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Peng JM, Zhang DD, Huang ZY, Fu MJ. The Stress of Fungicides Changes the Expression of Clock Protein CmFRQ and the Morphology of Fruiting Bodies of Cordyceps militaris. J Fungi (Basel) 2024; 10:150. [PMID: 38392822 PMCID: PMC10890350 DOI: 10.3390/jof10020150] [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: 01/09/2024] [Revised: 02/01/2024] [Accepted: 02/10/2024] [Indexed: 02/24/2024] Open
Abstract
The physiological, biochemical, and morphological changes brought about by fungi in response to fungicides can undoubtedly bring diversity to fungi. Cordyceps militaris strains TN (mating type genes MAT1-1-1, MAT1-1-2, and MAT1-2-1) and CmFRQ-454 (mating type genes MAT1-1-1 and MAT1-1-2) were treated with non-lethal doses of fungicides amphotericin B, L-cysteine, terbinafine, and 5-fluorocytosine. The results showed that the treatment with amphotericin B, terbinafine, and 5-fluorocytosine promoted an increase in the relative content of clock protein CmFRQ (C. militaris FREQUENCY) in the mycelium of strain TN, while the high concentration of L-cysteine inhibited the expression of CmFRQ in strain TN. These four fungicides could reduce the relative contents of CmFRQ in the mycelium of strain CmFRQ454. The relative contents of CmFRQ in the mycelium of strain TN were increased after removing the four fungicides, but the relative contents of CmFRQ in the mycelium of strain CmFRQ454 were decreased after removing the four fungicides. This indicates that the effect of fungicides on CmFRQ on mycelium was still sustained after removing the stress of fungicides, and the operation of the circadian clock was changed. The fruiting bodies of C. militaris strain TN and CmFRQ-454 were still degenerated to varying degrees after removing amphotericin B, L-cysteine, and terbinafine. However, the fruiting bodies of strain TN after removing 5-fluorocytosine did not show significant degeneration; the fruiting bodies of strain CmFRQ-454 after removing 5-fluorocytosine obtained rejuvenation. These results indicate that the stress of fungicides could lead to the degeneration of fruiting bodies as well as the rejuvenation of fruiting bodies, resulting in the morphological diversity of C. militaris. The increase or decrease of the CmFRQ-454, the main component of the circadian clock, caused by the stress of fungicants, might lead to the differential degeneration of different mating-type strains of C. militaris.
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Affiliation(s)
- Jing-Mei Peng
- College of Life Science, Jiangxi Normal University, No. 99, Ziyang Avenue, Nanchang 330022, China
| | - Dan-Dan Zhang
- College of Life Science, Jiangxi Normal University, No. 99, Ziyang Avenue, Nanchang 330022, China
| | - Zi-Yan Huang
- College of Life Science, Jiangxi Normal University, No. 99, Ziyang Avenue, Nanchang 330022, China
| | - Ming-Jia Fu
- College of Life Science, Jiangxi Normal University, No. 99, Ziyang Avenue, Nanchang 330022, China
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Osiewacz HD, Schürmanns L. A Network of Pathways Controlling Cellular Homeostasis Affects the Onset of Senescence in Podospora anserina. J Fungi (Basel) 2021; 7:jof7040263. [PMID: 33807190 PMCID: PMC8065454 DOI: 10.3390/jof7040263] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 03/28/2021] [Indexed: 01/07/2023] Open
Abstract
Research on Podospora anserina unraveled a network of molecular pathways affecting biological aging. In particular, a number of pathways active in the control of mitochondria were identified on different levels. A long-known key process active during aging of P. anserina is the age-related reorganization of the mitochondrial DNA (mtDNA). Mechanisms involved in the stabilization of the mtDNA lead to lifespan extension. Another critical issue is to balance mitochondrial levels of reactive oxygen species (ROS). This is important because ROS are essential signaling molecules, but at increased levels cause molecular damage. At a higher level of the network, mechanisms are active in the repair of damaged compounds. However, if damage passes critical limits, the corresponding pathways are overwhelmed and impaired molecules as well as those present in excess are degraded by specific enzymes or via different forms of autophagy. Subsequently, degraded units need to be replaced by novel functional ones. The corresponding processes are dependent on the availability of intact genetic information. Although a number of different pathways involved in the control of cellular homeostasis were uncovered in the past, certainly many more exist. In addition, the signaling pathways involved in the control and coordination of the underlying pathways are only initially understood. In some cases, like the induction of autophagy, ROS are active. Additionally, sensing and signaling the energetic status of the organism plays a key role. The precise mechanisms involved are elusive and remain to be elucidated.
