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Osiewacz HD. The impact of biomembranes and their dynamics on organismic aging: insights from a fungal aging model. FRONTIERS IN AGING 2024; 5:1356697. [PMID: 38327611 PMCID: PMC10847301 DOI: 10.3389/fragi.2024.1356697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 01/09/2024] [Indexed: 02/09/2024]
Abstract
Biomembranes fulfill several essential functions. They delimitate cells and control the exchange of compounds between cells and the environment. They generate specialized cellular reaction spaces, house functional units such as the respiratory chain (RC), and are involved in content trafficking. Biomembranes are dynamic and able to adjust their properties to changing conditions and requirements. An example is the inner mitochondrial membrane (IMM), which houses the RC involved in the formation of adenosine triphosphate (ATP) and the superoxide anion as a reactive oxygen species (ROS). The IMM forms a characteristic ultrastructure that can adapt to changing physiological situations. In the fungal aging model Podospora anserina, characteristic age-related changes of the mitochondrial ultrastructure occur. More recently, the impact of membranes on aging was extended to membranes involved in autophagy, an important pathway involved in cellular quality control (QC). Moreover, the effect of oleic acid on the lifespan was linked to basic biochemical processes and the function of membranes, providing perspectives for the elucidation of the mechanistic effects of this nutritional component, which positively affects human health and aging.
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Affiliation(s)
- Heinz D. Osiewacz
- Institute for Molecular Biosciences, Faculty of Biosciences, Goethe University, Frankfurt, Germany
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Warnsmann V, Meisterknecht J, Wittig I, Osiewacz HD. Aging of Podospora anserina Leads to Alterations of OXPHOS and the Induction of Non-Mitochondrial Salvage Pathways. Cells 2021; 10:cells10123319. [PMID: 34943827 PMCID: PMC8699231 DOI: 10.3390/cells10123319] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 01/19/2023] Open
Abstract
The accumulation of functionally impaired mitochondria is a key event in aging. Previous works with the fungal aging model Podospora anserina demonstrated pronounced age-dependent changes of mitochondrial morphology and ultrastructure, as well as alterations of transcript and protein levels, including individual proteins of the oxidative phosphorylation (OXPHOS). The identified protein changes do not reflect the level of the whole protein complexes as they function in-vivo. In the present study, we investigated in detail the age-dependent changes of assembled mitochondrial protein complexes, using complexome profiling. We observed pronounced age-depen-dent alterations of the OXPHOS complexes, including the loss of mitochondrial respiratory supercomplexes (mtRSCs) and a reduction in the abundance of complex I and complex IV. Additionally, we identified a switch from the standard complex IV-dependent respiration to an alternative respiration during the aging of the P. anserina wild type. Interestingly, we identified proteasome components, as well as endoplasmic reticulum (ER) proteins, for which the recruitment to mitochondria appeared to be increased in the mitochondria of older cultures. Overall, our data demonstrate pronounced age-dependent alterations of the protein complexes involved in energy transduction and suggest the induction of different non-mitochondrial salvage pathways, to counteract the age-dependent mitochondrial impairments which occur during aging.
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Affiliation(s)
- Verena Warnsmann
- Institute of Molecular Biosciences, Faculty of Biosciences, Goethe-University, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Jana Meisterknecht
- Functional Proteomics, Institute of Cardiovascular Physiology, Faculty of Medicine, Goethe-University, Theodor-Stein-Kai 7, 60590 Frankfurt am Main, Germany
| | - Ilka Wittig
- Functional Proteomics, Institute of Cardiovascular Physiology, Faculty of Medicine, Goethe-University, Theodor-Stein-Kai 7, 60590 Frankfurt am Main, Germany
| | - Heinz D Osiewacz
- Institute of Molecular Biosciences, Faculty of Biosciences, Goethe-University, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
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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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Heinz D, Krotova E, Hamann A, Osiewacz HD. Simultaneous Ablation of the Catalytic AMPK α-Subunit SNF1 and Mitochondrial Matrix Protease CLPP Results in Pronounced Lifespan Extension. Front Cell Dev Biol 2021; 9:616520. [PMID: 33748105 PMCID: PMC7969656 DOI: 10.3389/fcell.2021.616520] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 01/27/2021] [Indexed: 12/21/2022] Open
Abstract
Organismic aging is known to be controlled by genetic and environmental traits. Pathways involved in the control of cellular metabolism play a crucial role. Previously, we identified a role of PaCLPP, a mitochondrial matrix protease, in the control of the mitochondrial energy metabolism, aging, and lifespan of the fungal aging model Podospora anserina. Most surprisingly, we made the counterintuitive observation that the ablation of this component of the mitochondrial quality control network leads to lifespan extension. In the current study, we investigated the role of energy metabolism of P. anserina. An age-dependent metabolome analysis of the wild type and a PaClpP deletion strain verified differences and changes of various metabolites in cultures of the PaClpP mutant and the wild type. Based on these data, we generated and analyzed a PaSnf1 deletion mutant and a ΔPaSnf1/ΔPaClpP double mutant. In both mutants PaSNF1, the catalytic α-subunit of AMP-activated protein kinase (AMPK) is ablated. PaSNF1 was found to be required for the development of fruiting bodies and ascospores and the progeny of sexual reproduction of this ascomycete and impact mitochondrial dynamics and autophagy. Most interestingly, while the single PaSnf1 deletion mutant is characterized by a slight lifespan increase, simultaneous deletion of PaSnf1 and PaClpP leads to a pronounced lifespan extension. This synergistic effect is strongly reinforced in the presence of the mating-type "minus"-linked allele of the rmp1 gene. Compared to the wild type, culture temperature of 35°C instead of the standard laboratory temperature of 27°C leads to a short-lived phenotype of the ΔPaSnf1/ΔPaClpP double mutant. Overall, our study provides novel evidence for complex interactions of different molecular pathways involved in mitochondrial quality control, gene expression, and energy metabolism in the control of organismic aging.
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Affiliation(s)
| | | | | | - Heinz D. Osiewacz
- Institute of Molecular Biosciences, J.W. Goethe University, Frankfurt am Main, Germany
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Henkel V, Schürmanns L, Brunner M, Hamann A, Osiewacz HD. Role of sorting nexin PaATG24 in autophagy, aging and development of Podospora anserina. Mech Ageing Dev 2020; 186:111211. [PMID: 32007577 DOI: 10.1016/j.mad.2020.111211] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 12/12/2019] [Accepted: 01/27/2020] [Indexed: 12/18/2022]
Abstract
Sorting nexins are a conserved protein family involved in vesicle transport, membrane trafficking and protein sorting. The sorting nexin ATG24/SNX4 has been demonstrated to be involved in different autophagy pathways and in endosomal trafficking. However, its impact on cellular quality control and on aging and development is still elusive. Here we report studies analyzing the function of PaATG24 in the aging model Podospora anserina. Ablation of PaATG24 leads to a reduced growth rate, infertility, and to a pronounced lifespan reduction. These characteristics are accompanied by alterations of the morphology and size distribution of vacuoles and severe impairments in non-selective and selective autophagy of peroxisomes (pexophagy) and mitochondria (mitophagy). While general autophagy and pexophagy are almost completely blocked, a PaATG24-independent form of mitophagy is induced during aging. In the ΔPaAtg24 mutant a strong accumulation of peroxisomes occurs while mitochondrial abundance is only slightly increased. These mitochondria are partially affected in function. Most strikingly, although some PaATG24-independent mitophagy exists, it appears that this is not sufficient to remove dysfunctional mitochondria efficiently enough to prevent premature aging. Overall our data emphasize the key role of mitochondria in aging and of mitophagy in quality control to keep a population of "healthy" mitochondria during aging.
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Affiliation(s)
- Vanessa Henkel
- Goethe-University, Institute for Molecular Biosciences, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Lea Schürmanns
- Goethe-University, Institute for Molecular Biosciences, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Miriam Brunner
- Goethe-University, Institute for Molecular Biosciences, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Andrea Hamann
- Goethe-University, Institute for Molecular Biosciences, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Heinz D Osiewacz
- Goethe-University, Institute for Molecular Biosciences, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany.
