Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| the nada gene of aspergillus nidulans, encoding adenine deaminase, is subject to a unique regulatory pattern. | the adenine deaminase of a. nidulans, encoded by nada, can be considered both as a catabolic and a purine salvage enzyme. we show that its transcriptional regulation reflects this double metabolic role. as all other genes involved in purine utilisation it is induced by uric acid, and this induction is mediated by the uay transcription factor. however, it is also independently and synergistically induced by adenosine by a uay-independent mechanism. at variance with all other enzymes of purine cat ... | 2008 | 18055231 |
| functional characterization of the putative aspergillus nidulans dna damage binding protein homologue ddba. | nucleotide excision repair (ner) eliminates helix-distorting dna base lesions. seven xp-deficient genetic complementation groups (xpa to xpg) have already been identified in mammals, and their corresponding genes have been cloned. hereditary defects in ner are associated with several diseases, including xeroderma pigmentosum (xp). uv-ddb (xpe) is formed by two associated subunits, ddb1 and ddb2. uv-ddb was identified biochemically as a protein factor that exhibits very strong and specific bindin ... | 2008 | 18060432 |
| an eleven amino acid residue deletion expands the substrate specificity of acetyl xylan esterase ii (axe ii) from penicillium purpurogenum. | the soft-rot fungus penicillium purpurogenum secretes to the culture medium a variety of enzymes related to xylan biodegradation, among them three acetyl xylan esterases (axe i, ii and iii). axe ii has 207 amino acids; it belongs to family 5 of the carbohydrate esterases and its structure has been determined by x-ray crystallography at 0.9 a resolution (pdb 1g66). the enzyme possesses the alpha/beta hydrolase fold and the catalytic triad typical of serine esterases (ser90, his187 and asp175). ax ... | 2008 | 18060506 |
| crea-mediated repression in aspergillus nidulans does not require transcriptional auto-regulation, regulated intracellular localisation or degradation of crea. | the major regulatory protein in carbon repression in aspergillus nidulans is crea. strains constitutively over-expressing crea show normal responses to carbon repression, indicating that auto-regulation of crea is not essential for crea-mediated regulation. in these strains, high levels of crea are present whether cells are grown in repressing or derepressing conditions, indicating large-scale degradation of crea does not play a key role. crea is located in the nucleus and cytoplasm in cells whe ... | 2008 | 18063396 |
| aspergillus mycoviruses are targets and suppressors of rna silencing. | rna silencing can function as a virus defense mechanism in a diverse range of eukaryotes, and many viruses are capable of suppressing the silencing machinery targeting them. however, the extent to which this occurs between fungal rna silencing and mycoviruses is unclear. here, three aspergillus dsrna mycoviruses were partially characterized, and their relationship to rna silencing was investigated. aspergillus virus 1816 is related to agaricus bisporus white button mushroom virus 1 and suppresse ... | 2008 | 18065651 |
| rna silencing gene truncation in the filamentous fungus aspergillus nidulans. | the genus aspergillus is ideally suited for the investigation of rna silencing evolution because it includes species that have experienced a variety of rna silencing gene changes. our work on this subject begins here with the model species aspergillus nidulans. filamentous ascomycete fungi generally each encode two of the core rna silencing proteins, dicer and argonaute, but a. nidulans appears to have lost one of each to gene truncation events. although a role in growth, development, or rna sil ... | 2008 | 18065653 |
| preferential localization of the endocytic internalization machinery to hyphal tips underlies polarization of the actin cytoskeleton in aspergillus nidulans. | abpa, slab and ampa, three demonstrated components of the endocytic internalization machinery, are strongly polarized in aspergillus nidulans hyphae, forming a ring that embraces the hyphal tip, leaving an area of exclusion at the apex. abpa, a prototypic endocytic internalization marker, localizes to highly motile and transient (average half life, 24 +/- 5 s) peripheral punctate structures overlapping with actin patches, which also predominate in the tip. slab also localizes to peripheral patch ... | 2008 | 18179595 |
| reciprocal oxylipin-mediated cross-talk in the aspergillus-seed pathosystem. | in aspergilli, mycotoxin production and sporulation are governed, in part, by endogenous oxylipins (oxygenated, polyunsaturated fatty acids and metabolites derived therefrom). in aspergillus nidulans, oxylipins are synthesized by the dioxygenase enzymes ppoa, ppob and ppoc. structurally similar oxylipins are synthesized in seeds via the action of lipoxygenase (lox) enzymes. previous reports have shown that exogenous application of seed oxylipins to aspergillus cultures alters sporulation and myc ... | 2008 | 18181962 |
| implication of a regulator of g protein signalling (bbrgs1) in conidiation and conidial thermotolerance of the insect pathogenic fungus beauveria bassiana. | beauveria bassiana is an insect pathogenic fungus widely used as a biocontrol agent to infect and control insect pests. the conidium initiates pathogenesis and mediates disease transmission, however, little is known about genetic elements that control conidiation. here, the cloning and characterization of a regulatory g protein-signalling (rgs) gene bbrgs1 from b. bassiana is reported. phylogenetic analysis showed that bbrgs1 was orthologous to the rgs protein, flba from aspergillus nidulans. th ... | 2008 | 18201190 |
| inhibition of fusarium graminearum growth and development by farnesol. | the isoprenoid farnesol was previously shown to induce morphological features characteristic of apoptosis in the filamentous fungus aspergillus nidulans. this study demonstrates that under similar liquid media growth conditions, farnesol also triggers apoptosis in the plant pathogenic fungus fusarium graminearum. however, unlike a. nidulans, f. graminearum spores treated with farnesol exhibited altered germination patterns and most (>60%) lysed upon prolonged exposure. given the economic importa ... | 2008 | 18201191 |
| the tip growth apparatus of aspergillus nidulans. | hyphal tip growth in fungi is important because of the economic and medical importance of fungi, and because it may be a useful model for polarized growth in other organisms. we have investigated the central questions of the roles of cytoskeletal elements and of the precise sites of exocytosis and endocytosis at the growing hyphal tip by using the model fungus aspergillus nidulans. time-lapse imaging of fluorescent fusion proteins reveals a remarkably dynamic, but highly structured, tip growth a ... | 2008 | 18216285 |
| purification and biochemical characterization of a broad substrate specificity thermostable alkaline protease from aspergillus nidulans. | aspergillus nidulans pw1 produces an extracellular carboxylesterase activity that acts on several lipid esters when cultured in liquid media containing olive oil as a carbon source. the enzyme was purified by gel filtration and ion exchange chromatography. it has an apparent mw and pi of 37 kda and 4.5, respectively. the enzyme efficiently hydrolyzed all assayed glycerides, but showed preference toward short- and medium-length chain fatty acid esters. maximum activity was obtained at ph 8.5 at 4 ... | 2008 | 18224318 |
