| mitochondrial functions and aging. | in the filamentous ascomycete podospora anserina mitochondria play a major role in lifespan control. since the function of these organelles depends on a large number of individual components it is no surprise that a complex network of interacting branches of individual molecular pathways is involved in this process. recently, the nuclear encoded transcription factor grisea was found to significantly affect mitochondrial functions. grisea is involved in the control of cellular copper homeostasis. ... | 2002 | 11943461 |
| purification and characterization of an endo-exonuclease from podospora anserina mitochondria. | the senescence phenotype of podospora anserina wild-type strains depends on mitochondrial (mt) genome stability. characterization of activities implicated in the maintenance of the mt dna is therefore essential for a better understanding of these degenerative processes. to address this question we looked for a nuclease activity in this fungal mitochondria. here we describe the purification of an endo-exonuclease active on single-stranded, double-stranded and flap dna. the podospora nuclease also ... | 2002 | 11955615 |
| het-e and het-d belong to a new subfamily of wd40 proteins involved in vegetative incompatibility specificity in the fungus podospora anserina. | vegetative incompatibility, which is very common in filamentous fungi, prevents a viable heterokaryotic cell from being formed by the fusion of filaments from two different wild-type strains. such incompatibility is always the consequence of at least one genetic difference in specific genes (het genes). in podospora anserina, alleles of the het-e and het-d loci control heterokaryon viability through genetic interactions with alleles of the unlinked het-c locus. the het-d2(y) gene was isolated an ... | 2002 | 12019224 |
| amyloid aggregates of the het-s prion protein are infectious. | the [het-s] infectious element of the filamentous fungus podospora anserina is a prion. we have recently reported that recombinant het-s protein aggregates in vitro into amyloid fibers. in vivo, the protein aggregates specifically in the [het-s] prion strains. here, we show that biolistic introduction of aggregated recombinant het-s protein into fungal cells induces emergence of the [het-s] prion with a high frequency. thus, we demonstrate that prion infectivity can be created de novo, in vitro ... | 2002 | 12032295 |
| size and complexity of the nuclear genome of the ectomycorrhizal fungus paxillus involutus. | the basidiomycete paxillus involutus is forming ectomycorrhizal symbiosis with a broad range of forest trees. reassociation kinetics on p. involutus nuclear dna indicated a haploid genome size of 23 mb including 11% of repetitive dna. a similar genome size (20 mb) was estimated by genomic reconstruction analysis using three single copy genes. to assess the gene density in the p. involutus genome, a cosmid containing a 33-kb fragment of genomic dna was sequenced and used to identify putative open ... | 2002 | 12135579 |
| identification of six loci in which mutations partially restore peroxisome biogenesis and/or alleviate the metabolic defect of pex2 mutants in podospora. | peroxins (pex) are proteins required for peroxisome biogenesis. mutations in pex genes cause lethal diseases in humans, metabolic defects in yeasts, and developmental disfunctions in plants and filamentous fungi. here we describe the first large-scale screening for suppressors of a pex mutation. in podospora anserina, pex2 mutants exhibit a metabolic defect [inability to grow on medium containing oleic acid (oa medium) as sole carbon source] and a developmental defect (inability to differentiate ... | 2002 | 12136013 |
| prions as protein-based genetic elements. | fungal prions are fascinating protein-based genetic elements. they alter cellular phenotypes through self-perpetuating changes in protein conformation and are cytoplasmically partitioned from mother cell to daughter. the four prions of saccharomyces cerevisiae and podospora anserina affect diverse biological processes: translational termination, nitrogen regulation, inducibility of other prions, and heterokaryon incompatibility. they share many attributes, including unusual genetic behaviors, th ... | 2002 | 12142498 |
| copper homeostasis and aging in the fungal model system podospora anserina: differential expression of pactr3 encoding a copper transporter. | lifespan extension of podospora anserina mutant grisea is caused by a loss-of-function mutation in the nuclear gene grisea. this gene encodes the copper regulated transcription factor grisea recently shown to be involved in the expression of pasod2 encoding the mitochondrial manganese superoxide dismutase. here we report the identification and characterization of a second target gene. this gene, pactr3, encodes a functional homologue of the saccharomyces cerevisiae high affinity copper permease ... | 2002 | 12200031 |
| repeat-induced point mutation (rip) in magnaporthe grisea: implications for its sexual cycle in the natural field context. | repeat-induced point mutation (rip) is a process that detects dna duplications and peppers their sequences with c:g to t:a transitions in the sexual phase of the life cycle. so far, this unique mechanism has been identified as a currently active process in only two fungal species, neurospora crassa and podospora anserina. to determine whether a rip-like process operates in the plant pathogenic fungus magnaporthe grisea, the retrotransposon maggy and the hygromycin b phosphotransferase gene were ... | 2002 | 12207702 |
| a rapid and efficient method using chromoslots to assign any newly cloned dna sequence to its cognate chromosome in the filamentous fungus podospora anserina. | an efficient method was developed to assign cloned genes to individual chromosomes of the fungus podospora anserina. the chromosomes were separated by pulsed-field gel electrophoresis and the dna was isolated from the gel bands. the dna from the isolated chromosomes was slotted onto membranes; the resulting chromoslots were used to confirm that genetically mapped genes could be detected in the expected position. then, 20 genes, not yet assigned to a linkage group, were attributed to individual c ... | 2002 | 12423752 |
| two copies of mthmg1, encoding a novel mitochondrial hmg-like protein, delay accumulation of mitochondrial dna deletions in podospora anserina. | in the filamentous fungus podospora anserina, two degenerative processes which result in growth arrest are associated with mitochondrial genome (mitochondrial dna [mtdna]) instability. senescence is correlated with mtdna rearrangements and amplification of specific regions (sendnas). premature death syndrome is characterized by the accumulation of specific mtdna deletions. this accumulation is due to indirect effects of the as1-4 mutation, which alters a cytosolic ribosomal protein gene. the mth ... | 2002 | 12455999 |