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Rampello NG, Stenger M, Westermann B, Osiewacz HD. Impact of F1Fo-ATP-synthase dimer assembly factors on mitochondrial function and organismic aging. MICROBIAL CELL 2018; 5:198-207. [PMID: 29610761 PMCID: PMC5878687 DOI: 10.15698/mic2018.04.625] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In aerobic organisms, mitochondrial F1Fo-ATP-synthase is the major site of ATP production. Beside this fundamental role, the protein complex is involved in shaping and maintenance of cristae. Previous electron microscopic studies identified the dissociation of F1Fo-ATP-synthase dimers and oligomers during organismic aging correlating with a massive remodeling of the mitochondrial inner membrane. Here we report results aimed to experimentally proof this impact and to obtain further insights into the control of these processes. We focused on the role of the two dimer assembly factors PaATPE and PaATPG of the aging model Podospora anserina. Ablation of either protein strongly affects mitochondrial function and leads to an accumulation of senescence markers demonstrating that the inhibition of dimer formation negatively influences vital functions and accelerates organismic aging. Our data validate a model that links mitochondrial membrane remodeling to aging and identify specific molecular components triggering this process.
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Affiliation(s)
- Nadia G Rampello
- Department of Biosciences, Molecular Developmental Biology, Institute of Molecular Biosciences and Cluster of Excellence Frankfurt Macromolecular Complexes, J. W. Goethe University, 60438 Frankfurt, Germany
| | - Maria Stenger
- Cell Biology and Electron Microscopy, University of Bayreuth, 95440 Bayreuth, Germany
| | - Benedikt Westermann
- Cell Biology and Electron Microscopy, University of Bayreuth, 95440 Bayreuth, Germany
| | - Heinz D Osiewacz
- Department of Biosciences, Molecular Developmental Biology, Institute of Molecular Biosciences and Cluster of Excellence Frankfurt Macromolecular Complexes, J. W. Goethe University, 60438 Frankfurt, Germany
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Szklarczyk R, Nooteboom M, Osiewacz HD. Control of mitochondrial integrity in ageing and disease. Philos Trans R Soc Lond B Biol Sci 2015; 369:20130439. [PMID: 24864310 DOI: 10.1098/rstb.2013.0439] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Various molecular and cellular pathways are active in eukaryotes to control the quality and integrity of mitochondria. These pathways are involved in keeping a 'healthy' population of this essential organelle during the lifetime of the organism. Quality control (QC) systems counteract processes that lead to organellar dysfunction manifesting as degenerative diseases and ageing. We discuss disease- and ageing-related pathways involved in mitochondrial QC: mtDNA repair and reorganization, regeneration of oxidized amino acids, refolding and degradation of severely damaged proteins, degradation of whole mitochondria by mitophagy and finally programmed cell death. The control of the integrity of mtDNA and regulation of its expression is essential to remodel single proteins as well as mitochondrial complexes that determine mitochondrial functions. The redundancy of components, such as proteases, and the hierarchies of the QC raise questions about crosstalk between systems and their precise regulation. The understanding of the underlying mechanisms on the genomic, proteomic, organellar and cellular levels holds the key for the development of interventions for mitochondrial dysfunctions, degenerative processes, ageing and age-related diseases resulting from impairments of mitochondria.
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Affiliation(s)
- Radek Szklarczyk
- Centre for Molecular and Biomolecular Informatics, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands Department of Clinical Genetics, Unit Clinical Genomics, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
| | - Marco Nooteboom
- Department of Biochemistry (286), Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands
| | - Heinz D Osiewacz
- Faculty for Biosciences and Cluster of Excellence 'Macromolecular Complexes', Goethe University, Molecular Developmental Biology, 60438 Frankfurt am Main, Germany
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Tudzynski P, Esser K. Extrachromosomal genetics of Cephalosporium acremonium : II. Development of a mitochondrial DNA hybrid vector replicating in Saccharomyces cerevisiae. Curr Genet 2013; 6:153-8. [PMID: 24186482 DOI: 10.1007/bf00435215] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/1982] [Indexed: 11/26/2022]
Abstract
In order to facilitate strain improvement by concerted breeding in the cephalosporin producing imperfect filamentous fungus Cephalo sporium acremonium, it is attempted to develop a eukaryotic vector for molecular cloning based on mitochondrial (mt) DNA.Fragments of mtDNA from C. acremonium were inserted into a yeast/bacterial hybrid plasmid (pDAM1) lacking a eukaryotic replicon. Six hybrid plasmids were obtained each containing a different mt fragment which together comprise about 60% of the total mtDNA. One of these recombinant plasmid vectors (pCP2) showed a high replication efficiency which is comparable to that of vectors containing yeast 2 μm DNA. This plasmid therefore fulfills the requirements for practical application.
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Affiliation(s)
- P Tudzynski
- Lehrstuhl für Allgemeine Botanik, Ruhr-Universität, Postfach 102148, D-4630, Bochum 1, Germany
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Tudzynski P, Stahl U, Esser K. Development of a eukaryotic cloning system in Podospora anserina : I. Long-lived mutants as potential recipients. Curr Genet 2013; 6:219-22. [PMID: 24186548 DOI: 10.1007/bf00390341] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/1982] [Indexed: 10/26/2022]
Abstract
In developing a system for molecular cloning with the Podospora anserina plasmid (p1DNA) it is necessary to find recipient strains which are resistant to p1DNA mediated senescence. Three long lived double mutants which fail to exhibit spontaneous aging were genetically and biochemically analysed. All mutants were infected with p1DNA. The mutant ca viv became irreversibly senescent and therefore was not further tested. The second mutant, gr viv showed some symptoms of aging but never died. The third strain i viv remained resistant to aging from p1DNA infection and has thus proven to be the best host strain available for molecular cloning in this system.A DNA analysis of the latter two strains revealed: 1. There is no difference from the wild strain with respect to the structure of mtDNA and the integration site of the p1DNA. 2. Of the two strains, only i viv contains free p1DNA in its mitochondria but in low amounts if compared to the wild strain. These experimental results are interpreted as follows: 1. The gr viv strain does not liberate spontaneously the p1DNA from mtDNA, but following infection is able to replicate and express this plasmid and therefore is a potential host for transformation. 2. The i viv strain liberates the mitochondrial plasmid but does not express senescence even when infected with p1DNA. Therefore, this strain is an ideal recipient for transformation provided a marker other than senescence is cloned.
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Affiliation(s)
- P Tudzynski
- Lehrstuhl für Allgemeine Botanik, Ruhr-Universität, Postfach 102148, D-4630, Bochum 1, Germany
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Osíewacz HD, Esser K. The mitochondrial plasmid of Podospora anserina: A mobile intron of a mitochondrial gene. Curr Genet 2013; 8:299-305. [PMID: 24177799 DOI: 10.1007/bf00419728] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/1984] [Indexed: 11/26/2022]
Abstract
In the ascomycete Podospora anserina strain ageing (senescence) is caused by a mitochondrial plasmid. In juvenile mycelia it is an integral part of the mtDNA and becomes liberated during ageing. The nucleotide sequence of this plasmid and of its flanking regions was determined. It consists of 2,539 by and contains an un identified reading frame (URF) originating in the adjacent mtDNA upstream of excision point 1. Within the URF a putative 48 by autonomously replicating sequence (ars) was identified. At both excision sites of the plasmid there are two short nonidentical interrupted palindromes and a few base pairs apart from these palindromes, both upstream and downstream, two short inverted repeats are localised. The experimental data make it evident that the mt plasmid is an intron of the cytochrome c oxidase gene (subunit I) which may be excised at the DNA level and thus become the mobile infective agent causing senescence. The concept of this mobile intron and current hypotheses concerning the relationship between introns and transposons are stressed.