| identification of biomarkers for genotyping aspergilli using non-linear methods for clustering and classification. | in the present investigation, we have used an exhaustive metabolite profiling approach to search for biomarkers in recombinant aspergillus nidulans (mutants that produce the 6- methyl salicylic acid polyketide molecule) for application in metabolic engineering. | 2008 | 18226195 |
| functional analyses of heterotrimeric g protein g alpha and g beta subunits in gibberella zeae. | the homothallic ascomycete fungus gibberella zeae (anamorph: fusarium graminearum) is a major toxigenic plant pathogen that causes head blight disease on small-grain cereals. the fungus produces the mycotoxins deoxynivalenol (don) and zearalenone (zea) in infected hosts, posing a threat to human and animal health. despite its agricultural and toxicological importance, the molecular mechanisms underlying its growth, development and virulence remain largely unknown. to better understand such mecha ... | 2008 | 18227243 |
| characterisation of aspergillus nidulans polarisome component bema. | bema, the orthologue of saccharomyces cerevisiae bem1p, was identified through genome sequence comparison. we have shown that it plays a similar role to bem1p in yeast, acting as a cell growth protein. deletion of the gene produced a moderately abnormal hyphal tip morphology, and had an extremely detrimental effect on conidiospore production, with development stalling after conidiophore vesicle production. it was also shown that bema is required for vacuole fusion, similar to bem1p. this role is ... | 2008 | 18234530 |
| [ltr retrotransposons from genomes of aspergillus fumigatus and a. nidulans]. | fungi aspergillus spp. are able to infect all tissues and organs and often cause invasive mycosis (aspergillosis), which is usually a fatal disease, especially in the patients with compromised immune system. microbiological monitoring of these infectious agents is necessary in modem medical facilities. mobile elements can be used as markers for identification of species and strains of aspergillus found indoors as well as in aspergillosis diagnostics. genomic sequences of two representative asper ... | 2007 | 18240565 |
| mating type protein mat1-2 from asexual aspergillus fumigatus drives sexual reproduction in fertile aspergillus nidulans. | the lack of an experimentally amenable sexual genetic system in aspergillus fumigatus is a major limitation in the study of the organism's pathogenesis. a recent comparative genome analysis revealed evidence for potential sexuality in a. fumigatus. homologs of mating type genes as well as other genes of the "sexual machinery" have been identified in anamorphic a. fumigatus. the mat1-2 gene encodes a homolog of mata, an hmg box mating transcriptional factor (mat(hmg)) that regulates sexual develo ... | 2008 | 18245277 |
| genetic interactions of the aspergillus nidulans atmaatm homolog with different components of the dna damage response pathway. | ataxia telangiectasia mutated (atm) is a phosphatidyl-3-kinase-related protein kinase that functions as a central regulator of the dna damage response in eukaryotic cells. in humans, mutations in atm cause the devastating neurodegenerative disease ataxia telangiectasia. previously, we characterized the homolog of atm (atma) in the filamentous fungus aspergillus nidulans. in addition to its expected role in the dna damage response, we found that atma is also required for polarized hyphal growth. ... | 2008 | 18245360 |
| genetic analysis of the role of peroxisomes in the utilization of acetate and fatty acids in aspergillus nidulans. | peroxisomes are organelles containing a diverse array of enzymes. in fungi they are important for carbon source utilization, pathogenesis, development, and secondary metabolism. we have studied aspergillus nidulans peroxin (pex) mutants isolated by virtue of their inability to grow on butyrate or by the inactivation of specific pex genes. while all pex mutants are able to form colonies, those unable to import pts1 proteins are partially defective in asexual and sexual development. the pex mutant ... | 2008 | 18245820 |
| a novel screening method for cell wall mutants in aspergillus niger identifies udp-galactopyranose mutase as an important protein in fungal cell wall biosynthesis. | to identify cell wall biosynthetic genes in filamentous fungi and thus potential targets for the discovery of new antifungals, we developed a novel screening method for cell wall mutants. it is based on our earlier observation that the aspergillus niger agsa gene, which encodes a putative alpha-glucan synthase, is strongly induced in response to cell wall stress. by placing the agsa promoter region in front of a selectable marker, the acetamidase (amds) gene of a. nidulans, we reasoned that cell ... | 2008 | 18245853 |
| biochemical and molecular characterization of a putative endoglucanase in magnaporthe grisea. | microbial pathogens secrete an array of cell wall-degrading enzymes to break down the structure of the host cell wall to facilitate colonization of the host tissue. to better understand their role in the pathogenesis, a putative endoglucanase from magnaporthe grisea was characterized in this paper. signalp-3.0 analysis indicates that the protein encoded by gene mgg_02532.5 in m. grisea (named mgegl1 for m. grisea endoglucanase 1) contains a secretory signal peptide. multiple alignment shows that ... | 2008 | 18247030 |
| aspergillus nidulans hypb encodes a sec7-domain protein important for hyphal morphogenesis. | aspergillus nidulans strains containing the hypb5 temperature sensitive allele have a restrictive phenotype of wide, highly-branched hyphae. the hypb locus was cloned by phenotype complementation using a genomic plasmid library. hypb5 is predicted gene an6709 in the a. nidulans genome database, which encodes a putative sec7 domain protein, likely to act early in copi-mediated vesicle formation for retrograde golgi to er transport. the a. nidulans hypb5 allele has a single mutation, cytosine to g ... | 2008 | 18248749 |
| novel promoter sequence required for inductive expression of the aspergillus nidulans endoglucanase gene egla. | expression of the egla gene, encoding for a major endoglucanse eg a in aspergillus nidulans, is induced by cellulose and cellobiose, but not by xylose. this suggests that induction is independent of xlnr, a transcriptional activator of xylanolytic and cellulolytic genes in aspergillus. mutational analysis of the egla promoter was performed to identify the novel cis-element responsible for xlnr-independent induction. the region spanning -153 to -138 (ccgtacctttttagga), designated cere(cellulose r ... | 2008 | 18256482 |
| gfp-tagged expression analysis revealed that some histidine kinases of aspergillus nidulans show temporally and spatially different expression during the life cycle. | his-asp phosphorelays are signal transduction mechanisms widely found in both prokaryotes and eukaryotes. the phosphorelay comprises three types of signal transducers: a sensor with histidine kinase (hk), a response regulator containing a phospho-accepting receiver (rr), and a histidine-containing phosphotransmitter (hpt). in this study, we examined hk expression using a green fluorescent protein (gfp) reporter driven by hk promoters in aspergillus nidulans. all the transformants showed fluoresc ... | 2008 | 18256501 |