| lack of mitochondrial citrate synthase discloses a new meiotic checkpoint in a strict aerobe. | mitochondrial citrate synthase (mcs) is the initial enzyme of the tricarboxylic acid (tca) cycle. despite the key position of this protein in respiratory metabolism, very few studies have addressed the question of the effects of the absence of mcs in development. here we report on the characterization of 15 point mutations and a complete deletion of the cit1 gene, which encodes mcs in the filamentous fungus podospora anserina. this gene was identified genetically through a systematic search for ... | 2002 | 12456651 |
| autophagy is induced during cell death by incompatibility and is essential for differentiation in the filamentous fungus podospora anserina. | in filamentous fungi, a cell death reaction occurs when cells of unlike genotype fuse. this cell death reaction, known as incompatibility reaction, is genetically controlled by a set of loci termed het loci (for heterokaryon incompatibility loci). in podospora anserina, genes induced during this cell death reaction (idi genes) have been identified. the idi-6/pspa gene encodes a serine protease that is the orthologue of the vacuolar protease b of saccharomyces cerevisiae involved in autophagy. we ... | 2003 | 12519185 |
| glycolipid intermembrane transfer is accelerated by het-c2, a filamentous fungus gene product involved in the cell-cell incompatibility response. | among filamentous fungi capable of mycelial growth, het genes play crucial roles by regulating heterokaryon formation between different individuals. when fusion occurs between fungal mycelia that differ genetically at their het loci, the resulting heterokaryotic cells are quickly destroyed. it is unclear how het gene products of podospora anserina trigger heterokaryon incompatibility. one unexplored possibility is that glycosphingolipids play a role because the het-c2 gene encodes a protein that ... | 2003 | 12525182 |
| spore killing in the fungus podospora anserina: a connection between meiotic drive and vegetative incompatibility? | fungi in which the haploid nuclei resulting from meiosis are linearly arranged in asci provide unique opportunities to analyse abnormal segregation. any meiotic drive system in such fungi will be observed in a cross between a driving and a sensitive strain as spore killing: the degeneration of half the ascospores in a certain proportion of the asci. in a sample of some 100 strains isolated from a single natural population we have discovered at least six different meiotic drive elements (van der ... | 2003 | 12656573 |
| stimulation of a mitochondrial endo-exonuclease from podospora anserina by pcna. | in podospora anserina we have described the purification of an endo-exonuclease (biochim. biophys. acta 1574 (1) (2002) 72). given the description of several nucleases addressed to the mitochondria and known to interact with the pcna, we sought a possible effect of pcna on the mt nuclease. a significant stimulation of the nuclease activity with pcna was observed with double-stranded and flap structure dna. immuno-western blotting experiments realized with monoclonal antibodies raised against the ... | 2003 | 12659877 |
| rapamycin mimics the incompatibility reaction in the fungus podospora anserina. | in filamentous fungi, a programmed cell death (pcd) reaction occurs when cells of unlike genotype fuse. this reaction is caused by genetic differences at specific loci termed het loci (for heterokaryon incompatibility). although several het genes have been characterized, the mechanism of this cell death reaction and its relation to pcd in higher eukaryotes remains largely unknown. in podospora anserina, genes induced during the cell death reaction triggered by the het-r het-v interaction have be ... | 2003 | 12684373 |
| sexual transmission of the [het-s] prion leads to meiotic drive in podospora anserina. | in the filamentous fungus podospora anserina, two phenomena are associated with polymorphism at the het-s locus, vegetative incompatibility and ascospore abortion. two het-s alleles occur naturally, het-s and het-s. the het-s encoded protein is a prion propagating as a self-perpetuating amyloid aggregate. when prion-infected [het-s] hyphae fuse with [het-s] hyphae, the resulting heterokaryotic cells necrotize. [het-s] and [het-s] strains are sexually compatible. when, however, a female [het-s] c ... | 2003 | 12719532 |
| domain organization and structure-function relationship of the het-s prion protein of podospora anserina. | the [het-s] infectious element of the fungus podospora anserina is a prion protein involved in a genetically controlled cell death reaction termed heterokaryon incompatibility. previous analyses indicate that [het-s] propagates as a self-perpetuating amyloid aggregate. the het-s protein is 289 amino acids in length. herein, we identify the region of the het-s protein that is responsible for amyloid formation and prion propagation. the region of het-s spanning residues 218-289 forms amyloid fiber ... | 2003 | 12727874 |
| deletion of mdmb impairs mitochondrial distribution and morphology in aspergillus nidulans. | mitochondria form a dynamic network of interconnected tubes in the cells of saccharomyces cerevisiae or filamentous fungi such as aspergillus nidulans, neurospora crassa, or podospora anserina. the dynamics depends on the separation of mitochondrial fragments, their movement throughout the cell, and their subsequent fusion with the other parts of the organelle. interestingly, the microtubule network is required for the distribution in n. crassa and s. pombe, while s. cerevisiae and a. nidulans a ... | 2003 | 12740872 |
| conformational transition occurring upon amyloid aggregation of the het-s prion protein of podospora anserina analyzed by hydrogen/deuterium exchange and mass spectrometry. | the [het-s] infectious element of the filamentous fungus podospora anserina corresponds to the prion form of the het-s protein. het-s (289 amino acids in length) aggregates into amyloid fibers in vitro. such fibers obtained in vitro are infectious, indicating that the [het-s] prion can propagate as a self-perpetuating amyloid aggregate of the het-s protein. previous analyses have suggested that only a limited region of the het-s protein is involved in amyloid formation and prion propagation. to ... | 2003 | 12873146 |
| characterization of the genomic organization of the region bordering the centromere of chromosome v of podospora anserina by direct sequencing. | a podospora anserina bac library of 4800 clones has been constructed in the vector pbhyg allowing direct selection in fungi. screening of the bac collection for centromeric sequences of chromosome v allowed the recovery of clones localized on either sides of the centromere, but no bac clone was found to contain the centromere. seven bac clones containing 322,195 and 156,244bp from either sides of the centromeric region were sequenced and annotated. one 5s rrna gene, 5 trna genes, and 163 putativ ... | 2003 | 12892638 |
