Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| a protein kinase c-encoding gene, pkca, is essential to the viability of the filamentous fungus aspergillus nidulans. | a protein kinase c (pkc)-encoding gene (pkca) was isolated from the filamentous fungus aspergillus nidulans. although we attempted to isolate pkca deletion mutants, we obtained only heterokaryons that had both deltapkca and pkca(+) nuclei. conidia produced by the heterokaryon germinated. the germ tubes, however, lysed frequently and no colony formation was observed, indicating that the pkca gene is essential to the viability of a. nidulans. we constructed conditional mutants (alca(p)-pkca mutant ... | 2007 | 17986778 |
| identification of nutrient-dependent changes in extracellular ph and acid phosphatase secretion in aspergillus nidulans. | the present study was designed to identify nutrient-dependent changes in extracellular ph and acid phosphatase secretion in the bia1 palc4 mutant strain of aspergillus nidulans. the palc4 mutant was selected as lacking alkaline phosphatase, but having substantially increased acid phosphatase activity when grown on solid minimal medium under phosphate starvation, ph 6.5. gene palc was identified as a putative member of a conserved signaling cascade involved in ambient alkaline sensing whose sole ... | 2007 | 18050093 |
| [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 |
| regulation of hyphal morphogenesis by cdc42 and rac1 homologues in aspergillus nidulans. | the ability of filamentous fungi to form hyphae requires the establishment and maintenance of a stable polarity axis. based on studies in yeasts and animals, the gtpases cdc42 and rac1 are presumed to play a central role in organizing the morphogenetic machinery to enable axis formation and stabilization. here, we report that cdc42 (moda) and rac1 (raca) share an overlapping function required for polarity establishment in aspergillus nidulans. nevertheless, cdc42 appears to have a more important ... | 2007 | 18005099 |
| 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 |
| [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 |
| a type b feruloyl esterase from aspergillus nidulans with broad ph applicability. | a hypothetical protein an1772.2 of aspergillus nidulans was found to have a 56% identity with a known type c ferulic acid esterase (fae) from talaromyces stipitatus. in addition, it contained a 13-amino acid conserved region flanking the characteristic g-x-s-x-g motif of a serine esterase, suggesting a fae function for the protein. the putative fae was successfully cloned from the genomic dna and expressed in saccharomyces cerevisiae. the recombinant protein exhibited high fae activities. theref ... | 2007 | 17043824 |
| role of microtubules in tip growth of fungi. | polarized cell growth is observed ubiquitously in all living organisms. tip growth of filamentous fungi serves as a typical model for polar growth. it is well known that the actin cytoskeleton plays a central role in cellular growth. in contrast, the role of microtubules in polar growth of fungal tip cells has not been critically addressed. our recent study, using a green fluorescent protein (gfp)-labeled tubulin-expressing strain of the filamentous fungus aspergillus nidulans and treatment with ... | 2007 | 17021934 |
| aspergillus nidulans vea subcellular localization is dependent on the importin alpha carrier and on light. | the vea gene is a light-dependent regulator governing development and secondary metabolism in aspergillus nidulans. we have identified a putative bipartite nuclear localization signal (nls) motif in the a. nidulans vea amino acid sequence and demonstrated its functionality when expressed in yeast. furthermore, migration of vea to the nucleus was dependent on the importin alpha. this bipartite nls is also functional when vea is expressed in a. nidulans. interestingly, we found that vea migration ... | 2007 | 17163983 |
| an allosteric-feedback mechanism for protein-assisted group i intron splicing. | the i-anii maturase facilitates self-splicing of a mitochondrial group i intron in aspergillus nidulans. binding occurs in at least two steps: first, a specific but labile encounter complex rapidly forms and then this intermediate is slowly resolved into a native, catalytically active rna/protein complex. here we probe the structure of the rna throughout the assembly pathway. although inherently unstable, the intron core, when bound by i-anii, undergoes rapid folding to a near-native state in th ... | 2007 | 17164477 |