| sumoylation in aspergillus nidulans: sumo inactivation, overexpression and live-cell imaging. | sumoylation, the reversible covalent attachment of small ubiquitin-like modifier (sumo) peptides has emerged as an important regulator of target protein function. in saccharomyces cerevisiae, but not in schizosaccharyomes pombe, deletion of the gene encoding sumo peptides is lethal. we have characterized the sumo-encoding gene, sumo, in the filamentous fungus aspergillus nidulans. the sumo gene was deleted in a diploid and sumodelta haploids were recovered. the mutant was viable but exhibited im ... | 2008 | 18262811 |
| cloning and sequence characterization of a non-reducing polyketide synthase gene from the lichen xanthoparmelia semiviridis. | lichens produce a diverse array of secondary metabolites that have shown various biological activities. of particular interest are the coupled phenolics that originate from polyketide pathways, such as depsides, depsidones and usnic acids, which are produced almost solely by lichens. based on the presumed catalytic domains required for the synthesis of the key intermediates beta-orsellinic acid and methylphloroacetophenone, two pairs of degenerate primers were designed to target specifically the ... | 2008 | 18280724 |
| a defect of ligd (human lig4 homolog) for nonhomologous end joining significantly improves efficiency of gene-targeting in aspergillus oryzae. | gene-targeting by homologous recombination occurs rarely during transformation since nonhomologous recombination is predominant in aspergillus oryzae. to develop a highly efficient gene-targeting system for a. oryzae, we constructed disrupted strains harboring a gene (ligd) encoding human dna ligase iv homolog that is involved in the final step of dna nonhomologous end joining. the a. oryzae ligd disruptants showed no apparent defect in vegetative growth and/or conidiation, and exhibited increas ... | 2008 | 18282727 |
| 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 ... | 2008 | 18291652 |
| nucleosome positioning and histone h3 acetylation are independent processes in the aspergillus nidulans prnd-prnb bidirectional promoter. | in aspergillus nidulans, proline can be used as a carbon and nitrogen source, and its metabolism requires the integration of three signals, including proline induction and nitrogen and carbon metabolite derepression. we have previously shown that the bidirectional promoter in the prnd-prnb intergenic region undergoes drastic chromatin rearrangements such that proline induction leads to the loss of positioned nucleosomes, whereas simultaneous carbon and nitrogen metabolite repression results in t ... | 2008 | 18296621 |
| germination, duplication cycle and septum formation are altered by caffeine, caffeic acid and cinnamic acid in aspergillus nidulans. | phenolic and benzene compounds from vegetables have been described as being responsible for many biological activities including antifungal effects. caffeine, cinnamic and caffeic acids were here investigated for their action on a model fungus, aspergillus nidulans, at its initial stage of germination. conidia did not germinate in the presence of (1 mm) cinnamic acid. caffeine and caffeic acid exerted a negative effect on germination, on the nuclear duplication cycle and on first septum formatio ... | 2007 | 18297875 |
| investigations into the taxonomy of the mushroom pathogen verticillium fungicola and its relatives based on sequence analysis of nitrate reductase and its regions. | the full sequence of the nitrate reductase gene was obtained from a type isolate of verticilliumfungicola var. fungicola and used for phylogenetic analysis against other ascomycete fungi. sequencing obtained 2749 bp of coding region, 668 bp of 5' flanking sequence and 731 bp of 3' flanking sequence. in silico analysis indicated that the coding region contains a single intron and translates into an 893 amino acid protein, with blast analysis identifying five conserved nitrate reductase domains wi ... | 2007 | 18297878 |
| functional characterization of the aspergillus fumigatus crz1 homologue, crza. | the protein phosphatase calcineurin is an important mediator connecting calcium-dependent signalling to various cellular responses in multiple organisms. in fungi calcineurin acts largely through regulating crz1p-like transcription factors. here we characterize an aspergillus fumigatus crz1 homologue, crza and demonstrate its mediation of cellular tolerance to increased concentrations of calcium and manganese. in addition to acute sensitivity to these ions, and decreased conidiation, the crza nu ... | 2008 | 18298443 |
| acpa, a member of the gpr1/fun34/yaah membrane protein family, is essential for acetate permease activity in the hyphal fungus aspergillus nidulans. | in a previous study, alcs, a gene of the aspergillus nidulans alc cluster, was shown to encode a protein that belongs to the gpr1/fun34/yaah membrane protein family. blast screening of the a. nidulans genome data identified additional genes encoding hypothetical proteins that could belong to this family. in this study we report the functional characterization of one of them, an5226. its expression is induced by ethanol and ethyl acetate (two inducers of the alc genes) and is mediated by the spec ... | 2008 | 18302536 |
| ndel1 controls the dynein-mediated transport of vimentin during neurite outgrowth. | ndel1, the mammalian homologue of the aspergillus nidulans nude, is emergently viewed as an integrator of the cytoskeleton. by regulating the dynamics of microtubules and assembly of neuronal intermediate filaments (ifs), ndel1 promotes neurite outgrowth, neuronal migration, and cell integrity (1-6). to further understand the roles of ndel1 in cytoskeletal dynamics, we performed a tandem affinity purification of ndel1-interacting proteins. we isolated a novel ndel1 molecular complex composed of ... | 2008 | 18303022 |
| functional characterization of residues within the carnitine/acylcarnitine translocase rx2panaaxf distinct motif. | the mitochondrial carnitine/acylcarnitine carrier (cac) is characterized by the presence of a distinct motif, rxxpanaaxf, within its sixth transmembrane alpha-helix. in this study, we analysed the role of the amino acids of this motif in the structure-function relationships of the human cac by using two complementary approaches. first, we performed functional analysis in the model fungus aspergillus nidulans of selected mutations with structural and functional relevance. second, similar mutant h ... | 2008 | 18307102 |
| foly: an integrated database for the classification and functional annotation of fungal oxidoreductases potentially involved in the degradation of lignin and related aromatic compounds. | the breakdown of lignin by fungi is a key step during carbon recycling in terrestrial ecosystems. this process is of great interest for green and white biotechnological applications. given the importance of these enzymatic processes, we have classified the enzymes potentially involved in lignin catabolism into sequence-based families and integrated them in a newly developed database, designated fungal oxidative lignin enzymes (foly). families were defined after sequence similarity searches start ... | 2008 | 18308593 |
| [homology-dependent inactivation of ltr retrotransposons in genomes of aspergillus fumigatus and a. nidulans]. | repeat-induced point mutation (rip) is the most intriguing among the known mechanisms of repeated sequences inactivation because of its ability to produce irreversible mutation of repeated dna. discovered for the first time in neurospora crassa, rip is characterized by c:g to t:a transitions in duplicated sequences. the mechanisms and distribution of rip are still purely investigated. mobile elements are a common target for the processes which lead to homology-dependent silencing because of thei ... | 2007 | 18318114 |
