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mitop2: an integrative tool for the analysis of the mitochondrial proteome.mitochondria are crucial for normal cell metabolism and maintenance. mitochondrial dysfunction has been implicated in a spectrum of human diseases, ranging from rare monogenic to common multifactorial disorders. important for the understanding of organelle function is the assignment of its constituents, and although over 1,500 proteins are predicted to be involved in mammalian mitochondrial function, so far only about 900 are assigned to mitochondria with reasonable certainty. continuing efforts ...200818780189
the information highways of a biotechnological workhorse--signal transduction in hypocrea jecorina.the ascomycete hypocrea jecorina (anamorph trichoderma reesei) is one of the most prolific producers of biomass-degrading enzymes and frequently termed an industrial workhorse. to compete for nutrients in its habitat despite its shortcoming in certain degradative enzymes, efficient perception and interpretation of environmental signals is indispensable. a better understanding of these signals as well as their transmission machinery can provide sources for improvement of biotechnological processe ...200818803869
novel apocarotenoid intermediates in neurospora crassa mutants imply a new biosynthetic reaction sequence leading to neurosporaxanthin formation.neurosporaxanthin, beta-apo-4'-carotenoic acid (c35), represents the end-product of the carotenoid pathway in neurospora crassa. it is supposed to be synthesized in three steps catalyzed by sequential al-2, cao-2 and ylo-1 activities: (i) cyclization of 3,4-didehydrolycopene (c40); (ii) cleavage of torulene into beta-apo-4'-carotenal (c35); and finally (iii) oxidation of beta-apo-4'-carotenal. however, analyses of the ylo-1 mutant revealed the accumulation of intermediates other than beta-apo-4' ...200818812228
sulphur metabolism and cellulase gene expression are connected processes in the filamentous fungus hypocrea jecorina (anamorph trichoderma reesei).sulphur compounds like cysteine, methionine and s-adenosylmethionine are essential for the viability of most cells. thus many organisms have developed a complex regulatory circuit that governs the expression of enzymes involved in sulphur assimilation and metabolism. in the filamentous fungus hypocrea jecorina (anamorph trichoderma reesei) little is known about the participants in this circuit.200818842142
mitogen-activated protein kinase cascade required for regulation of development and secondary metabolism in neurospora crassa.mitogen-activated protein kinase (mapk) signaling cascades are composed of mapk kinase kinases (mapkkks), mapk kinases (mapkks), and mapks. in this study, we characterize components of a mapk cascade in neurospora crassa (mik-1, mapkkk; mek-1, mapkk; and mak-1, mapk) homologous to that controlling cell wall integrity in saccharomyces cerevisiae. growth of basal hyphae is significantly reduced in mik-1, mek-1, and mak-1 deletion mutants on solid medium. all three mutants formed short aerial hypha ...200818849472
mglig4, a homolog of neurospora crassa mus-53 (dna ligase iv), is involved in, but not essential for, non-homologous end-joining events in magnaporthe grisea.in many eukaryotic organisms, the non-homologous end-joining (nhej) system is a major pathway for the repair of dna double-strand breaks (dsbs). dna ligase iv is a component of the nhej system and is strictly required for the nhej system in saccharomyces cerevisiae and in neurospora crassa. to investigate the functions of dna ligase iv in magnaporthe grisea, we generated deletion mutants of mglig4, which encodes a homolog of n. crassa dna ligase iv. mutants (mglig4) showed no defects in asexual ...200818854221
functional and physical interaction of blue- and red-light sensors in aspergillus nidulans.light sensing is very important for organisms in all biological kingdoms to adapt to changing environmental conditions. it was discovered recently that plant-like phytochrome is involved in light sensing in the filamentous fungus aspergillus nidulans[1]. here, we show that phytochrome (fpha) is part of a protein complex containing lrea (wc-1) and lreb (wc-2) [2, 3], two central components of the neurospora crassa blue-light-sensing system. we found that fpha represses sexual development and myco ...200818291652
phenotype of a mechanosensitive channel mutant, mid-1, in a filamentous fungus, neurospora crassa.in the yeast saccharomyces cerevisiae, the mid1 (mating-induced death) gene encodes a stretch-activated channel which is required for successful mating; the mutant phenotype is rescued by elevated extracellular calcium. homologs of the mid1 gene are found in fungi that are morphologically complex compared to yeast, both basidiomycetes and ascomycetes. we explored the phenotype of a mid-1 knockout mutant in the filamentous ascomycete neurospora crassa. the mutant exhibits lower growth vigor than ...200818296620
repeat induced point mutation in two asexual fungi, aspergillus niger and penicillium chrysogenum.repeat induced point mutation (rip) is a gene silencing mechanism present in fungal genomes. during rip, duplicated sequences are efficiently and irreversibly mutated by transitions from c:g to t:a. for the first time, we have identified traces of rip in transposable elements of aspergillus niger and penicillium chrysogenum, two biotechnologically relevant fungi. we found that rip in p. chrysogenum has affected a large set of sequences, which also contain other mutations. on the other hand, rip ...200818347798
a novel gene, phca from pseudomonas syringae induces programmed cell death in the filamentous fungus neurospora crassa.the phytopathogen pseudomonas syringae competes with other epiphytic organisms, such as filamentous fungi, for resources. here we characterize a gene in p. syringae pv. syringae b728a and p. syringae pv. tomato dc3000, termed phca, that has homology to a filamentous fungal gene called het-c. phca is conserved in many p. syringae strains, but is absent in one of the major clades, which includes the p. syringae pathovar phaseolicola. in the filamentous fungus neurospora crassa, het-c regulates a c ...200818363647
properties of family 79 beta-glucuronidases that hydrolyze beta-glucuronosyl and 4-o-methyl-beta-glucuronosyl residues of arabinogalactan-protein.the carbohydrate moieties of arabinogalactan-proteins (agps), which are mainly composed of gal, l-ara, glca, and 4-me-glca residues, are essential for the physiological functions of these proteoglycans in higher plants. for this study, we have identified two genes encoding family 79 beta-glucuronidases, designated anglcaase and ncglcaase, in aspergillus niger and neurospora crassa, respectively, based on the amino acid sequence of a native beta-glucuronidase purified from a commercial pectolytic ...200818377882
specificity of commercial anti-spectrin antibody in the study of fungal and oomycete spectrin: cross-reaction with proteins other than spectrin.spectrin was first described in erythrocytes where it forms a filamentous network in the cytoplasmic face of the plasma membrane and participates in the membrane's structural integrity in addition to controlling the lateral mobility of integral membrane proteins. in fungi, spectrin-like proteins have been described in the plasma membrane, concentrated mainly in the region of maximum apical expansion. this localization led to the idea of a spectrin based membrane skeleton in fungi participating i ...200818378170