| overexpression of a human and a fungal abc transporter similarly suppresses the differentiation defects of a fungal peroxisomal mutant but introduces pleiotropic cellular effects. | among the peroxisome membrane proteins, some are required for peroxisome biogenesis (e.g. pex2) while others are not, e.g. abc (atp-binding cassette) transporters. unexpectedly, overproduction of the peroxisomal abc transporter pmp70 was found to be able to restore peroxisome biogenesis in mammalian pex2 mutant cell lines. in the filamentous fungus podospora anserina, pex2 mutations not only impair peroxisome biogenesis but also cause a precise cell differentiation defect. here, we show that bot ... | 2003 | 12940987 |
| [the possibility of obtaining reciprocal crosses in the ascomycete, podospora anserina]. | | 1953 | 13067332 |
| [localization of s gene and some peculiarities of crossing-over in podospora anserina]. | | 1953 | 13067346 |
| [phenomena of incompatibility between strains of different origins in podospora anserina]. | | 1953 | 13107128 |
| [impossibility of obtaining uninterrupted and unlimited multiplication of the ascomycete podospora anserina]. | | 1953 | 13107134 |
| [longevity of strains of podospora anserina]. | | 1953 | 13107159 |
| [incompatibility between geographical strains of podospora anserina (ces.) rehm. i. genetic analysis of semi-compatibility]. | | 1956 | 13393176 |
| [incompatibility relationships between geographical races of podospora anserina (ces.) rehm. iii. studies on the gene physiology of barrage formation and semi-incompatibility]. | | 1959 | 13855763 |
| [cellular incompatibility and nucleo-cytoplasmic interactions in the "barrage" phenomena in podospora anserina]. | | 1962 | 13970337 |
| [phenoloxidases in the ascomycete podospora anserina. i. the identification of laccase and tyrosinase in the wild strain]. | | 1963 | 14044835 |
| [phenoloxidases of the ascomycete podospora anserina. ii. purification and properties of laccase]. | | 1964 | 14249043 |
| [on the cytoplasmic factors associated with a pair of s-s genes in podospora anserina]. | | 1959 | 14437699 |
| mapping and characterization of polymorphism in mtdna of cryphonectria parasitica: evidence of the presence of an optional intron. | the mitochondrial dna (mtdna) of the filamentous ascomycete cryphonectria parasitica is large and polymorphic so, to better understand the nature of the polymorphisms within populations, a small collection of italian strains of the fungus was examined. known mtdna polymorphisms were mapped and found to cluster in four regions of the mtdna molecule, particularly in the rflp region 2 where five different mtdna haplotypes out of 13 strains were identified. this region included an area of 8.4kbp whi ... | 2003 | 14599889 |
| impact of a disruption of a pathway delivering copper to mitochondria on podospora anserina metabolism and life span. | a global depletion of cellular copper as the result of a deficiency in high-affinity copper uptake was previously shown to affect the phenotype and life span of the filamentous fungus podospora anserina. we report here the construction of a strain in which the delivery of copper to complex iv of the mitochondrial respiratory chain is affected. this strain, pacox17::ble, is a pacox17-null mutant that does not synthesize the molecular chaperone targeting copper to cytochrome c oxidase subunit ii. ... | 2004 | 14871950 |
| incomplete penetrance and variable expressivity of a growth defect as a consequence of knocking out two k(+) transporters in the euascomycete fungus podospora anserina. | we describe an example of incomplete penetrance and variable expressivity in the filamentous fungus podospora anserina, two genetic properties classically associated with mutations in more complex organisms, such as green plants and animals. we show that the knockouts of two trk-related k(+) transporters of this ascomycete present variability in their phenotype that cannot be attributed to fluctuations of the genetic background or the environment. thalli of the knockout strains derived from inde ... | 2004 | 15020412 |
| the podospora rmp1 gene implicated in nucleus-mitochondria cross-talk encodes an essential protein whose subcellular location is developmentally regulated. | it has been previously reported that, at the time of death, the podospora anserina as1-4 mutant strains accumulate specific deleted forms of the mitochondrial genome and that their life spans depend on two natural alleles (variants) of the rmp1 gene: as1-4 rmp1-2 strains exhibit life spans strikingly longer than those of as1-4 rmp1-1. here, we show that rmp1 is an essential gene. in silico analyses of eight rmp1 natural alleles present in podospora isolates and of the putative homologs of this o ... | 2004 | 15020413 |
| supramolecular organization of cytochrome c oxidase- and alternative oxidase-dependent respiratory chains in the filamentous fungus podospora anserina. | to elucidate the molecular basis of the link between respiration and longevity, we have studied the organization of the respiratory chain of a wild-type strain and of two long-lived mutants of the filamentous fungus podospora anserina. this established aging model is able to respire by either the standard or the alternative pathway. in the latter pathway, electrons are directly transferred from ubiquinol to the alternative oxidase and thus bypass complexes iii and iv. we show that the cytochrome ... | 2004 | 15044453 |
| paask1, a mitogen-activated protein kinase kinase kinase that controls cell degeneration and cell differentiation in podospora anserina. | mapkkk are kinases involved in cell signaling. in fungi, these kinases are known to regulate development, pathogenicity, and the sensing of external conditions. we show here that podospora anserina strains mutated in paask1, a mapkkk of the mek family, are impaired in the development of crippled growth, a cell degeneration process caused by c, a nonconventional infectious element. they also display defects in mycelium pigmentation, differentiation of aerial hyphae, and making of fruiting bodies, ... | 2004 | 15082544 |
| heterotypic interactions among nacht domains: implications for regulation of innate immune responses. | proteins of the nacht [naip (neuronal apoptosis inhibitory protein), ciita (mhc class ii transcription activator), het-e (incompatibility locus protein from podospora anserina) and tp1 (telomerase-associated protein)] family may serve as critical pathogen-sensing and signal-transducing molecules within the innate immune system. in the present paper, we show that clan [card (caspase-recruitment domain), lrr (leucine-rich repeat) and nacht domain-containing protein], a nacht-containing protein ori ... | 2004 | 15107016 |
