Publications
Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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swi/snf-gcn5-dependent chromatin remodelling determines induced expression of gdh3, one of the paralogous genes responsible for ammonium assimilation and glutamate biosynthesis in saccharomyces cerevisiae. | it is accepted that saccharomyces cerevisiae genome arose from complete duplication of eight ancestral chromosomes; functionally normal ploidy was recovered because of the massive loss of 90% of duplicated genes. there is evidence that indicates that part of this selective conservation of gene pairs is compelling to yeast facultative metabolism. as an example, the duplicated nadp-glutamate dehydrogenase pathway has been maintained because of the differential expression of the paralogous gdh1 and ... | 2005 | 15948967 |
isolation and characterization of the aspergillus nidulans eglc gene encoding a putative beta-1,3-endoglucanase. | the aspergillus nidulans eglc gene, which encodes a putative beta-1,3-endoglucanase, was isolated from a chromosome-specific library by using an expressed sequence tag, esd0113. the eglc open reading frame encodes a 465 amino acid polypeptide, of which the amino acid sequence showed 46% similarity to that of saccharomyces cerevisiae beta-1,3-endoglucanase. the eglc transcript level at the early stages of asexual and sexual developments was dependent on the presence of the nsdd gene that encodes ... | 2005 | 15950156 |
evolution of beta-lactam biosynthesis genes and recruitment of trans-acting factors. | penicillins and cephalosporins belong chemically to the group of beta-lactam antibiotics. the formation of hydrophobic penicillins has been reported in fungi only, notably penicillium chrysogenum and emericella nidulans, whereas the hydrophilic cephalosporins are produced by both fungi, e.g., acremonium chrysogenum (cephalosporin c), and bacteria. the producing bacteria include gram-negatives and gram-positives, e.g. lysobacter lactamdurans (cephabacins) and streptomyces clavuligerus (cephamycin ... | 2005 | 15950251 |
the nucleobase-ascorbate transporter (nat) signature motif in uapa defines the function of the purine translocation pathway. | uapa, a member of the nat/ncs2 family, is a high affinity, high capacity, uric acid-xanthine/h+ symporter of aspergillus nidulans. we have previously presented evidence showing that a highly conserved signature motif ([q/e/p]408-n-x-g-x-x-x-x-t-[r/k/g])417 is involved in uapa function. here, we present a systematic mutational analysis of conserved residues in or close to the signature motif of uapa. we show that even the most conservative substitutions of residues q408, n409 and g411 modify the ... | 2005 | 15953615 |
occurrence of fungal species and mycotoxins from decayed sugarcane (saccharrum officinarum) in egypt. | seventy-three fungal species belonging to forty-three genera were isolated from 40 samples of saccharrum officinarum (collected from naage-hamadi canal in qena governorate, egypt). aspergillus, trichoderma, mucor and pythium were the most common genera on the two isolation media. the dominant species of aspergillus were a. niger, a. flavus, a. ustus, a. terreus and a. wentii. some species were dominant on 40 g/l sucrose such as aspergillus niger, a. flavus, emericella nidulans, trichoderma virid ... | 2005 | 24049478 |
parameiosis in aspergillus nidulans in response to doxorubicin. | the recombinagenic effect of doxorubicin (an anticancer agent that impairs dna synthesis and causes chromosome breaks) was used to induce parameiotic events in aspergillus nidulans. heterokaryons formed with master strains and uvs mutants were inoculated with and without doxorubicin. haploid segregants (parameiotics and parents) and aneuploids were selected as heterokaryon-derived visible sectors. among parameiotic segregants, recombinants by intergenic mitotic crossing-over and recombinants by ... | 2004 | 15881406 |
synthesis and biological evaluations of sulfa derivatives bearing heterocyclic moieties. | some new sulfa derivatives bearing a heterocyclic moieties fural, pyrimidinone, thiazolidinone, benzimidazole and 1,2,4-triazinone and the related compounds 2-19 have been synthesized from treatment of sulfa drugs with thioisocyanate, acid chlorides, 3-chloro-1,2,4-triazines, aldehydes, esters and/or 2-methylbenzoxazole followed by ring closure reactions. structures of the products have been deduced from their elemental analysis and spectral data. significant antimicrobial activities were observ ... | 2004 | 15881802 |
plasmid vectors for protein production, gene expression and molecular manipulations in aspergillus niger. | we constructed three sets of plasmids for use in aspergillus niger. these plasmids were assembled using various combinations of a series of modular dna cassettes that included a selectable marker, pyrg, derived from aspergillus nidulans; two promoter regions for directing protein expression; a cassette derived from the ama1 replicator sequence to support autonomous replication; and a reporter gene based on the a. niger laca gene. one set included integrating and autonomously replicating plasmids ... | 2004 | 15848224 |
regulation of penicillin biosynthesis in filamentous fungi. | the beta-lactam antibiotic penicillin is one of the mainly used antibiotics for the therapy of infectious diseases. it is produced as end product by some filamentous fungi only, most notably by aspergillus (emericella) nidulans and penicillium chrysogenum. the penicillin biosynthesis is catalysed by three enzymes which are encoded by the following three genes: acva (pcbab), ipna (pcbc) and aata (pende). the genes are organised into a gene cluster. although the production of secondary metabolites ... | 2004 | 15719552 |
cloning and use of sc as homologous marker for aspergillus niger transformation. | the sc sequence from aspergillus niger was cloned and developed into a homologous marker system for genetic transformation. the coding region of the sc gene amplified by pcr from the a. niger genome was provided with aspergillus nidulans expression signals (gpda promoter and trpc terminator). this chimeric construct was used to successfully transform a spontaneous sc- isolate of a. niger to prototrophy. the transformants analyzed by southern analysis showed integration of multiple copies of the ... | 2004 | 15722148 |
ferrichrome in schizosaccharomyces pombe--an iron transport and iron storage compound. | schizosaccharomyces pombe has been assumed not to produce siderophores. nevertheless, the genomic sequence of this fission yeast revealed the presence of siderophore biosynthetic genes for hydroxamates. applying a bioassay based on an aspergillus nidulans strain deficient in siderophore biosynthesis, and using reversed-phase hplc and mass spectrometry analysis, we demonstrate that s. pombe excretes and accumulates intracellularly the hydroxamate-type siderophore ferrichrome. under iron-limiting ... | 2004 | 15689108 |
transformation of fusarium oxysporum by particle bombardment and characterisation of the resulting transformants expressing a gfp transgene. | fusarium is the causative agent of a variety of economically significant vascular wilt diseases of vegetables, flowers and field crops. the completion of the first fusarium genome and the availability of an est database now provides a platform for both forward and reverse genetic approaches to ascribe gene function in this phytopathogen. to underpin these strategies effective gene transfer procedures will be required. here we describe an efficient and robust procedure for fusarium oxysporum tran ... | 2004 | 15702267 |