genetic analysis of the neurospora crassa rad14 homolog mus-43 and the rad10 homolog mus-44 reveals that they belong to the mus-38 pathway of two nucleotide excision repair systems.saccharomyces cerevisiae rad14 and rad10 proteins are essential for nucleotide excision repair (ner). rad14 is a uv-damaged dna binding protein and rad10 is a structure-specific endonuclease that functions in a complex with rad1. in this study, we identified and characterized the rad14 and rad10 homolog genes in neurospora crassa, which we named mus-43 and mus-44, respectively. disruption of mus-43 and mus-44 conferred sensitivity to uv and 4-nitroquinoline 1-oxide, but not to methyl methanesulf ...200818379129
identification and evolution of fungal mitochondrial tyrosyl-trna synthetases with group i intron splicing activity.the bifunctional neurospora crassa mitochondrial tyrosyl-trna synthetase (cyt-18 protein) both aminoacylates mitochondrial trna(tyr) and acts as a structure-stabilizing splicing cofactor for group i introns. previous studies showed that cyt-18 has distinct trna(tyr) and group i intron-binding sites, with the latter formed by three small "insertions" in the nucleotide-binding fold and other structural adaptations compared with nonsplicing bacterial tyrosyl-trna synthetases. here, analysis of geno ...200818413600
an f-actin-depleted zone is present at the hyphal tip of invasive hyphae of neurospora crassa.the distribution of filamentous actin (f-actin) in invasive and noninvasive hyphae of the ascomycete neurospora crassa was investigated. eighty six percent of noninvasive hyphae had f-actin in the tip region compared to only 9% of invasive hyphae. the remaining 91% of the invasive hyphae had no obvious tip high concentration of f-actin staining; instead they had an f-actin-depleted zone in this region, although some f-actin, possibly associated with the spitzenkörper, remained at the tip. the si ...200818421548
dynamin-like protein-dependent formation of woronin bodies in saccharomyces cerevisiae upon heterologous expression of a single protein.filamentous ascomycetes harbor woronin bodies and glyoxysomes, two types of microbodies, within one cell at the same time. the dominant protein of the neurospora crassa woronin body, hex1, forms a hexagonal core crystal via oligomerization and evidence has accumulated that woronin bodies bud off from glyoxysomes. we analyzed whether hex1 is sufficient to induce woronin body formation upon heterologous expression in saccharomyces cerevisiae, an organism devoid of this specialized organelle. in wi ...200818435762
dynamics of the preprotein translocation channel of the outer membrane of mitochondria.the protein translocase of the outer mitochondrial membrane (tom) serves as the main entry site for virtually all mitochondrial proteins. like many other protein translocases it also has an ion channel activity that can be used to study the dynamical properties of this supramolecular complex. we have purified tom core complex and tom40, the main pore forming subunit, from mitochondria of the filamentous fungus neurospora crassa and incorporated them into planar lipid bilayers. we then examined t ...200818456827
the genome sequence of the model ascomycete fungus podospora anserina.the dung-inhabiting ascomycete fungus podospora anserina is a model used to study various aspects of eukaryotic and fungal biology, such as ageing, prions and sexual development.200818460219
structural insights into biosynthesis of resorcinolic lipids by a type iii polyketide synthase in neurospora crassa.microbial type iii polyketide synthases (pkss) have revealed remarkable mechanistic as well as functional versatility. recently, a type iii pks homolog from azotobacter has been implicated in the biosynthesis of resorcinolic lipids, thus adding a new functional significance to this class of proteins. here, we report the structural and mutational investigations of a novel type iii pks protein from neurospora crassa involved in the biosynthesis of resorcinolic metabolites by utilizing long chain f ...200818462950
the nuclear dbf2-related kinase cot1 and the mitogen-activated protein kinases mak1 and mak2 genetically interact to regulate filamentous growth, hyphal fusion and sexual development in neurospora crassa.ndr kinases, such as neurospora crassa cot1, are important for cell differentiation and polar morphogenesis, yet their input signals as well as their integration into a cellular signaling context are still elusive. here, we identify the cot-1 suppressor gul-4 as mak-2 and show that mutants of the gul-4/mak-2 mitogen-activated protein (map) kinase pathway suppress cot-1 phenotypes along with a concomitant reduction in protein kinase a (pka) activity. furthermore, mak-2 pathway defects are partial ...200818562669
nadph oxidases nox-1 and nox-2 require the regulatory subunit nor-1 to control cell differentiation and growth in neurospora crassa.we have proposed that reactive oxygen species (ros) play essential roles in cell differentiation. enzymes belonging to the nadph oxidase (nox) family produce superoxide in a regulated manner. we have identified three distinct nox subfamilies in the fungal kingdom and have shown that noxa is required for sexual cell differentiation in aspergillus nidulans. here we show that neurospora crassa nox-1 elimination results in complete female sterility, decreased asexual development, and reduction of hy ...200818567788
multiple gene disruptions by marker recycling with highly efficient gene-targeting background (deltaligd) in aspergillus oryzae.previously we reported that double disruption of the proteinase genes (tppa and pepe) improved heterologous protein production by aspergillus oryzae (jin et al. appl microbiol biotechnol 76:1059-1068, 2007). since a. oryzae has 134 protease genes, the number of auxotrophy in a single host is limited for multiple disruptions of many protease genes. in order to rapidly perform multiple gene disruptions in a. oryzae, we generated the marker recycling system in highly efficient gene-targeting backgr ...200818574559
a cytosine methyltransferase homologue is essential for sexual development in aspergillus nidulans.the genome defense processes rip (repeat-induced point mutation) in the filamentous fungus neurospora crassa, and mip (methylation induced premeiotically) in the fungus ascobolus immersus depend on proteins with dna methyltransferase (dmt) domains. nevertheless, these proteins, rid and masc1, respectively, have not been demonstrated to have dmt activity. we discovered a close homologue in aspergillus nidulans, a fungus thought to have no methylation and no genome defense system comparable to rip ...200818575630
the fate of gene duplicates in the genomes of fungal pathogens.understanding how molecular changes underlie phenotypic variation within and between species is one of the main goals of evolutionary biology and comparative genetics. the recent proliferation of sequenced fungal genomes offers a unique opportunity to start elucidating the extreme phenotypic diversity in the kingdom fungi.1-4 we attempted to investigate the contribution of gene families to the evolutionary forces shaping the diversity of pathogenic lifestyles among the fungi.5 we studied a famil ...200819513258
kinetic model of the effects of electrogenic enzymes on the membrane potential.electrogenic enzymes contribute to the electrical field existing across biological membranes by using a source of free energy to generate an ionic current. the model introduced here permits one to evaluate this contribution. since the model incorporates the electrogenic enzyme in the form of a sequential kinetic diagram, it permits one to study the kinetic effects of the concentration of the enzyme, the substrates and the different ligands on the membrane potential. ionic electrodiffusion is exp ...20082593671