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Affiliation(s)
- H D Osíewacz
- Lehrstuhl für Allgemeine Botanik, Ruhr-Universität, Postfach 102148, D-4630, Bochum 1, Germany
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Ethidium bromide rejuvenation of senescent cultures of Podospora anserina : Loss of senescence-specific DNA and recovery of normal mitochondrial DNA. Curr Genet 2013; 8:127-34. [PMID: 24177587 DOI: 10.1007/bf00420231] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/1983] [Indexed: 10/26/2022]
Abstract
The effect of ethidium bromide (EB) which is known to be able to "rejuvenate" senescent mycelia in Podospora anserina, has been investigated at the level of the mitochondrial DNA (mtDNA) by restriction analysis and molecular hybridization. While senescent mycelia display a very low growth ability and gross mtDNA modifications (tandem amplification of short sequences and disorganization of the mitochondrial chromosome: deletion of large sequences), the rejuvenated mycelia display a normal life span and contain a mtDNA in all respects identical to that of wild type mycelium (neither circular molecules nor amplified fragments could be detected). These results demonstrate a strict correlation between the senescent state and the presence of amplified mtDNA and suggest that EB rejuvenation could proceed by an efficient selection of intact mitochondrial chromosomes still present in senescent cultures.
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Tudzynski P, Düvell A, Esser K. Extrachromosomal genetics of Claviceps purpurea : I. Mitochondrial DNA and mitochondrial plasmids. Curr Genet 2013; 7:145-50. [PMID: 24173157 DOI: 10.1007/bf00365640] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/1982] [Indexed: 10/26/2022]
Abstract
In order to establish a system for gene cloning in the ergot fungus Claviceps purpurea mitochondrial DNA was purified from two wild strains and four descendants of production strains. A characterization of the mt DNA with respect to buoyant density, molecular weight (45 kb corresponding to acontour lenght of 14 μm) showed no differences. However, considerable differences were detected in the restriction pattern, with the exception of two commercial strains of possibly common origin. From this it follows that restriction patterns of mt DNA may be used as finger prints to identify related strains.In one of the wild strains plasmids associated with the mitochondria were found. A characterization of two species p11 and p12 having molecular weights of 6.6 and 5.3 kb revealed that these genetic units are linear having respective contour lengths of 2.1 and 1.7 μm. According to Southern blot analyses both plasmids show homology to each other, but not to the mitochondrial "chromosome". Accordingly, p11 and p12, despite localization in the mitochondria, are evidently not an integral part of the mt "chromosome". The possibility to use the mt DNA and mitochondrial plasmids to establish a vector system for molecular cloning in imperfect strains of Claviceps purpurea has been pointed out.
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Affiliation(s)
- P Tudzynski
- Lehrstuhl für Allgemeine Botanik, Ruhr-Universität, Postfach 102148, D-4630, Bochum 1, Germany
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Scheckhuber CQ, Houthoofd K, Weil AC, Werner A, De Vreese A, Vanfleteren JR, Osiewacz HD. Alternative oxidase dependent respiration leads to an increased mitochondrial content in two long-lived mutants of the aging model Podospora anserina. PLoS One 2011; 6:e16620. [PMID: 21305036 PMCID: PMC3029406 DOI: 10.1371/journal.pone.0016620] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Accepted: 01/07/2011] [Indexed: 01/29/2023] Open
Abstract
The retrograde response constitutes an important signalling pathway from mitochondria to the nucleus which induces several genes to allow compensation of mitochondrial impairments. In the filamentous ascomycete Podospora anserina, an example for such a response is the induction of a nuclear-encoded and iron-dependent alternative oxidase (AOX) occurring when cytochrome-c oxidase (COX) dependent respiration is affected. Several long-lived mutants are known which predominantly or exclusively respire via AOX. Here we show that two AOX-utilising mutants, grisea and PaCox17::ble, are able to compensate partially for lowered OXPHOS efficiency resulting from AOX-dependent respiration by increasing mitochondrial content. At the physiological level this is demonstrated by an elevated oxygen consumption and increased heat production. However, in the two mutants, ATP levels do not reach WT levels. Interestingly, mutant PaCox17::ble is characterized by a highly increased release of the reactive oxygen species (ROS) hydrogen peroxide. Both grisea and PaCox17::ble contain elevated levels of mitochondrial proteins involved in quality control, i. e. LON protease and the molecular chaperone HSP60. Taken together, our work demonstrates that AOX-dependent respiration in two mutants of the ageing model P. anserina is linked to a novel mechanism involved in the retrograde response pathway, mitochondrial biogenesis, which might also play an important role for cellular maintenance in other organisms.
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Affiliation(s)
- Christian Q Scheckhuber
- Faculty for Biosciences, Molecular Developmental Biology, Cluster of Excellence Macromolecular Complexes, Johann Wolfgang Goethe University, Frankfurt, Germany.
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Brambl R. Fungal physiology and the origins of molecular biology. Microbiology (Reading) 2009; 155:3799-3809. [DOI: 10.1099/mic.0.035238-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Molecular biology has several distinct origins, but especially important are those contributed by fungal and yeast physiology, biochemistry and genetics. From the first gene action studies that became the basis of our understanding of the relationship between genes and proteins, through chromosome structure, mitochondrial genetics and membrane biogenesis, gene silencing and circadian clocks, studies with these organisms have yielded basic insight into these processes applicable to all eukaryotes. Examples are cited of pioneering studies with fungi that have stimulated new research in clinical medicine and agriculture; these studies include sexual interactions, cell stress responses, the cytoskeleton and pathogenesis. Studies with the yeasts and fungi have been effective in applying the techniques and insights gained from other types of experimental systems to research in fungal cell signalling, cell development and hyphal morphogenesis.
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Affiliation(s)
- Robert Brambl
- Department of Plant Biology, The University of Minnesota, 250 Biological Sciences Center, Saint Paul, MN 55108, USA
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Matrosova EV, Masheyka IS, Kudryavtseva OA, Kamzolkina OV. Mitochondrial morphogenesis and ultrastructure of basidiomycetes from genera Agaricus and Pleurotus. ACTA ACUST UNITED AC 2009. [DOI: 10.1134/s1990519x09040099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Soerensen M, Gredilla R, Müller-Ohldach M, Werner A, Bohr VA, Osiewacz HD, Stevnsner T. A potential impact of DNA repair on ageing and lifespan in the ageing model organism Podospora anserina: decrease in mitochondrial DNA repair activity during ageing. Mech Ageing Dev 2009; 130:487-96. [PMID: 19486911 DOI: 10.1016/j.mad.2009.05.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Accepted: 05/21/2009] [Indexed: 12/21/2022]
Abstract
The free radical theory of ageing states that ROS play a key role in age-related decrease in mitochondrial function via the damage of mitochondrial DNA (mtDNA), proteins and lipids. In the sexually reproducing ascomycete Podospora anserina ageing is, as in other eukaryotes, associated with mtDNA instability and mitochondrial dysfunction. Part of the mtDNA instabilities may arise due to accumulation of ROS induced mtDNA lesions, which, as previously suggested for mammals, may be caused by an age-related decrease in base excision repair (BER). Alignments of known BER protein sequences with the P. anserina genome revealed high homology. We report for the first time the presence of BER activities in P. anserina mitochondrial extracts. DNA glycosylase activities decrease with age, suggesting that the increased mtDNA instability with age may be caused by decreased ability to repair mtDNA damage and hence contribute to ageing and lifespan control in this ageing model. Additionally, we find low DNA glycosylase activities in the long-lived mutants grisea and DeltaPaCox17::ble, which are characterized by low mitochondrial ROS generation. Overall, our data identify a potential role of mtDNA repair in controlling ageing and life span in P. anserina, a mechanism possibly regulated in response to ROS levels.