expression of a cephalosporin c esterase gene in acremonium chrysogenum for the direct production of deacetylcephalosporin c. | a recombinant fungal microorganism capable of producing deacetylcephalosporin c was constructed by transforming a cephalosporin c esterase gene from rhodosporidium toruloides into acremonium chrysogenum. the cephalosporin c esterase gene can be expressed from its endogenous r. toruloides promoter or from the aspergillus nidulans trpc promoter under standard acremonium chrysogenum fermentation conditions. the expression of an active cephalosporin c esterase enzyme in a. chrysogenum results in the ... | 2004 | 15672283 |
endogenous lipogenic regulators of spore balance in aspergillus nidulans. | the ability of fungi to produce both meiospores and mitospores has provided adaptive advantages in survival and dispersal of these organisms. here we provide evidence of an endogenous mechanism that balances meiospore and mitospore production in the model filamentous fungus aspergillus nidulans. we have discovered a putative dioxygenase, ppoc, that functions in association with a previously characterized dioxygenase, ppoa, to integrate fatty acid derived oxylipin and spore production. in contras ... | 2004 | 15590815 |
fostua, encoding a basic helix-loop-helix protein, differentially regulates development of three kinds of asexual spores, macroconidia, microconidia, and chlamydospores, in the fungal plant pathogen fusarium oxysporum. | the soil-borne fungus fusarium oxysporum causes vascular wilt of a wide variety of plant species. f. oxysporum produces three kinds of asexual spores, macroconidia, microconidia, and chlamydospores. falcate macroconidia are formed generally from terminal phialides on conidiophores and rarely from intercalary phialides on hyphae. ellipsoidal microconidia are formed from intercalary phialides on hyphae. globose chlamydospores with thick walls are developed by the modification of hyphal and conidia ... | 2004 | 15590816 |
potential link between the nima mitotic kinase and nuclear membrane fission during mitotic exit in aspergillus nidulans. | we have isolated tinc as a nima-interacting protein by using the yeast two-hybrid system and have confirmed that tinc interacts with nima in aspergillus nidulans. the tinc-nima interaction is stabilized in the absence of phosphatase inhibitors and in the presence of kinase-inactive nima, suggesting that the interaction is enhanced when nima is not fully activated. tinc is a cytoplasmic protein. tinc homologues and a tinc-like protein (a. nidulans hetc) are conserved in other filamentous fungi. n ... | 2004 | 15590818 |
alcohol-mediated haemolysis in yeast. | although yeast are generally non-haemolytic, we have found that addition of alcohol vapour confers haemolytic properties on many strains of yeast and other fungi. we have called this phenomenon 'microbial alcohol-conferred haemolysis' (mach). mach is species- and strain-specific: whereas all six candida tropicalis strains tested were haemolytic in the presence of ethanol, none among 10 c. glabrata strains tested exhibited this phenomenon. among 27 c. albicans strains and 11 saccharomyces cerevis ... | 2004 | 15565638 |
local induction of the alc gene switch in transgenic tobacco plants by acetaldehyde. | the alc promoter system, derived from the filamentous fungi aspergillus nidulans, allows chemically regulated gene expression in plants and thereby the study of gene function as well as metabolic and developmental processes. in addition to ethanol, this system can be activated by acetaldehyde, described as the physiological inducer in a. nidulans. here, we show that in contrast to ethanol, acetaldehyde allows tissue-specific activation of the alc promoter in transgenic tobacco plants. soil drenc ... | 2004 | 15574832 |
mitochondrial beta-oxidation in aspergillus nidulans. | beta-oxidation (beta-ox) occurs exclusively in the peroxisomes of saccharomyces cerevisiae and other yeasts, leading to the supposition that fungi lack mitochondrial beta-ox. here we present unequivocal evidence that the filamentous fungus aspergillus nidulans houses both peroxisomal and mitochondrial beta-ox. while growth of a peroxisomal beta-ox disruption mutant (deltafoxa) was eliminated on a very long-chain fatty acid (c(22:1)), growth was only partially impeded on a long-chain fatty acid ( ... | 2004 | 15554960 |
partial nuclear pore complex disassembly during closed mitosis in aspergillus nidulans. | many organisms undergo closed mitosis and locate tubulin and mitotic kinases to nuclei only during mitosis. how this is regulated is unknown. interestingly, the nima kinase of aspergillus nidulans interacts with two nuclear pore complex (npc) proteins and nima is required for mitotic localization of the cdk1 kinase to nuclei. therefore, we wished to define the mechanism by which the npc is regulated during a. nidulans' closed mitosis. | 2004 | 15556859 |
patterns of intron gain and loss in fungi. | little is known about the patterns of intron gain and loss or the relative contributions of these two processes to gene evolution. to investigate the dynamics of intron evolution, we analyzed orthologous genes from four filamentous fungal genomes and determined the pattern of intron conservation. we developed a probabilistic model to estimate the most likely rates of intron gain and loss giving rise to these observed conservation patterns. our data reveal the surprising importance of intron gain ... | 2004 | 15562318 |
penicillium chrysogenum glucose oxidase -- a study on its antifungal effects. | purification and characterization of the high molecular mass candida albicans-killing protein secreted by penicillium chrysogenum. | 2004 | 15546411 |
cadre: the central aspergillus data repository. | cadre is a public resource for housing and analysing genomic data extracted from species of aspergillus. it arose to enable maintenance of the complete annotated genomic sequence of aspergillus fumigatus and to provide tools for searching, analysing and visualizing features of fungal genomes. by implementing cadre using ensembl, a framework is in place for storing and comparing several genomes: the resource will thus expand by including other aspergillus genomes (such as aspergillus nidulans) as ... | 2004 | 14681443 |
a phylogenomic approach to reconstructing the diversification of serine proteases in fungi. | using a phylogenomic approach with 10 fungi of very different virulence and habitat, we determined that there was substantial diversification of subtilase-type proteases early in ascomycete history (with subsequent loss in many lineages) but with no comparable diversification of trypsins. patterns of intron loss and the degree of divergence between paralogues demonstrated that the proliferation of proteinase k subtilases and subtilisin type subtilases seen in pathogenic ascomycetes (metarhizium ... | 2004 | 15525405 |
acfkh1, a novel member of the forkhead family, associates with the rfx transcription factor cpcr1 in the cephalosporin c-producing fungus acremonium chrysogenum. | in the filamentous fungus acremonium chrysogenum, a complex regulatory network of transcription factors controls the expression of at least seven cephalosporin c biosynthesis genes. the rfx transcription factor cpcr1 binds to regulatory sequences in the promoter region of cephalosporin c biosynthesis genes, and is involved in the transcriptional regulation of the pcbc gene which encodes isopenicillin n synthase. in this study, we used cpcr1 in a yeast two-hybrid screen to identify potential prot ... | 2004 | 15527986 |