glutamine assimilation pathways in neurospora crassa growing on glutamine as sole nitrogen and carbon source.neurospora crassa wild-type is almost unable to grow on glutamine as sole nitrogen and carbon source but a gdh-; gs +/- double mutant strain, lacking nadp-dependent glutamate dehydrogenase and partially lacking glutamine synthetase did grow. under these conditions, the double mutant had a higher chemical energy content than the wild-type. enzyme assays and labelling experiments with glutamine indicated that in the double mutant glutamine was degraded to ammonium and to carbon skeletons by glutam ...20082576659
inducible responses to dna damaging or stress inducing agents in neurospora crassa.two-dimensional polyacrylamide gel electrophoresis has been used to analyze proteins from wild type and mutagen sensitive mutants of neurospora crassa under constitutive conditions and after treatment with mutagens and other stress inducing agents. several proteins have been detected that are either induced or show changes in electrophoretic mobility in response to uv irradiation, 4-nqo, x-ray, paraquat and heat shock. ten proteins were found to respond to more than one of the stress inducing ag ...20082525961
a natural case of rip: degeneration of the dna sequence in an ancestral tandem duplication.5s rrna genes of neurospora crassa are generally dispersed in the genome and are unmethylated. the xi-eta region of oak ridge strains represents an informative exception. most of the cytosines in this region, which consists of a diverged tandem duplication of a 0.8-kilobase-pair segment including a 5s rrna gene, appear to be methylated (e. u. selker and j. n. stevens, proc. natl. acad. sci. usa 82:8114-8118, 1985). previous work demonstrated that the xi-eta region functions as a portable signal ...20082531278
unstable mitochondrial dna in natural-death nuclear mutants of neurospora crassa.the natural-death mutant of neurospora crassa has an accelerated senescence phenotype caused by a recessive mutation, nd, in a nuclear gene that is located in linkage group i. an examination of mitochondrial functions, however, revealed that the mutant has phenotypic and molecular defects similar to those commonly associated with maternally transmitted fungal senescence syndromes, including (i) deficiencies in cytochromes aa3 and b; (ii) a deficit in small subunits of mitochondrial ribosomes, an ...20082531276
the actions of neurospora endo-exonuclease on double strand dnas.neurospora crassa endo-exonuclease, an enzyme implicated in recombinational dna repair, was found previously to have a distributive endonuclease activity with a high specificity for single strand dna and a highly processive exonuclease activity. the activities of endo-exonuclease on double strand dna substrates have been further explored. endo-exonuclease was shown to have a low bona fide endonuclease activity with completely relaxed covalently closed circular dna and made site-specific breaks i ...20082546947
involvement of tyrosyl-trna synthetase in splicing of group i introns in neurospora crassa mitochondria: biochemical and immunochemical analyses of splicing activity.we reported previously that mitochondrial tyrosyl-trna synthetase, which is encoded by the nuclear gene cyt-18 in neurospora crassa, functions in splicing several group i introns in n. crassa mitochondria (r. a. akins and a. m. lambowitz, cell 50:331-345, 1987). two mutants in the cyt-18 gene (cyt-18-1 and cyt-18-2) are defective in both mitochondrial protein synthesis and splicing, and an activity that splices the mitochondrial large rrna intron copurifies with a component of mitochondrial tyro ...20082526294
regulation of fructose 2,6-bisphosphate levels in neurospora crassa.both wild type and cr-1 mutant (adenylate cyclase and cyclic amp-deficient) strains of neurospora crassa contain fructose 2,6-bisphosphate at levels of 27 nmol/g dry tissue weight. this level decreases by about 50% in both strains upon depriving the cells of carbon or nitrogen sources for 3 h. an increase in cyclic amp levels produced by addition of lysine to nitrogen-starved cells produced no increase in fructose 2,6-bisphosphate levels. both strains respond to short-term addition of salicylate ...20083040112
ability to grow on lipids accounts for the fully virulent phenotype in neutropenic mice of aspergillus fumigatus null mutants in the key glyoxylate cycle enzymes.incidence and mortality rates of invasive aspergillosis clearly indicate the need of novel antifungals to treat patients suffering from this disease. fungal proteins playing a crucial role in pathogenesis and with no orthologue in human cells are considered as primary therapeutic targets for the development of new antifungals with a high therapeutic index, one of the major drawbacks of the standard antifungal therapy, so far. in this work, we have analyzed the role in pathogenesis of the key enz ...200817616408
neurospora crassa ve-1 affects asexual conidiation.the velvet factor of the homothallic fungus aspergillus nidulans promotes sexual fruiting body formation. the encoding vea gene is conserved among fungi, including the ascomycete neurospora crassa. there, the orthologous ve-1 gene encodes a deduced protein with high similarity to a. nidulans vea. cross-complementation experiments suggest that both the promoter and the coding sequence of n. crassa ve-1 are functional to complement the phenotype of an a. nidulans deletion mutant. moreover, ve-1 ex ...200817631397
fungal multienzyme production on industrial by-products of the citrus-processing industry.orange peels is the principal solid by-product of the citrus processing industry and the disposal of the fresh peels is becoming a major problem to many factories. dry citrus peels are rich in pectin, cellulose and hemicellulose and may be used as a fermentation substrate. production of multienzyme preparations containing pectinolytic, cellulolytic and xylanolytic enzymes by the mesophilic fungi aspergillus niger btl, fusarium oxysporum f3, neurospora crassa dsm 1129 and penicillium decumbens un ...200817604624
meiosis and ascospore development in cochliobolus heterostrophus.cochliobolus heterostrophus produces eight filiform ascospores per ascus, following meiosis and a postmeiotic mitosis. early ascus development and nuclear divisions in c. heterostrophus resemble those of the prototypic pyrenomycete neurospora crassa. however, the two fungi differ in several important details owing to differences in ascus and ascospore shape, spindle pole body (spb) behavior during spore delimitation, and ascospore development. in c. heterostrophus, the two spindles at meiosis ii ...200817931917
the neurospora crassa uvs-3 epistasis group encodes homologues of the atr/atrip checkpoint control system.the mutagen sensitive uvs-3 and mus-9 mutants of neurospora show mutagen and hydroxyurea sensitivity, mutator effects and duplication instability typical of recombination repair and dna damage checkpoint defective mutants. to determine the nature of these genes we used cosmids from a genomic library to clone the uvs-3 gene by complementation for mms sensitivity. mutation induction by transposon insertion and rip defined the coding sequence. rflp analysis confirmed that this sequence maps in the ...200817983847