| optimization of heterologous production of the polyketide 6-msa in saccharomyces cerevisiae. | polyketides are a group of natural products that have gained much interest due to their use as antibiotics, cholesterol lowering agents, immunosuppressors, and as other drugs. many organisms that naturally produce polyketides are difficult to cultivate and only produce these metabolites in small amounts. it is therefore of general interest to transfer polyketide synthase (pks) genes from their natural sources into heterologous hosts that can over-produce the corresponding polyketides. in this st ... | 2007 | 17171715 |
| the first filamentous fungal genome sequences: aspergillus leads the way for essential everyday resources or dusty museum specimens? | the published aspergillus genome sequences (a. nidulans, a. fumigatus, a. oryzae) and further sequence data from a. clavatus, neosartorya fischeri, a. flavus, a. niger, a. parasiticus and a. terreus are the first from a group of related filamentous fungi. they indicate the gains possible from genomic approaches, but also problems that arise after the sequences are finished. benefits include a greater understanding of genome structure and evolution, insights into gene regulation, predictions of n ... | 2007 | 17185529 |
| susceptibility of environmental versus clinical strains of pathogenic aspergillus. | the objective of this study was to compare the antifungal susceptibility profiles of 307 environmental strains and 139 clinical isolates of aspergillus belonging to six different species. clinical and environmental strains with minimal inhibitory concentrations (mics) or minimal effective concentrations >or=4microg/ml to amphotericin b (amb), itraconazole (itc), voriconazole and caspofungin were seldom detected. however, the susceptibility profile of environmental aspergillus non-fumigatus strai ... | 2007 | 17189101 |
| novel phacb-encoded cytochrome p450 monooxygenase from aspergillus nidulans with 3-hydroxyphenylacetate 6-hydroxylase and 3,4-dihydroxyphenylacetate 6-hydroxylase activities. | aspergillus nidulans catabolizes phenylacetate (phac) and 3-hydroxy-, 4-hydroxy-, and 3,4-dihydroxyphenylacetate (3-oh-phac, 4-oh-phac, and 3,4-dioh-phac, respectively) through the 2,5-dihydroxyphenylacetate (homogentisic acid) catabolic pathway. using cdna subtraction techniques, we isolated a gene, denoted phacb, which is strongly induced by phac (and its hydroxyderivatives) and encodes a new cytochrome p450 (cyp450). a disrupted phacb strain (delta phacb) does not grow on 3-hydroxy-, 4-hydrox ... | 2007 | 17189487 |
| nuclear export of the transcription factor nira is a regulatory checkpoint for nitrate induction in aspergillus nidulans. | nira, the specific transcription factor of the nitrate assimilation pathway of aspergillus nidulans, accumulates in the nucleus upon induction by nitrate. nira interacts with the nuclear export factor kapk, which bridges an interaction with a protein of the nucleoporin-like family (npla). nitrate induction disrupts the nira-kapk interaction in vivo, whereas kapk associates with nira when this protein is exported from the nucleus. a kpak leptomycin-sensitive mutation leads to inducer-independent ... | 2007 | 17116695 |
| the protein kinase c orthologue pkca plays a role in cell wall integrity and polarized growth in aspergillus nidulans. | the calc2 mutation in aspergillus nidulans causes hypersensitivity to calcofluor white, along with other drug sensitivities that indicate a defect in cell wall integrity. we have cloned calc by complementation, isolating the a. nidulans orthologue of protein kinase c (pkca). the pkca allele of the calc2 strain contains a mutation predicted to introduce a charged arginine residue in place of neutral glycine at a conserved site located immediately beside the c1b regulatory domain. both pkca and ca ... | 2007 | 17118679 |
| a chitinase gene, chib, involved in the autolytic process of aspergillus nidulans. | chitinases are thought to be involved in the morphogenesis and autolysis of filamentous fungi. we cloned a gene (chib) encoding a class v chitinase from aspergillus nidulans. chib expressed in escherichia coli had chitin-hydrolyzing activity, indicating that chib encoded a chitinase. deletion of chib affected neither germination efficiency nor hyphal growth rate, but considerably reduced the intracellular and extracellular chitinase activities. the decrease in hyphal dry weight during autolytic ... | 2007 | 17119968 |