the fungal stre-element-binding protein seb1 is involved but not essential for glycerol dehydrogenase (gld1) gene expression and glycerol accumulation in trichoderma atroviride during osmotic stress. | fungi counteract extracellular osmotic pressure by producing intracellular polyols to prevent loss of water. in yeast osmotic signaling involves a map-kinase pathway culminating at the stre-binding transcription factors msn2/4. we investigated the role of a putative stre-binding orthologue of trichoderma atroviride, seb1, in osmotic stress signaling. t. atroviride, subjected to osmotic stress (10% glucose or glycerol, 1m kcl or nacl), responds by raising its intracellular glycerol level. in cont ... | 2004 | 15531216 |
modulation of the ligand binding properties of the transcription repressor nmra by gata-containing dna and site-directed mutagenesis. | nmra is a negative transcription-regulating protein that binds to the c-terminal region of the gata transcription-activating protein area. the proposed molecular mechanism of action for nmra is to inhibit area binding to its target promoters. in contrast to this proposal, we report that a c-terminal fragment of area can bind individually to gata-containing dna and nmra and that in the presence of a mixture of gata-containing dna and nmra, the area fragment binds preferentially to the gata-contai ... | 2004 | 15537757 |
nek2a interacts with mad1 and possibly functions as a novel integrator of the spindle checkpoint signaling. | chromosome segregation in mitosis is orchestrated by protein kinase signaling cascades. a biochemical cascade named spindle checkpoint ensures the spatial and temporal order of chromosome segregation during mitosis. here we report that spindle checkpoint protein mad1 interacts with nek2a, a human orthologue of the aspergillus nidulans nima kinase. mad1 interacts with nek2a in vitro and in vivo via a leucine zipper-containing domain located at the c terminus of mad1. like mad1, nek2a is localized ... | 2004 | 14978040 |
a putative g protein-coupled receptor negatively controls sexual development in aspergillus nidulans. | g protein-coupled receptors (gpcrs) are key components of heterotrimeric g protein-mediated signalling pathways that detect environmental signals and confer rapid cellular responses. to broaden our understanding of signalling mechanisms in the filamentous fungus aspergillus nidulans, intensive analyses of the aspergillus nidulans genome have been carried out and nine genes (gpra approximately gpri) that are predicted to encode seven transmembrane spanning gpcrs have been identified. six of nine ... | 2004 | 14982628 |
disruption of the gene encoding the v-atpase subunit a results in inhibition of normal growth and abolished sporulation in aspergillus nidulans. | the authors have previously reported on molecular responses of aspergillus nidulans to bacterial antifungal metabolites, e.g. bafilomycins and the related concanamycins. these compounds are known inhibitors of v-atpases and cause dramatic effects on mycelial growth and morphology. in neurospora crassa, studies have shown that disruption of the gene encoding subunit a of the v-atpase results in morphological changes and reduced growth similar to those observed after addition of concanamycin. this ... | 2004 | 14993324 |
recent advances in the characterization of ambient ph regulation of gene expression in filamentous fungi and yeasts. | all microorganisms must adapt to the ph of their environment. one aspect of this adaptation, particularly important for organisms that grow over a wide ph range, is the ability to express appropriately genes whose roles ultimately involve functions at the cell surface or in the environment. genes encoding permeases, secreted enzymes, enzymes involved in synthesis of exported metabolites such as toxins and antibiotics, and probably enzymes modifying secreted proteins posttranslationally all fall ... | 2004 | 15487944 |
gas-inducible transgene expression in mammalian cells and mice. | we describe the design and detailed characterization of a gas-inducible transgene control system functional in different mammalian cells, mice and prototype biopharmaceutical manufacturing. the acetaldehyde-inducible alcr-p(alca) transactivator-promoter interaction of the aspergillus nidulans ethanol-catabolizing regulon was engineered for gas-adjustable transgene expression in mammalian cells. fungal alcr retained its transactivation characteristics in a variety of mammalian cell lines and reve ... | 2004 | 15502819 |
synthesis and antimicrobial activity of some netropsin analogues. | nine novel lexitropsins were synthesized by linking two netropsin-like moieties through three different dicarboxylic acids; 9,10-dihydro-2,7-phenanthrenedicarboxylic acid; [(3-[[(carboxymethyl)amino]carbonyl]benzoyl)amino]acetic acid and indole-2,5-dicarboxylic acid. the netropsin residues were modified by the use of n-isopentylpyrrole, 5-methylthiophene or 5-isopropylthiazole heterocyclic building blocks in place of the usual n-methylpyrrole. the compounds were tested against five gram-positive ... | 2004 | 15505717 |
connection of propionyl-coa metabolism to polyketide biosynthesis in aspergillus nidulans. | propionyl-coa is an intermediate metabolite produced through a variety of pathways including thioesterification of propionate and catabolism of odd chain fatty acids and select amino acids. previously, we found that disruption of the methylcitrate synthase gene, mcsa, which blocks propionyl-coa utilization, as well as growth on propionate impaired production of several polyketides-molecules typically derived from acetyl-coa and malonyl-coa-including sterigmatocystin (st), a potent carcinogen, an ... | 2004 | 15514053 |
[antibiotic properties of some species of genus aspergillus mich]. | antibiotic activity screening of some species of genus aspergillus (64 strains) to different test-organisms (gram positive, gram negative, phytopathogenic bacteria and yeasts) has been carried out. the researched strains a. parvulus, a. ochraceus, a. ustus, a. versicolor, a.fumigatus, a. niger, a. deflectus, a. clavatus were characterized by a wide spectrum of antibiotic activity; the strains a. flavipes, a. sydowii, a. terreus, a. flavus, a. nidulans, a. alliaceus, a. fluticulosus were characte ... | 2004 | 15515902 |
tama interacts with leub, the homologue of saccharomyces cerevisiae leu3p, to regulate gdha expression in aspergillus nidulans. | previous studies have shown that expression of the gdha gene, encoding nadp-linked glutamate dehydrogenase (nadp-gdh), in aspergillus nidulans is regulated by the major nitrogen regulatory protein area and its co-activator tama. we show here that loss of tama function has a more severe effect on the levels of gdha expression than loss of area function. using tama as the bait in a yeast two-hybrid screen, we have identified a second protein that interacts with tama. sequencing analysis and functi ... | 2004 | 15517391 |
regulation of aflatoxin synthesis by fada/camp/protein kinase a signaling in aspergillus parasiticus. | analysis of fada and pkaa mutants in the filamentous fungus aspergillus nidulans demonstrated that fada (galpha) stimulates cyclic amp (camp)-dependent protein kinase a (pka) activity resulting, at least in part, in inhibition of conidiation and sterigmatocystin (st) biosynthesis. in contrast, camp added to the growth medium stimulates aflatoxin (af) synthesis in aspergillus parasiticus. our goal was to explain these conflicting reports and to provide mechanistic detail on the role of fada, camp ... | 2004 | 15518351 |