evidence for the absence of meiotic silencing by unpaired dna in neurospora tetrasperma.meiotic silencing by unpaired dna is a posttranscriptional gene silencing process in neurospora crassa. any gene without a homolog in the same chromosomal position during meiotic prophase generates a sequence-specific signal that prevents expression of all copies of that gene, but only during meiosis. meiotic silencing is epigenetic and involves components of a meiosis-specific rna silencing machinery. although n. tetrasperma is closely related to n. crassa, its sexual biology is significantly d ...200818023372
vegetative hyphal fusion is not essential for plant infection by fusarium oxysporum.vegetative hyphal fusion (vhf) is a ubiquitous phenomenon in filamentous fungi whose biological role is poorly understood. in neurospora crassa, the mitogen-activated protein kinase (mapk) mak-2 and the ww domain protein so are required for efficient vhf. a mapk orthologous to mak-2, fmk1, was previously shown to be essential for root penetration and pathogenicity of the vascular wilt fungus fusarium oxysporum. here we took a genetic approach to test two hypotheses, that (i) vhf and plant infect ...200818039941
alternative modes of binding by u2af65 at the polypyrimidine tract.during initial recognition of an intron in pre-mrna, the 3' end of the intron is bound by essential splicing factors. notably, the consensus rna sequences bound by these proteins are highly degenerate in humans. this raises the question of 3' splicing factor function in introns lacking canonical binding sites. investigating the introns of the model organism neurospora crassa revealed a different organization at the 3' end of the intron compared to most eukaryotic organisms. the predicted branch ...200818067274
function of the c-terminal domain of the dead-box protein mss116p analyzed in vivo and in vitro.the dead-box proteins cyt-19 in neurospora crassa and mss116p in saccharomyces cerevisiae are general rna chaperones that function in splicing mitochondrial group i and group ii introns and in translational activation. both proteins consist of a conserved atp-dependent rna helicase core region linked to n and c-terminal domains, the latter with a basic tail similar to many other dead-box proteins. in cyt-19, this basic tail was shown to contribute to non-specific rna binding that helps tether th ...200818096186
large-scale expressed sequence tag analysis for the chestnut blight fungus cryphonectria parasitica.cryphonectria parasitica is the causal fungal agent responsible for the chestnut blight disease. we report the generation of 14,263 expressed sequence tags representing 6318 unisequences for the fungus. functional annotation of these unisequences revealed different gene expression patterns for wild-type and hypovirus-infected cultures at the sporulation stage and allowed the reconstruction of key c. parasitica signal transduction pathways conserved in the sorbidaryomycetes. a list of homologous ...200818166491
structure of a tyrosyl-trna synthetase splicing factor bound to a group i intron rna.the 'rna world' hypothesis holds that during evolution the structural and enzymatic functions initially served by rna were assumed by proteins, leading to the latter's domination of biological catalysis. this progression can still be seen in modern biology, where ribozymes, such as the ribosome and rnase p, have evolved into protein-dependent rna catalysts ('rnpzymes'). similarly, group i introns use rna-catalysed splicing reactions, but many function as rnpzymes bound to proteins that stabilize ...200818172503
cloning and characterization of the blr2, the homologue of the blue-light regulator of neurospora crassa wc-2, in the phytopathogenic fungus bipolaris oryzae.bipolaris oryzae is a filamentous ascomycetous fungus that causes brown leaf spot disease in rice. we isolated and characterized blr2, a gene that encodes a putative blue-light regulator similar to neurospora crassa white collar-2 (wc-2). the deduced amino acid sequence of the blr2 showed significant homology to other fungal blue-light regulator proteins in the per-arnt-sim (pas) protein-protein interaction domain, nuclear localization signal, and gata zinc finger dna-binding domains. the blr2-s ...200818172720
functional characterization of fusarium verticillioides cpp1, a gene encoding a putative protein phosphatase 2a catalytic subunit.fusarium verticillioides produces the mycotoxin fumonisin b(1) (fb(1)) on maize kernels. in this study, we identified a putative protein phosphatase gene cpp1 in f. verticillioides, and investigated its role in fb(1) regulation. previous work has shown that cpp1 expression is elevated in an fb(1)-suppressing genetic background. thus, we hypothesized that cpp1 is negatively associated with fb(1) production. to test this hypothesis, we generated a cpp1 knockout mutant, pp179, and studied the effec ...200818174151
hydrolysis and fermentation of brewer's spent grain by neurospora crassa.in this study, the ethanol production by the mesophilic fungus neurospora crassa from bg was studied and optimized concerning the induction of lignocellulose degrading enzymes and the production phase as well. the production of cellulolytic and hemicellulolytic enzymes was studied under solid-state cultivation (ssc). ssc in a laboratory horizontal bioreactor using the optimized medium, ws and bg in the ratio 1:1 and initial moisture level 61.5%, allowed the large scale production of the multienz ...200818178432
protein kinases fpk1p and fpk2p are novel regulators of phospholipid asymmetry.type 4 p-type atpases (flippases) are implicated in the generation of phospholipid asymmetry in membranes by the inward translocation of phospholipids. in budding yeast, the drs2/dnf family members lem3p-dnf1p/dnf2p and cdc50p-drs2p are putative flippases that are localized, respectively, to the plasma membrane and endosomal/trans-golgi network (tgn) compartments. herein, we identified a protein kinase gene, fpk1, as a mutation that exhibited synthetic lethality with the cdc50delta mutation. the ...200818199685
the white collar protein wcoa of fusarium fujikuroi is not essential for photocarotenogenesis, but is involved in the regulation of secondary metabolism and conidiation.the fungal proteins of the white collar photoreceptor family, represented by wc-1 from neurospora crassa, mediate the control by light of different biochemical and developmental processes, such as carotenogenesis or sporulation. carotenoid biosynthesis is induced by light in the gibberellin-producing fungus fusarium fujikuroi. in an attempt to identify the photoreceptor for this response, we cloned the only wc-1-like gene present in the available fusarium genomes, that we called wcoa. the predic ...200818203635
characterization of mutations in alhk1 gene from alternaria longipes: implication of limited function of two-component histidine kinase on conferring dicarboximide resistance.four series (s, m, r, and w) of alternaria longipes isolates were obtained based on consecutive induction with dimethachlon (dim) and ultraviolet irradiation. these isolates were then characterized according to their tolerance to dim, sensitivity to osmotic stress, and phenotypic properties. all the induced dim-resistant isolates showed a higher osmosensitivity than the parental strains, and the last generation was more resistant than the first generation in the m, r, and w series. in addition, ...200818239410
bioelectrorheological model of the cell. 8. cellular deformation under prolonged and recurrent shear stress.the influence of a prolonged and recurrent shear stress created by a periodic electric field on the mechanical properties of neurospora crassa cells was investigated. conditions were found under which modifications of cellular structures responding to stress become irreversible, and plastic flow of the viscoelastic structural elements is observed. the symmetry of the response of the cell under stress application and relaxation was lost, when compared to the reference conditions. to interpret the ...200810474657
