Biallelic variants in DNA2 cause microcephalic primordial dwarfism. Hum Mutat 2019; 40:1063-1070. [PMID: 31045292 PMCID: PMC6773220 DOI: 10.1002/humu.23776] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 03/15/2019] [Accepted: 04/28/2019] [Indexed: 11/11/2022]
Abstract
Microcephalic primordial dwarfism (MPD) is a group of rare single-gene disorders characterized by the extreme reduction in brain and body size from early development onwards. Proteins encoded by MPD-associated genes play important roles in fundamental cellular processes, notably genome replication and repair. Here we report the identification of four MPD individuals with biallelic variants in DNA2, which encodes an adenosine triphosphate (ATP)-dependent helicase/nuclease involved in DNA replication and repair. We demonstrate that the two intronic variants (c.1764-38_1764-37ins(53) and c.74+4A>C) found in these individuals substantially impair DNA2 transcript splicing. Additionally, we identify a missense variant (c.1963A>G), affecting a residue of the ATP-dependent helicase domain that is highly conserved between humans and yeast, with the resulting substitution (p.Thr655Ala) predicted to directly impact ATP/ADP (adenosine diphosphate) binding by DNA2. Our findings support the pathogenicity of these variants as biallelic hypomorphic mutations, establishing DNA2 as an MPD disease gene.
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Affiliation(s)
- Žygimantė Tarnauskaitė
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUnited Kingdom
| | - Louise S. Bicknell
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUnited Kingdom
| | - Joseph A. Marsh
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUnited Kingdom
| | - Jennie E. Murray
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUnited Kingdom
| | - David A. Parry
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUnited Kingdom
| | - Clare V. Logan
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUnited Kingdom
| | - Michael B. Bober
- Division of Genetics, Department of PediatricsNemours/Alfred I. duPont Hospital for ChildrenWilmingtonDelaware
| | - Deepthi C. de Silva
- Department of Physiology, Faculty of MedicineUniversity of KelaniyaColomboSri Lanka
| | - Angela L. Duker
- Division of Genetics, Department of PediatricsNemours/Alfred I. duPont Hospital for ChildrenWilmingtonDelaware
| | - David Sillence
- Discipline of Genomic Medicine, Faculty of Medicine and HealthUniversity of SydneySydneyAustralia
- Western Sydney Genetics ProgramSydney Children's Hospitals NetworkWestmeadAustralia
| | - Carol Wise
- Sarah M. and Charles E. Seay Center for Musculoskeletal ResearchTexas Scottish, Rite Hospital for ChildrenDallasTexas
- McDermott Center for Human Growth and DevelopmentUniversity of Texas, Southwestern Medical CenterDallasTexas
- Department of Orthopaedic SurgeryUniversity of Texas Southwestern Medical CenterDallasTexas
- Department of PediatricsUniversity of Texas Southwestern Medical CenterDallasTexas
| | - Andrew P. Jackson
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUnited Kingdom
| | - Olga Murina
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUnited Kingdom
| | - Martin A. M. Reijns
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular MedicineUniversity of EdinburghEdinburghUnited Kingdom
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39
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Ranjha L, Levikova M, Altmannova V, Krejci L, Cejka P. Sumoylation regulates the stability and nuclease activity of Saccharomyces cerevisiae Dna2. Commun Biol 2019; 2:174. [PMID: 31098407 PMCID: PMC6506525 DOI: 10.1038/s42003-019-0428-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 04/10/2019] [Indexed: 02/06/2023] Open
Abstract
Dna2 is an essential nuclease-helicase that acts in several distinct DNA metabolic pathways including DNA replication and recombination. To balance these functions and prevent unscheduled DNA degradation, Dna2 activities must be regulated. Here we show that Saccharomyces cerevisiae Dna2 function is controlled by sumoylation. We map the sumoylation sites to the N-terminal regulatory domain of Dna2 and show that in vitro sumoylation of recombinant Dna2 impairs its nuclease but not helicase activity. In cells, the total levels of the non-sumoylatable Dna2 variant are elevated. However, non-sumoylatable Dna2 shows impaired nuclear localization and reduced recruitment to foci upon DNA damage. Non-sumoylatable Dna2 reduces the rate of DNA end resection, as well as impedes cell growth and cell cycle progression through S phase. Taken together, these findings show that in addition to Dna2 phosphorylation described previously, Dna2 sumoylation is required for the homeostasis of the Dna2 protein function to promote genome stability.