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Affiliation(s)
- Mette Soerensen
- Danish Centre for Molecular Gerontology and Danish Aging Research Center, Aarhus University, Department of Molecular Biology, University of Aarhus, Aarhus C, Denmark
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Scheckhuber CQ, Grief J, Boilan E, Luce K, Debacq-Chainiaux F, Rittmeyer C, Gredilla R, Kolbesen BO, Toussaint O, Osiewacz HD. Age-related cellular copper dynamics in the fungal ageing model Podospora anserina and in ageing human fibroblasts. PLoS One 2009; 4:e4919. [PMID: 19305496 PMCID: PMC2654708 DOI: 10.1371/journal.pone.0004919] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Accepted: 02/11/2009] [Indexed: 12/14/2022] Open
Abstract
In previous investigations an impact of cellular copper homeostasis on ageing of the ascomycete Podospora anserina has been demonstrated. Here we provide new data indicating that mitochondria play a major role in this process. Determination of copper in the cytosolic fraction using total reflection X-ray fluorescence spectroscopy analysis and eGfp reporter gene studies indicate an age-related increase of cytosolic copper levels. We show that components of the mitochondrial matrix (i.e. eGFP targeted to mitochondria) become released from the organelle during ageing. Decreasing the accessibility of mitochondrial copper in P. anserina via targeting a copper metallothionein to the mitochondrial matrix was found to result in a switch from a copper-dependent cytochrome-c oxidase to a copper-independent alternative oxidase type of respiration and results in lifespan extension. In addition, we demonstrate that increased copper concentrations in the culture medium lead to the appearance of senescence biomarkers in human diploid fibroblasts (HDFs). Significantly, expression of copper-regulated genes is induced during in vitro ageing in medium devoid of excess copper suggesting that cytosolic copper levels also increase during senescence of HDFs. These data suggest that the identified molecular pathway of age-dependent copper dynamics may not be restricted to P. anserina but may be conserved from lower eukaryotes to humans.
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Affiliation(s)
- Christian Q. Scheckhuber
- Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Jürgen Grief
- Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Emmanuelle Boilan
- Research Unit on Cellular Biology, University of Namur, Namur, Belgium
| | - Karin Luce
- Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | | | - Claudia Rittmeyer
- Institute of Inorganic Chemistry/Analytical Chemistry, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Ricardo Gredilla
- Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Bernd O. Kolbesen
- Institute of Inorganic Chemistry/Analytical Chemistry, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Olivier Toussaint
- Research Unit on Cellular Biology, University of Namur, Namur, Belgium
| | - Heinz D. Osiewacz
- Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
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19
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Scheckhuber CQ, Osiewacz HD. Podospora anserina: a model organism to study mechanisms of healthy ageing. Mol Genet Genomics 2008; 280:365-74. [PMID: 18797929 DOI: 10.1007/s00438-008-0378-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Accepted: 08/29/2008] [Indexed: 12/18/2022]
Abstract
The filamentous ascomycete Podospora anserina has been extensively studied as an experimental ageing model for more than 50 years. As a result, a huge body of data has been accumulated and various molecular pathways have been identified as part of a molecular network involved in the control of ageing and life span. The aim of this review is to summarize data on P. anserina ageing, including aspects like respiration, cellular copper homeostasis, mitochondrial DNA (mtDNA) stability/instability, mitochondrial dynamics, apoptosis, translation efficiency and pathways directed against oxidative stress. It becomes clear that manipulation of several of these pathways bears the potential to extend the healthy period of time, the health span, within the life time of the fungus. Here we put special attention on recent work aimed to identify and characterize this type of long-lived P. anserina mutants. The study of the molecular pathways which are modified in these mutants can be expected to provide important clues for the elucidation of the mechanistic basis of this type of 'healthy ageing' at the organism level.
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Affiliation(s)
- Christian Q Scheckhuber
- Cluster of Excellence Macromolecular Complexes and Faculty for Biosciences, Molecular Developmental Biology, Johann Wolfgang Goethe University, Max-von-Laue-Str. 9, 60438, Frankfurt/Main, Germany
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20
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Groebe K, Krause F, Kunstmann B, Unterluggauer H, Reifschneider NH, Scheckhuber CQ, Sastri C, Stegmann W, Wozny W, Schwall GP, Poznanović S, Dencher NA, Jansen-Dürr P, Osiewacz HD, Schrattenholz A. Differential proteomic profiling of mitochondria from Podospora anserina, rat and human reveals distinct patterns of age-related oxidative changes. Exp Gerontol 2007; 42:887-98. [PMID: 17689904 DOI: 10.1016/j.exger.2007.07.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Revised: 06/18/2007] [Accepted: 07/06/2007] [Indexed: 01/07/2023]
Abstract
According to the 'free radical theory of ageing', the generation and accumulation of reactive oxygen species are key events during ageing of biological systems. Mitochondria are a major source of ROS and prominent targets for ROS-induced damage. Whereas mitochondrial DNA and membranes were shown to be oxidatively modified with ageing, mitochondrial protein oxidation is not well understood. The purpose of this study was an unbiased investigation of age-related changes in mitochondrial proteins and the molecular pathways by which ROS-induced protein oxidation may disturb cellular homeostasis. In a differential comparison of mitochondrial proteins from young and senescent strains of the fungal ageing model Podospora anserina, from brains of young (5 months) vs. older rats (17 and 31 months), and human cells, with normal and chemically accelerated in vitro ageing, we found certain redundant posttranslationally modified isoforms of subunits of ATP synthase affected across all three species. These appear to represent general susceptible hot spot targets for oxidative chemical changes of proteins accumulating during ageing, and potentially initiating various age-related pathologies and processes. This type of modification is discussed using the example of SAM-dependent O-methyltransferase from P. anserina (PaMTH1), which surprisingly was found to be enriched in mitochondrial preparations of senescent cultures.
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21
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Osiewacz HD, Scheckhuber CQ. Impact of ROS on ageing of two fungal model systems: Saccharomyces cerevisiae and Podospora anserina. Free Radic Res 2007; 40:1350-8. [PMID: 17090424 DOI: 10.1080/10715760600921153] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
To provide a foundation for the development of effective interventions to counteract various age-related diseases in humans, ageing processes have been extensively studied in various model organisms and systems. However, the mechanisms underlying ageing are still not unravelled in detail in any system including rather simple organisms. In this article, we review some of the molecular mechanisms that were found to affect ageing in two fungal models, the unicellular ascomycete Saccharomyces cerevisiae and the filamentous ascomycete Podospora anserina. A selection of issues like retrograde response, genomic instability, caloric restriction, mtDNA reorganisation and apoptosis is presented and discussed with special emphasis on the role reactive oxygen species (ROS) play in these diverse molecular pathways.
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Affiliation(s)
- Heinz D Osiewacz
- Institute of Molecular Biosciences, Molecular Developmental Biology, Johann Wolfgang Goethe University, Frankfurt, Germany.
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22
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Koll F, Begel O, Belcour L. Insertion of short poly d(A) d(T) sequences at recombination junctions in mitochondrial DNA of Podospora. ACTA ACUST UNITED AC 2006; 209:630-2. [PMID: 17193717 DOI: 10.1007/bf00331176] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We have characterized the DNA sequences at recombination points in the mitochondrial DNA of two independent mitochondrial mutants of Podospora anserina. These sequences reveal the presence of foreign DNA at each recombination border, consisting of short stretches of A and T residues. We discuss the possible origin of this DNA and suggest the involvement of a reverse transcriptase activity.