carbon source affects pka-dependent polarity of neurospora crassa in a cre-1-dependent and independent manner.a defect in mcb, encoding the camp-dependent protein kinase a (pka) regulatory subunit in neurospora crassa, which confers an apolar growth phenotype, is accompanied by an increase in pka activity levels. both pka and cre-1 [a key carbon catabolite repression (ccr) regulator] mediate the cellular response to carbon-source availability. inactivation of the cre-1 gene resulted in reduced growth rate, abnormal hyphal morphology and altered ccr. both pka and cre-1 affected morphology in a carbon-dep ...200817625933
genetic analysis of chk1 and chk2 homologues revealed a unique cross talk between atm and atr pathways in neurospora crassa.dna damage checkpoint is an important mechanism for organisms to maintain genome integrity. in neurospora crassa, mus-9 and mus-21 are homologues of atr and atm, respectively, which are pivotal factors of dna damage checkpoint in mammals. a n. crassa clock gene prd-4 has been identified as a chk2 homologue, but its role in dna damage response had not been elucidated. in this study, we identified another chk2 homologue and one chk1 homologue from the n. crassa genome database. as disruption of th ...200818790091
systems biology of the clock in neurospora crassa.a model-driven discovery process, computing life, is used to identify an ensemble of genetic networks that describe the biological clock. a clock mechanism involving the genes white-collar-1 and white-collar-2 (wc-1 and wc-2) that encode a transcriptional activator (as well as a blue-light receptor) and an oscillator frequency (frq) that encodes a cyclin that deactivates the activator is used to guide this discovery process through three cycles of microarray experiments. central to this discover ...200818769678
toward predicting self-splicing and protein-facilitated splicing of group i introns.in the current era of massive discoveries of noncoding rnas within genomes, being able to infer a function from a nucleotide sequence is of paramount interest. although studies of individual group i introns have identified self-splicing and nonself-splicing examples, there is no overall understanding of the prevalence of self-splicing or the factors that determine it among the >2300 group i introns sequenced to date. here, the self-splicing activities of 12 group i introns from various organisms ...200818768647
a connection between mapk pathways and circadian clocks.circadian clocks and mitogen-activated protein kinase (mapk) signaling pathways are fundamental features of eukaryotic cells. both pathways provide mechanisms for cells to respond to environmental stimuli, and links between them are known. we recently reported that the circadian clock in neurospora crassa regulates daily rhythms in accumulation of phosphorylated, and thus active, os-2 mapk, a relative of mammalian p38 mapk, when cells are grown in constant conditions. in the absence of acute str ...200818728391
the rho1-specific gtpase-activating protein lrg1 regulates polar tip growth in parallel to ndr kinase signaling in neurospora.regulation of rho gtpase signaling is critical for cell shape determination and polarity. here, we investigated the role of lrg1, a novel member of the gtpase-activating proteins (gaps) of neurospora crassa. lrg1 is essential for apical tip extension and to restrict excessive branch formation in subapical regions of the hypha and is involved in determining the size of the hyphal compartments. lrg1 localizes to hyphal tips and sites of septation via its three lim domains. the accumulation of lrg1 ...200818716060
the cys3-cys4 loop of the hydrophobin eas is not required for rodlet formation and surface activity.class i hydrophobins are fungal proteins that self-assemble into robust amphipathic rodlet monolayers on the surface of aerial structures such as spores and fruiting bodies. these layers share many structural characteristics with amyloid fibrils and belong to the growing family of functional amyloid-like materials produced by microorganisms. although the three-dimensional structure of the soluble monomeric form of a class i hydrophobin has been determined, little is known about the molecular str ...200818674544
differential potency of drosomycin to neurospora crassa and its mutant: implications for evolutionary relationship between defensins from insects and plants.drosomycin, the first inducible antifungal peptide isolated from drosophila, belongs to the superfamily of csalphabeta-type defensins. in the present study we report a modified approach for high-level expression of drosomycin, which allows us to evaluate its differential potency on the filamentous fungus neurospora crassa wt (wild type) and n. crassa mut16, a specific resistance mutant strain to plant defensins, by using different approaches. the results presented here show for the first time th ...200818651922
neurospora crassa heat shock factor 1 is an essential gene; a second heat shock factor-like gene, hsf2, is required for asexual spore formation.appropriate responses of organisms to heat stress are essential for their survival. in eukaryotes, adaptation to high temperatures is mediated by heat shock transcription factors (hsfs). hsfs regulate the expression of heat shock proteins, which function as molecular chaperones assisting in protein folding and stability. in many model organisms a great deal is known about the products of hsf genes. an important exception is the filamentous fungus and model eukaryote neurospora crassa. here we sh ...200818586951
dna-binding specificity of the cys3 transcription factor of neurospora crassa defined by binding-site selection.the cys3 transcription factor is a basic region-leucine zipper (bzip) dna-binding protein that is essential for the expression of a coordinately regulated group of genes involved in the acquisition and utilization of sulfur in neurospora crassa. an approach of using binding-site selection from random-sequence oligonucleotides was used to define cys3-binding specificity. the derived consensus-binding site of atggcgccat defines a symmetrical sequence (half-site a t g/t g/a c/t) that resembles that ...200818565773
osrecq1, a qde-3 homologue in rice, is required for rna silencing induced by particle bombardment for inverted repeat dna, but not for double-stranded rna.based on the nucleotide sequence of qde-3 in neurospora crassa, which is involved in rna silencing, rice (oryza sativa) mutant lines disrupted by the insertion of the rice retrotransposon tos17 were selected. homozygous individuals from the m(1) and m(2) generations were screened and used for further analyses. the expression of the gene was not detected in leaves or calli of the mutant lines, in contrast to the wild type (wt). induction of rna silencing by particle bombardment was performed to i ...200818564381
[stress factor-induced changes in the activity of antioxidant protective mechanisms in the wild type strain of neurospora crassa and in its photoreceptor complex mutants].the effect of stress factors (changes in oxygen content, temperature, and illumination) on superoxide dismutase (sod) and catalase activity, as well as on the content of thiol and disulfide groups in low-molecular-weight compounds and proteins of neurospora crassa mycelium was studied in the wild type strain and white collar-1 (wc-1) and white collar-2 (wc-2) mutants. environmental stress factors induced the activation of both sod and catalase, as well as an increase in the thiol level in the wi ...200818522316