| the sequences appended to the amyloid core region of the het-s prion protein determine higher-order aggregate organization in vivo. | the [het-s] prion of the fungus podospora anserina propagates as a self-perpetuating amyloid form of the het-s protein. this protein triggers a cell death reaction termed heterokaryon incompatibility when interacting with the het-s protein, an allelic variant of het-s. het-s displays two distinct domains, a n-terminal globular domain and a c-terminal unstructured prion-forming domain (residues 218-289). here, we describe the characterization of het-s(157-289), a truncated form of het-s bearing a ... | 2004 | 15159455 |
| altering a gene involved in nuclear distribution increases the repeat-induced point mutation process in the fungus podospora anserina. | repeat-induced point mutation (rip) is a homology-dependent gene-silencing mechanism that introduces c:g-to-t:a transitions in duplicated dna segments. cis-duplicated sequences can also be affected by another mechanism called premeiotic recombination (pr). both are active over the sexual cycle of some filamentous fungi, e.g., neurospora crassa and podospora anserina. during the sexual cycle, several developmental steps require precise nuclear movement and positioning, but connections between rip ... | 2004 | 15166143 |
| the mitochondrial plasmid pal2-1 reduces calorie restriction mediated life span extension in the filamentous fungus podospora anserina. | calorie restriction is the only life span extending regimen known that applies to all aging organisms. although most fungi do not appear to senesce, all natural isolates of the modular filamentous fungus podospora anserina have a limited life span. in this paper, we show that calorie restriction extends life span also in podospora anserina. the response to glucose limitation varies significantly among 23 natural isolates from a local population in the netherlands, ranging from no effect up to a ... | 2004 | 15288022 |
| cloning of genes expressed early during cellulase induction in hypocrea jecorina by a rapid subtraction hybridization approach. | the cellulase system of the filamentous fungus hypocrea jecorina (trichoderma reesei) is encoded by several cellobiohydrolase, endoglucanase and beta-glucosidase genes, which are co-ordinately expressed upon induction by cellulose or the disaccharide sophorose. to identify genes, which are specifically expressed under these inducing conditions and possibly related to the induction process, we applied rapid subtraction hybridization (rash) to sophorose induced mrnas from the wild-type strain h. j ... | 2004 | 15288024 |
| bistability and hysteresis of the 'secteur' differentiation are controlled by a two-gene locus in nectria haematococca. | bistability and hysteresis are increasingly recognized as major properties of regulatory networks governing numerous biological phenomena, such as differentiation and cell cycle progression. the full scope of the underlying molecular mechanisms leading to bistability and hysteresis remains elusive. nectria haemaotcocca, a saprophytic or pathogenic fungus with sexual reproduction, exhibits a bistable morphological modification characterized by a reduced growth rate and an intense pigmentation. bi ... | 2004 | 15312233 |
| characterization of idi-4, a bzip transcription factor inducing autophagy and cell death in the fungus podospora anserina. | in filamentous fungi a cell death reaction occurs when hyphae of unlike genotype fuse. this phenomenon is referred to as heterokaryon incompatibility. in podospora anserina, this cell death reaction was found to be associated with the transcriptional induction of a set of genes termed idi genes (for induced during incompatibility) and activation of autophagy. herein, we describe the characterization of idi-4, a novel idi gene encoding a bzip transcription factor. expression of idi-4 is induced d ... | 2004 | 15341644 |
| two nadph oxidase isoforms are required for sexual reproduction and ascospore germination in the filamentous fungus podospora anserina. | nadph oxidases are enzymes that produce reactive oxygen species (ros) using electrons derived from intracellular nadph. in plants and mammals, ros have been proposed to be second messengers that signal defence responses or cell proliferation. by inactivating panox1 and panox2, two genes encoding nadph oxidases, we demonstrate the crucial role of these enzymes in the control of two key steps of the filamentous fungus podospora anserina life cycle. panox1 mutants are impaired in the differentiatio ... | 2004 | 15465387 |
| oxy2 as a transcriptional activator gene for copper uptake in cryptococcus neoformans. | cryptococcus neoformans is subject to oxidative attack by host immune cells; consequently, oxidant-resistant mechanisms may be important in pathogenesis. mutations at the oxy2 locus confer decreased laccase and increased sensitivity to hyperbaric oxygen in the background of the oxyl mutation, but, alone, do not confer sensitivity to oxidants. because metal deficiency can potentiate or ameliorate sensitivity to oxidants, and because the melanin-synthesizing laccase contains copper, we investigate ... | 2004 | 15473357 |
| insight into trichoderma reesei's genome content, organization and evolution revealed through bac library characterization. | trichoderma reesei is an important industrial fungus known for its ability to efficiently secrete large quantities of protein as well as its wide variety of biomass degrading enzymes. past research on this fungus has primarily focused on extending its protein production capabilities, leaving the structure of its 33 mb genome essentially a mystery. to begin to address these deficiencies and further our knowledge of t. reesei's secretion and cellulolytic potential, we have created a genomic framew ... | 2004 | 15531212 |
| genetic analysis of spore killing in the filamentous ascomycete podospora anserina. | in the present study, we analysed different podospora anserina strains for their ability to induce spore killing and identified three new killer strains. test crosses of killer strains with different sensitive strains revealed different second division segregation ratios suggesting an influence of the sensitive strain on the crossing-over frequency. in crosses of killer strain o with a sensitive strain, the frequency of two-spored asci was found to vary extremely from perithecium to perithecium. ... | 2004 | 15531213 |
| interaction between the oxa1 and rmp1 genes modulates respiratory complex assembly and life span in podospora anserina. | a causal link between deficiency of the cytochrome respiratory pathway and life span was previously shown in the filamentous fungus podospora anserina. to gain more insight into the relationship between mitochondrial function and life span, we have constructed a strain carrying a thermosensitive mutation of the gene oxa1. oxa1 is a membrane protein conserved from bacteria to human. the mitochondrial oxa1 protein is involved in the assembly/insertion of several respiratory complexes. we show here ... | 2005 | 15545650 |
