| a phosphoglucose isomerase mutant in aspergillus nidulans is defective in hyphal polarity and conidiation. | upon germination aspergillus nidulans swom1 exhibits abnormal development by extending a primary germ tube that quickly reverts to isotropic growth and results in an enlarged, swollen apex with pronounced wall thickenings. apical lysis occurs in 38% of the germlings. a point mutation in the an6037.3 gene encoding the only phosphoglucose isomerase in a. nidulans is responsible for the defect. loss of polarity is bypassed when glucose is replaced with alternate carbon sources but in all cases the ... | 2006 | 16798030 |
| lipid signaling in pathogenic fungi. | recent studies have highlighted the importance of lipid signaling molecules in the development and pathogenicity of clinically important fungi. in cryptococcus neoformans, sphingolipid-derived diacylglycerol has been shown to induce the transcription of the putative virulence factor app1, which inhibits the phagocytosis of fungal cells by alveolar macrophages, as well as to activate the protein kinase c pkc1, which promotes cell-wall stability and increased melanin production. in candida albican ... | 2006 | 16798065 |
| a phe389leu substitution in erga confers terbinafine resistance in aspergillus fumigatus. | replacement of phenylalanine with leucine at position 391 in squalene epoxidase was identified as being responsible for terbinafine resistance in mutants of aspergillus nidulans. the equivalent mutation was engineered into the erga gene of aspergillus fumigatus, resulting in an f389l substitution that also conferred resistance to this pathogenic mold. | 2006 | 16801438 |
| mutants of aspergillus nidulans affected in asexual development. | | 2006 | 16809845 |
| structure, organization, and transcriptional regulation of a family of copper radical oxidase genes in the lignin-degrading basidiomycete phanerochaete chrysosporium. | the white rot basidiomycete phanerochaete chrysosporium produces an array of nonspecific extracellular enzymes thought to be involved in lignin degradation, including lignin peroxidases, manganese peroxidases, and the h2o2-generating copper radical oxidase, glyoxal oxidase (glx). preliminary analysis of the p. chrysosporium draft genome had identified six sequences with significant similarity to glx and designated cro1 through cro6. the predicted mature protein sequences diverge substantially fr ... | 2006 | 16820482 |
| use of laccase as a novel, versatile reporter system in filamentous fungi. | laccases are copper-containing enzymes which oxidize phenolic substrates and transfer the electrons to oxygen. many filamentous fungi contain several laccase-encoding genes, but their biological roles are mostly not well understood. the main interest in laccases in biotechnology is their potential to be used to detoxify phenolic substances. we report here on a novel application of laccases as a reporter system in fungi. we purified a laccase enzyme from the ligno-cellulolytic ascomycete stachybo ... | 2006 | 16820501 |
| the aspergillus nidulans f-box protein grra links scf activity to meiosis. | cellular differentiation relies on precise and controlled means of gene expression that act on several levels to ensure a flexible and defined spatio-temporal expression of a given gene product. in our aim to identify transcripts enriched during fruiting body formation of the homothallic ascomycete aspergillus (emericella) nidulans, the grra gene could be identified in a negative subtraction hybridization screening procedure. it encodes a protein similar to fungal f-box proteins, which function ... | 2006 | 16824096 |
| interactions between iron availability, aluminium toxicity and fungal siderophores. | the influence of iron, aluminium and of the combined application of both metals on microbial biomass and production of siderophores by three fungi (aspergillus nidulans, neurospora crassa and hymenoscyphus ericae) were investigated. all three species showed a strong iron regulation and al-sensitivity of siderophore biosynthesis although several differences remained species dependent. inhibitory effects of fe and al on siderophore-production were additive and the higher binding capacity of sidero ... | 2006 | 16841246 |
| development and application of a suite of polysaccharide-degrading enzymes for analyzing plant cell walls. | to facilitate analysis of plant cell wall polysaccharide structure and composition, we cloned 74 genes encoding polysaccharide-degrading enzymes from aspergillus nidulans, aspergillus fumigatus, and neurospora crassa and expressed the genes as secreted proteins with c-terminal myc and 6x his tags. most of the recombinant enzymes were active in enzyme assays, and optima for ph and temperature were established. a subset of the enzymes was used to fragment polysaccharides from the irregular xylem 9 ... | 2006 | 16844780 |