increased resistance of complex i mutants to phytosphingosine-induced programmed cell death.we have studied the effects of phytosphingosine (phs) on cells of the filamentous fungus neurospora crassa. highly reduced viability, impairment of asexual spore germination, dna condensation and fragmentation, and production of reactive oxygen species were observed in conidia treated with the drug, suggesting that phs induces an apoptosis-like death in this fungus. interestingly, we found that complex i mutants are more resistant to phs treatment than the wild type strain. this effect appears t ...200818474589
a systematic approach to identify stre-binding proteins of the gsn glycogen synthase gene promoter in neurospora crassa.the gene encoding glycogen synthase in neurospora crassa (gsn) is transcriptionally down-regulated when mycelium is exposed to a heat shock from 30 to 45 degrees c. the gsn promoter has one stress response element (stre) motif that is specifically bound by heat shock activated nuclear proteins. in this work, we used biochemical approaches together with mass spectrometric analysis to identify the proteins that bind to the stre motif and could participate in the gsn transcription regulation during ...200818425733
effects of oxygen limitation on xylose fermentation, intracellular metabolites, and key enzymes of neurospora crassa as3.1602.the effects of oxygen limitation on xylose fermentation of neurospora crassa as3.1602 were studied using batch cultures. the maximum yield of ethanol was 0.34 g/g at oxygen transfer rate (otr) of 8.4 mmol/l.h. the maximum yield of xylitol was 0.33 g/g at otr of 5.1 mmol/l.h. oxygen limitation greatly affected mycelia growth and xylitol and ethanol productions. the specific growth rate (micro) decreased 82% from 0.045 to 0.008 h(-1) when otr changed from 12.6 to 8.4 mmol/l.h. intracellular metabo ...200818425610
the evolutionarily conserved family of cyanovirin-n homologs: structures and carbohydrate specificity.solution structures for three members of the recently discovered cyanovirin-n (cv-n) homolog family of lectins have been determined. cyanovirin-n homologs (cvnhs) from tuber borchii, ceratopteris richardii, and neurospora crassa, representing each of the three phylogenetic groups, were selected. all proteins exhibit the same fold, and the overall structures resemble that of the founding member of the family, cv-n, albeit with noteworthy differences in loop conformation and detailed local structu ...200818400178
lack of the gtpase rho-4 in neurospora crassa causes a reduction in numbers and aberrant stabilization of microtubules at hyphal tips.the multinucleate hyphae of the filamentous ascomycete fungus neurospora crassa grow by polarized hyphal tip extension. both the actin and microtubule cytoskeleton are required for maximum hyphal extension, in addition to other vital processes. previously, we have shown that the monomeric gtpase encoded by the n. crassa rho-4 locus is required for actin ring formation during the process of septation; rho-4 mutants lack septa. however, other phenotypic aspects of the rho-4 mutant, such as slow gr ...200818387834
likelihood of a particular order of genetic markers and the construction of genetic maps.we model the recombination process of fungal systems via chromatid exchange in meiosis, which accounts for any type of bivalent configuration in a genetic interval in any specified order of genetic markers, for both random spore and tetrad data. first, a probability model framework is developed for two genes and then generalized for an arbitrary number of genes. maximum likelihood estimators (mles) for both random and tetrad data are developed. it is shown that the mle of recombination for tetra ...200818324750
interlocked feedback loops of the circadian clock of neurospora crassa.circadian clocks drive daily rhythms in physiology and behaviour, and thus allow organisms to better adapt to rhythmic changes in the environment. circadian oscillators are cell-autonomous systems, which generate via transcriptional, post-transcriptional, translational and post-translational control mechanisms a daily activity-rhythm of a circadian transcription factor complex. according to recent models, this complex of transcription factors controls directly or indirectly expression of a large ...200818312266
replacement of two invariant serine residues in chorismate synthase provides evidence that a proton relay system is essential for intermediate formation and catalytic activity.chorismate synthase is the last enzyme of the common shikimate pathway, which catalyzes the anti-1,4-elimination of the 3-phosphate group and the c-(6pror) hydrogen from 5-enolpyruvylshikimate 3-phosphate (epsp) to generate chorismate, a precursor for the biosynthesis of aromatic compounds. enzyme activity relies on reduced fmn, which is thought to donate an electron transiently to the substrate, facilitating c(3)-o bond breakage. the crystal structure of the enzyme with bound epsp and the flavi ...200818279385
isoform switching facilitates period control in the neurospora crassa circadian clock.a striking and defining feature of circadian clocks is the small variation in period over a physiological range of temperatures. this is referred to as temperature compensation, although recent work has suggested that the variation observed is a specific, adaptive control of period. moreover, given that many biological rate constants have a q(10) of around 2, it is remarkable that such clocks remain rhythmic under significant temperature changes. we introduce a new mathematical model for the neu ...200818277380
dominant suppression of repeat-induced point mutation in neurospora crassa by a variant catalytic subunit of dna polymerase zeta.crosses involving the adiopodoumé strain of neurospora crassa are defective for repeat-induced point mutation (rip), a genome defense mechanism of fungi. we show here that the adiopodoumé strain possesses an incompletely penetrant and variably expressive dominant suppressor of rip (srp) that maps to an approximately 34-kbp genome segment that is approximately 26 kbp proximal to mat on linkage group il. gene disruption experiments revealed that srp is the upr-1 allele of adiopodoumé (upr-1(ad)) t ...200818245848
isolation and transcript analysis of two-component histidine kinase gene le.nik1 in shiitake mushroom, lentinula edodes.le.nik1, a two-component histidine kinase gene of lentinula edodes, the shiitake mushroom, was identified. the relationship between this two-component signal transduction system and mushroom development was studied. we used a modified rna arbitrarily-primed pcr (rap-pcr) method to isolate le.nik1 as a differentially expressed gene during l. edodes development. we determined the 6.29kb full-length cdna sequence of le.nik1. it had high sequence homology to neurospora crassa nik1, which encoded a h ...200818234485
making two organelles from one: woronin body biogenesis by peroxisomal protein sorting.woronin bodies (wbs) are dense-core organelles that are found exclusively in filamentous fungi and that seal the septal pore in response to wounding. these organelles consist of a membrane-bound protein matrix comprised of the hex protein and, although they form from peroxisomes, their biogenesis is poorly understood. in neurospora crassa, we identify woronin sorting complex (wsc), a pmp22/mpv17-related membrane protein with dual functions in wb biogenesis. wsc localizes to large peroxisome memb ...200818227279