the early impact of genetics on our understanding of cell cycle regulation in aspergillus nidulans. | the application of genetic analysis was crucial to the rapid progress that has been made in cell cycle research. ron morris, one of the first to apply genetics to cell cycle research, developed aspergillus nidulans into an important model system for the analysis of many aspects of cell biology. within the area of cell cycle research, ron's laboratory is noted for development of novel cell biological and molecular genetic approaches as well as seminal insights regarding the regulation of mitosis, ... | 2004 | 14998523 |
nuclear migration and positioning in filamentous fungi. | genetic analyses of nuclear distribution mutants have indicated that functions of the microtubule motor, cytoplasmic dynein, and its regulators are important for nuclear positioning in filamentous fungi. here we review these studies and also present the need to further dissect how dynein and its associated microtubule cytoskeleton are involved mechanistically in nuclear positioning in the multinucleated hyphae. | 2004 | 14998524 |
tubulins in aspergillus nidulans. | the discovery and characterization of the tubulin superfamily in aspergillus nidulans is described. remarkably, the genes that encode alpha-, beta-, and gamma-tubulins were all identified first in a. nidulans. there are two alpha-tubulin genes, tuba and tubb, two beta-tubulin genes, bena and tubc, and one gamma-tubulin gene, mipa. hyphal tubulin is encoded mainly by the essential genes tuba and bena. tubc is expressed during conidiation and tubb is required for the sexual cycle. promoter swappin ... | 2004 | 14998525 |
aspergillus nidulans as a model system to characterize the dna damage response in eukaryotes. | interest in dna repair in aspergillus nidulans had mainly grown out of studies of three different biological processes, namely mitotic recombination, inducible responses to detrimental environmental changes, and genetic control of the cell cycle. ron morris started the investigation of the genetic control of the cell cycle by screening hundreds of cell cycle temperature sensitive aspergillus mutants. the sequencing and innovative analysis of these genes revealed not only several components of th ... | 2004 | 14998526 |
insight into the genome of aspergillus fumigatus: analysis of a 922 kb region encompassing the nitrate assimilation gene cluster. | aspergillus fumigatus is the most ubiquitous opportunistic filamentous fungal pathogen of human. as an initial step toward sequencing the entire genome of a. fumigatus, which is estimated to be approximately 30 mb in size, we have sequenced a 922 kb region, contained within 16 overlapping bacterial artificial chromosome (bac) clones. fifty-four percent of the dna is predicted to be coding with 341 putative protein coding genes. functional classification of the proteins showed the presence of a h ... | 2004 | 14998527 |
identification of a novel gene hbrb required for polarised growth in aspergillus nidulans. | we have cloned a novel gene, hbrb, by complementation of a temperature sensitive hyperbranching (hbr) mutant of aspergillus nidulans. the mutant, hbrb3, exhibits hyperseptation and shows a marked increase in hyphal branching at the restrictive temperature. a genomic library incorporating the ama1 sequence, which confers autonomous replication on the plasmid, was used to clone the gene. co-ordinate loss of the complementing plasmid and wild type phenotype was shown. the 847 amino acid predicted p ... | 2004 | 14998529 |
a sensitive predictor for potential gpi lipid modification sites in fungal protein sequences and its application to genome-wide studies for aspergillus nidulans, candida albicans, neurospora crassa, saccharomyces cerevisiae and schizosaccharomyces pombe. | the fungal transamidase complex that executes glycosylphosphatidylinositol (gpi) lipid anchoring of precursor proteins has overlapping but distinct sequence specificity compared with the animal system. therefore, a taxon-specific prediction tool for the recognition of the c-terminal signal in fungal sequences is necessary. we have collected a learning set of fungal precursor protein sequences from the literature and fungal proteomes. although the general four segment scheme of the recognition si ... | 2004 | 15003443 |
combining transcriptome data with genomic and cdna sequence alignments to make confident functional assignments for aspergillus nidulans genes. | whole genome sequencing of several filamentous ascomycetes is complete or in progress; these species, such as aspergillus nidulans, are relatives of saccharomyces cerevisiae. however, their genomes are much larger and their gene structure more complex, with genes often containing multiple introns. automated annotation programs can quickly identify open reading frames for hypothetical genes, many of which will be conserved across large evolutionary distances, but further information is required t ... | 2004 | 15449589 |
[rgs proteins (regulators of g protein signaling) and their roles in regulation of immune response]. | rgs proteins (regulators of g-protein signaling) comprise a protein family responsible for regulating g proteins. by enhancing the gtpase activity of the a subunit, they speed up the reconstruction of the heterotrimeric structure of g protein, thus inhibiting its signal transduction. sst2 protein in yeast saccharomyces cervisiae, flba in fungus aspergillus nidulans, and egl-10 in the nematode caenorhabditis elegans are the first native g regulators with gtpase activity (gaps:--gtpase-activating ... | 2004 | 15459549 |
comparison of ligand-induced conformational changes and domain closure mechanisms, between prokaryotic and eukaryotic dehydroquinate synthases. | dehydroquinate synthase (dhqs) is a potential target for the development of novel broad-spectrum antimicrobial drugs, active against both prokaryotes and lower eukaryotes. structures have been reported for aspergillus nidulans dhqs (andhqs) in complexes with a range of ligands. analysis of these andhqs structures showed that a large-scale domain movement occurs during the normal catalytic cycle, with a complex series of structural elements propagating substrate binding-induced conformational cha ... | 2004 | 15465043 |
double-joint pcr: a pcr-based molecular tool for gene manipulations in filamentous fungi. | gene replacement via homologous double crossover in filamentous fungi requires relatively long (preferentially >0.5 kb) flanking regions of the target gene. for this reason, gene replacement cassettes are usually constructed through multiple cloning steps. to facilitate gene function studies in filamentous fungi avoiding tedious cloning steps, we have developed a pcr-assisted dna assembly procedure and applied it to delete genes in filamentous fungi. while the principle of this procedure is esse ... | 2004 | 15465386 |
identification and complementation of abnormal hyphal branch mutants ahba1 and ahbb1 in aspergillus nidulans. | branching generates new axes of polar growth in filamentous fungi and is critical for development, reproduction, and pathogenicity. to investigate branching we screened an aspergillus nidulans temperature-sensitive mutant collection for abnormal hyphal branch (ahb) mutants. we identified two mutants, ahba1, which showed reduced branching relative to wild type at restrictive temperature, and ahbb1, which showed increased branching relative to wild type at restrictive temperature. both mutants als ... | 2004 | 15465388 |
the aspergillus fumigatus cell wall is organized in domains that are remodelled during polarity establishment. | aspergillus fumigatus is a life-threatening and increasingly frequent pathogen of the immunocompromised. like other filamentous fungi a. fumigatus grows in a highly polar manner, adding new cell wall to the apical region of hyphae. mabs were raised against isolated a. fumigatus cell walls. fifteen antibodies bound reproducibly to isolated cell walls in elisas and to the walls of intact cells in immunofluorescence experiments. surprisingly, individual mabs showed distinct patterns of localization ... | 2004 | 15470106 |