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Khan AH, Zou Z, Xiang Y, Chen S, Tian XL. Conserved signaling pathways genetically associated with longevity across the species. Biochim Biophys Acta Mol Basis Dis 2018; 1865:1745-1755. [PMID: 31109448 DOI: 10.1016/j.bbadis.2018.09.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/26/2018] [Accepted: 09/04/2018] [Indexed: 02/08/2023]
Abstract
Advanced age is an independent risk factor for natural death and common diseases, such as cardiovascular diseases, dementia, and cancers, which are life-threatening and cause disabilities. On the other hand, individual with healthy longevity is a plausible model for successful aging. Thus, search for longevity-associated genes and pathways likely provides a unique approach to understand the genetic mechanisms underlying aging and healthspan, and emerging evidence from model organisms has highlighted the significance of genetic components in longevity. Here we reviewed the uses of model organisms including yeast, ciliate, nematode, arthropod, fish, rodent, and primate as well as human to identify the genetic determinants of longevity and discussed the genetic contributions of conserved longevity pathways, such as adrenergic system, AMPK, insulin/IGF-1, and mTOR signaling pathways.
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Affiliation(s)
- Abdul Haseeb Khan
- Human population genetics, Human Aging Research Institute (HARI), Nanchang University, Xuefu Rd 999, Honggutan New District, Nanchang, Jiangxi Province 330031, China; School of Life Science, Nanchang University, Xuefu Rd 999, Honggutan New District, Nanchang, Jiangxi Province 330031, China
| | - Zhiwen Zou
- School of Life Science, Nanchang University, Xuefu Rd 999, Honggutan New District, Nanchang, Jiangxi Province 330031, China
| | - Yang Xiang
- Human population genetics, Human Aging Research Institute (HARI), Nanchang University, Xuefu Rd 999, Honggutan New District, Nanchang, Jiangxi Province 330031, China; School of Life Science, Nanchang University, Xuefu Rd 999, Honggutan New District, Nanchang, Jiangxi Province 330031, China
| | - Shenghan Chen
- Human population genetics, Human Aging Research Institute (HARI), Nanchang University, Xuefu Rd 999, Honggutan New District, Nanchang, Jiangxi Province 330031, China; School of Life Science, Nanchang University, Xuefu Rd 999, Honggutan New District, Nanchang, Jiangxi Province 330031, China
| | - Xiao-Li Tian
- Human population genetics, Human Aging Research Institute (HARI), Nanchang University, Xuefu Rd 999, Honggutan New District, Nanchang, Jiangxi Province 330031, China; School of Life Science, Nanchang University, Xuefu Rd 999, Honggutan New District, Nanchang, Jiangxi Province 330031, China.