simple sequence repeats in neurospora crassa: distribution, polymorphism and evolutionary inference.simple sequence repeats (ssrs) have been successfully used for various genetic and evolutionary studies in eukaryotic systems. the eukaryotic model organism neurospora crassa is an excellent system to study evolution and biological function of ssrs.200818215294
x-ray structure and microtubule interaction of the motor domain of neurospora crassa nckin3, a kinesin with unusual processivity.neurospora crassa kinesin nckin3 belongs to a unique fungal-specific subgroup of small kinesin-3-related motor proteins. one of its functions appears to be the transport of mitochondria along microtubules. here, we present the x-ray structure of a c-terminally truncated monomeric construct of nckin3 comprising the motor domain and the neck linker, and a 3-d image reconstruction of this motor domain bound to microtubules, by cryoelectron microscopy. the protein contains mg.adp bound to the active ...200818205396
characterization of interactions between and among components of the meiotic silencing by unpaired dna machinery in neurospora crassa using bimolecular fluorescence complementation.bimolecular fluorescence complementation (bifc) is based on the complementation between two nonfluorescent fragments of the yellow fluorescent protein (yfp) when they are united by interactions between proteins covalently linked to them. we have successfully applied bifc in neurospora crassa using two genes involved in meiotic silencing by unpaired dna (msud) and observed macromolecular complex formation involving only sad-1 proteins, only sad-2 proteins, and mixtures of sad-1 and sad-2 proteins ...200818202398
a genetic selection for neurospora crassa mutants altered in their light regulation of transcription.transcription of the neurospora crassa gene con-10 is induced during conidiation and following exposure of vegetative mycelia to light, but light activation is transient due to photoadaptation. we describe mutational analyses of photoadaptation using a n. crassa strain bearing a translational fusion of con-10, including its regulatory region, to a selectable bacterial gene conferring hygromycin resistance (hph). growth of this strain was sensitive to hygromycin, upon continuous culture in the li ...200818202366
conidiation rhythm and light entrainment in superoxide dismutase mutant in neurospora crassa.conidial formation in the filamentous fungus neurospora crassa is regulated by nutritional conditions, light, and the circadian clock. we found that a sod-1 mutant, with a defective superoxide dismutase catalyzing the conversion of superoxide to hydrogen peroxide, had a slightly shorter period length than the wild type and clear conidial banding similar to a mutant of band (bd). however, unlike the bd mutant, the sod-1 mutant could sustain conidial banding with light pulses on a nutrient-rich me ...200818084778
identification of all fk506-binding proteins from neurospora crassa.immunophilins are intracellular receptors of immunosuppressive drugs, carrying peptidyl-prolyl cis-trans isomerase activity, with a general role in protein folding but also involved in specific regulatory mechanisms. four immunophilins of the fkbp-type (fk506-binding proteins) were identified in the genome of neurospora crassa. previously, fkbp22 has been located in the endoplasmic reticulum as part of chaperone/folding complexes and fkbp13 has been found to have a dual location in the cytoplasm ...200818948221
rapid snp discovery and genetic mapping using sequenced rad markers.single nucleotide polymorphism (snp) discovery and genotyping are essential to genetic mapping. there remains a need for a simple, inexpensive platform that allows high-density snp discovery and genotyping in large populations. here we describe the sequencing of restriction-site associated dna (rad) tags, which identified more than 13,000 snps, and mapped three traits in two model organisms, using less than half the capacity of one illumina sequencing run. we demonstrated that different marker d ...200818852878
synchronization of the fungal and the plant circadian clock by light.circadian clocks are endogenous time keeping devices that provide temporal control of physiology in accordance with predicted daily changes in the environment. photoentrainment is the process that synchronizes circadian clocks-and thereby clock-controlled gene expression and physiology-to the environmental day/night cycles. light is primarily detected by specialized photoreceptors that are coupled--directly or through other signaling components--to the rhythm-generating oscillator. as a conseque ...200818850603
microtubule dynamics and the role of molecular motors in neurospora crassa.live-cell imaging methods were used to study microtubule dynamics in the apical regions of leading hyphae and germ tubes of neurospora crassa expressing beta-tubulin-gfp. microtubule polymerization rates in hyphae of n. crassa were much faster than those previously reported in any other eukaryotic organism. in order to address the roles of motor proteins in microtubule dynamic instability in n. crassa, the microtubule-motor mutant strains, deltankin and ro-1, were examined. polymerization and de ...200818069024
the rna-dependent rna polymerase essential for post-transcriptional gene silencing in neurospora crassa interacts with replication protein a.post-transcriptional gene silencing (ptgs) pathways play a role in genome defence and have been extensively studied, yet how repetitive elements in the genome are identified is still unclear. it has been suggested that they may produce aberrant transcripts (arna) that are converted by an rna-dependent rna polymerase (rdrp) into double-stranded rna (dsrna), the essential intermediate of ptgs. however, how rdrp enzymes recognize aberrant transcripts remains a key question. here we show that in neu ...200818048414
titration of repeat-induced point mutation (rip) by chromosome segment duplications in neurospora crassa.repeat-induced point mutation (rip) is a hypermutational process that alters duplicated dna sequences in neurospora crassa. in previous studies, five of six large ( > 100 kb) chromosome segment duplications (dp's) examined were shown to dominantly suppress rip in smaller (< 5 kb) duplications. the suppressor duplications were > 270 kb, whereas the lone non-suppressor duplication was approximately 117 kb. we have now screened another 33 duplications and found 29 more suppressors and four more non ...200818046508
the evolution of the pheromonal signal system and its potential role for reproductive isolation in heterothallic neurospora.comparative sequencing studies among a wide range of taxonomic groups, including fungi, provide the overall pattern that reproductive genes evolve more rapidly than other genes, and this divergence is believed to be important in the establishment of reproductive barriers between species. in this study, we investigated the molecular evolution of the pheromone receptor genes pre-1 and pre-2 of strains belonging to 12 and 13 heterothallic taxa, respectively, of the model genus neurospora. furthermo ...200818024989
metabolism of androst-4-en-3,17-dione by the filamentous fungus neurospora crassa.microbial transformation of androst-4-en-3,17-dione (ad; i) using neurospora crassa afforded six metabolites; 6beta,14alpha-dihydroxyandrost-4-en-3,17-dione (ii), 6beta,9alpha-dihydroxyandrost-4-en-3,17-dione (iii), 7alpha-hydroxyandrost-4-en-3,17-dione (iv), 9alpha-hydroxyandrost-4-en-3,17-dione (v), 14alpha-hydroxyandrost-4-en-3,17-dione (vi), and androst-4,6-dien-3,17-dione (vii). the steroid products were assigned by interpretation of their spectral data such as (1)h nmr, (13)c nmr, ftir, an ...200817981313