| efficacy of female culex quinquefasciatus with entomopathogenic fungus fusarium pallidoroseum. | this study was conducted to isolate and identify natural entomopathogenic fungi from female culex quinquefasciatus and to test their adulticidal activity. field-collected female c. quinquefasciatus died early and were placed on a saboraud's dextrose agar plates for growth and isolation of natural entomopathogenic fungi. the plates were maintained in an incubator at 24+/-2 degrees c for 3 days. four fungal species were isolated in two genera namely, aspergillus and fusarium. the identified fungal ... | 2008 | 18327611 |
| characterization of an acyl-coa: carboxylate coa-transferase from aspergillus nidulans involved in propionyl-coa detoxification. | filamentous fungi metabolize toxic propionyl-coa via the methylcitrate cycle. disruption of the methylcitrate synthase gene leads to an accumulation of propionyl-coa and attenuates virulence of aspergillus fumigatus. however, addition of acetate, but not ethanol, to propionate-containing medium strongly reduces the accumulation of propionyl-coa and restores growth of the methylcitrate synthase mutant. therefore, the existence of a coa-transferase was postulated, which transfers the coash moiety ... | 2008 | 18331473 |
| the role of actin, fimbrin and endocytosis in growth of hyphae in aspergillus nidulans. | filamentous fungi are ideal systems to study the process of polarized growth, as their life cycle is dominated by hyphal growth exclusively at the cell apex. the actin cytoskeleton plays an important role in this growth. until now, there have been no tools to visualize actin or the actin-binding protein fimbrin in live cells of a filamentous fungus. we investigated the roles of actin (acta) and fimbrin (fima) in hyphal growth in aspergillus nidulans. we examined the localization of acta::gfp and ... | 2008 | 18331474 |
| a trispecies aspergillus microarray: comparative transcriptomics of three aspergillus species. | the full-genome sequencing of the filamentous fungi aspergillus nidulans, aspergillus niger, and aspergillus oryzae has opened possibilities for studying the cellular physiology of these fungi on a systemic level. as a tool to explore this, we are making available an affymetrix genechip developed for transcriptome analysis of any of the three above-mentioned aspergilli. transcriptome analysis of triplicate batch cultivations of all three aspergilli on glucose and xylose media was used to validat ... | 2008 | 18332432 |
| characterization of fusarium graminearum mes1 reveals roles in cell-surface organization and virulence. | the surfaces of fungal hyphae are mosaics of carbohydrates and cell-surface proteins. presently, very little is known about the role of these proteins and their organization at the cell surface. here, we characterize two fusarium graminearum genes implicated in cell-surface organization, mes1 (fgsg_06680) and pls1 (fgsg_08695). mes1 is a homologue of mesa, which is required for the formation of stable polarity axes in aspergillus nidulans. pls1 encodes a tetraspanin, which belongs to a class of ... | 2008 | 18339563 |
| norsolorinic acid from aspergillus nidulans inhibits the proliferation of human breast adenocarcinoma mcf-7 cells via fas-mediated pathway. | norsolorinic acid, isolated from the aspergillus nidulans, was investigated for its antiproliferative activity in human breast adenocarcinoma mcf-7 cells. to identity the anticancer mechanism of norsolorinic acid, we assayed its effect on apoptosis, cell cycle distribution, and levels of p53, p21/waf1, fas/apo-1 receptor and fas ligand. the results showed that norsolorinic acid induced apoptosis of mcf-7 cells without mediation of p53 and p21/waf1. we suggest that fas/fas ligand apoptotic system ... | 2008 | 18346044 |
| aspergillus nidulans natural product biosynthesis is regulated by mpkb, a putative pheromone response mitogen-activated protein kinase. | the aspergillus nidulans putative mitogen-activated protein kinase encoded by mpkb has a role in natural product biosynthesis. an mpkb mutant exhibited a decrease in sterigmatocystin gene expression and low mycotoxin levels. the mutation also affected the expression of genes involved in penicillin and terrequinone a synthesis. mpkb was necessary for normal expression of laea, which has been found to regulate secondary metabolism gene clusters. | 2008 | 18378656 |
| screening of aspergillus species for occurrence of lectins and their characterization. | ten species of aspergillus were screened for occurrence of lectins. each of the species was investigated for the occurrence of extracellular, surface-bound and intracellular lectin activities. as many as four species namely, aspergillus niger, aspergillus versicolor, aspergillus rugulosus and aspergillus nidulans, were found to possess intracellular lectin activities, while none of the species showed extracellular or surface-bound lectin activities. each of the lectin was characterized with resp ... | 2008 | 18383222 |
| influence of farnesol on the morphogenesis of aspergillus niger. | farnesol was the first quorum-sensing regulator to be found in eukaryotic cells. in candida albicans, a dimorphic fungal human pathogen, farnesol blocks the yeast-to-filamentous growth transition. here we show that in aspergillus niger farnesol acts as an inhibitor of conidiation: colonies grown on media containing farnesol were unable to develop conidia. although farnesol treated a. niger cultures exhibited a colony morphology resembling the "fluffy" phenotype of a. nidulans, which is caused by ... | 2008 | 18383232 |
| the aspergillus nidulans fcyb cytosine-purine scavenger is highly expressed during germination and in reproductive compartments and is downregulated by endocytosis. | we cloned and characterized an aspergillus nidulans gene, called fcyb, encoding the closest homologue to the yeast fcy2p/fcy21p permeases. deletion of fcyb (deltafcyb) does not affect growth, development, reproduction or bulk purine uptake, but eliminates the leaky growth on purines of deltaazgadeltauapcdeltauapa strains, lacking all known purine transporters, and confers resistance to the antifungal 5-fluorocytosine. kinetic analyses showed fcyb is a low-capacity, high-affinity, cytosine-purine ... | 2008 | 18384518 |
| quantifying metabolic activity of filamentous fungi using a colorimetric xtt assay. | the filamentous nature and robust cell walls of many fungi render traditional measurements of active biomass (e.g., turbidity, dry cell weight) ineffective for most fungal bioprocesses. to overcome this challenge, an assay for quantification of overall metabolic activity is developed using 2,3-bis(2-methoxy-4-nitro-5-sulfophenly)-5-[(phenylamino) carbonyl]-2h-tetrazolium hydroxide (xtt), which in the presence of active mitochondria is converted to a water-soluble formazan derivative that absorbs ... | 2008 | 18386938 |
| the nuclear migration protein nudf/lis1 forms a complex with nudc and bnfa at spindle pole bodies. | nuclear migration depends on microtubules, the dynein motor complex, and regulatory components like lis1 and nudc. we sought to identify new binding partners of the fungal lis1 homolog nudf to clarify its function in dynein regulation. we therefore analyzed the association between nudf and nudc in aspergillus nidulans. nudf and nudc directly interacted in yeast two-hybrid experiments via nudf's wd40 domain. nudc-green fluorescent protein (nudc-gfp) was localized to immobile dots in the cytoplasm ... | 2008 | 18390647 |