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Affiliation(s)
- F Koll
- Centre de Génétique Moléculaire, Centre National de la Recherche Scientifique, F-91190 Gif sur Yvette, France
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23
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Scheckhuber CQ, Erjavec N, Tinazli A, Hamann A, Nyström T, Osiewacz HD. Reducing mitochondrial fission results in increased life span and fitness of two fungal ageing models. Nat Cell Biol 2006; 9:99-105. [PMID: 17173038 DOI: 10.1038/ncb1524] [Citation(s) in RCA: 248] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2006] [Accepted: 10/31/2006] [Indexed: 11/08/2022]
Abstract
Ageing of biological systems is accompanied by alterations in mitochondrial morphology, including a transformation from networks and filaments to punctuate units. The significance of these alterations with regard to ageing is not known. Here, we demonstrate that the dynamin-related protein 1 (Dnm1p), a mitochondrial fission protein conserved from yeast to humans, affects ageing in the two model systems we studied, Podospora anserina and Saccharomyces cerevisiae. Deletion of the Dnm1 gene delays the transformation of filamentous to punctuate mitochondria and retards ageing without impairing fitness and fertility typically observed in long-lived mutants. Our data further suggest that reduced mitochondrial fission extends life span by increasing cellular resistance to the induction of apoptosis and links mitochondrial dynamics, apoptosis and life-span control.
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Affiliation(s)
- C Q Scheckhuber
- Johann Wolfgang Goethe University, Institute of Molecular Biosciences, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
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24
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Abstract
Fungi are eukaryotic microorganisms studied in various areas of general and applied biology. A few species were among the first systems in which specific aspects of aging were addressed experimentally. Various factors, both environmental and genetic, were found to affect lifespan and aging. Mitochondrial pathways play a paramount role. Since mitochondria are semiautonomous organelles and depend on both nuclear as well as mitochondrial genes, mitochondrial-nuclear interactions are of major relevance. As a main generator of reactive oxygen species (ROS), mitochondria are prone to molecular damage. However, cells can cope with the negative effects of ROS utilizing different scavenging systems and, once defects became manifested, by repair of damaged molecules. Both, lowering ROS generation and increasing mitochondrial "caretaker" systems bear great potential to interfere with natural aging processes.
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Affiliation(s)
- Heinz D Osiewacz
- Botanisches Institut, Johann Wolfgang Goethe-Universität, Molekulare Entwicklungsbiologie und Biotechnologie, Marie-Curie-Str. 9, D-60439, Frankfurt/Main, Germany.
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25
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Abstract
In experimental gerontology, there is a long tradition in the use of both unicellular and filamentous species of fungi. In the last three decades, biochemical, genetic and molecular approaches have proved very fruitful in elucidating different aspects of ageing. It was shown that various genes and molecular pathways are involved in life span control. The oxygenic energy metabolism plays a central role. During mitochondrial energy transduction, reactive oxygen species (ROS) are generated as by-products. These molecules are able to damage all cellular compounds leading to cellular dysfunctions. Within certain limits, however, cells are able to cope with ROS-related problems. First, ROS scavengers can be induced which are effective in lowering the molecular burden of ROS on cellular functions. Second, if damage occurs, specific repair mechanisms and the general turnover of affected molecules can maintain cellular functions. Finally, if damage of essential components is too severe, cells may induce specific pathways to compensate for the corresponding impairments. A coordinated interaction between different cellular compartments is involved in these processes. In this review I shall concentrate on the ageing in the filamentous ascomycete Podospora anserina. It is clear that both environmental as well as genetic traits are involved in the control of life span and that mitochondrial-nuclear interactions play a paramount role.
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Affiliation(s)
- Heinz D Osiewacz
- Molekulare Entwicklungsbiologie und Biotechnologie, Botanisches Institut, Johann Wolfgang Goethe-Universität, Marie-Curie-Street 9, D-60439, Frankfurt am Main, Germany.
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26
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Osiewacz HD, Stumpferl SW. Metabolism and aging in the filamentous fungus Podospora anserina. Arch Gerontol Geriatr 2001; 32:185-97. [PMID: 11395166 DOI: 10.1016/s0167-4943(01)00096-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In Podospora anserina, lifespan is under the control of environmental and genetic factors. Both suggest an important impact of metabolism on lifespan and aging. Environmental changes of temperature, of the carbon source in the growth medium, or the addition of specific inhibitors to the growth medium are some of the investigated factors. Genetic approaches underscore the significance of metabolism. In particular, the mitochondrial electron transport plays a major role. As a by-product of a cytochrome oxidase (COX) dependent energy transduction, reactive oxygen species (ROS) are generated and lead to damage of cellular biomolecules. Damaged mitochondria, compromised at complex IV (COX) of the respiratory chain, signal to the nucleus and induce a nuclear gene, PaAox, encoding an alternative oxidase (AOX). This pathway resembles the retrograde response that, at least in yeast, is induced by dysfunctional mitochondria. ROS generation is lowered when electrons are transferred via an alternative pathway utilizing the AOX. As a consequence, lifespan of the corresponding strains is increased. Cellular copper levels were found to play a significant role not only in the generation of ROS but also have an impact on the cytoplasmic and the mitochondrial superoxide dismutase (SOD). In addition, copper is involved in the control of mitochondrial DNA rearrangements and affects the ability of the system to remodel damaged mitochondria. All these different components and pathways are part of the complex molecular network involved in lifespan control of this aging model.
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Affiliation(s)
- H D Osiewacz
- Botanisches Institut, Johann Wolfgang Goethe-Universität, Marie-Curie-Str. 9 D-60439, Frankfurt am Main, Germany
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27
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Borghouts C, Werner A, Elthon T, Osiewacz HD. Copper-modulated gene expression and senescence in the filamentous fungus Podospora anserina. Mol Cell Biol 2001; 21:390-9. [PMID: 11134328 PMCID: PMC86578 DOI: 10.1128/mcb.21.2.390-399.2001] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have previously shown that the control of cellular copper homeostasis by the copper-modulated transcription factor GRISEA has an important impact on the phenotype and lifespan of Podospora anserina. Here we demonstrate that copper depletion leads to the induction of an alternative respiratory pathway and to an increase in lifespan. This response compensates mitochondrial dysfunctions via the expression of PaAox, a nuclear gene coding for an alternative oxidase. It resembles the retrograde response in Saccharomyces cerevisiae. In P. anserina, this pathway appears to be induced by specific impairments of the copper-dependent cytochrome c oxidase. It is not induced as the result of a general decline of mitochondrial functions during senescence. We cloned and characterized PaAox. Transcript levels are decreased when cellular copper, superoxide, and hydrogen peroxide levels are raised. Copper also controls transcript levels of PaSod2, the gene encoding the mitochondrial manganese superoxide dismutase (PaSOD2). PaSod2 is a target of transcription factor GRISEA. During the senescence of wild-type strain s, the activity of PaSOD2 decreases, whereas the activity of the cytoplasmic copper/zinc superoxide dismutase (PaSOD1) increases. Collectively, the data explain the postponed senescence of mutant grisea as a defined consequence of copper depletion, ultimately leading to a reduction of oxidative stress. Moreover, they suggest that during senescence of the wild-type strain, copper is released from mitochondria. The involved mechanism is unknown. However, it is striking that the permeability of mitochondrial membranes in animal systems changes during apoptosis and that mitochondrial proteins with an important impact on this type of cellular death are released.
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Affiliation(s)
- C Borghouts
- Botanisches Institut, Johann Wolfgang Goethe-Universität, D-60439 Frankfurt am Main, Germany
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28
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Osiewacz HD, Borghouts C. Cellular copper homeostasis, mitochondrial DNA instabilities, and lifespan control in the filamentous fungus Podospora anserina. Exp Gerontol 2000; 35:677-86. [PMID: 11053657 DOI: 10.1016/s0531-5565(00)00142-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In the fungal aging model Podospora anserina, lifespan is controlled by mitochondrial and nuclear genetic traits. Different nuclear genes are known to affect the integrity of the mitochondrial DNA (mtDNA). One gene of this type is Grisea encoding a copper-modulated transcription factor involved in the control of cellular copper homeostasis. The characterization of a long-lived mutant with a loss-of-function mutation in this gene revealed that the last step in the pathway, homologous recombination, leading to the characteristic age-related mtDNA reorganizations is copper-dependent. In growing parts of the culture, the stabilization of the mtDNA has an important impact on the biogenesis of functional mitochondria, on their capacity to remodel damaged respiratory chains and on longevity.