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4
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Knuppertz L, Hamann A, Pampaloni F, Stelzer E, Osiewacz HD. Identification of autophagy as a longevity-assurance mechanism in the aging model Podospora anserina. Autophagy 2014; 10:822-34. [PMID: 24584154 PMCID: PMC5119060 DOI: 10.4161/auto.28148] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 02/07/2014] [Accepted: 02/07/2014] [Indexed: 12/28/2022] Open
Abstract
The filamentous ascomycete Podospora anserina is a well-established aging model in which a variety of different pathways, including those involved in the control of respiration, ROS generation and scavenging, DNA maintenance, proteostasis, mitochondrial dynamics, and programmed cell death have previously been demonstrated to affect aging and life span. Here we address a potential role of autophagy. We provide data demonstrating high basal autophagy levels even in strains cultivated under noninduced conditions. By monitoring an N-terminal fusion of EGFP to the fungal LC3 homolog PaATG8 over the lifetime of the fungus on medium with and without nitrogen supplementation, respectively, we identified a significant increase of GFP puncta in older and in nitrogen-starved cultures suggesting an induction of autophagy during aging. This conclusion is supported by the demonstration of an age-related and autophagy-dependent degradation of a PaSOD1-GFP reporter protein. The deletion of Paatg1, which leads to the lack of the PaATG1 serine/threonine kinase active in early stages of autophagy induction, impairs ascospore germination and development and shortens life span. Under nitrogen-depleted conditions, life span of the wild type is increased almost 4-fold. In contrast, this effect is annihilated in the Paatg1 deletion strain, suggesting that the ability to induce autophagy is beneficial for this fungus. Collectively, our data identify autophagy as a longevity-assurance mechanism in P. anserina and as another surveillance pathway in the complex network of pathways affecting aging and development. These findings provide perspectives for the elucidation of the mechanisms involved in the regulation of individual pathways and their interactions.
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Affiliation(s)
- Laura Knuppertz
- Institute of Molecular Biosciences and Cluster of Excellence Frankfurt Macromolecular Complexes; Department of Biosciences; J W Goethe University; Frankfurt, Germany
| | - Andrea Hamann
- Institute of Molecular Biosciences and Cluster of Excellence Frankfurt Macromolecular Complexes; Department of Biosciences; J W Goethe University; Frankfurt, Germany
| | - Francesco Pampaloni
- Physical Biology Group; Buchmann Institute of Molecular Life Sciences; Cluster of Excellence Frankfurt Macromolecular Complexes; Frankfurt, Germany
| | - Ernst Stelzer
- Physical Biology Group; Buchmann Institute of Molecular Life Sciences; Cluster of Excellence Frankfurt Macromolecular Complexes; Frankfurt, Germany
| | - Heinz D Osiewacz
- Institute of Molecular Biosciences and Cluster of Excellence Frankfurt Macromolecular Complexes; Department of Biosciences; J W Goethe University; Frankfurt, Germany
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5
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Plohnke N, Hamann A, Poetsch A, Osiewacz HD, Rögner M, Rexroth S. Proteomic analysis of mitochondria from senescent Podospora anserina casts new light on ROS dependent aging mechanisms. Exp Gerontol 2014; 56:13-25. [PMID: 24556281 DOI: 10.1016/j.exger.2014.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 02/04/2014] [Accepted: 02/11/2014] [Indexed: 11/25/2022]
Abstract
The mitochondrial free radical theory of aging (MFRTA) states that reactive oxygen species (ROS) generated at the respiratory electron transport chain are active in causing age-related damage of biomolecules like lipids, nucleic acids and proteins. Accumulation of this kind of damage results in functional impairments, aging and death of biological systems. Here we report data of an analysis to monitor the age-related quantitative protein composition of the mitochondria of the fungal aging model Podospora anserina. The impact of senescence on mitochondrial protein composition was analyzed by LC-MS. In an untargeted proteomic approach, we identified 795 proteins in samples from juvenile and senescent wild-type cultures and obtained quantitative information for 226 of these proteins by spectral counting. Despite the broad coverage of the proteome, no substantial changes in known age-related pathways could be observed. For a more detailed analysis, a targeted proteome analysis was applied focusing on 15 proteins from respiratory, ROS-scavenging and quality control pathways. Analyzing six distinct age-stages from juvenile to senescent P. anserina cultures revealed low, but statistically significant changes for the mitochondrial respiratory complexes. A P. anserina PaSod3 over-expression mutant with a phenotype of mitochondrial ROS over-production was used for biological evaluation of changes observed during aging. LC-MS analysis of the mutant revealed severe changes to the mitochondrial proteome--substantially larger than observed during senescence. Interestingly the amount of ATP synthase subunit g, involved in cristae formation is significantly decreased in the mutant implicating ROS-induced impairments in ATP synthase dimer and cristae formation. The difference between protein-profiles of aging wild type and ROS stressed mutant suggests that oxidative stress within the mitochondria is not the dominating mechanism for the aging process in P. anserina. Collectively, while our data do not exclude an effect of ROS on specific proteins and in signaling and control of pathways which are governing aging of P. anserina, it contradicts increasing ROS as a cause of a gross general and non-selective accumulation of damaged proteins during senescence. Instead, ROS may be effective by controlling specific regulators of mitochondrial function.