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Affiliation(s)
- Lepakshi Ranjha
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland
| | - Maryna Levikova
- Institute of Molecular Cancer Research, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Veronika Altmannova
- Department of Biology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
- International Clinical Research Center, St. Anne’s University Hospital, 656 91 Brno, Czech Republic
| | - Lumir Krejci
- Department of Biology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
- International Clinical Research Center, St. Anne’s University Hospital, 656 91 Brno, Czech Republic
- National Center for Biomolecular Research, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Petr Cejka
- Institute for Research in Biomedicine, Università della Svizzera italiana (USI), Faculty of Biomedical Sciences, Via Vincenzo Vela 6, 6500 Bellinzona, Switzerland
- Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), 8093 Zürich, Switzerland
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40
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Falquet B, Rass U. Structure-Specific Endonucleases and the Resolution of Chromosome Underreplication. Genes (Basel) 2019; 10:E232. [PMID: 30893921 PMCID: PMC6470701 DOI: 10.3390/genes10030232] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 03/11/2019] [Accepted: 03/13/2019] [Indexed: 12/11/2022] Open
Abstract
Complete genome duplication in every cell cycle is fundamental for genome stability and cell survival. However, chromosome replication is frequently challenged by obstacles that impede DNA replication fork (RF) progression, which subsequently causes replication stress (RS). Cells have evolved pathways of RF protection and restart that mitigate the consequences of RS and promote the completion of DNA synthesis prior to mitotic chromosome segregation. If there is entry into mitosis with underreplicated chromosomes, this results in sister-chromatid entanglements, chromosome breakage and rearrangements and aneuploidy in daughter cells. Here, we focus on the resolution of persistent replication intermediates by the structure-specific endonucleases (SSEs) MUS81, SLX1-SLX4 and GEN1. Their actions and a recently discovered pathway of mitotic DNA repair synthesis have emerged as important facilitators of replication completion and sister chromatid detachment in mitosis. As RS is induced by oncogene activation and is a common feature of cancer cells, any advances in our understanding of the molecular mechanisms related to chromosome underreplication have important biomedical implications.
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Affiliation(s)
- Benoît Falquet
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058 Basel, Switzerland.
- Faculty of Natural Sciences, University of Basel, Petersplatz 10, CH-4003 Basel, Switzerland.
| | - Ulrich Rass
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK.
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41
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Abstract
The mitochondrial genome encodes proteins essential for the oxidative phosphorylation and, consequently, for proper mitochondrial function. Its localization and, possibly, structural organization contribute to higher DNA damage accumulation, when compared to the nuclear genome. In addition, the mitochondrial genome mutates at rates several times higher than the nuclear, although the causal relationship between these events are not clearly established. Maintaining mitochondrial DNA stability is critical for cellular function and organismal fitness, and several pathways contribute to that, including damage tolerance and bypass, degradation of damaged genomes and DNA repair. Despite initial evidence suggesting that mitochondria lack DNA repair activities, most DNA repair pathways have been at least partially characterized in mitochondria from several model organisms, including humans. In this chapter, we review what is currently known about how the main DNA repair pathways operate in mitochondria and contribute to mitochondrial DNA stability, with focus on the enzymology of mitochondrial DNA repair.
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Affiliation(s)
- Rebeca R Alencar
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Caio M P F Batalha
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Thiago S Freire
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Nadja C de Souza-Pinto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil.
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42
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Stodola JL, Burgers PM. Mechanism of Lagging-Strand DNA Replication in Eukaryotes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1042:117-133. [PMID: 29357056 DOI: 10.1007/978-981-10-6955-0_6] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This chapter focuses on the enzymes and mechanisms involved in lagging-strand DNA replication in eukaryotic cells. Recent structural and biochemical progress with DNA polymerase α-primase (Pol α) provides insights how each of the millions of Okazaki fragments in a mammalian cell is primed by the primase subunit and further extended by its polymerase subunit. Rapid kinetic studies of Okazaki fragment elongation by Pol δ illuminate events when the polymerase encounters the double-stranded RNA-DNA block of the preceding Okazaki fragment. This block acts as a progressive molecular break that provides both time and opportunity for the flap endonuclease 1 (FEN1) to access the nascent flap and cut it. The iterative action of Pol δ and FEN1 is coordinated by the replication clamp PCNA and produces a regulated degradation of the RNA primer, thereby preventing the formation of long-strand displacement flaps. Occasional long flaps are further processed by backup nucleases including Dna2.
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Affiliation(s)
- Joseph L Stodola
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO, USA
| | - Peter M Burgers
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO, USA.