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Affiliation(s)
- H D Osiewacz
- Botanisches Institut, Molekulare Entwicklungsbiologie und Biotechnologie, Johann Wolfgang Goethe-Universität, Marie-Curie-Str. 9, D-60439, Frankfurt am Main, Germany.
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29
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Bertrand H. Role of Mitochondrial DNA in the Senescence and Hypovirulence of Fungi and Potential for Plant Disease Control. ANNUAL REVIEW OF PHYTOPATHOLOGY 2000; 38:397-422. [PMID: 11701848 DOI: 10.1146/annurev.phyto.38.1.397] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The unique coenocytic anatomy of the mycelia of the filamentous fungi and the formation of anastomoses between hyphae from different mycelia enable the intracellular accumulation and infectious transmission of plasmids and mutant mitochondrial DNAs (mtDNAs) that cause senescence. For reasons that are not fully apparent, mitochondria that are rendered dysfunctional by so-called "suppressive" mtDNA mutations proliferate rapidly in growing cells and gradually displace organelles that contain wild-type mtDNA molecules and are functional. The consequence of this process is senescence and death if the suppressive mtDNA contains a lethal mutation. Suppressive mtDNA mutations and mitochondrial plasmids can elicit cytoplasmically transmissible "mitochondrial hypovirulence" syndromes in at least some of the phytopathogenic fungi. In the chestnut-blight fungus Cryphonectria parasitica, the pattern of asexual transmission of mutant mtDNAs and mitochondrial plasmids resembles the pattern of "infectious" transmission displayed by the attenuating virus that is most commonly used for the biological control of this fungus. At least some of the attenuating mitochondrial hypovirulence factors are inherited maternally in crosses, whereas the viruses are not transmitted sexually. The natural control of blight in an isolated stand of chestnut trees has resulted from the invasion of the local population of C. parasitica by a senescence-inducing mutant mtDNA. Moreover, a mitochondrial plasmid, pCRY1, attenuates at least some virulent strains of C. parasitica, suggesting that such factors could be applied to control plant diseases caused by fungi.
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Affiliation(s)
- Helmut Bertrand
- Department of Microbiology, Michigan State University, East Lansing, Michigan 48824; e-mail:
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30
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Osiewacz HD, Borghouts C. Mitochondrial oxidative stress and aging in the filamentous fungus Podospora anserina. Ann N Y Acad Sci 2000; 908:31-9. [PMID: 10911945 DOI: 10.1111/j.1749-6632.2000.tb06633.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the filamentous fungus Podospora anserina, mitochondrial oxidative stress is a major contributor to aging. Reactive oxygen species (ROS) generated as a result of electron leakage during respiration lead to damage of components of the electron transport chain. In aging wild-type cultures, damaged proteins cannot be replaced because the mitochondrial genes encoding some of the corresponding subunits gradually become deleted from the mitochondrial DNA (mtDNA). Consequently, these defects result in an increased generation of reactive oxygen species and respiration deficits leading to cell death. Analyses of wild-type strains and of different long-lived mutants of P. anserina provide strong evidence that molecular mechanisms controlling aging processes in this fungus are complex and act at different levels. A basic mechanism (e.g., damage by ROS) appears to be overlaid by prominent instabilities of the mtDNA.
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Affiliation(s)
- H D Osiewacz
- Johann Wolfgang Goethe-Universität, Botanisches Institut, Frankfurt am Main, Germany.
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31
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Abstract
In fungi, mitochondrial-nuclear interactions are part of a complex molecular network involved in the control of aging processes. The generation of reactive oxygen species at the mitochondrial respiratory chain plays a major role in this network. Mitochondrial DNA instabilities, which are under the control of nuclear genes, affect the generation of reactive oxygen species and modulate the rate of aging. As mitochondria become dysfunctional, they transduce signals to the nucleus and induce the expression of a set of nuclear genes, a process termed retrograde regulation. Molecular data are emerging which suggest that retrograde regulation is involved in lifespan control.
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Affiliation(s)
- H D Osiewacz
- Botanisches Institut, Molekulare Entwicklungsbiologie und Biotechnologie, Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
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32
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Salvo JL, Rodeghier B, Rubin A, Troischt T. Optional introns in mitochondrial DNA of Podospora anserina are the primary source of observed size polymorphisms. Fungal Genet Biol 1998; 23:162-8. [PMID: 9578629 DOI: 10.1006/fgbi.1997.1030] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The significant differences in mitochondrial genome size among seven races (B, E, M, T, U, W, and Y) of Podospora anserina have been found to be primarily due to the presence and/or absence of introns, including four introns not previously known to be optional. Information from physical mapping of races M and T, and sequence data from races A and s, was used to identify regions likely to contain insertions or deletions, which were then characterized using PCR and sequence analysis. Newly confirmed optional introns are the first intron of the large ribosomal RNA (LSUr1), the single intron of NADH dehydrogenase subunit 3 (ND3i1), the single intron in ATPase subunit 6 (ATPase6), and the fifth intron of cytochrome oxidase subunit I (COIi5). We have also found that race M exists in two forms as determined by mitochondrial DNA. These results bring to nine (including races A and s) the number of races characterized by mitochondrial intron content with a total of six known optional introns and one optional insertion. Eight of the nine races contain a distinct set of introns, providing a more reliable means for identification and comparison. The identification of optional mitochondrial introns in P. anserina may have evolutionary implications regarding the transfer and/or mobility of these introns.
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Affiliation(s)
- J L Salvo
- Department of Biology, Union College, Schenectady, New York 12308, USA.
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Borghouts C, Kimpel E, Osiewacz HD. Mitochondrial DNA rearrangements of Podospora anserina are under the control of the nuclear gene grisea. Proc Natl Acad Sci U S A 1997; 94:10768-73. [PMID: 9380708 PMCID: PMC23480 DOI: 10.1073/pnas.94.20.10768] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Podospora anserina is a filamentous fungus with a limited life span. Life span is controlled by nuclear and extranuclear genetic traits. Herein we report the nature of four alterations in the nuclear gene grisea that lead to an altered morphology, a defect in the formation of female gametangia, and an increased life span. Three sequence changes are located in the 5' upstream region of the grisea ORF. One mutation is a G --> A transition at the 5' splice site of the single intron of the gene, leading to a RNA splicing defect. This loss-of-function affects the amplification of the first intron of the mitochondrial cytochrome c oxidase subunit I gene (COI) and the specific mitochondrial DNA rearrangements that occur during senescence of wild-type strains. Our results indicate that the nuclear gene grisea is part of a molecular machinery involved in the control of mitochondrial DNA reorganizations. These DNA instabilities accelerate but are not a prerequisite for the aging of P. anserina cultures.
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Affiliation(s)
- C Borghouts
- Molekulare Entwicklungsbiologie und Biotechnologie, Johann Wolfgang Goethe-Universität, Botanisches Institut, Marie-Curie-Str. 9, D-60439 Frankfurt am Main, Germany
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34
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Osiewacz HD, Nuber U. GRISEA, a putative copper-activated transcription factor from Podospora anserina involved in differentiation and senescence. MOLECULAR & GENERAL GENETICS : MGG 1996; 252:115-24. [PMID: 8804410 DOI: 10.1007/bf02173211] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Podospora anserina is a filamentous fungus with a limited lifespan. Lifespan is controlled by both environmental and genetic factors. Using a combination of genetic and molecular approaches we have cloned one of these factors, gerontogene grisea. The cloned wild-type copy of grisea complements the altered morphological characteristics (e.g., colony and ascospore color), the defect in gametangia development, and the increased lifespan of the pleiotropic mutant grisea. A molecular analysis revealed that grisea is a discontinuous gene with a single intron. The deduced amino acid sequence shows significant homology to MAC1, ACE1 and AMT1, indicating that GRISEA, like the proteins from Saccharomyces cerevisiae (MAC1 and ACE1) and Candida glabrata (AMT1), codes for a copper-activated transcription factor. This conclusion is consistent with the pleiotropic nature of the grisea phenotype. We suggest that the gerontoprotein GRISEA is one component of a transcription apparatus involved in the genetic control of morphogenesis and aging.