| polarized growth in fungi--interplay between the cytoskeleton, positional markers and membrane domains. | one kind of the most extremely polarized cells in nature are the indefinitely growing hyphae of filamentous fungi. a continuous flow of secretion vesicles from the hyphal cell body to the growing hyphal tip is essential for cell wall and membrane extension. because microtubules (mt) and actin, together with their corresponding motor proteins, are involved in the process, the arrangement of the cytoskeleton is a crucial step to establish and maintain polarity. in saccharomyces cerevisiae and schi ... | 2008 | 18399939 |
| analysis of aspergillus nidulans metabolism at the genome-scale. | aspergillus nidulans is a member of a diverse group of filamentous fungi, sharing many of the properties of its close relatives with significance in the fields of medicine, agriculture and industry. furthermore, a. nidulans has been a classical model organism for studies of development biology and gene regulation, and thus it has become one of the best-characterized filamentous fungi. it was the first aspergillus species to have its genome sequenced, and automated gene prediction tools predicted ... | 2008 | 18405346 |
| egld, a putative endoglucanase, with an expansin like domain is localized in the conidial cell wall of aspergillus nidulans. | although the process of conidial germination in filamentous fungi has been extensively studied, many aspects remain to be elucidated since the asexual spore or conidium is vital in their life cycle. breakage and reformation of cell wall polymer bonds along with the maintenance of cell wall plasticity during conidia germination depend upon a range of hydrolytic enzymes whose activity is analogous to that of expansins, a highly conserved group of plant cell wall proteins with characteristic wall l ... | 2008 | 18406638 |
| arp11 affects dynein-dynactin interaction and is essential for dynein function in aspergillus nidulans. | the dynactin complex contains proteins including p150 that interacts with cytoplasmic dynein and an actin-related protein arp1 that forms a minifilament. proteins including arp11 and p62 locate at the pointed end of the arp1 filament, but their biochemical functions are unclear (schroer ta. dynactin. annu rev cell dev biol 2004;20:759-779). in aspergillus nidulans, loss of arp11 or p62 causes the same nuclear distribution (nud) defect displayed by dynein mutants, indicating that these pointed-en ... | 2008 | 18410488 |
| 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 ... | 2008 | 18413600 |
| functional equivalence of translation factor eif5b from candida albicans and saccharomyces cerevisiae. | eukaryotic translation initiation factor 5b (eif5b) plays a role in recognition of the aug codon in conjunction with translation factor eif2, and promotes joining of the 60s ribosomal subunit. to see whether the eif5b proteins of other organisms function in saccharomyces cerevisiae, we cloned the corresponding genes from oryza sativa, arabidopsis thaliana, aspergillus nidulans and candida albican and expressed them under the control of the galactose-inducible gal promoter in the fun12delta strai ... | 2008 | 18414002 |
| crea mediates repression of the regulatory gene xlnr which controls the production of xylanolytic enzymes in aspergillus nidulans. | the aspergillus nidulans xlnr gene encodes a zn(2)cys(6) transcription activator necessary for the synthesis of the main xylanolytic enzymes, i.e. endo-xylanases x(22), x(24) and x(34), and beta-xilosidase xlnd. expression of xlnr is not sufficient for induction of genes encoding the xylanolytic complex, the presence of xylose is absolutely required. it has been established previously that the wide-domain carbon catabolite repressor crea indirectly represses xlna (encodes x(22)) and xlnb (encode ... | 2008 | 18420433 |
| aspergillus nidulans chia is a glycosylphosphatidylinositol (gpi)-anchored chitinase specifically localized at polarized growth sites. | it is believed that chitinases play important physiological roles in filamentous fungi since chitin is one of the major cell wall components in these organisms. in this paper we investigated a chitinase gene, chia, of aspergillus nidulans and found that the gene product of chia consists of a signal sequence, a region including chitinase consensus motifs, a ser/thr/pro-rich region and a glycosylphosphatidylinositol (gpi)-anchor attachment motif. phosphatidylinositol-specific phospholipase c treat ... | 2008 | 18420434 |
| [molecular mechanism of lissencephaly--how lis1 and ndel1 regulate cytoplasmic dynein?]. | lissencephaly is a devastating neurological disorder characterized by smooth cerebral surface, thick cortex and dilated lateral ventricules due to defective neuronal migration. lis1 was identified as a mutated gene in classical lissencephaly patients, and turned out to be a beta-subunit of platelet activating factor acetylhydrolase. studies in model organisms, particularly aspergillus nidulans, as well as those in the mouse, have uncovered an evolutionarily conserved pathway that involves lis1 a ... | 2008 | 18421979 |
| localization and function of adp ribosylation factor a in aspergillus nidulans. | filamentous fungi undergo polarized hyphal growth throughout the majority of their life cycle. the spitzenkörper is a structure unique to filamentous fungi that participates in hyphal growth and is composed largely of vesicles. an important class of proteins involved in vesicle assembly and trafficking are the adp-ribosylation factors (arfs). in saccharomyces cerevisiae, arf1p and arf2p are involved in secretion. aspergillus nidulans arfa is a homolog of scarf1p and scarf2p with 75% of amino aci ... | 2008 | 18430001 |
| ndel1 promotes axon regeneration via intermediate filaments. | failure of axons to regenerate following acute or chronic neuronal injury is attributed to both the inhibitory glial environment and deficient intrinsic ability to re-grow. however, the underlying mechanisms of the latter remain unclear. in this study, we have investigated the role of the mammalian homologue of aspergillus nidulans nude, ndel1, emergently viewed as an integrator of the cytoskeleton, in axon regeneration. ndel1 was synthesized de novo and upregulated in crushed and transected sci ... | 2008 | 18431495 |
| the unprocessed preprotein form iatc103s of the isopenicillin n acyltransferase is transported inside peroxisomes and regulates its self-processing. | previous studies in penicillium chrysogenum and aspergillus nidulans suggested that self-processing of the isopenicillin n acyltransferase (iat) is an important differential factor in these fungi. expression of a mutant pende(c103s) gene in p. chrysogenum gave rise to an unprocessed inactive variant of iat (iat(c103s)) located inside peroxisomes, which indicates that transport of the proiat inside these organelles is not dependent on the processing state of the protein. co-expression of the pend ... | 2008 | 18439860 |