introns and splicing elements of five diverse fungi. | genomic sequences and expressed sequence tag data for a diverse group of fungi (saccharomyces cerevisiae, schizosaccharomyces pombe, aspergillus nidulans, neurospora crassa, and cryptococcus neoformans) provided the opportunity to accurately characterize conserved intronic elements. an examination of large intron data sets revealed that fungal introns in general are short, that 98% or more of them belong to the canonical splice site (ss) class (5'gu...ag3'), and that they have polypyrimidine tra ... | 2004 | 15470237 |
rapid production of gene replacement constructs and generation of a green fluorescent protein-tagged centromeric marker in aspergillus nidulans. | a method to rapidly generate gene replacement constructs by fusion pcr is described for aspergillus nidulans. the utility of the approach is demonstrated by green fluorescent protein (gfp) tagging of a. nidulans ndc80 to visualize centromeres through the cell cycle. the methodology makes possible large-scale gfp tagging, promoter swapping, and deletion analysis of a. nidulans. | 2004 | 15470263 |
mesa, a novel fungal protein required for the stabilization of polarity axes in aspergillus nidulans. | the aspergillus nidulans proteome possesses a single formin, sepa, which is required for actin ring formation at septation sites and also plays a role in polarized morphogenesis. previous observations imply that complex regulatory mechanisms control the function of sepa and ensure its correct localization within hyphal tip cells. to characterize these mechanisms, we undertook a screen for mutations that enhance sepa defects. of the mutants recovered, mesa1 causes the most dramatic defect in pola ... | 2004 | 15155805 |
crea-mediated carbon catabolite repression of beta-galactosidase formation in aspergillus nidulans is growth rate dependent. | carbon catabolite repression by the crea-transcriptional repressor is widespread in filamentous fungi, but the mechanism by which glucose triggers carbon catabolite repression is still poorly understood. we investigated the hypothesis that the growth rate on glucose may control crea-dependent carbon catabolite repression by using glucose-limited chemostat cultures and the intracellular beta-galactosidase activity of aspergillus nidulans, which is repressed by glucose, as a model system. chemosta ... | 2004 | 15158274 |
altering a gene involved in nuclear distribution increases the repeat-induced point mutation process in the fungus podospora anserina. | repeat-induced point mutation (rip) is a homology-dependent gene-silencing mechanism that introduces c:g-to-t:a transitions in duplicated dna segments. cis-duplicated sequences can also be affected by another mechanism called premeiotic recombination (pr). both are active over the sexual cycle of some filamentous fungi, e.g., neurospora crassa and podospora anserina. during the sexual cycle, several developmental steps require precise nuclear movement and positioning, but connections between rip ... | 2004 | 15166143 |
streptomyces lividans and brevibacterium lactofermentum as heterologous hosts for the production of x22 xylanase from aspergillus nidulans. | the aspergillus nidulans gene xlna coding for the fungal xylanase x22 has been cloned and expressed in two heterologous bacterial hosts: streptomyces lividans and brevibacterium lactofermentum. streptomyces strains yielded 10 units/ml of xylanase when the protein was produced with its own signal peptide, and 19 units/ml when its signal peptide was replaced by the one for xylanase xys1 from streptomyces halstedii. b. lactofermentum was also able to produce xylanase x22, affording 6 units/ml upon ... | 2004 | 15168093 |
pina is essential for growth and positively influences nima function in aspergillus nidulans. | the phospho-ser/thr-directed prolyl-isomerase pin1 was originally identified in vertebrate systems as a negative regulator of nima, a ser/thr protein kinase that regulates the g(2)/m transition in aspergillus nidulans. here we explore the physiological roles of the pin1 orthologue, pina, in a. nidulans and evaluate the relevance of the interaction of pina with nima in this fungus. we find pina to be an essential gene in a. nidulans. in addition, when pina levels are reduced 50-fold the cells gro ... | 2004 | 15178679 |
the dual nature of the wheat xylanase protein inhibitor xip-i: structural basis for the inhibition of family 10 and family 11 xylanases. | the xylanase inhibitor protein i (xip-i) from wheat triticum aestivum is the prototype of a novel class of cereal protein inhibitors that inhibit fungal xylanases belonging to glycoside hydrolase families 10 (gh10) and 11 (gh11). the crystal structures of xip-i in complex with aspergillus nidulans (gh10) and penicillium funiculosum (gh11) xylanases have been solved at 1.7 and 2.5 a resolution, respectively. the inhibition strategy is novel because xip-i possesses two independent enzyme-binding s ... | 2004 | 15181003 |
fungal metabolic model for type i 3-methylglutaconic aciduria. | aspergillus nidulans catabolizes leu to acetyl-coa and acetoacetate through a pathway homologous to that used by humans. fungal hlya encodes a bifunctional polypeptide comprising the last two enzymes in this pathway, 3-methylglutaconyl-coa hydratase and 3-hydroxy-3-methylglutaryl-coa lyase. hlya transcription is specifically induced by leu. a delta hlya mutation removing the complete 3-methylglutaconyl-coa hydratase c-terminal domain prevents growth on leu but not on lactose or other amino acids ... | 2004 | 15181004 |
molecular characterization of protein o-mannosyltransferase and its involvement in cell-wall synthesis in aspergillus nidulans. | protein o-glycosylation is essential for protein modification and plays important roles in eukaryotic cells. o-mannosylation of proteins occurs in the filamentous fungus aspergillus. the structure and function of the pmta gene, encoding protein o-d-mannosyltransferase, which is responsible for the initial o-mannosylation reaction in aspergillus nidulans, was characterized. disruption of the pmta gene resulted in the reduction of in vitro protein o-d-mannosyltransferase activity to 6 % of that of ... | 2004 | 15184583 |
the kip3-like kinesin kipb moves along microtubules and determines spindle position during synchronized mitoses in aspergillus nidulans hyphae. | kinesins are motor proteins which are classified into 11 different families. we identified 11 kinesin-like proteins in the genome of the filamentous fungus aspergillus nidulans. relatedness analyses based on the motor domains grouped them into nine families. in this paper, we characterize kipb as a member of the kip3 family of microtubule depolymerases. the closest homologues of kipb are saccharomyces cerevisiae kip3 and schizosaccharomyces pombe klp5 and klp6, but sequence similarities outside ... | 2004 | 15189985 |
candida albicans rim13p, a protease required for rim101p processing at acidic and alkaline phs. | candida albicans is an important commensal of mucosal surfaces that is also an opportunistic pathogen. this organism colonizes a wide range of host sites that differ in ph; thus, it must respond appropriately to this environmental stress to survive. the ability to respond to neutral-to-alkaline phs is governed in part by the rim101 signal transduction pathway. here we describe the analysis of c. albicans rim13p, a homolog of the rim13p/palb calpain-like protease member of the rim101/pacc pathway ... | 2004 | 15189995 |