| probing the structure of the infectious amyloid form of the prion-forming domain of het-s using high resolution hydrogen/deuterium exchange monitored by mass spectrometry. | the het-s prion protein of podospora anserina represents a valuable model system to study the structural basis of prion propagation. in this system, prion infectivity can be generated in vitro from a recombinant protein. we have previously identified the region of the het-s protein involved in amyloid formation and prion propagation. herein, we show that a recombinant peptide corresponding to the c-terminal prion-forming domain of het-s (residues 218-289) displays infectivity. we used high resol ... | 2005 | 15647259 |
| the function of the coding sequences for the putative pheromone precursors in podospora anserina is restricted to fertilization. | we cloned the pheromone precursor genes of podospora anserina in order to elucidate their role in the biology of this fungus. the mfp gene encodes a 24-amino-acid polypeptide finished by the caax motif, characteristic of fungal lipopeptide pheromone precursors similar to the a-factor precursor of saccharomyces cerevisiae. the mfm gene encodes a 221-amino-acid polypeptide, which is related to the s. cerevisiae alpha-factor precursor and contains two 13-residue repeats assumed to correspond to the ... | 2005 | 15701803 |
| dna-binding specificity of the idi-4 basic leucine zipper factor of podospora anserina defined by systematic evolution of ligands by exponential enrichment (selex). | heterokaryon incompatibility is a cell destruction process that occurs when fungal cells of unlike genotype fuse. in podospora anserina, autophagy is engaged during cell death by incompatibility and a number of genes are induced at the transcriptional level. these genes are termed idi (induced during incompatibility) genes. among these is idi-4, a gene encoding a basic leucine zipper (bzip) factor. idi-4 displays similarity to the gcn4/cross-pathway control (cpc) factors that control gene expres ... | 2005 | 15701809 |
| peroxide accumulation and cell death in filamentous fungi induced by contact with a contestant. | podospora anserina and coprinopsis cinerea (syn. coprinus cinereus) are endowed with a defence system able to differentiate self vs. non-self and involving the generation of peroxide. indeed, they produce peroxide when confronted with a filamentous fungus, only in non-self confrontations. both species are not able to recognize yeasts and show a differential response to bacteria. the accumulation of peroxides in the ascomycete podospora anserina requires an nadph oxidase and a map kinase cascade, ... | 2005 | 15839098 |
| discovery of a novel superfamily of type iii polyketide synthases in aspergillus oryzae. | identification of genes encoding type iii polyketide synthase (pks) superfamily members in the industrially useful filamentous fungus, aspergillus oryzae, revealed that their distribution is not specific to plants or bacteria. among other aspergilli (aspergillus nidulans and aspergillus fumigatus), a. oryzae was unique in possessing four chalcone synthase (chs)-like genes (csya, csyb, csyc, and csyd). expression of csya, csyb, and csyd genes was confirmed by rt-pcr. comparative genome analyses r ... | 2005 | 15845386 |
| two new fungal inteins. | until recently the only intein known to be encoded by the nuclear genome of a eukaryote was the vma intein in the vacuolar atpase precursor of several species of saccharomycete yeast. this intein has been intensively studied and much information has been gained about its structure, mode of action and evolutionary history. we recently reported a second nuclear intein, cne prp8, encoded within the prp8 gene of the basidiomycete cryptococcus neoformans. subsequent studies have found allelic prp8 in ... | 2005 | 15849795 |
| genetic control of an epigenetic cell degeneration syndrome in podospora anserina. | filamentous fungi frequently present degenerative processes, whose molecular basis is very often unknown. here, we present three mutant screens that result in the identification of 29 genes that directly or indirectly control crippled growth (cg), an epigenetic cell degeneration of the filamentous ascomycete podospora anserina. two of these genes were previously shown to encode a map kinase kinase kinase and an nadph oxidase involved in a signal transduction cascade that participates in stationa ... | 2005 | 15869888 |
| correlation of structural elements and infectivity of the het-s prion. | prions are believed to be infectious, self-propagating polymers of otherwise soluble, host-encoded proteins. this concept is now strongly supported by the recent findings that amyloid fibrils of recombinant prion proteins from yeast, podospora anserina and mammals can induce prion phenotypes in the corresponding hosts. however, the structural basis of prion infectivity remains largely elusive because acquisition of atomic resolution structural properties of amyloid fibrils represents a largely u ... | 2005 | 15944710 |
| non-mendelian inheritance of the het-s prion or het-s prion domains determines the het-s spore killing system in podospora anserina. | two alleles of the het-s/s locus occur naturally in the filamentous fungus podospora anserina, het-s and het-s. the het-s encoded protein can form a prion that propagates a self-perpetuating amyloid aggregate, resulting in two phenotypes for the het-s strains. the prion-infected [het-s] shows an antagonistic interaction to het-s whereas the prion-free [het-s*] is neutral in interaction to het-s. the antagonism between [het-s] and het-s is seen as heterokaryon incompatibility at the somatic level ... | 2005 | 16043372 |
| circadian rhythms in neurospora crassa: clock gene homologues in fungi. | computer-based analysis of a total of 17 filamentous fungal and yeasts genomes has shown: (1) homologues of frq, wc-1, wc-2, and vvd, key gene components of the neurospora crassa clock, are present in magnaporthe grisea, gibberella zeae, and podospora anserina, suggesting an frq-based oscillator in these organisms; (2) some fungal species that are more distantly related to neurospora, such as rhizopus oryzae do not appear to have frq homologues; (3) many fungal species that do not appear to cont ... | 2005 | 16154782 |
| a two-step protocol for efficient deletion of genes in the filamentous ascomycete podospora anserina. | deletion of genes in podospora anserina via conventional methods is an inefficient and time-consuming process since homologous recombination occurs normally only at low frequency (about 1%). to improve the efficiency of replacement, we adopted the two-step protocol developed for aspergillus nidulans (chaveroche et al. in nucleic acids res 28:e97, 2000). as a prerequisite, a vector was generated containing a blasticidin resistance cassette for selection in the escherichia coli host strain ks272 ( ... | 2005 | 16160832 |