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Affiliation(s)
- Nicole Plohnke
- Plant Biochemistry, Faculty of Biology & Biotechnology, Ruhr University Bochum, D-44780 Bochum, Germany.
| | - Andrea Hamann
- Institute of Molecular Biosciences, Faculty for Biosciences and Cluster of Excellence Macromolecular Complexes, Johann Wolfgang Goethe University, D-60438 Frankfurt, Germany.
| | - Ansgar Poetsch
- Plant Biochemistry, Faculty of Biology & Biotechnology, Ruhr University Bochum, D-44780 Bochum, Germany.
| | - Heinz D Osiewacz
- Institute of Molecular Biosciences, Faculty for Biosciences and Cluster of Excellence Macromolecular Complexes, Johann Wolfgang Goethe University, D-60438 Frankfurt, Germany.
| | - Matthias Rögner
- Plant Biochemistry, Faculty of Biology & Biotechnology, Ruhr University Bochum, D-44780 Bochum, Germany.
| | - Sascha Rexroth
- Plant Biochemistry, Faculty of Biology & Biotechnology, Ruhr University Bochum, D-44780 Bochum, Germany.
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Nuclear and mitochondrial DNA repair in selected eukaryotic aging model systems. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2012; 2012:282438. [PMID: 23050036 PMCID: PMC3462412 DOI: 10.1155/2012/282438] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2012] [Accepted: 08/26/2012] [Indexed: 12/21/2022]
Abstract
Knowledge about the different mechanisms underlying the aging process has increased exponentially in the last decades. The fact that the basic mechanisms involved in the aging process are believed to be universal allows the use of different model systems, from the simplest eukaryotic cells such as fungi to the most complex organisms such as mice or human. As our knowledge on the aging mechanisms in those model systems increases, our understanding of human aging and the potential interventions that we could approach rise significantly. Among the different mechanisms that have been implicated in the aging process, DNA repair is one of the processes which have been suggested to play an important role. Here, we review the latest investigations supporting the role of these mechanisms in the aging process, stressing how beneficial the use of different model systems is. We discuss how human genetic studies as well as several investigations on mammalian models and simpler eukaryotic organisms have contributed to a better understanding of the involvement of DNA repair mechanisms in aging.
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Mitochondrial quality control in aging and lifespan control of the fungal aging model Podospora anserina. Biochem Soc Trans 2012; 39:1488-92. [PMID: 21936839 DOI: 10.1042/bst0391488] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Aging of biological systems is a fundamental process controlled by a complex network of molecular pathways. In the filamentous fungus Podospora anserina, a model in which organismal aging can conveniently be analysed, mitochondria play a central role. A wide range of relevant pathways were identified that contribute to the maintenance of a population of functional mitochondria. These pathways act in a hierarchical manner, but all the pathways are limited in capacity. At the end of the life cycle, when the various surveillance pathways are overwhelmed and damage has passed certain thresholds, programmed cell death brings the life of individual P. anserina to an end.