simulating dark expressions and interactions of frq and wc-1 in the neurospora circadian clock.circadian rhythms are considered to play an essential part in the adaptation of organisms to their environments. the occurrence of circadian oscillations appears to be based on the presence of transcriptional-translational negative feedback loops. in neurospora crassa, the protein frequency (frq) is part of such a negative feedback loop apparently by a direct interaction with its transcription factor white collar-1 (wc-1). based on the observation that nuclear frq levels are significantly lower ...200817965132
fully codon-optimized luciferase uncovers novel temperature characteristics of the neurospora clock.we report the complete reconstruction of the firefly luciferase gene, fully codon optimized for expression in neurospora crassa. this reporter enhances light output by approximately 4 log orders over that with previously available versions, now producing light that is visible to the naked eye and sufficient for monitoring the activities of many poorly expressed genes. time lapse photography of strains growing in race tubes, in which the frq or eas/ccg-2 promoter is used to drive luciferase, show ...200817766461
protein phosphatase pp1 is required for normal dna methylation in neurospora.covalent modifications of histones integrate intracellular and extracellular cues to regulate the genome. h3 lys 9 methylation (h3k9me) can direct heterochromatin formation and dna methylation, while phosphorylation of h3 ser 10 (h3s10p) drives gene activation and chromosome condensation. to examine the relationship between h3s10p, h3k9me, and dna methylation in neurospora crassa, we built and tested mutants of the putative h3s10 phosphatase, pp1. a pp1-impaired mutant showed increased h3s10p an ...200819141471
the influence of sterols on the conformation of recombinant mitochondrial porin in detergent.mitochondrial porins (voltage-dependent anion-selective channels, vdac) are key contributors to cellular metabolism. when isolated from mitochondria porins copurify with sterols, and some isolated forms of the protein require sterol for insertion into artificial membranes. nonetheless, the contributions of sterols to the folded state of mitochondrial porin are not understood. recently, with the goal of high-resolution structural studies, several laboratories have developed methods for folding re ...200819088801
the fungus neurospora crassa displays telomeric silencing mediated by multiple sirtuins and by methylation of histone h3 lysine 9.silencing of genes inserted near telomeres provides a model to investigate the function of heterochromatin. we initiated a study of telomeric silencing in neurospora crassa, a fungus that sports dna methylation, unlike most other organisms in which telomeric silencing has been characterized.200819014414
c(35)-apocarotenoids in the yellow mutant neurospora crassa ylo.the neurospora crassa mutant ylo exhibits a yellow phenotype instead of the red-orange pigmentation of the wild type. recently, it was shown that the mutant ylo is defective in a specific aldehyde dehydrogenase which catalyses the last step of carotenogenesis to the formation of neurosporaxanthin [estrada, a.f., youssar, l., scherzinger, d., al-babili, s., avalos, j., 2008. the ylo-1 gene encodes an aldehyde dehydrogenase responsible for the last reaction in the neurospora carotenoid pathway. mo ...200819007949
closing the circadian negative feedback loop: frq-dependent clearance of wc-1 from the nucleus.in neurospora crassa, a transcription factor, wcc, activates the transcription of frq. frq forms homodimers as well as complexes with an rna helicase, frh, and the wcc, and translocates into the nucleus to inactivate the wcc, closing the time-delayed negative feedback loop. the detailed mechanism for closing this loop, however, remains incompletely understood. in particular within the nucleus, the low amount of frq compared with that of wc-1 creates a conundrum: how can the nuclear frq inactivat ...200818997062
cell fusion in the filamentous fungus, neurospora crassa.hyphal fusion occurs at different stages in the vegetative and sexual life cycle of filamentous fungi. similar to cell fusion in other organisms, the process of hyphal fusion requires cell recognition, adhesion, and membrane merger. analysis of the hyphal fusion process in the model organism neurospora crassa using fluorescence and live cell imaging as well as cell and molecular biological techniques has begun to reveal its complex cellular regulation. several genes required for hyphal fusion ha ...200818979236
[cloning and bioinformatic analysis of calcineurin b gene in setosphaeria turcica].to clone and identify cnb gene from setosphaeria turcica and to perform the primary bioinformatic analysis.200819062640
molecular analysis of the laccase gene from the chestnut blight fungus and selective suppression of its expression in an isogenic hypovirulent strain.the gene encoding laccase in the chestnut blight fungus, cryphonectria parasitica, has been cloned and characterized. the predicted c. parasitica laccase amino acid sequence (591 aa) was 57% identical to the neurospora crassa laccase sequence and contained four potential copper-binding regions that are conserved in a number of copper-binding proteins. treatment of a virulent c. parasitica strain with 3 microm cycloheximide resulted in a marked increase in laccase mrna accumulation, whereas ident ...20081535523
ageing of neurospora crassa. i. evidence for the free radical theory of ageing from studies of a natural-death mutant.a recessive mutant of neurospora crassa, called natural-death, is characterized by a decreasing clonal growth potential under all nutritional conditions and the irreversible cessation of growth. the primary molecular defect of this mutant is not known. evidence presented here, based upon measurements of the activities and thermolabilities of several enzymes, suggests that faulty protein synthesis is probably not a cause of the senescence and death of the mutant, as suggested by lewis and hollida ...2008132583
preparation of functional group analogs of unsaturated fatty acids and their effects on the circadian rhythm of a fatty-acid-deficient mutant of neurospora crassa.functional group analogs of oleic, linoleic and linolenic acids were prepared by coverting their double bonds to dibromo, cyclopropyl, epoxy, methoxy, and, in the case of oleic acid, hydroxy groups. these compounds were supplemented to the bd csp cel strain of the mold neurospora crassa. the cel mutation confers a partial requirement for saturated fatty acids and, also, perturbs the circadian rhythm of spore formation. for example, the period of bd csp cel's rhythm is dramatically lengthened upo ...20082931204
dominance and complementation relationships of conidial longevity mutants of neurospora crassa.previously we reported the occurrence of 16 linked conidial longevity determinant genes in neurospora. mutations of those genes are characterized by a reduction of longevity, a pleiotropic morphological defect, and deficiency of five antioxygenic enzymes. on the basis of the linkage and biochemical data, it was proposed that the genes are spatially and functionally redundant. the results of the present investigation support the hypothesis of functional redundancy. all of the mutants examined wer ...20076233463
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