| differential physiological and developmental expression of the uapa and azga purine transporters in aspergillus nidulans. | in this article we study the cellular expression of uapa and azga, the two major purine transporters of aspergillus nidulans, by constructing strains expressing, from their native promoters, fully functional fluorescent (uapa-sgfp, azga-sgfp) or immunological (uapa-his) chimeric transporters. epifluorescence microscopy and immunodetection showed that under different physiological conditions and during aspergillus development: (i) uapa and azga expression in the plasma membrane becomes evident ea ... | 2007 | 17126042 |
| a synchrotron ftir microspectroscopy investigation of fungal hyphae grown under optimal and stressed conditions. | synchrotron ftir can provide high spatial resolution (<10 microm pixel size) in situ biochemical analyses of intact biotissues, an area of increasing importance in the post-genomic era, as gene functions and gene networks are coming under direct scrutiny. with this technique, we can simultaneously assess multiple aspects of cell biochemistry and cytoplasmic composition. in this paper, we report the first results of our synchrotron ftir examination of hyphae of three important fungal model system ... | 2007 | 17106657 |
| aspergillus nidulans dis1/xmap215 protein alpa localizes to spindle pole bodies and microtubule plus ends and contributes to growth directionality. | the dynamics of cytoplasmic microtubules (mts) is largely controlled by a protein complex at the mt plus end. in schizosaccharomyces pombe and in filamentous fungi, mt plus end-associated proteins also determine growth directionality. we have characterized the dis1/xmap215 family protein alpa from aspergillus nidulans and show that it determines mt dynamics as well as hyphal morphology. green fluorescent protein-tagged alpa localized to mt-organizing centers (centrosomes) and to mt plus ends. th ... | 2007 | 17237365 |
| point mutations in the stem region and the fourth aaa domain of cytoplasmic dynein heavy chain partially suppress the phenotype of nudf/lis1 loss in aspergillus nidulans. | cytoplasmic dynein performs multiple cellular tasks but its regulation remains unclear. the dynein heavy chain has a n-terminal stem that binds to other subunits and a c-terminal motor unit that contains six aaa (atpase associated with cellular activities) domains and a microtubule-binding site located between aaa4 and aaa5. in aspergillus nidulans, nudf (a lis1 homolog) functions in the dynein pathway, and two nudf6 partial suppressors were mapped to the nuda dynein heavy chain locus. here we i ... | 2007 | 17237507 |
| a novel interaction between n-myristoylation and the 26s proteasome during cell morphogenesis. | n-myristoylation is a protein lipidation event in which myristate is covalently linked to the n-terminal glycine of target proteins. in aspergillus nidulans, the n-myristoylation deficient swof1 mutant was previously shown to lose cell polarity during the early morphogenic event of germ tube emergence. to further investigate this defect, we mutagenized swof1 and recovered six partial suppressors designated ssf (suppressor of swof1). the secondary mutations enabled swof1 to partially bypass its g ... | 2007 | 17238925 |
| highly efficient concerted evolution in the ribosomal dna repeats: total rdna repeat variation revealed by whole-genome shotgun sequence data. | repeat families within genomes are often maintained with similar sequences. traditionally, this has been explained by concerted evolution, where repeats in an array evolve "in concert" with the same sequence via continual turnover of repeats by recombination. another form of evolution, birth-and-death evolution, can also explain this pattern, although in this case selection is the critical force maintaining the repeats. the level of intragenomic variation is the key difference between these two ... | 2007 | 17200233 |
| sulfate transport in aspergillus nidulans: a novel gene encoding alternative sulfate transporter. | in aspergillus nidulans sulfate is taken up by sulfate permease encoded by the sb gene. a unique tight auxotrophic mutant with an impaired promoter region of the sulfate permease gene, sb1(pr), was isolated. three suppressor genes were cloned by complementation of this mutation. one of them, described here, is the asta gene (alternative sulfate transporter) derived from a genomic library of the japanese a. nidulans iam 2006 strain. in the reference strain of glasgow origin the asta gene was foun ... | 2007 | 17223367 |