| nudc is required for plk1 targeting to the kinetochore and chromosome congression. | the equal distribution of chromosomes during mitosis is critical for maintaining the integrity of the genome. essential to this process are the capture of spindle microtubules by kinetochores and the congression of chromosomes to the metaphase plate . polo-like kinase 1 (plk1) is a mitotic kinase that has been implicated in microtubule-kinetochore attachment, tension generation at kinetochores, tension-responsive signal transduction, and chromosome congression . the tension-sensitive substrates ... | 2006 | 16860740 |
| arugosins g and h: prenylated polyketides from the marine-derived fungus emericellanidulans var. acristata. | the fungus emericella nidulans var. acristata was isolated as an endophyte from a mediterranean green alga. cultivation of this fungus yielded two new compounds, arugosins g (1) and h (2), together with the known metabolites 3-9. arugosins (1-4) are benzophenone derivatives, biosynthetically related to the xanthones 5, 6, and 9. the indole alkaloid 7 displayed antitumor activity in a panel of 36 human tumor cell lines, exhibiting a mean ic(50) value of 5.5 microg/ml in an in vitro survival and p ... | 2006 | 16872131 |
| parasexuality in asexual development mutants of aspergillus nidulans. | the parasexual cycle with parameiosis has been characterized previously by the occurrence of genetic recombination and haploidization inside heterokaryotic hyphae prior to conidial formation. the aim of current research was to characterize, through genetic and cytological analyses, an asexual development mutant strain of a. nidulans and to use it to obtain parameiotic segregants. analyses showed the medusa phenotype of the b84 strain, whose mutant allele was mapped in the chromosome i. the heter ... | 2006 | 16874405 |
| generation and analysis of expressed sequence tags from botrytis cinerea. | botrytis cinerea is a filamentous plant pathogen of a wide range of plant species, and its infection may cause enormous damage both during plant growth and in the post-harvest phase. we have constructed a cdna library from an isolate of b. cinerea and have sequenced 11,482 expressed sequence tags that were assembled into 1,003 contigs sequences and 3,032 singletons. approximately 81% of the unigenes showed significant similarity to genes coding for proteins with known functions: more than 50% of ... | 2006 | 16874411 |
| nmr metabolic profiling of aspergillus nidulans to monitor drug and protein activity. | we describe a general protocol for using comparative nmr metabolomics data to infer in vivo efficacy, specificity and toxicity of chemical leads within a drug discovery program. the methodology is demonstrated using aspergillus nidulans to monitor the activity of urate oxidase and orotidine-5'-phosphate decarboxylase and the impact of 8-azaxanthine, an inhibitor of urate oxidase. 8-azaxanthine is shown to inhibit a. nidulans hyphal growth by in vivo inactivation of urate oxidase. | 2006 | 16889413 |
| fungal surface remodelling visualized by atomic force microscopy. | most fungal growth is localized to the tips of hyphae, however, early stages of spore germination and the growth of certain morphological mutant strains exhibit non-polarized expansion. we used atomic force microscopy (afm) to document changes in aspergillus nidulans wall surfaces during non-polarized growth: spore germination, and growth in a strain containing the hypa1 temperature sensitive morphogenesis defect. we compared wall surface structures of both wild-type and mutant a. nidulans follo ... | 2006 | 16891105 |
| fungal metabolic model for tyrosinemia type 3: molecular characterization of a gene encoding a 4-hydroxy-phenyl pyruvate dioxygenase from aspergillus nidulans. | mutations in the human hpd gene (encoding 4-hydroxyphenylpyruvic acid dioxygenase) cause hereditary tyrosinemia type 3 (ht3). we deleted the aspergillus nidulans homologue (hpda). we showed that the mutant strain is not able to grow in the presence of phenylalanine and that it accumulates increased concentrations of tyrosine and 4-hydroxyphenylpyruvic acid, mimicking the human ht3 phenotype. | 2006 | 16896227 |
| cloning, sequence analysis and heterologous expression of the myrothecium gramineum orotidine-5'-monophosphate decarboxylase gene. | a 2918 bp sequence coding for the orotidine-5'-monophosphate decarboxylase enzyme (ompd) was isolated from the genome of myrothecium gramineum. this sequence was analysed and, remarkably, it is the first ompd gene of a sordariomycete that has an intron. the gene codes for an enzyme of 282 amino acids. the nucleotide sequence and the amino acid sequence were compared with fungal ompd sequences. they show the highest similarity to ompd genes and enzymes of aspergillus sp., penicillium sp. and clad ... | 2006 | 16907730 |
| aspergillus genomes: secret sex and the secrets of sex. | the genomic sequences of three species of aspergillus, including the model organism a. nidulans (which is homothallic: having no differentiated mating types, a strain being able to cross with itself), suggest that a. fumigatus and a. oryzae, considered to be asexual, might in fact be heterothallic (having two differentiated mating types, a strain being able to cross only with strains of opposite mating type). the genomic data have implications for the understanding of the evolution and the mecha ... | 2006 | 16911845 |