successful elimination of an invasive aspergillus nidulans lung infection by voriconazole after failure of a combination of caspofungin and liposomal amphotericin b in a boy with chronic granulomatous disease. | chronic granulomatous disease is an inherited defect in host defense mechanisms mainly affecting neutrophil function. pulmonary infection with aspergillus nidulans in a child with chronic granulomatous disease could not be eliminated by a combination of caspofungin and liposomal amphotericin b. voriconazole was successful in clearing the infection. | 2004 | 15194848 |
a nudel-dependent mechanism of neurofilament assembly regulates the integrity of cns neurons. | the cytoskeleton controls the architecture and survival of central nervous system (cns) neurons by maintaining the stability of axons and dendrites. although neurofilaments (nfs) constitute the main cytoskeletal network in these structures, the mechanism that underlies subunit incorporation into filaments remains a mystery. here we report that nudel, a mammalian homologue of the aspergillus nidulans nuclear distribution molecule nude, is important for nf assembly, transport and neuronal integrit ... | 2004 | 15208636 |
regulators of g-protein signalling in aspergillus nidulans: rgsa downregulates stress response and stimulates asexual sporulation through attenuation of ganb (galpha) signalling. | regulators of g-protein signalling play a crucial role in controlling the degree of heterotrimeric g-protein signalling. in addition to the previously studied flba, we have identified three genes (rgsa, rgsb and rgsc) encoding putative rgs proteins in the genome of aspergillus nidulans. characterization of the rgsa gene revealed that rgsa downregulates pigment production and conidial germination, but stimulates asexual sporulation (conidiation). deletion of rgsa (deltargsa) resulted in reduced c ... | 2004 | 15228532 |
tangled nudels? | 2004 | 15232582 | |
agrobacterium tumefaciens-mediated genetic transformation of the entomopathogenic fungus beauveria bassiana. | agrobacterium tumefaciens-mediated transformation (agro-transformation) was successfully applied to the entomogenous fungus beauveria bassiana. conidia of b. bassiana were transformed to hygromycin b resistance using the hph gene of escherichia coli as the selective trait, under the control of a heterologous fungal promoter and the aspergillus nidulans trpc terminator. the efficiency of transformation was up to 28 and 96 transformants per 10(4) and 10(5) target conidia, respectively, using three ... | 2004 | 15234517 |
airborne fungi in industrial environments--potential agents of respiratory diseases. | investigations on airborne fungi in a poultry house, a swinery, a feed preparing and storing house, a grain mill, a wooden panel producing factory, and organic waste recycling facilities have been carried out in lithuania. low concentrations of fungal spores were detected in the wooden panel producing factory, the swinery, the feed preparing and storing house, and the poultry house; moderate concentrations were found in the organic waste recycling facilities; high concentrations were revealed at ... | 2004 | 15236494 |
ph control of the production of recombinant glucose oxidase in aspergillus nidulans. | recombinant aspergillus nidulans sval040, capable of synthesizing and secreting glucose oxidase derived from aspergillus niger was used to study the influence of ph and carbon source on enzyme production. | 2004 | 15239699 |
the pho80-like cyclin of aspergillus nidulans regulates development independently of its role in phosphate acquisition. | in saccharomyces cerevisiae, phosphate acquisition enzymes are regulated by a cyclin-dependent kinase (pho85), a cyclin (pho80), the cyclin-dependent kinase inhibitor pho81, and the helix-loop-helix transcription factor pho4 (the pho system). previous studies in aspergillus nidulans indicate that a pho85-like kinase, phoa, does not regulate the classic pho system but regulates development in a phosphate-dependent manner. a pho80-like cyclin has now been isolated through its interaction with phoa ... | 2004 | 15247298 |
a role for cred, a carbon catabolite repression gene from aspergillus nidulans, in ubiquitination. | in aspergillus nidulans, it is known that creb encodes a deubiquitinating enzyme that forms a complex with the wd40 motif containing protein encoded by crec, that mutations in these genes lead to altered carbon source utilization and that the cred34 mutation suppresses the phenotypic effects of mutations in crec and creb. therefore, cred was characterized in order to dissect the regulatory network that involves the creb-crec deubiquitination complex. cred contains arrestin domains and py motifs ... | 2004 | 15255903 |
physiological and morphological changes in autolyzing aspergillus nidulans cultures. | physiological and morphological changes in carbon-limited autolyzing cultures of aspergillus nidulans were described. the carbon starvation arrested conidiation while the formation of filamentous and "yeast-like" hyphal fragments with profoundly altered metabolism enabled the fungus to survive the nutritional stress. the morphological and physiological stress responses, which maintained the cellular integrity of surviving hyphal fragments at the expense of autolyzing cells, were highly concerted ... | 2004 | 15259768 |
on the mechanism of action of the antifungal agent propionate. | propionate is used to protect bread and animal feed from moulds. the mode of action of this short-chain fatty acid was studied using aspergillus nidulans as a model organism. the filamentous fungus is able to grow slowly on propionate, which is oxidized to acetyl-coa via propionyl-coa, methylcitrate and pyruvate. propionate inhibits growth of a. nidulans on glucose but not on acetate; the latter was shown to inhibit propionate oxidation. when grown on glucose a methylcitrate synthase deletion mu ... | 2004 | 15265042 |
the ganb galpha-protein negatively regulates asexual sporulation and plays a positive role in conidial germination in aspergillus nidulans. | we isolated the ganb gene encoding the galpha-protein homolog from aspergillus nidulans. to investigate the cellular function of ganb, various mutant strains were isolated. deletion of constitutively inactive ganb mutants showed conidiation and derepressed brla expression in a submerged culture. constitutive activation of ganb caused a reduction in hyphal growth and a severe defect in asexual sporulation. we therefore propose that ganb may negatively regulate asexual sporulation through the brla ... | 2004 | 15280244 |
molecular cloning and characterization of a cdna encoding the n-acetyl-beta-d-glucosaminidase homologue of paracoccidioides brasiliensis. | a cdna encoding the n-acetyl-beta-d-glucosaminidase (nag) protein of paracoccidioides brasiliensis, pb nag1, was cloned and characterized. the 2663-nucleotide sequence of the cdna consisted of a single open reading frame encoding a protein with a predicted molecular mass of 64.73 kda and an isoeletric point of 6.35. the predicted protein includes a putative 30-amino-acid signal peptide. the protein as a whole shares considerable sequence similarity with 'classic' nag. the primary sequence of pb ... | 2004 | 15283239 |
vea is required for toxin and sclerotial production in aspergillus parasiticus. | it was long been noted that secondary metabolism is associated with fungal development. in aspergillus nidulans, conidiation and mycotoxin production are linked by a g protein signaling pathway. also in a. nidulans, cleistothecial development and mycotoxin production are controlled by a gene called vea. here we report the characterization of a vea ortholog in the aflatoxin-producing fungus a. parasiticus. cleistothecia are not produced by aspergillus parasiticus; instead, this fungus produces sp ... | 2004 | 15294809 |