| characterization of regulatory non-catalytic hexokinases in aspergillus nidulans. | hexokinases catalyse the first step in glucose metabolism and play a role in glucose sensing in mammals, plants and fungi. we describe a new class of hexokinases that appear to be solely regulatory in function. the aspergillus nidulans hxkd gene (formerly named xprf) encodes a hexokinase-like protein. we constructed hxkddelta gene disruption mutants which showed increased levels of extracellular protease in response to carbon starvation. the hxkddelta mutations are not completely recessive, indi ... | 2007 | 17226029 |
| development of novel real-time pcr assays for detection and differentiation of eleven medically important aspergillus and candida species in clinical specimens. | in the present study, novel real-time pcr assays targeting the fungal its2 region were developed for the detection and differentiation of medically important aspergillus species (aspergillus fumigatus, aspergillus flavus, aspergillus nidulans, aspergillus niger, and aspergillus terreus) and candida species (candida albicans, candida dubliniensis, candida glabrata, candida krusei, candida parapsilosis, and candida tropicalis) using a lightcycler instrument. the combination of a group-specific and ... | 2007 | 17251398 |
| two aspergillus nidulans genes encoding methylenetetrahydrofolate reductases are up-regulated by homocysteine. | methylenetetrahydrofolate reductase (mthfr) catalyzes the reduction of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a co-substrate in the synthesis of methionine from homocysteine. we have cloned and characterized two aspergillus nidulans genes encoding mthfrs: meta and metf. mutations in either gene result in methionine requirement; the meta-encoded enzyme is responsible for only 10-15% of total mthfr activity. these two enzymes belong to different classes of mthfrs. mutations in ... | 2007 | 17257865 |
| proteome map of aspergillus nidulans during osmoadaptation. | the model filamentous fungus aspergillus nidulans, when grown in a moderate level of osmolyte (+0.6m kcl), was previously found to have a significantly reduced cell wall elasticity (biotech prog, 21:292, 2005). in this study, comparative proteomic analysis via two-dimensional gel electrophoresis (2de) and matrix-assisted laser desorption ionization/time-of-flight (maldi-tof) mass spectrometry was used to assess molecular level events associated with this phenomenon. thirty of 90 differentially e ... | 2007 | 17258477 |
| synthesis, characterization and biological activity of complexes of 2-hydroxy-3,5-dimethylacetophenoneoxime (hdmaox) with copper(ii), cobalt(ii), nickel(ii) and palladium(ii). | a new series of complexes of 2-hydroxy-3,5-dimethyl acetophenone oxime (hdmaox) with cu(ii), co(ii), ni(ii) and pd(ii) have been prepared and characterized by different physical techniques. infrared spectra of the complexes indicate deprotonation and coordination of the phenolic oh. it also confirms that nitrogen atom of the oximino group contributes to the complexation. electronic spectra and magnetic susceptibility measurements reveal square planar geometry for cu(ii), ni(ii) and pd(ii) comple ... | 2007 | 17258502 |
| l-arginine influences the structure and function of arginase mrna in aspergillus nidulans. | expression of the arginase structural gene (agaa) in aspergillus nidulans is subject to complex transcriptional and post-transcriptional regulation. arginase mrna has a long 5'-utr sequence. analysis of this sequence in silico revealed its putative complex secondary structure, the presence of arginine-binding motifs (arginine aptamers) and a short intron with two potential 3' splicing sites. in this report we present evidence that l-arginine (i) binds directly to the arginase 5'-utr; (ii) invoke ... | 2007 | 17261076 |
| suppression of the acuh13 and acuh31 nonsense mutations in the carnitine/acylcarnitine translocase (acuh) gene of aspergillus nidulans by the g265s substitution in the domain 2 of the release factor erf1. | a search for suppressors of the carnitine/acylcarnitine translocase (cact) deficiency in aspergillus nidulans permitted the identification of the suae7 mutation, mapping at a new translational suppressor (suae) gene. the suae gene is essential in a. nidulans and encodes the eukaryotic release factor 1 (erf1). the suae7 mutation suppresses two acuh alleles (acuh13 and acuh31), both carrying nonsense mutations in the cact encoding gene that involve the replacement of a cag (gln) codon with a prema ... | 2007 | 16971148 |