| accelerated cell death in podospora autophagy mutants. | although autophagy is characteristic of type ii programmed cell death (pcd), its role in cell death is currently debated. both cell death-promoting and prosurvival roles of autophagy have been reported depending on the organism and the cell type. in filamentous fungi, a cell death reaction known as an incompatibility reaction occurs when cells of unlike genotype fuse. cell death by incompatibility is characterized by a dramatic vacuolar enlargement and cell lysis. in podospora anserina, autophag ... | 2005 | 16278443 |
| some coprophilous fungi from kenya. | the occurrence of coprophilous fungi on samples of antelope, buffalo, zebra and hippopotamus dung collected from the marula estates in kenya was recorded. a hundred and seventy three fungal isolates representative of 40 genera and 59 species were identified. among these species, 23 were ascomycetes (39%), 30 deuteromycetes (50.8%), 5 zygomycetes (8.5%) and 1 basidiomycete (1.7%). ascobolus immersus, coprotus niveus, iodophanus carneus, lasiobolus lasioboloides, podospora anserina, p. australis a ... | 1998 | 16284849 |
| structural evidence for adaptive ligand binding of glycolipid transfer protein. | glycolipids participate in many important cellular processes and they are bound and transferred with high specificity by glycolipid transfer protein (gltp). we have solved three different x-ray structures of bovine gltp at 1.4 angstroms, 1.6 angstroms and 1.8 angstroms resolution, all with a bound fatty acid or glycolipid. the 1.4 angstroms structure resembles the recently characterized apo-form of the human gltp but the other two structures represent an intermediate conformation of the apo-gltp ... | 2006 | 16309699 |
| comparative studies of extracellular fungal laccases. | various basidiomycetes, ascomycetes, and deuteromycetes, grown in a sugar-rich liquid medium, were compared for laccase-producing ability and for the inducing effect of 2,5-xylidine on laccase production. clear stimulation of the extracellular enzyme formation by xylidine was obtained in the cultures of fomes annosus, pholiota mutabilis, pleurotus ostreatus, and trametes versicolor, whereas rhizoctonia praticola and botrytis cinerea were not affected by the xylidine, and in the case of podospora ... | 1984 | 16346649 |
| genomics reveals traces of fungal phenylpropanoid-flavonoid metabolic pathway in the f ilamentous fungus aspergillus oryzae. | fungal secondary metabolites constitute a wide variety of compounds which either play a vital role in agricultural, pharmaceutical and industrial contexts, or have devastating effects on agriculture, animal and human affairs by virtue of their toxigenicity. owing to their beneficial and deleterious characteristics, these complex compounds and the genes responsible for their synthesis have been the subjects of extensive investigation by microbiologists and pharmacologists. a majority of the funga ... | 2005 | 16410762 |
| mitochondrial free radical generation and lifespan control in the fungal aging model podospora anserina. | in the filamentous fungus podospora anserina a central role of mitochondria in the control of aging has been repeatedly demonstrated. interestingly, impairments in cytochrome c oxidase (cox) activity induce an enhancement in the expression of the quinol-oxygen alternative oxidoreductase (aox) correlating with an extension of lifespan. this effect is thought to be determined by a reduction of the free radical generation in mitochondria. in the current investigation we have analyzed the electron t ... | 2006 | 16530367 |
| podospora anserina target of rapamycin. | we have isolated the podospora anserina tor gene. the pator protein displayed strong identities with tor proteins from other eukaryotes especially in the frb domain and the kinase domain. genome analysis suggests that a single tor gene exists in podospora. the serine residue known to be one site of missense mutations conferring rapamycin resistance in other organisms is conserved in the pator protein (s1895). a pator-s1895r mutated allele has been constructed and introduced in the wild-type stra ... | 2006 | 16614869 |
| a novel in vitro filter trap assay identifies tannic acid as an amyloid aggregation inducer for het-s. | in this work we present an easy and low cost in vitro filter trap assay to quickly identify direct actors on amyloid prion aggregation. we chose the recombinant purified prion protein het-s from podospora anserina as a reference. het-s was labelled with a fluorophore prior to aggregation assays in a 96 well micro-array system. aggregation assays were carried out in presence of a number of chemical compounds, followed by a filter trap assay through a cellulose acetate membrane and the straight de ... | 2006 | 16621084 |
| mitochondrial metabolism and aging in the filamentous fungus podospora anserina. | the filamentous fungus podospora anserina has a limited lifespan. in this organism, aging is systematically associated to mitochondrial dna instability. we recently provided evidence that the respiratory function is a key determinant of its lifespan. loss of function of the cytochrome pathway leads to the compensatory induction of an alternative oxidase, to a decreased production of reactive oxygen species and to a striking increase in lifespan. these changes are associated to the stabilization ... | 2006 | 16624249 |
| methods for the in vivo and in vitro analysis of [het-s] prion infectivity. | prions have been described in mammals and fungi. the [het-s] infectious genetic element of the filamentous fungus podospora anserina is the prion form of the het-s protein. this protein is involved in the control of a cell death reaction termed heterokaryon incompatibility. the infectious form of het-s corresponds to a self-perpetuating amyloid. the purpose of the present paper is to describe the techniques that can be used to analyse [het-s] prion propagation in vivo and het-s amyloid aggregati ... | 2006 | 16750391 |
| oxphos supercomplexes: respiration and life-span control in the aging model podospora anserina. | recent biochemical evidence has indicated the existence of respiratory supercomplexes as well as atp synthase oligomers in the inner mitochondrial membrane of different eukaryotes. we have studied the organization of the respiratory chain of a wild-type strain and of two long-lived mutants of the filamentous fungus podospora anserina. this aging model is able to respire by either the standard or the alternative pathway. in the latter, electrons are directly transferred from ubiquinol to the alte ... | 2006 | 16803975 |
| the formation of bioactive amyloid species by prion proteins in vitro and in cells. | amyloid proteins are a group of proteins that can polymerize into cross beta-sheeted amyloid species. we have found that enhancing cellular 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (mtt) formazan exocytosis is a common property of bioactive amyloid species formed from all of the amyloid proteins tested to date. in this report, we show that the infectious amyloid species of the prion protein het-s of the filamentous fungus podospora anserina, like other amyloidogenic proteins, ... | 2006 | 16916580 |