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43
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Li Z, Liu B, Jin W, Wu X, Zhou M, Liu VZ, Goel A, Shen Z, Zheng L, Shen B. hDNA2 nuclease/helicase promotes centromeric DNA replication and genome stability. EMBO J 2018; 37:embj.201796729. [PMID: 29773570 PMCID: PMC6043852 DOI: 10.15252/embj.201796729] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 04/16/2018] [Accepted: 04/25/2018] [Indexed: 11/18/2022] Open
Abstract
DNA2 is a nuclease/helicase that is involved in Okazaki fragment maturation, replication fork processing, and end resection of DNA double‐strand breaks. Similar such helicase activity for resolving secondary structures and structure‐specific nuclease activity are needed during DNA replication to process the chromosome‐specific higher order repeat units present in the centromeres of human chromosomes. Here, we show that DNA2 binds preferentially to centromeric DNA. The nuclease and helicase activities of DNA2 are both essential for resolution of DNA structural obstacles to facilitate DNA replication fork movement. Loss of DNA2‐mediated clean‐up mechanisms impairs centromeric DNA replication and CENP‐A deposition, leading to activation of the ATR DNA damage checkpoints at centromeric DNA regions and late‐S/G2 cell cycle arrest. Cells that escape arrest show impaired metaphase plate formation and abnormal chromosomal segregation. Furthermore, the DNA2 inhibitor C5 mimics DNA2 knockout and synergistically kills cancer cells when combined with an ATR inhibitor. These findings provide mechanistic insights into how DNA2 supports replication of centromeric DNA and give further insights into new therapeutic strategies.
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Affiliation(s)
- Zhengke Li
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, USA
| | - Bochao Liu
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, New Brunswick, NJ, USA
| | - Weiwei Jin
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, USA.,Department of Gastroenterology & Pancreatic Surgery, Zhejiang Provincial People's Hospital, Hangzhou, Zhejiang, China
| | - Xiwei Wu
- Department of Molecular and Cellular Biology, Beckman Research Institute, City of Hope, Duarte, CA, USA
| | - Mian Zhou
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, USA
| | - Vincent Zewen Liu
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, USA.,Department of Computer Science, Columbia University, New York, NY, USA
| | - Ajay Goel
- Center for Gastrointestinal Research, Center for Translational Genomics and Oncology, Baylor Scott and White Research Institute and Charles A. Sammons Cancer Center, Baylor University Medical Center, Dallas, TX, USA
| | - Zhiyuan Shen
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, New Brunswick, NJ, USA
| | - Li Zheng
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, USA
| | - Binghui Shen
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope, Duarte, CA, USA
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44
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The mitochondrial outer-membrane location of the EXD2 exonuclease contradicts its direct role in nuclear DNA repair. Sci Rep 2018; 8:5368. [PMID: 29599527 PMCID: PMC5876329 DOI: 10.1038/s41598-018-23690-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 03/13/2018] [Indexed: 11/08/2022] Open
Abstract
EXD2 is a recently identified exonuclease that has been implicated in nuclear double-strand break repair. Given our long standing interest in mitochondrial DNA maintenance and indications that EXD2 could also be a mitochondrial protein we sought to determine its cellular localization and possible mitochondrial associated functions. Our results show that EXD2 indeed shows mitochondrial localization, but, surprisingly, is found predominantly associated with the mitochondrial outer-membrane. Gradient purified nuclei show only the faintest hint of EXD2 presence while overexpression of the predicted full-length protein shows exclusive mitochondrial localization. Importantly, induction of double-strand DNA breaks via X-irradiation or Zeocin treatment does not support the notion that EXD2 re-locates to the nucleus following double-strand breaks and thus is unlikely to have a direct role in nuclear DNA repair. Knockdown or overexpression of EXD2 affects the cellular distribution of mitochondria. These results suggest that the reported defects in nuclear DNA repair following EXD2 depletion are likely an indirect consequence of altered mitochondrial dynamics and/or function.
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45
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Abstract
Dna2 is a nuclease and helicase that functions redundantly with other proteins in Okazaki fragment processing, double-strand break resection, and checkpoint kinase activation. Dna2 is an essential enzyme, required for yeast and mammalian cell viability. Here, we report that numerous mutations affecting the DNA damage checkpoint suppress dna2∆ lethality in Saccharomyces cerevisiaedna2∆ cells are also suppressed by deletion of helicases PIF1 and MPH1, and by deletion of POL32, a subunit of DNA polymerase δ. All dna2∆ cells are temperature sensitive, have telomere length defects, and low levels of telomeric 3' single-stranded DNA (ssDNA). Interestingly, Rfa1, a subunit of the major ssDNA binding protein RPA, and the telomere-specific ssDNA binding protein Cdc13, often colocalize in dna2∆ cells. This suggests that telomeric defects often occur in dna2∆ cells. There are several plausible explanations for why the most critical function of Dna2 is at telomeres. Telomeres modulate the DNA damage response at chromosome ends, inhibiting resection, ligation, and cell-cycle arrest. We suggest that Dna2 nuclease activity contributes to modulating the DNA damage response at telomeres by removing telomeric C-rich ssDNA and thus preventing checkpoint activation.