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Affiliation(s)
- H D Osiewacz
- Abteilung Molekularbiologie der Alterungsprozesse, Deutsches Krebsforschungszentrum, Heidelberg, Germany
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35
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Koll F, Boulay J, Belcour L, d'Aubenton-Carafa Y. Contribution of ultra-short invasive elements to the evolution of the mitochondrial genome in the genus Podospora. Nucleic Acids Res 1996; 24:1734-41. [PMID: 8649993 PMCID: PMC145831 DOI: 10.1093/nar/24.9.1734] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In the filamentous fungus Podospora anserina, senescence is associated with major rearrangements of the mitochondrial DNA. The undecamer GGCGCAAGCTC has been described as a preferential site for these recombination events. We show that: (i) copies of this short sequence GGCGCAAGCTC are present in unexpectedly high numbers in the mitochondrial genome of this fungus; (ii) a short cluster of this sequence, localised in a group II intronic ORF, encodes amino acids that disrupt a protein domain that is otherwise highly conserved between various species; (iii) most of the polymorphisms observed between three related species, P.anserina, P.curvicolla and P.comata, are associated with the presence/absence of this sequence; (iv) this element lies at the boundaries of major rearrangements of the mitochondrial genomes; (v) at least two other short elements in the Podospora mitochondrial genomes display similar features. We suggest that these short elements, called MUSEs (mitochondrial ultra-short elements), could be mobile and that they contribute to evolution of the mitochondrial genome in the genus Podospora. A model for mobility involving a target DNA-primed reverse transcription step is discussed.
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Affiliation(s)
- F Koll
- Centre de Génétique Moléculaire, CNRS, Gif sur Yvette, France
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36
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Schwartz T, Osiewacz HD. Telomere length does not change during senescence of the ascomycete Podospora anserina. Mutat Res 1996; 316:193-9. [PMID: 8649454 DOI: 10.1016/s0921-8734(96)90003-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
All strains of the filamentous fungus Podospora anserina are characterized by a well defined life span. Senescence is controlled by nuclear and extranuclear genetic traits. In order to test whether or not the ends of the chromosomes of this ascomycete shorten during senescence and thus telomere shortening may be linked to the well analyzed, age-related reorganizations of the mitochondrial DNA (mtDNA), we analyzed the genomic DNA of P. anserina wild-type strain s. We found that, although the mtDNA becomes reorganized when cultures age, the telomeres remain constant suggesting that telomere shortening does not play a major role in normal aging of this particular biological system.
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Affiliation(s)
- T Schwartz
- Deutsches Krebsforschungszentrum, Angewandte Tumorvirologie, Abteilung Molekularbiologie der Alterungsprozesse, Heidelberg, Germany
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37
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Hermanns J, Debets F, Hoekstra R, Osiewacz HD. A novel family of linear plasmids with homology to plasmid pAL2-1 of Podospora anserina. MOLECULAR & GENERAL GENETICS : MGG 1995; 246:638-47. [PMID: 7700237 DOI: 10.1007/bf00298971] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Three recently isolated wild-type strains of the ascomycete Podospora anserina were analyzed for the presence of linear mitochondrial plasmids. In one of these strains, designated Wat, at least 12 distinct plasmid-like elements were identified. From molecular analyses a minimum number of 78 individual linear molecules with proteins bound to their 5' ends was estimated. In addition, the different members of this family of typical linear plasmids were shown to possess a common central region and terminal sequences which differ from one plasmid to another due to the presence of different numbers of a 2.4 kb sequence module. Finally, the pWa6 plasmids share a high degree of sequence similarity with pAL2-1, a linear plasmid previously identified in mitochondria of a long-lived mutant of P.anserina. A mechanism is proposed which explains the generation of these distinct, closely related extra-chromosomal genetic traits.
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Affiliation(s)
- J Hermanns
- German Cancer Research Center, Department of Molecular Biology of Aging Processes, Heidelberg
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38
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Hermanns J, Osiewacz HD. Three mitochondrial unassigned open reading frames of Podospora anserina represent remnants of a viral-type RNA polymerase gene. Curr Genet 1994; 25:150-7. [PMID: 8087884 DOI: 10.1007/bf00309541] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The mitochondrial DNA of Podospora anserina is complex, consisting of a characteristic set of genes with a large number of introns and a substantial amount of sequence of unknown function and origin. In addition, as indicated by various types of reorganization, this genome is highly flexible. Here we report the identification of three unassigned mitochondrial open reading frames (ORF P', ORF Q', ORF 11) as remnants of a rearranged viral-type RNA polymerase gene. These ORFs are not transcribed and may be derived from the integration of a linear plasmid of the type recently identified in a mutant of P. anserina.
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Affiliation(s)
- J Hermanns
- Department of Molecular Biology of Aging Processes, German Cancer Research Center, Heidelberg
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39
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Abstract
Among mobile genetic elements, self-splicing introns are of particular interest. They belong to either group I or group II depending on their three-dimensional structure. Homing, the systematic intron invasion of an intronless gene when it encounters its homologous intron-bearing allele, is the only means for intron mobility so far demonstrated. It depends on the activity of the intron-encoded protein and is very specific for the acceptor site. Intron transposition, the transfer of an intron to a novel site, predicted on the basis of phylogenetic studies and in vitro reverse-splicing experiments, has been proposed to be responsible for evolutionary intron spreading. Here we present results from polymerase chain reaction experiments consistent with transposition of a group II intron. This event is proposed to account for the site-specific deletion in the mitochondrial chromosome of the fungus Podospora anserina that is associated with the premature death syndrome and might also be involved in the senescence process affecting this species.
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Affiliation(s)
- C H Sellem
- Centre de Génétique Moléculaire CNRS, Gif-sur-Yvette, France
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40
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Osiewacz HD, Hermanns J. The role of mitochondrial DNA rearrangements in aging and human diseases. AGING (MILAN, ITALY) 1992; 4:273-86. [PMID: 1294242 DOI: 10.1007/bf03324108] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Instabilities and point mutations of the high molecular weight mitochondrial DNA (mtDNA) were shown to be correlated with various degenerative processes in both lower eukaryotes as well as in mammals. In filamentous fungi, circular and linear plasmids were demonstrated to be involved in mtDNA rearrangements and in the genetic control of senescence. In addition, in these eukaryotic microorganisms, which have proved to be ideal model systems in experimental gerontology, a number of nuclear genes were identified controlling the stability of the mitochondrial genome. Although the mitochondrial genome of mammals, including humans, appears to be quite stable in comparison to other species, mtDNA instabilities of the type described in fungi were observed in mitochondria of patients with different mitochondrial degenerative disorders (CPEO, KSS, Pearson syndrome, LHON, MERRF, MELAS). It was later demonstrated that such mtDNA rearrangements appear to accumulate progressively during aging in human subjects. These data suggest that instabilities of the mitochondrial genome may play an important role in the control of life span not only in lower eukaryotes, but also in humans.
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Affiliation(s)
- H D Osiewacz
- Deutsches Krebsforschungszentrum, Institut für Virusforschung, Heidelberg, Germany
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41
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Hermanns J, Osiewacz HD. The linear mitochondrial plasmid pAL2-1 of a long-lived Podospora anserina mutant is an invertron encoding a DNA and RNA polymerase. Curr Genet 1992; 22:491-500. [PMID: 1473181 DOI: 10.1007/bf00326415] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The molecular characterization of an additional DNA species (pAL2-1) which was identified previously in a long-lived extrachromosomal mutant (AL2) of Podospora anserina revealed that this element is a mitochondrial linear plasmid. pAL2-1 is absent from the corresponding wild-type strain, has a size of 8395 bp and contains perfect long terminal inverted repeats (TIRs) of 975 bp. Exonuclease digestion experiments indicated that proteins are covalently bound at the 5' termini of the plasmid. Two long, non-overlapping open reading frames, ORF1 (3,594 bp) and ORF2 (2847 bp), have been identified, which are located on opposite strands and potentially encode a DNA and an RNA polymerase, respectively. The ORF1-encoded polypeptide contains three conserved regions which may be responsible for a 3'-5' exonuclease activity and the typical consensus sequences for DNA polymerases of the D type. In addition, an amino-acid sequence motif (YSRLRT), recently shown to be conserved in terminal proteins from various bacteriophages, has been identified in the amino-terminal part of the putative protein. According to these properties, this first linear plasmid identified in P. anserina shares all characteristics with invertrons, a group of linear mobile genetic elements.