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Weil A, Luce K, Dröse S, Wittig I, Brandt U, Osiewacz HD. Unmasking a temperature-dependent effect of the P. anserina i-AAA protease on aging and development. Cell Cycle 2011; 10:4280-90. [PMID: 22134244 PMCID: PMC3272260 DOI: 10.4161/cc.10.24.18560] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 10/27/2011] [Indexed: 12/15/2022] Open
Abstract
Different molecular pathways involved in maintaining mitochondrial function are of fundamental importance to control cellular homeostasis. Mitochondrial i-AAA protease is part of such a surveillance system and PaIAP is the putative ortholog in the fungal aging model Podospora anserina. Here we investigated the role of PaIAP in aging and development. Deletion of the gene encoding PaIAP resulted in a specific phenotype. When incubated at 27°C, spore germination and fruiting body formation are not different from that of the corresponding wild-type strain. Unexpectedly, the lifespan of the deletion strain is strongly increased. In contrast, cultivation at an elevated temperature of 37°C leads to impairments in spore germination and fruiting body formation, and to a reduced lifespan. The higher PaIAP abundance in wild-type strains of the fungus grown at elevated temperature and the phenotype of the deletion strain unmasks a temperature-related role of the protein. The protease appears to be part of a molecular system that has evolved to allow survival under changing temperatures as they characteristically occur in nature.
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Affiliation(s)
- Andrea Weil
- Goethe University, Faculty for Biosciences & Cluster of Excellence Macromolecular Complexes Frankfurt, Institute of Molecular Biosciences, Frankfurt, Germany
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9
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DNA repair in organelles: Pathways, organization, regulation, relevance in disease and aging. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:186-200. [DOI: 10.1016/j.bbamcr.2010.10.002] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 10/01/2010] [Accepted: 10/05/2010] [Indexed: 12/20/2022]
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10
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Gredilla R. DNA damage and base excision repair in mitochondria and their role in aging. J Aging Res 2010; 2011:257093. [PMID: 21234332 PMCID: PMC3018712 DOI: 10.4061/2011/257093] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 12/14/2010] [Indexed: 12/28/2022] Open
Abstract
During the last decades, our knowledge about the processes involved in the aging process has exponentially increased. However, further investigation will be still required to globally understand the complexity of aging. Aging is a multifactorial phenomenon characterized by increased susceptibility to cellular loss and functional decline, where mitochondrial DNA mutations and mitochondrial DNA damage response are thought to play important roles. Due to the proximity of mitochondrial DNA to the main sites of mitochondrial-free radical generation, oxidative stress is a major source of mitochondrial DNA mutations. Mitochondrial DNA repair mechanisms, in particular the base excision repair pathway, constitute an important mechanism for maintenance of mitochondrial DNA integrity. The results reviewed here support that mitochondrial DNA damage plays an important role in aging.
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Affiliation(s)
- Ricardo Gredilla
- Department of Physiology, Faculty of Medicine, Complutense University, Plaza Ramón y Cajal s/n. 28040 Madrid, Spain
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Osiewacz HD, Brust D, Hamann A, Kunstmann B, Luce K, Müller-Ohldach M, Scheckhuber CQ, Servos J, Strobel I. Mitochondrial pathways governing stress resistance, life, and death in the fungal aging model Podospora anserina. Ann N Y Acad Sci 2010; 1197:54-66. [PMID: 20536834 DOI: 10.1111/j.1749-6632.2010.05190.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Work from more than 50 years of research has unraveled a number of molecular pathways that are involved in controlling aging of the fungal model system Podospora anserina. Early research revealed that wild-type strain aging is linked to gross reorganization of the mitochondrial DNA. Later it was shown that aging of P. anserina does also take place, although at a slower pace, when the wild-type specific mitochondrial DNA rearrangements do not occur. Now it is clear that a network of different pathways is involved in the control of aging. Branches of these pathways appear to be connected and constitute a hierarchical system of responses. Although cross talk between the individual pathways seems to be fundamental in the coordination of the overall system, the precise underlying interactions remain to be unraveled. Such a systematic approach aims at a holistic understanding of the process of biological aging, the ultimate goal of modern systems biology.
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Affiliation(s)
- Heinz D Osiewacz
- Institute of Molecular Biosciences, Faculty for Biosciences and Cluster of Excellence Macromolecular Complexes, Johann Wolfgang Goethe University, Frankfurt, Germany.