| rapd typing of aspergillus chevalieri, aspergillus nidulans, aspergillus tetrazonus (quadrilineatus) and their teleomorphs using 5'-d[aacgcgcaac]-3' and 5'-d[cccgtcagca]-3' primers. | sexuality in fungi has long been a matter of concerns and debates that always necessitated extensive analysis of the relationship between organisms assumed to represent different developmental forms of the same organism. moreover, mating-virulence correlation and the growing worry of opportunistic fungal infections in immunocompromised states associated with aids, cancer chemotherapy and organ transplantation protocols have been critically addressed nowadays. in view of that, we genetically char ... | 2008 | 17268891 |
| ambient ph signaling regulates expression of the serine protease gene (spr1) in pine wilt nematode-trapping fungus, monacrosporium megalosporum. | we have cloned and characterized spr1, a putative serine protease gene, from a nematode-trapping fungus, monacrosporium megalosporum. the gene was present as a single copy in the genome. the predicted protein sequence of spr1 is homologous to the putative cuticle-degrading serine proteases pii and azo1 from the nematode-trapping fungus, arthrobotrys oligospora. in the 5' untranslated region near the initiation codon, consensus sequences to an area binding site, a well-known mediator of nitrogen ... | 2008 | 16697631 |
| 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 |
| 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 |
| nitrite transport is mediated by the nitrite-specific high-affinity nita transporter and by nitrate transporters nrta, nrtb in aspergillus nidulans. | disruption of the aspergillus nidulans high-affinity nitrate transporter genes (nrta and nrtb) prevents growth on nitrate but not nitrite. we identified a distinct nitrite transporter (k(m)=4.2+/-1 microm, v(max)=168+/-21 nmolmg(-1)dw(-1)h(-1)), designated nita. disruption of nrta, nrtb and nita blocked growth on nitrite, despite low rates of nitrite depletion we ascribe to passive nitrous acid permeation. growth of the single mutant nita16 on nitrite was wild-type, suggesting that nrta and/or n ... | 2008 | 18024100 |
| the aspergillus nidulans enzyme tdib catalyzes prenyltransfer to the precursor of bioactive asterriquinones. | the asterriquinones represent a class of ascomycete metabolic products whose significance stems from remarkable and useful pharmacological activities, among those antiretroviral (e.g., against the hi-virus), antitumor, and antidiabetes properties. recently, the first genetic locus for an asterriquinone, the clustered terrequinone genes tdia-e, was identified during a genome-wide screen in aspergillus nidulans for "orphan" natural product biosynthesis loci. here, we describe overexpression and ch ... | 2008 | 18029206 |
| overexpression of the plg1 gene encoding pectin lyase in penicillium griseoroseum. | the pectin lyase (pl) is an industrially important enzyme since it is used for maceration and clarification in the process of fruit juice production in food industries. in order to increase the yields of pectin lyase we cloned the plg1 (pectin lyase 1) from penicillium griseoroseum gene under the control of the strong constitutive promoter of the glyceraldehyde-3-phosphate dehydrogenase gene (gpda) and the terminator region of the tryptophan synthetase (trpc) gene from aspergillus nidulans (plas ... | 2008 | 18030511 |
| characterization of active site variants of xanthine hydroxylase from aspergillus nidulans. | xanthine/alpha-ketoglutarate (alphakg) dioxygenase (xana) is a non-heme mononuclear fe(ii) enzyme that decarboxylates alphakg to succinate and co(2) while hydroxylating xanthine to generate uric acid. in the absence of a xana crystal structure, a homology model was used to target several putative active site residues for mutagenesis. wild-type xana and ten enzyme variants were purified from recombinant escherichia coli cells and characterized. the h149a and d151a variants were inactive and the h ... | 2008 | 18036331 |
| 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 |
| 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 |