| characterization of a highly active promoter, pbbgpd, in beauveria bassiana. | the promoter of glyceraldehyde-3-phosphate dehydrogenase (gpd) gene from aspergillus nidulans (pgpda) is widely used to direct expression of target genes constitutively in fungi. however, in some species, a heterogeneous promoter is found to be of low efficiency. to obtain a high-efficiency promoter for transformation of beauveria bassiana, an entomopathogenic fungus widely used as an mycoinsecticide, a glyceraldehyde-3-phosphate dehydrogenase gene (bbgpd) promoter, was cloned and characterized. ... | 2008 | 18443858 |
| rapid tip-directed movement of golgi equivalents in growing aspergillus nidulans hyphae suggests a mechanism for delivery of growth-related materials. | golgi equivalents (ges) process materials in the fungal secretory pathway. despite the importance of localized secretion in fungal tip growth, ge behaviour in living hyphae has not been documented. the distribution was monitored of an aspergillus nidulans putative ge-associated protein, copa, tagged with gfp (copa-gfp). this co-localized with a golgi body/ge marker established in other systems, alpha-2,6-sialyltransferase, tagged with red fluorescent protein (st-rfp). copa-gfp and st-rfp distrib ... | 2008 | 18451063 |
| crystal structure of a new type of nadph-dependent quinone oxidoreductase (qor2) from escherichia coli. | escherichia coli qor2 [nad(p)h-dependent quinone oxidoreductase; a ytfg gene product], which catalyzes two-electron reduction of methyl-1,4-benzoquinone, is a new type of quinone-reducing enzyme with distinct primary sequence and oligomeric conformation from previously known quinone oxidoreductases. the crystal structures of native qor2 and the qor2-nadph (nicotinamide adenine dinucleotide phosphate, reduced form) complex reveal that qor2 consists of two domains (n-domain and c-domain) resemblin ... | 2008 | 18455185 |
| ambient ph gene regulation in fungi: making connections. | many fungi grow over a wide ph range and their gene expression is tailored to the environmental ph. in aspergillus nidulans, the transcription factor pacc, an activator of genes expressed in alkaline conditions and a repressor of those expressed in acidic conditions, undergoes two processing proteolyses, the first being ph-signal dependent and the second proteasomal. signal transduction involves a 'go-between' connecting two complexes, one of which comprises two plasma membrane proteins and an a ... | 2008 | 18457952 |
| the vea regulatory system and its role in morphological and chemical development in fungi. | in fungi, the velvet gene, or vea, is involved in the regulation of diverse cellular processes, including control of asexual and sexual development as well as secondary metabolism. this global regulator is conserved in numerous fungal species. interestingly, in aspergilli, where most of the studies on vea have been carried out, this gene has been described to mediate development in response to light. in recent years the knowledge of this important regulatory system has expanded through the use o ... | 2008 | 18457967 |
| two zinc finger transcription factors, crza and slta, are involved in cation homoeostasis and detoxification in aspergillus nidulans. | to investigate cation adaptation and homoeostasis in aspergillus nidulans, two transcription-factor-encoding genes have been characterized. the a. nidulans orthologue crza of the saccharomyces cerevisiae crz1 gene, encoding a transcription factor mediating gene regulation by ca(2+), has been identified and deleted. the crza deletion phenotype includes extreme sensitivity to alkaline ph, ca(2+) toxicity and aberrant morphology connected with alterations of cell-wall-related phenotypes such as red ... | 2008 | 18471095 |
| apparent mrna instability in aspergillus nidulans and aspergillus terreus of a heterologous cdna encoding the major capsid antigen of rotavirus. | two expression plasmids designed to produce the rotaviral vp6 protein in aspergillus nidulans and aspergillus terreus have been constructed. in one of these plasmids the inducible a. terreus gla1 glucoamylase gene promoter and gla1 signal sequence are fused to the vp6 cdna to enable induction and extracellular secretion of the final protein product; in the other, the strong, constitutive a. nidulans gpda gene promoter has been employed. a. nidulans and a. terreus transformants containing intact ... | 1999 | 18473559 |
| effect of culture temperature on the heterologous expression of pleurotus eryngii versatile peroxidase in aspergillus hosts. | production of recombinant versatile peroxidase in aspergillus hosts was optimized through the modification of temperature during bioreactor cultivations. to further this purpose, the cdna encoding a versatile peroxidase of pleurotus eryngii was expressed under control of the alcohol dehydrogenase (alca) promoter of aspergillus nidulans. a dependence of recombinant peroxidase production on cultivation temperature was found. lowering the culture temperature from 28 to 19 degrees c enhanced the lev ... | 2009 | 18481101 |
| sexual and vegetative compatibility genes in the aspergilli. | gene flow within populations can occur by sexual and/or parasexual means. analyses of experimental and in silico work are presented relevant to possible gene flow within the aspergilli. first, the discovery of mating-type (mat) genes within certain species of aspergillus is described. the implications for self-fertility, sexuality in supposedly asexual species and possible uses as phylogenetic markers are discussed. second, the results of data mining for heterokaryon incompatibility (het) and pr ... | 2007 | 18490952 |
| more than a repair enzyme: aspergillus nidulans photolyase-like crya is a regulator of sexual development. | cryptochromes are blue-light receptors that have presumably evolved from the dna photolyase protein family, and the genomes of many organisms contain genes for both types of molecules. both protein structures resemble each other, which suggests that light control and light protection share a common ancient origin. in the genome of the filamentous fungus aspergillus nidulans, however, only one cryptochrome/photolyase-encoding gene, termed crya, was identified. deletion of the crya gene triggers s ... | 2008 | 18495868 |
| structural characterisation of pina ww domain and a comparison with other group iv ww domains, pin1 and ess1. | the nmr solution structure of the pina ww domain from aspergillus nidulans is presented. the backbone of the pina ww domain is composed of a triple-stranded anti-parallel beta-sheet and an alpha-helix similar to ess1 and pin1 without the alpha-helix linker. large rms deviations in loop i were observed both from the nmr structures and molecular dynamics simulation suggest that the loop i of pina ww domain is flexible and solvent accessible, thus enabling it to bind the ps/pt-p motif. the ww domai ... | 2008 | 18503784 |
| the interaction of induction, repression and starvation in the regulation of extracellular proteases in aspergillus nidulans: evidence for a role for crea in the response to carbon starvation. | in aspergillus nidulans, production of extracellular proteases in response to carbon starvation and to a lesser extent nitrogen starvation is controlled by xprg, a putative transcriptional activator. in this study the role of genes involved in carbon catabolite repression and the role of protein as an inducer of extracellular protease gene expression were examined. the addition of exogenous protein to the growth medium did not increase extracellular protease activity whether or not additional ca ... | 2008 | 18512059 |