rapid differentiation of aspergillus species from other medically important opportunistic molds and yeasts by pcr-enzyme immunoassay. | we developed a pcr-based assay to differentiate medically important species of aspergillus from one another and from other opportunistic molds and yeasts by employing universal, fungus-specific primers and dna probes in an enzyme immunoassay format (pcr-eia). oligonucleotide probes, directed to the internal transcribed spacer 2 region of ribosomal dna from aspergillus flavus, aspergillus fumigatus, aspergillus nidulans, aspergillus niger, aspergillus terreus, aspergillus ustus, and aspergillus v ... | 2004 | 15297489 |
the metarhizium anisopliae trp1 gene: cloning and regulatory analysis. | the trp1 gene from the entomopathogenic fungus metarhizium anisopliae, cloned by heterologous hybridization with the plasmid carrying the trpc gene from aspergillus nidulans, was sequence characterized. the predicted translation product has the conserved catalytic domains of glutamine amidotransferase (g domain), indoleglycerolphosphate synthase (c domain), and phosphoribosyl anthranilate isomerase (f domain) organized as nh2-g-c-f-cooh. the orf is interrupted by a single intron of 60 nt that is ... | 2004 | 15297933 |
effect of ph on the stability of pleurotus eryngii versatile peroxidase during heterologous production in emericella nidulans. | complementary dna (cdna) encoding the new versatile peroxidase from the ligninolytic basidiomycete pleurotus eryngii has been expressed in the ascomycete emericella nidulans. in recombinant e. nidulans cultures, the ph reached values as high as 8.3, correlating with a sharp decrease in peroxidase activity. peroxidase was rapidly inactivated at alkaline ph, but was comparatively stable at acidic ph. the peroxidase inactivation in alkaline buffer could be reversed by adding ca(2+) and lowering the ... | 2004 | 15300480 |
chpa, a cysteine- and histidine-rich-domain-containing protein, contributes to maintenance of the diploid state in aspergillus nidulans. | the alternation of eukaryotic life cycles between haploid and diploid phases is crucial for maintaining genetic diversity. in some organisms, the growth and development of haploid and diploid phases are nearly identical, and one might suppose that all genes required for one phase are likely to be critical for the other phase. here, we show that targeted disruption of the chpa (cysteine- and histidine-rich-domain- [chord]-containing protein a) gene in haploid aspergillus nidulans strains gives ri ... | 2004 | 15302831 |
prp8 intein in fungal pathogens: target for potential antifungal drugs. | inteins are self-splicing intervening sequences in proteins, and inteins of pathogenic organisms can be attractive drug targets. here, we report an intein in important fungal pathogens including aspergillus fumigatus, aspergillus nidulans, histoplasma capsulatum, and different serotypes of cryptococcus neoformans. this intein is inside the extremely conserved and functionally essential prp8 protein, and it varies in size from 170 aa in c. neoformans to 819 aa in a. fumigatus, which is caused by ... | 2004 | 15304322 |
effect of vitamin e on autolysis and sporulation of aspergillus nidulans. | the morphologic and physiologic effects of vitamin e, a powerful antioxidant, on the autolysis and sporulation of aspergillus nidulans fgsc26 were studied. in carbon-depleted submerged cultures, reactive oxygen species (ros) accumulated in the cells and, concomitantly, progressing autolysis was observed, which was characterized by decreasing dry cell masses and pellet diameters as well as by increasing extracellular chitinase activities. vitamin e supplemented at a concentration of 1 g/l hindere ... | 2004 | 15304761 |
influence of fadag203r and deltaflba mutations on morphology and physiology of submerged aspergillus nidulans cultures. | morphologic and physiologic changes taking place in carbon-limited submerged cultures of aspergillus nidulans deltaflba and fadag203r strains were studied. loss-of-function mutation of the flba gene resulted in an altered germination with unusually thick germination tubes, "fluffy" pellet morphology, as well as a reduced fragmentation rate of hyphae during autolysis. in the fadag203r mutant strain, conidiophores formed in the stationary phase of growth, and the size of pellets shrank considerabl ... | 2004 | 15304762 |
histone methyltransferases in aspergillus nidulans: evidence for a novel enzyme with a unique substrate specificity. | we have studied enzymes involved in histone arginine methylation in the filamentous fungus aspergillus nidulans. three distinct protein arginine methyltransferases (prmts) could be identified, which all exhibit intrinsic histone methyltransferase activity when expressed as glutathione s-transferase (gst) fusion proteins. two of these proteins, termed rmta (arginine methyltransferase a) and rmtc, reveal significant sequence homology to the well-characterized human proteins prmt1 and prmt5, respec ... | 2004 | 15311944 |
an appropriate increase in the transcription of aspergillus nidulans uvsc improved gene targeting efficiency. | gene targeting to knock out the activity of specific genes has become important due to recent progress in genomics research. but this technique is still unavailable for many organisms, including economically important microorganisms, due to the high background of ectopic integration during genetic transformation. strategies to improve targeting efficiency have included manipulating the expression of genes that are involved in homologous recombination. in this study, transcription of aspergillus ... | 2004 | 15322347 |
unprecedented mechanism of chain length determination in fungal aromatic polyketide synthases. | fungal aromatic polyketides show remarkable structural diversity fundamentally derived from variations in chain length and cyclization pattern. their basic skeletons are synthesized by multifunctional iterative type i polyketide synthases (pkss). recently, we have found that the c-terminal thioesterase (te)-like domain of aspergillus nidulans wa catalyzes claisen-type cyclization to form the b-ring of naphthopyrone ywa1. here we report the unprecedented mechanism of chain length determination by ... | 2004 | 15324811 |
a single subunit of a heterotrimeric ccaat-binding complex carries a nuclear localization signal: piggy back transport of the pre-assembled complex to the nucleus. | an unresolved question concerns the nuclear localization of the heterotrimeric ccaat-binding complex, which is evolutionarily conserved in eukaryotic organisms including fungi, plants and mammals. all three subunits are necessary for dna binding. in the filamentous fungus aspergillus nidulans the corresponding complex was designated ancf (a.nidulans ccaat-binding factor). ancf consists of the hapb, hapc and hape subunits. here, by using various green fluorescent protein constructs, a nuclear loc ... | 2004 | 15327951 |
identification and characterization of a novel delta12-fatty acid desaturase gene from rhizopus arrhizus. | based on the sequence information of delta12-fatty acid desaturase genes (from mucor circinelloides, mortierella alpina, mucor rouxii and aspergillus nidulans), which were involved in the conversion from c18:1 to c18:2, a cdna sequence putatively encoding a delta12-fatty acid desaturase was isolated from rhizopus arrhizus using the combination of reverse transcription-polymerase chain reaction (rt-pcr) and rapid amplification of cdna ends (race) methods. sequence analysis indicated that it had a ... | 2004 | 15327973 |