| a mitotically inheritable unit containing a map kinase module. | prions are novel kinds of hereditary units, relying solely on proteins, that are infectious and inherited in a non-mendelian fashion. to date, they are either based on autocatalytic modification of a 3d conformation or on autocatalytic cleavage. here, we provide further evidence that in the filamentous fungus podospora anserina, a map kinase cascade is probably able to self-activate and generate c, a hereditary unit that bears many similarities to prions and triggers cell degeneration. we show t ... | 2006 | 16938837 |
| the peroxisomal import proteins pex2, pex5 and pex7 are differently involved in podospora anserina sexual cycle. | pex5, pex7 and pex2 are involved in the peroxisomal matrix protein import machinery. pex5 and pex7 are the receptors for the proteins harbouring, respectively, a pts1 and a pts2 peroxisomal targeting sequence and cycle between the cytoplasm and the peroxisome. pex2 belongs to the ring-finger complex located in the peroxisomal membrane and acts in protein import downstream of pex5 and pex7; it is therefore required for the import of both pts1 and pts2 proteins. we have shown previously that pex2 ... | 2006 | 16987176 |
| evolutionary relationships of vertebrate nacht domain-containing proteins. | phylogenetic analyses of conserved [neuronal apoptosis inhibitory protein (naip), mhc class ii transcription activator (ciita), incompatibility locus protein from podospora anserina (het-e), and telomerase-associated protein (tp1)] (nacht) domains were used to reconstruct the evolutionary history of vertebrate nacht-containing proteins. the results supported the hypothesis that nod3 is basal to the other nacht-containing proteins found in tetrapods. the latter formed two strongly supported clust ... | 2006 | 17006665 |
| the homologue of het-c of neurospora crassa lacks vegetative compatibility function in fusarium proliferatum. | for two fungal strains to be vegetatively compatible and capable of forming a stable vegetative heterokaryon they must carry matching alleles at a series of loci variously termed het or vic genes. cloned het/vic genes from neurospora crassa and podospora anserina have no obvious functional similarity and have various cellular functions. our objective was to identify the homologue of the neurospora het-c gene in fusarium proliferatum and to determine if this gene has a vegetative compatibility fu ... | 2006 | 17021201 |
| a mutation in the gene encoding cytochrome c1 leads to a decreased ros content and to a long-lived phenotype in the filamentous fungus podospora anserina. | we present here the properties of a complex iii loss-of-function mutant of the filamentous fungus podospora anserina. the mutation corresponds to a single substitution in the second intron of the gene cyc1 encoding cytochrome c(1), leading to a splicing defect. the cyc1-1 mutant is long-lived, exhibits a defect in ascospore pigmentation, has a reduced growth rate and a reduced ros production associated with a stabilisation of its mitochondrial dna. we also show that increased longevity is linked ... | 2007 | 17081785 |
| impact of ros on ageing of two fungal model systems: saccharomyces cerevisiae and podospora anserina. | 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 cerevi ... | 2006 | 17090424 |
| integration of a pal2-1 homologous mitochondrial plasmid associated with life span extension in podospora anserina. | we isolated and characterized a novel spontaneous longevity mutant of podospora anserina strain wa32 carrying one of the pal2-1 homologous mitochondrial plasmids. this mutant is at least ten fold longer-lived than the wild type, and is hence a formal suppressor of both the regular and the 'plasmid-based' senescence process. we show that the longevity trait is maternally inherited and coincides with the presence of a copy of the plasmid integrated in the 5' utr of the mitochondrial complex i gene ... | 2007 | 17166751 |
| reducing mitochondrial fission results in increased life span and fitness of two fungal ageing models. | 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 ... | 2007 | 17173038 |
| mass analysis by scanning transmission electron microscopy and electron diffraction validate predictions of stacked beta-solenoid model of het-s prion fibrils. | fungal prions are infectious filamentous polymers of proteins that are soluble in uninfected cells. in its prion form, the het-s protein of podospora anserina participates in a fungal self/non-self recognition phenomenon called heterokaryon incompatibility. like other prion proteins, het-s has a so-called "prion domain" (its c-terminal region, het-s-(218-289)) that is responsible for induction and propagation of the prion in vivo and for fibril formation in vitro. prion fibrils are thought to ha ... | 2007 | 17178708 |
| identification and biochemical analysis of a mitochondrial endonuclease of podospora anserina related to curved-dna binding proteins. | we purified and characterized previously from podospora anserina mitochondria an endonuclease, active on single-stranded, double-stranded and flap dna, with rnase h activity, named p49 according to the major 49 kda band observed on sds-page. edman sequencing allowed us to identify the corresponding gene called nuc49. here we report the properties of the (his)-tagged nuc49 protein expressed in e. coli. we show that this protein does exhibit an endonuclease activity on plasmid dna, circular recess ... | 2007 | 17188431 |
| structure, function, and amyloidogenesis of fungal prions: filament polymorphism and prion variants. | infectious proteins (prions) became an important medical issue when they were identified as agents of the transmissible spongiform encephalopathies. more recently, prions have been found in fungi and their investigation has been facilitated by greater experimental tractability. in each case, the normal form of the prion protein may be converted into the infectious form (the prion itself) in an autocatalytic process; conversion may either occur spontaneously or by transmission from an already inf ... | 2006 | 17190613 |
| insertion of short poly d(a) d(t) sequences at recombination junctions in mitochondrial dna of podospora. | 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. | 1987 | 17193717 |
| cell death by incompatibility in the fungus podospora. | filamentous fungi are naturally able of somatic fusions. when cells of unlike genotype at specific het loci fuse, non-self recognition operates in the fusion cell and a cell death reaction termed cell death by incompatibility is triggered. in podospora anserina cell death by incompatibility is characterized by a dramatic vacuolar enlargement, induction of autophagy and cell lysis. autophagy contributes neither to vacuolar morphological changes nor to cell death but rather protects cells against ... | 2007 | 17204431 |