| a single amino acid substitution in one of the lipases of aspergillus nidulans confers resistance to the antimycotic drug undecanoic acid. | a plausible approach to evaluate the inhibitory action of antifungals is through the investigation of the fungal resistance to these drugs. we describe here the molecular cloning and initial characterization of the a. nidulans lipa gene, where mutation (lipa1) conferred resistance to undecanoic acid, the most fungitoxic fatty acid in the c(7:0)-c(18:0) series. the lipa gene codes for a putative lipase with the sequence consensus gvsis and wifggg as the catalytic signature. comparison of the wild ... | 2008 | 18516670 |
| ambient ph signalling in the yeast yarrowia lipolytica involves ylrim23p/palc, which interacts with snf7p/vps32p, but does not require the long c terminus of ylrim9p/pali. | a conserved ambient ph signal transduction pathway has been evidenced in both ascomycetous yeasts and filamentous fungi, called the rim or pal pathway, respectively. however, closely related palc orthologues are found only in yarrowia lipolytica and in filamentous fungi, where the rim9p/pali factor has a much longer c-terminal tail than in other yeasts. we show here that, like aspergillus nidulans pali mutants, a ylrim9delta mutant has a less extreme phenotype than other mutants of the pathway, ... | 2008 | 18524921 |
| aspergillus nidulans arfb plays a role in endocytosis and polarized growth. | filamentous fungi undergo polarized growth throughout most of their life cycles. the spitzenkörper is an apical organelle composed primarily of vesicles that is unique to filamentous fungi and is likely to act as a vesicle supply center for tip growth. vesicle assembly and trafficking are therefore important for hyphal growth. adp ribosylation factors (arfs), a group of small gtpase proteins, play an important role in nucleating vesicle assembly. little is known about the role of arfs in filamen ... | 2008 | 18539885 |
| production of the polyketide 6-msa in yeast engineered for increased malonyl-coa supply. | the heterologous production of fungal polyketides was investigated using 6-methylsalicylic acid synthase (6-msas) as a model polyketide synthase and saccharomyces cerevisiae as a host. in order to improve the production of 6-msa by enhancing the supply of precursors, the promoter of the gene (acc1) encoding acetyl-coa carboxylase, which catalyzes the conversion of acetyl-coa to malonyl-coa, was replaced with a strong, constitutive promoter (tef1p) in a strain harboring two plasmids carrying the ... | 2008 | 18555717 |
| developmental biology. sex and poison in the dark. | 2008 | 18556538 | |
| velb/vea/laea complex coordinates light signal with fungal development and secondary metabolism. | differentiation and secondary metabolism are correlated processes in fungi that respond to light. in aspergillus nidulans, light inhibits sexual reproduction as well as secondary metabolism. we identified the heterotrimeric velvet complex velb/vea/laea connecting light-responding developmental regulation and control of secondary metabolism. vea, which is primarily expressed in the dark, physically interacts with velb, which is expressed during sexual development. vea bridges velb to the nuclear ... | 2008 | 18556559 |
| molecular genetic mining of the aspergillus secondary metabolome: discovery of the emericellamide biosynthetic pathway. | the recently sequenced genomes of several aspergillus species have revealed that these organisms have the potential to produce a surprisingly large range of natural products, many of which are currently unknown. we have found that a. nidulans produces emericellamide a, an antibiotic compound of mixed origins with polyketide and amino acid building blocks. additionally, we describe the discovery of four previously unidentified, related compounds that we designate emericellamide c-f. using recentl ... | 2008 | 18559263 |
| induction of mitotic crossing-over in diploid strains of aspergillus nidulans using low-dose x-rays. | as a contribution towards detecting the genetic effects of low doses of genotoxic physical agents, this paper deals with the consequences of low-dose x-rays in the aspergillus nidulans genome. the irradiation doses studied were those commonly used in dental clinics (1-5 cgy). even very low doses promoted increased mitotic crossing-over frequencies in diploid strains heterozygous for several genetic markers including the ones involved in dna repair and recombination mechanisms. genetic markers of ... | 2008 | 18561380 |
| 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 ... | 2008 | 18567788 |
| 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 ... | 2008 | 18575630 |
| pichia expression and mutagenesis of 7,8-linoleate diol synthase change the dioxygenase and hydroperoxide isomerase. | linoleate diol synthases (lds) are homologous 8(r)-dioxygenases with hydroperoxide isomerase activities, expressed in fungal pathogens of humanitarian importance. we report for the first time expression and site-directed mutagenesis of lds. 7,8-lds of the take-all fungus, expressed in pichia pastoris, oxygenated 18:2n-6 to 8(r)-hydroperoxylinoleic acid, which was unexpectedly isomerized to 5,8(r)-dihydroxylinoleic acid (60% 5s) and to 8(r),13-dihydroxyoctadeca-9(e),11(e)-dienoic acid. the latter ... | 2008 | 18586008 |
| genome mining of cyanide-degrading nitrilases from filamentous fungi. | a variety of fungal species are known to degrade cyanide through the action of cyanide hydratases, a specialized subset of nitrilases which hydrolyze cyanide to formamide. in this paper, we report on two previously unknown and uncharacterized cyanide hydratases from neurospora crassa and aspergillus nidulans. recombinant forms of four cyanide hydratases from n. crassa, a. nidulans, gibberella zeae, and gloeocercospora sorghi were prepared after their genes were cloned with n-terminal hexahistidi ... | 2008 | 18587571 |
| [progress in research on apoptosis in filamentous fungi--a review]. | apoptosis is a conserved mechanism that plays an essential role in eukaryotes. malfunction of apoptosis contributes to many human diseases including cancer and aids. compared with yeast, a monocellular eukaryote, which is the model organism for apoptosis research, investigation on filamentous fungi apoptosis has particular advantages, which remained unrecognized until recent years. filamentous fungi, especially aspergillus nidulans and aspergillus fumigatus, are expected to become new model spec ... | 2008 | 18590245 |
| heterotrimeric g protein mediated regulation of proteinase production in aspergillus nidulans. | extracellular proteinase production induced by carbon starvation was studied in a series of heterotrimeric g protein signaling pathway mutants of aspergillus nidulans. all the mutants tested--including deltafada (galpha), deltasfad (gbeta), deltagpga (ggamma) and deltasfga (regulator of fada signaling)--showed an elevated proteinase production after glucose depletion. our results strongly support the view that during growth, fada/sfad/gpga g protein signaling inhibits proteinase production via b ... | 2008 | 18595316 |
| lactose and d-galactose catabolism in the filamentous fungus aspergillus nidulans. | the disaccharide lactose is a byproduct of cheese production accumulating to amounts of 800,000 tons per year worldwide, of which 15% is used as a carbon source for various microbial fermentations. nevertheless, little is known about the regulation of its metabolism in filamentous fungi. lactose is metabolized slowly, and some important fungi such as a. niger cannot use it at all. a more detailed knowledge on the rate-limiting steps would be helpful to improve its industrial application. we have ... | 2008 | 18595317 |