terbinafine resistance mediated by salicylate 1-monooxygenase in aspergillus nidulans. | resistance to antifungal agents is a recurring and growing problem among patients with systemic fungal infections. uv-induced aspergillus nidulans mutants resistant to terbinafine have been identified, and we report here the characterization of one such gene. a sib-selected, 6.6-kb genomic dna fragment encodes a salicylate 1-monooxygenase (sala), and a fatty acid synthase subunit (fasc) confers terbinafine resistance upon transformation of a sensitive strain. subfragments carrying sala but not f ... | 2004 | 15328121 |
the gpra and gprb genes encode putative g protein-coupled receptors required for self-fertilization in aspergillus nidulans. | the filamentous fungus aspergillus nidulans possesses both asexual and sexual reproductive cycles. sexual fruiting bodies (cleistothecia) can be formed in both homothallic (self) and heterothallic (outcross) conditions. in this study, we characterized two genes, gpra and gprb, that are predicted to encode putative g protein-coupled receptors (gpcrs) similar to fungal pheromone receptors. deletion (delta) of gpra or gprb resulted in the production of a few small cleistothecia carrying a reduced n ... | 2004 | 15341643 |
the aspergillus nidulans npka gene encodes a cdc2-related kinase that genetically interacts with the uvsbatr kinase. | the dna damage response is a protective mechanism that ensures the maintenance of genomic integrity. we have used aspergillus nidulans as a model system to characterize the dna damage response caused by the antitopoisomerase i drug, camptothecin. we report the molecular characterization of a p34cdc2-related gene, npka, from a. nidulans. the npka gene is transcriptionally induced by camptothecin and other dna-damaging agents, and its induction in the presence of camptothecin is dependent on the u ... | 2004 | 15342504 |
characterization of the aspergillus parasiticus delta12-desaturase gene: a role for lipid metabolism in the aspergillus-seed interaction. | in the mycotoxigenic oilseed pathogens aspergillus flavus and aspergillus parasiticus and the model filamentous fungus aspergillus nidulans, unsaturated fatty acids and their derivatives act as important developmental signals that affect asexual conidiospore, sexual ascospore and/or sclerotial development. to dissect the relationship between lipid metabolism and fungal development, an a. parasiticus delta(12)-desaturase mutant that was unable to convert oleic acid to linoleic acid and was thus i ... | 2004 | 15347747 |
the role of thiol species in the hypertolerance of aspergillus sp. p37 to arsenic. | aspergillus sp. p37 is an arsenate-hypertolerant fungus isolated from a river in spain with a long history of contamination with metals. this strain is able to grow in the presence of 0.2 m arsenate, i.e. 20-fold higher than the reference strain, aspergillus nidulans ts1. although aspergillus sp. p37 reduces as(v) to as(iii), which is slowly pumped out of the cell, the measured efflux of oxyanions is insufficient to explain the high tolerance levels of this strain. to gain an insight into this p ... | 2004 | 15364940 |
efficient gene disruption in the koji-mold aspergillus sojae using a novel variation of the positive-negative method. | when no phenotypic screen is available, gene disruption in the koji-mold aspergillus sojae is a time-consuming process, owing to the low frequency of homologous recombination. to achieve efficient gene disruption in the koji-mold, we developed a novel positive-negative selection method to enrich for homologous recombinants. the pyrg gene from a. sojae was used as a positive selection marker for transformants, and the olic31 gene of a. nidulans, which codes for a mutant form of subunit 9 of the f ... | 2004 | 15375695 |
functional analysis of the homoserine o-acetyltransferase gene and its identification as a selectable marker in gibberella zeae. | we used restriction enzyme-mediated integration (remi) to identify a methionine auxotrophic mutant of gibberella zeae, an important cereal pathogen. in addition to its methionine requirement, the g. zeae remi mutant designated z43r3912 showed pleiotropic phenotypes, including reduced virulence on host plants and lack of sexual development. outcrossing of z43r3912 with a mat1-1 deletion strain confirmed that the mutation of z43r3912 was tagged with the hygromycin b resistance marker. the vector i ... | 2004 | 15378266 |
inhibitors of types i and ii dehydroquinase. | inhibitors of varying potency have been developed for types i and ii 3-dehydroquinate dehydratase (dehydroquinase), enzymes from the shikimate and quinate pathways that catalyse the dehydration of dehydroquinate to dehydroshikimate. these inhibitors have resulted from enzyme mechanistic studies and from the direct search for enzyme inhibitors with herbicidal, fungicidal or antimicrobial potential. this review discusses the design of the various inhibitors that have been produced so far and some ... | 2004 | 15379642 |
unique biosynthesis of dehydroquinic acid? | a search of the genomic sequences of the thermophilic microorganisms aquifex aeolicus, archaeoglobus fulgidus, methanobacterium thermoautotrophicum, and methanococcus jannaschii for the first seven enzymes (arog, b, d, e, k, a, and c ) involved in the shikimic acid biosynthetic pathway reveal two key enzymes are missing. the first enzyme in the pathway, 3-deoxy-d-arabino-heptulosonic acid 7-phosphate synthase (arog) and the second enzyme in the pathway, 5-dehydroquinic acid synthase (arob) are " ... | 2004 | 15381397 |
multi-copy suppression of an aspergillus nidulans mutant sensitive to camptothecin by a putative monocarboxylate transporter. | the mono carboxylate transporter (mct) is a family of membrane proteins from the major facilitator superfamily (mfs) of transporters. here, we report the first identified aspergillus nidulans mct homologue, amca. the amca gene was isolated by high copy number suppression of the hydroxyurea (hu) sensitivity of an a. nidulans camptothecin-sensitive mutant. expression of amca is increased when hyphae are grown in media containing acetate or pyruvate as single carbon source, and after exposure to se ... | 2004 | 15386109 |
the effect of crea in glucose and xylose catabolism in aspergillus nidulans. | the catabolism of glucose and xylose was studied in a wild type and crea deleted (carbon catabolite de-repressed) strain of aspergillus nidulans. both strains were cultivated in bioreactors with either glucose or xylose as the sole carbon source, or in the presence of both sugars. in the cultivations on single carbon sources, it was demonstrated that xylose acted as a carbon catabolite repressor (xylose cultivations), while the enzymes in the xylose utilisation pathway were also subject to repre ... | 2004 | 12920487 |
the azga purine transporter of aspergillus nidulans. characterization of a protein belonging to a new phylogenetic cluster. | the azga gene of aspergillus nidulans encodes a hypoxanthine-adenine-guanine transporter. it has been cloned by a novel transposon methodology. the null phenotype of azga was defined by a number of mutations, including a large deletion. in mycelia, the azga gene is, like other genes of purine catabolism, induced by uric acid and repressed by ammonium. its transcription depends on the pathway-specific uay zinc binuclear cluster protein and the broad domain area gata factor. azga is not closely re ... | 2004 | 14597637 |