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van Diepeningen AD, Goedbloed DJ, Slakhorst SM, Koopmanschap AB, Maas MFPM, Hoekstra RF, Debets AJM. Mitochondrial recombination increases with age in Podospora anserina. Mech Ageing Dev 2010; 131:315-22. [PMID: 20226205 DOI: 10.1016/j.mad.2010.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Revised: 03/02/2010] [Accepted: 03/03/2010] [Indexed: 12/15/2022]
Abstract
With uniparental inheritance of mitochondria, there seems little reason for homologous recombination in mitochondria, but the machinery for mitochondrial recombination is quite well-conserved in many eukaryote species. In fungi and yeasts heteroplasmons may be formed when strains fuse and transfer of organelles takes place, making it possible to study mitochondrial recombination when introduced mitochondria contain different markers. A survey of wild-type isolates from a local population of the filamentous fungus Podospora anserina for the presence of seven optional mitochondrial introns indicated that mitochondrial recombination does take place in nature. Moreover the recombination frequency appeared to be correlated with age: the more rapidly ageing fraction of the population had a significantly lower linkage disequilibrium indicating more recombination. Direct confrontation experiments with heterokaryon incompatible strains with different mitochondrial markers at different (relative) age confirmed that mitochondrial recombination increases with age. We propose that with increasing mitochondrial damage over time, mitochondrial recombination - even within a homoplasmic population of mitochondria - is a mechanism that may restore mitochondrial function.
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Affiliation(s)
- Anne D van Diepeningen
- Laboratory of Genetics, Plant Sciences, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
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Gredilla R, Bohr VA, Stevnsner T. Mitochondrial DNA repair and association with aging--an update. Exp Gerontol 2010; 45:478-88. [PMID: 20096766 DOI: 10.1016/j.exger.2010.01.017] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 01/10/2010] [Accepted: 01/14/2010] [Indexed: 01/07/2023]
Abstract
Mitochondrial DNA is constantly exposed to oxidative injury. Due to its location close to the main site of reactive oxygen species, the inner mitochondrial membrane, mtDNA is more susceptible than nuclear DNA to oxidative damage. The accumulation of DNA damage is thought to play a critical role in the aging process and to be particularly deleterious in post-mitotic cells. Thus, DNA repair is an important mechanism for maintenance of genomic integrity. Despite the importance of mitochondria in the aging process, it was thought for many years that mitochondria lacked an enzymatic DNA repair system comparable to that in the nuclear compartment. However, it is now well established that DNA repair actively takes place in mitochondria. Oxidative DNA damage processing, base excision repair mechanisms were the first to be described in these organelles, and consequently the best understood. However, new proteins and novel DNA repair pathways, thought to be exclusively present in the nucleus, have recently been described also to be present in mitochondria. Here we review the main mitochondrial DNA repair pathways and their association with the aging process.
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Affiliation(s)
- Ricardo Gredilla
- Danish Center for Molecular Gerontology, Department of Molecular Biology, Aarhus University, C.F. Moellers allé 3, Aarhus C, Denmark
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Deletion of the mitochondrial NADH kinase increases mitochondrial DNA stability and life span in the filamentous fungus Podospora anserina. Exp Gerontol 2010; 45:543-9. [PMID: 20096769 DOI: 10.1016/j.exger.2010.01.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 12/31/2009] [Accepted: 01/14/2010] [Indexed: 01/19/2023]
Abstract
In the filamentous fungus Podospora anserina, aging is systematically associated with mitochondrial DNA (mtDNA) instability. A causal link between deficiency of the cytochrome respiratory pathway and lifespan extension has been demonstrated. Knock out of the cytochrome respiratory pathway induces the expression of an alternative oxidase and is associated with a reduction in free radical production. The question of the links between mtDNA stability, ROS generation and lifespan is therefore clearly raised in this organism. NADPH lies at the heart of many anti-oxidant defenses of the cell. In Saccharomyces cerevisiae, the mitochondrial NADPH is largely provided by the Pos5 NADH kinase. We show here that disruption of PaNdk1 encoding the potential mitochondrial NADH kinase of P. anserina leads to severe somatic and sexual defects and to hypersensitivity to hydrogen peroxide and paraquat. Surprisingly, it also leads to a spectacular increase of mtDNA stability and lifespan. We propose that an adaptative metabolic change including the induction of the alternative oxidase can account for these results.
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