| two gdp-mannose transporters contribute to hyphal form and cell wall integrity in aspergillus nidulans. | in order to identify novel genes affecting cell wall integrity, we have generated mutant strains of the filamentous fungus aspergillus nidulans that show hypersensitivity to the chitin-binding agent calcofluor white (cfw). affected loci are designated cal loci. the phenotype of one of these alleles, cali11, also includes shortened hyphal compartments and increased density of branching in the absence of cfw, as well as reduced staining of cell walls by the lectin fitc-concanavalin a (cona), which ... | 2008 | 18599832 |
| structural analysis of the recognition of the negative regulator nmra and dna by the zinc finger from the gata-type transcription factor area. | amongst the most common protein motifs in eukaryotes are zinc fingers (zfs), which, although largely known as dna binding modules, also can have additional important regulatory roles in forming protein:protein interactions. area is a transcriptional activator central to nitrogen metabolism in aspergillus nidulans. area contains a gata-type zf that has a competing dual recognition function, binding either dna or the negative regulator nmra. we report the crystal structures of three area zf-nmra c ... | 2008 | 18602114 |
| aspergillus fumigatus rasa regulates asexual development and cell wall integrity. | the ras family of proteins is a large group of monomeric gtpases. members of the fungal ras family act as molecular switches that transduce signals from the outside of the cell to signaling cascades inside the cell. a. fumigatus rasa is 94% identical to the essential rasa gene of aspergillus nidulans and is the ras family member sharing the highest identity to ras homologs studied in many other fungi. in this study, we report that rasa is not essential in a. fumigatus, but its absence is associa ... | 2008 | 18606827 |
| kinetics of cell growth and heterologous glucoamylase production in recombinant aspergillus nidulans. | in the work, a study of cell growth and the regulation of heterologous glucoamylase synthesis under the control of the positively regulated alca promoter in a recombinant aspergillus nidulans is presented. we found that similar growth rates were obtained for both the host and recombinant cells when either glucose or fructose was employed as sole carbon and energy source. use of the potent inducer cyclopentanone in concentrations greater than 3 mm resulted n maximum glucoamylase concentration and ... | 1993 | 18609547 |
| symmetric branching model for the kinetics of mycelial growth. | a mathematical model, linking microscopic to macroscopic parameters of the kinetics of mycelial growth is presented. the model consists of two parts: (a) a microscopic description, based on the assumption that growth of a mycelium can be represented approximately by the growth of a symmetric binary tree, where the branching level (microscopic state variable) is logarithmically related to the number of tips and segments; and (b) a macroscopic description which makes use of the microscopic descrip ... | 1993 | 18609641 |
| expression of active spinach glycolate oxidase in aspergillus nidulans. | the biocatalytic production of glyoxylic acid from glycolic acid requires two enzymes: glycolate oxidase, which catalyzes the oxidation of glycolic acid by oxygen to produce glyoxylic acid and hydrogen peroxide, and catalase, which decomposes the byproduct hydrogen peroxide. as an alternative to isolation from the leaf peroxisomes of spinach, glycolate oxidase has now been cloned and expressed in transformants of aspergillus nidulans t580 at levels ranging from 1.7 to 36 iu/g dry wt. cells. the ... | 1996 | 18626962 |
| a new protein carrying an nmra-like domain is required for cell differentiation and development in dictyostelium discoideum. | we have isolated a dictyostelium mutant unable to induce expression of the prestalk-specific marker ecmb in monolayer assays. the disrupted gene, pada, leads to a range of phenotypic defects in growth and development. we show that pada is essential for growth, and we have generated a thermosensitive mutant allele, pada(-). at the permissive temperature, mutant cells grow poorly; they remain longer at the slug stage during development and are defective in terminal differentiation. at the restrict ... | 2008 | 18638468 |
| molecular detection and identification of aspergillus spp. from clinical samples using real-time pcr. | the definite and rapid diagnosis of invasive aspergillosis is necessary because of the high mortality caused. the objective of this study was to evaluate a real-time pcr assay to detect aspergillus spp. in clinical samples, based on the light cycler technology. specificity was assessed by using dna extracted from pathogenic and non-pathogenic bacteria/fungi from spanish collection including: two aspergillus flavus, four aspergillus fumigatus, two aspergillus nidulans, two aspergillus niger and t ... | 2009 | 18643921 |
| comparison between polyethylene glycol- and polyethylenimine-mediated transformation of aspergillus nidulans. | genetic transformation of many filamentous fungi is carried out by a protocol that utilizes polyethylene glycol (peg) and calcium ion (ca2+). this method has remained practically unchanged for more than 20 years, but the roles these molecules play are not definitively understood. to gain a better understanding, we have compared peg transformation to a protocol using polyethylenimine (pei) that is the basis for non-viral transfection in mammals and which has a well established molecular model for ... | 2008 | 18649081 |
| expression of a synthetic artemesia annua amorphadiene synthase in aspergillus nidulans yields altered product distribution. | a gene encoding a plant terpene cyclase, artemisia annua amorpha-4,11-diene synthase (ads), was expressed in aspergillus nidulans under control of a strong constitutive promoter, (p)gpda. the transformants produced only small amounts of amorphadiene, but much larger amounts of similar sesquiterpenes normally produced as minor by-products in planta. in contrast, expression of ads in escherichia coli produced almost exclusively amorpha-4,11-diene. these results indicate that the host environment c ... | 2008 | 18651187 |
| functional diversity of chitin synthases of aspergillus nidulans in hyphal growth, conidiophore development and septum formation. | fungal chitin synthases are classified into seven classes. recent advances in genome sequence analyses have revealed that there are more than seven chitin synthase-encoding genes in the genome of filamentous ascomycete fungi. to clarify the functional differences among these genes in the morphogenesis and hyphal tip growth, we have cloned six chitin synthase-encoding genes from aspergillus nidulans and analyzed their functions. the results obtained suggest that chitin synthases are structurally ... | 2009 | 18651309 |
| role of the lolp cytochrome p450 monooxygenase in loline alkaloid biosynthesis. | the insecticidal loline alkaloids, produced by neotyphodium uncinatum and related endophytes, are exo-1-aminopyrrolizidines with an ether bridge between c-2 and c-7. loline alkaloids vary in methyl, acetyl, and formyl substituents on the 1-amine, which affect their biological activity. enzymes for key loline biosynthesis steps are probably encoded by genes in the lol cluster, which is duplicated in n. uncinatum, except for a large deletion in lolp2. the role of lolp1 was investigated by its repl ... | 2008 | 18655839 |