| temporal action of mutations inhibiting the accomplishment of quiescence or disrupting development in the fungus podospora anserina. | two podospora mutants carrying mutations mode and modf were persumed to be quiescent defective, because, when grown under glucose limitation, they differed from the wild-type strain in an excess of dry weight production and a reduction of cell survival. new insight on the action of mode and modf mutations was provided by the study of double mutants resulting from the association of mode or modf mutations with unrelated developmental mutations.-mode and modf were first coupled to three allelic mu ... | 1985 | 17246250 |
| a new method for the screening of mutations related to protoplasmic incompatibility, differentiation and plasma membrane in the fungus podospora anserina. | in podospora anserina previous investigations showed that mutations in genes involved in the control of protoplasmic incompatibility cause defects at various stages of differentiation during the life cycle and also modify properties of the plasma membrane. to establish these relationships in another way, a new method for screening mutations has been developed as a first step. eighty-five new mutants were selected for resistance to toxic products (sorbose or thiourea); in a second step these muta ... | 1985 | 17246298 |
| protoplasmic incompatibility and cell lysis in podospora anserina. i. genetic investigations on mutations of a novel modifier gene that suppresses cell destruction. | in podospora anserina, protoplasmic incompatibility (a phenomenon that prevents heterokaryon formation because of the destruction of the fused cells) can be studied in homokaryotic strains that combine nonallelic incompatibility genes or carry mutations at the lys loci. in these strains cell destruction occurs early in development and is associated with an arrest of growth.-from the self-lysing strains lysa(1) and rv (r and v are nonallelic incompatibility genes) mutations have been selected tha ... | 1977 | 17248762 |
| protoplasmic incompatibility in podospora anserina: a possible role for its associated proteolytic activity. | a mutation (modd) was selected in a gene involved in the control of protoplasmic incompatibility. previous results (labarere and bernet 1979) showed that modd decreased the density of protoperithecia and caused a defect in ascospore germination. in addition, modd has a third defect: when modd stationary cells were isolated in order to obtain further development, renewal of growth rarely ensued. instead, the modd cells lysed or produced microthalli from which normal growth never occurred. these d ... | 1979 | 17248972 |
| protoplasmic incompatibility in podospora anserina: a possible function for incompatibility genes. | the suppression of protoplasmic incompatibility resulting from nonallelic gene interactions has been obtained by the coupled effect of mutations in the moda and modb genes (bernet 1971). due to their female sterility, moda modb strains provide an experimental tool to determine whether or not the mod and incompatibility loci are involved in a function other than protoplasmic incompatibility. present results show that moda modb female sterility is a nonautonomous trait since heterokaryotic mycelia ... | 1980 | 17249066 |
| a mitochondrial mutator plasmid that causes senescence under dietary restricted conditions. | calorie or dietary restriction extends life span in a wide range of organisms including the filamentous fungus podospora anserina. under dietary restricted conditions, p. anserina isolates are several-fold longer lived. this is however not the case in isolates that carry one of the pal2-1 homologous mitochondrial plasmids. | 2007 | 17407571 |
| idc1, a pezizomycotina-specific gene that belongs to the pampk1 map kinase transduction cascade of the filamentous fungus podospora anserina. | components involved in the activation of the mapk cascades in filamentous fungi are not well known. here, we provide evidence that idc1, a pezizomycotina-specific gene is involved along with the panox1 nadph oxidase in the nuclear localization of the pampk1 map kinase, a prerequisite for mapk activity. mutants of idc1 display the same phenotypes as mutants in panox1 and pampk1, i.e., lack of pigment and of aerial hyphae, female sterility, impairment in hyphal interference and inability to develo ... | 2007 | 17517525 |
| prion and non-prion amyloids of the het-s prion forming domain. | het-s is a prion protein of the fungus podospora anserina. a plausible structural model for the infectious amyloid fold of the het-s prion-forming domain, het-s(218-289), makes it an attractive system to study structure-function relationships in amyloid assembly and prion propagation. here, we report on the diversity of het-s(218-289) amyloids formed in vitro. we distinguish two types formed at ph 7 from fibrils formed at ph 2, on morphological grounds. unlike ph 7 fibrils, the ph 2 fibrils show ... | 2007 | 17532341 |
| a non-q/n-rich prion domain of a foreign prion, [het-s], can propagate as a prion in yeast. | prions are self-propagating, infectious aggregates of misfolded proteins. the mammalian prion, prp(sc), causes fatal neurodegenerative disorders. fungi also have prions. while yeast prions depend upon glutamine/asparagine (q/n)-rich regions, the podospora anserina het-s and prp prion proteins lack such sequences. nonetheless, we show that the het-s prion domain fused to gfp propagates as a prion in yeast. analogously to native yeast prions, transient overexpression of the het-s fusion induces ri ... | 2007 | 17612491 |
| deletion of putative apoptosis factors leads to lifespan extension in the fungal ageing model podospora anserina. | podospora anserina is a filamentous fungus with a limited lifespan. after a strain-specific period of growth, cultures turn to senescence and ultimately die. here we provide evidence that the last step in the ageing of p. anserina is not accidental but programmed. in this study, paamid1, a homologue of a mammalian 'aif-homologous mitochondrion-associated inducer of death', was analysed as a putative member of a caspase-independent signalling pathway. in addition, two metacaspases, pamca1 and pam ... | 2007 | 17627766 |
| differential proteomic profiling of mitochondria from podospora anserina, rat and human reveals distinct patterns of age-related oxidative changes. | 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 an ... | 2007 | 17689904 |
| identification of papks1, a polyketide synthase involved in melanin formation and its use as a genetic tool in podospora anserina. | in the filamentous fungus podospora anserina, many pigmentation mutations map to the median region of the complex locus '14', called segment '29'. the data presented in this paper show that segment 29 corresponds to a gene encoding a polyketide synthase, designated papks1, and identifies two mutations that completely or partially abolish the activity of the papks1 polypeptide. we present evidence that the p. anserina green pigment is a (dhn)-melanin. using the powerful genetic system of papks1 c ... | 2007 | 17707627 |