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46
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Jia PP, Junaid M, Ma YB, Ahmad F, Jia YF, Li WG, Pei DS. Role of human DNA2 (hDNA2) as a potential target for cancer and other diseases: A systematic review. DNA Repair (Amst) 2017; 59:9-19. [PMID: 28903076 DOI: 10.1016/j.dnarep.2017.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 08/29/2017] [Accepted: 09/01/2017] [Indexed: 11/28/2022]
Abstract
DNA nuclease/helicase 2 (DNA2), a multi-functional protein protecting the high fidelity of genomic transmission, plays critical roles in DNA replication and repair processes. In the maturation of Okazaki fragments, DNA2 acts synergistically with other enzymes to cleave the DNA-RNA primer flaps via different pathways. DNA2 is also involved in the stability of mitochondrial DNA and the maintenance of telomeres. Moreover, DNA2 potentially participates in controlling the cell cycle by repairing the DNA replication faults at main checkpoints. In addition, previous evidences demonstrated that DNA2 also functions in the repair process of DNA damages, such as base excision repair (BER). Currently, large studies revealed the structures and functions of DNA2 in prokaryotes and unicellular eukaryotes, such as bacteria and yeast. However, the studies that highlighted the functions of human DNA2 (hDNA2) and the relationships with other multifunctional proteins are still elusive, and more precise investigations are immensely needed. Therefore, this review mainly encompasses the key functions of DNA2 in human cells with various aspects, especially focusing on the genome integrity, and also generalizes the recent insights to the mechanisms related to the occurrence of cancer and other diseases potentially linked to the mutations in DNA2.
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Affiliation(s)
- Pan-Pan Jia
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122, China; College of Life Science, Henan Normal University, Xinxiang 453007, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Muhammad Junaid
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan-Bo Ma
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122, China
| | - Farooq Ahmad
- Sustainable Development Study Centre, GC University Lahore, Pakistan
| | - Yong-Fang Jia
- College of Life Science, Henan Normal University, Xinxiang 453007, China
| | - Wei-Guo Li
- College of Life Science, Henan Normal University, Xinxiang 453007, China.
| | - De-Sheng Pei
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 401122, China.
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Pawłowska E, Szczepanska J, Blasiak J. DNA2-An Important Player in DNA Damage Response or Just Another DNA Maintenance Protein? Int J Mol Sci 2017; 18:ijms18071562. [PMID: 28718810 PMCID: PMC5536050 DOI: 10.3390/ijms18071562] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 07/13/2017] [Accepted: 07/17/2017] [Indexed: 02/01/2023] Open
Abstract
The human DNA2 (DNA replication helicase/nuclease 2) protein is expressed in both the nucleus and mitochondria, where it displays ATPase-dependent nuclease and helicase activities. DNA2 plays an important role in the removing of long flaps in DNA replication and long-patch base excision repair (LP-BER), interacting with the replication protein A (RPA) and the flap endonuclease 1 (FEN1). DNA2 can promote the restart of arrested replication fork along with Werner syndrome ATP-dependent helicase (WRN) and Bloom syndrome protein (BLM). In mitochondria, DNA2 can facilitate primer removal during strand-displacement replication. DNA2 is involved in DNA double strand (DSB) repair, in which it is complexed with BLM, RPA and MRN for DNA strand resection required for homologous recombination repair. DNA2 can be a major protein involved in the repair of complex DNA damage containing a DSB and a 5' adduct resulting from a chemical group bound to DNA 5' ends, created by ionizing radiation and several anticancer drugs, including etoposide, mitoxantrone and some anthracyclines. The role of DNA2 in telomere end maintenance and cell cycle regulation suggests its more general role in keeping genomic stability, which is impaired in cancer. Therefore DNA2 can be an attractive target in cancer therapy. This is supported by enhanced expression of DNA2 in many cancer cell lines with oncogene activation and premalignant cells. Therefore, DNA2 can be considered as a potential marker, useful in cancer therapy. DNA2, along with PARP1 inhibition, may be considered as a potential target for inducing synthetic lethality, a concept of killing tumor cells by targeting two essential genes.
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Affiliation(s)
- Elzbieta Pawłowska
- Department of Orthodontics, Medical University of Lodz, 92-216 Lodz, Poland.
| | - Joanna Szczepanska
- Department of Pediatric Dentistry, Medical University of Lodz, 92-216 Lodz, Poland.
| | - Janusz Blasiak
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland.