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Affiliation(s)
- J Hermanns
- Deutsches Krebsforschungszentrum, Forschungsschwerpunkt: Angewandte Tumorvirologie, Abteilung: Molekularbiologie der Alterungsprozesse, Heidelberg, Federal Republic of Germany
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42
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Schmidt U, Budde E, Stahl U. Self-splicing of a mitochondrial group I intron from the cytochrome b gene of the ascomycete Podospora anserina. MOLECULAR & GENERAL GENETICS : MGG 1992; 233:71-80. [PMID: 1376408 DOI: 10.1007/bf00587563] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have shown that the second intron of the Podospora mitochondrial gene coding for cytochrome b (Cytb 12) splices autocatalytically, using in vitro transcripts generated from the T7 promoter. The reaction takes place at 37 degrees C in the presence of 50 mM TRIS-HCl pH 7.5, 60 mM MgCl2 and 1 mM GTP but shows a low efficiency even at high KCl concentrations of up to 1.2 M. Under these conditions, intron bI2 follows the conventional pathway of group I splicing, and all characteristic products, with regard to both transesterification and hydrolysis, could be identified. Moreover, the intron is capable of undergoing cyclization, thereby releasing the noncoded G and one additional nucleotide (U) from the 5' end. The 5' cleavage site is preceded by the same two nucleotides, indicating a base-pairing at the same site of the internal guide sequence (IGS) for both splicing and cyclization ("one-binding-site model"). In addition, products resulting from site-specific hydrolysis 138 nucleotides downstream of the 5' splice site were detected. Unusually, the shortened intron is also able to form a circular RNA and an alternative sequence that aligns the cyclization site to the catalytic core of the intron must be assumed.
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Affiliation(s)
- U Schmidt
- Technische Universität Berlin, Fachgebiet Mikrobiologie und Genetik, FRG
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43
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Meyer RJ. Mitochondrial DNAs and plasmids as taxonomic characteristics in Trichoderma viride. Appl Environ Microbiol 1991; 57:2269-76. [PMID: 1768099 PMCID: PMC183562 DOI: 10.1128/aem.57.8.2269-2276.1991] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Mitochondrial DNA (mtDNA) was purified from 12 isolates of the Trichoderma viride aggregate and found to be, on the average, 32.7 kb in size. Plasmids were present in the mtDNA preparations from 8 of 12 strains of T. viride examined. Plasmids in four of the strains produced ladderlike banding patterns on gels, and these plasmids were studied in detail. The ladderlike patterns were produced by single molecules that were supercoiled to various degrees. Plasmids from two of the strains do not have homology with the mtDNA but do have a limited amount of homology with each other. No phenotype could be associated with the presence of a plasmid. Restriction endonuclease digestion of the mtDNAs produced patterns in which the presence or absence of certain fragments correlated with the classification of the strains into T. viride group I or II. Phenetic cluster analysis and parsimony analysis of the fragment patterns produced groups that corresponded to T. viride groups I and II. The fragment patterns were very diverse, with nearly all strains having a unique pattern. However, two strains of T. viride group I from widely different geographical locations did have identical restriction patterns for all the enzymes used in this study. This result indicates that it may not be possible to use mtDNA restriction patterns alone to identify Trichoderma strains.
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Affiliation(s)
- R J Meyer
- Systematic Botany and Mycology Laboratory, U.S. Department of Agriculture, Beltsville, Maryland 20705
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Sellem CH, Sainsard-Chanet A, Belcour L. Detection of a protein encoded by a class II mitochondrial intron of Podospora anserina. MOLECULAR & GENERAL GENETICS : MGG 1990; 224:232-40. [PMID: 2277641 DOI: 10.1007/bf00271556] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In the filamentous fungus Podospora anserina, the amplification as circular DNA molecules of the first intron (intron alpha) of the CO1 mitochondrial gene, encoding the cytochrome oxidase subunit 1, is known to be strongly associated with aging of strains. In this study we have attempted to detect the protein potentially encoded by the open reading frame (ORF) contained in this intron. This was done by the Western blot technique using specific antisera raised against three polypeptides encoded by three non-overlapping fragments of this ORF adapted to the universal code and overexpressed in Escherichia coli. We examined about thirty independent subclones of Podospora derived from two different geographic races (A, s), using wild-type and mutant strains, young and senescent cultures. A 100 kDa polypeptide, encoded by the class II intron alpha, was detected in five senescent subclones which all showed strong amplification of the intronic alpha sequence (Sen DNA alpha).
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Affiliation(s)
- C H Sellem
- Centre de Génétique Moléculaire, C.N.R.S., Gif-sur-Yvette, France
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45
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Abstract
The ability of eukaryotic organisms of the same genotype to vary in developmental pattern or in phenotype according to varying environmental conditions is frequently associated with changes in extrachromosomal circular DNA (eccDNA) sequences. Although variable in size, sequence complexity, and copy number, the best characterized of these eccDNAs contain sequences homologous to chromosomal DNA which indicates that they might arise from genetic rearrangements, such as homologous recombination. The abundance of repetitive sequence families in eccDNAs is consistent with the notion that tandem repeats and dispersed repetitive elements participate in intrachromosomal recombination events. There is also evidence that a fraction of this DNA has characteristics similar to retrotransposons. It has been suggested that eccDNAs could reflect altered patterns of gene expression or an instability of chromosomal sequences during development and aging. This article reviews some of the findings and concepts regarding eccDNAs and sequence plasticity in eukaryotic genomes.
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Affiliation(s)
- J W Gaubatz
- Department of Biochemistry, University of South Alabama College of Medicine, Mobile 36688
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Kempken F, Meinhardt F, Esser K. In organello replication and viral affinity of linear, extrachromosomal DNA of the ascomycete Ascobolus immersus. MOLECULAR & GENERAL GENETICS : MGG 1989; 218:523-30. [PMID: 2573821 DOI: 10.1007/bf00332419] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Linear, extrachromosomal DNA's of the filamentous fungus Ascobolus immersus are localized within the mitochondria. These linear plasmids have no homology to the high molecular weight mtDNA (hmw mtDNA). For analysis of plasmid replication an in organello DNA synthesis system was developed, in which radionucleotides were incorporated into intact mitochondria. Plasmid DNA is labelled preferentially in this system. From replication analysis of a specific plasmid there is evidence of a virus-like protein-primed replication. Sequence analysis of this plasmid reveals that a viral DNA polymerase is encoded. Thus, these genetic elements presumably are viral remnants rather than true plasmids.
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Affiliation(s)
- F Kempken
- Ruhr-Universität Bochum, Lehrstuhl für Allgemeine Botanik, Federal Republic of Germany
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47
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48
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Extrachromosomal mutants from Podospora anserina: Permanent vegetative growth in spite of multiple recombination events in the mitochondrial genome. ACTA ACUST UNITED AC 1988. [DOI: 10.1007/bf00330614] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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49
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Wolf K, Del Giudice L. The variable mitochondrial genome of ascomycetes: organization, mutational alterations, and expression. ADVANCES IN GENETICS 1988; 25:185-308. [PMID: 3057820 DOI: 10.1016/s0065-2660(08)60460-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- K Wolf
- Institut für Genetik und Mikrobiologie, Universität München, Munich, Federal Republic of Germany
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50
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