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48
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Crouch JD, Brosh RM. Mechanistic and biological considerations of oxidatively damaged DNA for helicase-dependent pathways of nucleic acid metabolism. Free Radic Biol Med 2017; 107:245-257. [PMID: 27884703 PMCID: PMC5440220 DOI: 10.1016/j.freeradbiomed.2016.11.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 11/11/2016] [Accepted: 11/13/2016] [Indexed: 12/21/2022]
Abstract
Cells are under constant assault from reactive oxygen species that occur endogenously or arise from environmental agents. An important consequence of such stress is the generation of oxidatively damaged DNA, which is represented by a wide range of non-helix distorting and helix-distorting bulkier lesions that potentially affect a number of pathways including replication and transcription; consequently DNA damage tolerance and repair pathways are elicited to help cells cope with the lesions. The cellular consequences and metabolism of oxidatively damaged DNA can be quite complex with a number of DNA metabolic proteins and pathways involved. Many of the responses to oxidative stress involve a specialized class of enzymes known as helicases, the topic of this review. Helicases are molecular motors that convert the energy of nucleoside triphosphate hydrolysis to unwinding of structured polynucleic acids. Helicases by their very nature play fundamentally important roles in DNA metabolism and are implicated in processes that suppress chromosomal instability, genetic disease, cancer, and aging. We will discuss the roles of helicases in response to nuclear and mitochondrial oxidative stress and how this important class of enzymes help cells cope with oxidatively generated DNA damage through their functions in the replication stress response, DNA repair, and transcriptional regulation.
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Affiliation(s)
- Jack D Crouch
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, 251 Bayview Blvd, Baltimore, MD 21224, USA
| | - Robert M Brosh
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, 251 Bayview Blvd, Baltimore, MD 21224, USA.
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49
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Mitochondrial DNA replication: a PrimPol perspective. Biochem Soc Trans 2017; 45:513-529. [PMID: 28408491 PMCID: PMC5390496 DOI: 10.1042/bst20160162] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 02/20/2017] [Accepted: 02/21/2017] [Indexed: 12/20/2022]
Abstract
PrimPol, (primase-polymerase), the most recently identified eukaryotic polymerase, has roles in both nuclear and mitochondrial DNA maintenance. PrimPol is capable of acting as a DNA polymerase, with the ability to extend primers and also bypass a variety of oxidative and photolesions. In addition, PrimPol also functions as a primase, catalysing the preferential formation of DNA primers in a zinc finger-dependent manner. Although PrimPol's catalytic activities have been uncovered in vitro, we still know little about how and why it is targeted to the mitochondrion and what its key roles are in the maintenance of this multicopy DNA molecule. Unlike nuclear DNA, the mammalian mitochondrial genome is circular and the organelle has many unique proteins essential for its maintenance, presenting a differing environment within which PrimPol must function. Here, we discuss what is currently known about the mechanisms of DNA replication in the mitochondrion, the proteins that carry out these processes and how PrimPol is likely to be involved in assisting this vital cellular process.
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50
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Bruni F, Lightowlers RN, Chrzanowska-Lightowlers ZM. Human mitochondrial nucleases. FEBS J 2017; 284:1767-1777. [PMID: 27926991 PMCID: PMC5484287 DOI: 10.1111/febs.13981] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/22/2016] [Accepted: 11/30/2016] [Indexed: 12/26/2022]
Abstract
Mitochondria are cytosolic organelles that have many essential roles including ATP production via oxidative phosphorylation, apoptosis, iron‐sulfur cluster biogenesis, heme and steroid synthesis, calcium homeostasis, and regulation of cellular redox state. One of the unique features of these organelles is the presence of an extrachromosomal mitochondrial genome (mtDNA), together with all the machinery required to replicate and transcribe mtDNA. The accurate maintenance of mitochondrial gene expression is essential for correct organellar metabolism, and is in part dependent on the levels of mtDNA and mtRNA, which are regulated by balancing synthesis against degradation. It is clear that although a number of mitochondrial nucleases have been identified, not all those responsible for the degradation of DNA or RNA have been characterized. Recent investigations, however, have revealed the contribution that mutations in the genes coding for these enzymes has made to causing pathogenic mitochondrial diseases.
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Affiliation(s)
- Francesco Bruni
- The Wellcome Trust Centre for Mitochondrial Research, The Medical School, Newcastle University, UK
| | - Robert N Lightowlers
- The Wellcome Trust Centre for Mitochondrial Research, The Medical School, Newcastle University, UK
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