| comparative kinetic analysis of azga and fcy21p, prototypes of the two major fungal hypoxanthine-adenine-guanine transporter families. | in fungi, uptake of salvageable purines is carried out by members of two evolutionarily distinct protein families, the purine-related transporters (prt/ncs1) and the azga-like transporters. we carried out a comparative kinetic analysis of two prototypes of these transporter families. the first was fcy21p, a herein characterized protein of candida albicans, and the second was azga, a transporter of aspergillus nidulans. our results showed that: (i) azga and fcy21p are equally efficient high-affin ... | 2006 | 16923723 |
| the first transmembrane segment (tms1) of uapa contains determinants necessary for expression in the plasma membrane and purine transport. | uapa, a member of the nat/ncs2 family, is a high affinity, high capacity, uric acid-xanthine/h+ symporter in aspergillus nidulans. determinants critical for substrate binding and transport lie in a highly conserved signature motif downstream from tms8 and within tms12. here we examine the role of tms1 in uapa biogenesis and function. first, using a mutational analysis, we studied the role of a short motif (q85h86), conserved in all nats. q85 mutants were cryosensitive, decreasing (q85l, q85n, q8 ... | 2006 | 16923727 |
| investigation of the functional properties and regulation of three glutamine synthetase-like genes in streptomyces coelicolor a3(2). | streptomyces coelicolor a3(2) has three additional glna-type genes besides the glutamine synthetase genes glna (encoding gsi) and glnii (encoding gsii). the aim of this work was to characterize their functional properties and regulation. sequence analyses revealed that glna2, glna3, and glna4 are dissimilar to s. coelicolor gsi and lack highly conserved amino acid residues involved in catalysis. in heterologous expression experiments, glna2, glna3, and glna4, in contrast to glna and glnii, were ... | 2006 | 16932908 |
| a caps test allowing a rapid distinction of penicillium expansum among fungal species collected on grape berries, inferred from the sequence and secondary structure of the mitochondrial ssu-rrna. | penicillium expansum is a fungal species highly damageable for the postharvest conservation of numerous fruits. in vineyards, this fungus is sometimes isolated from grape berries where its presence may lead to the production of geosmin, a powerful earthy odorant, which can impair grapes and wines aromas. however, the discrimination of p. expansum from related fungi is difficult because it is based on ambiguous phenotypic characters and/or expensive and time-consuming molecular tests. in this con ... | 2006 | 16935376 |
| plant growth-promoting methylobacterium induces defense responses in groundnut (arachis hypogaea l.) compared with rot pathogens. | this study, framed in two different phases, studied the plant-growth promotion and the induction of systemic resistance in groundnut by methylobacterium. seed imbibition with methylobacterium sp. increased germination by 19.5% compared with controls. combined inoculation of methylobacterium sp. with rhizobium sp. also significantly increased plant growth, nodulation, and yield attributes in groundnut compared with individual inoculation of rhizobium sp. methylobacterium sp. challenge-inoculated ... | 2006 | 16941245 |
| posaconazole for treatment of refractory invasive fungal disease. | invasive fungal infections are usually associated with immunocompromised states about 40-60% of these patients are refractory to standard antifungal therapy we describe the effect of posaconazole in the treatment of a 12 years-old girl with uncontrolled diabetes mellitus with life-threatening cerebral mucor mycosis and a 4 year old girl boy with chronic granulomatous disease presenting with invasive aspergillus nidulans infection. | 2006 | 16961581 |
| phylogenomic analysis of non-ribosomal peptide synthetases in the genus aspergillus. | fungi from the genus aspergillus are important saprophytes and opportunistic human fungal pathogens that contribute in these and other diverse ways to human well-being. part of their impact on human well-being stems from the production of small molecular weight secondary metabolites, which may contribute to the ability of these fungi to cause invasive fungal infections and allergic diseases. in this study, we identified one group of enzymes responsible for secondary metabolite production in five ... | 2006 | 16962256 |
| nonsense-mediated mrna decay mutation in aspergillus nidulans. | an aspergillus nidulans mutation, designated nmda1, has been selected as a partial suppressor of a frameshift mutation and shown to truncate the homologue of the saccharomyces cerevisiae nonsense-mediated mrna decay (nmd) surveillance component nmd2p/upf2p. nmda1 elevates steady-state levels of premature termination codon-containing transcripts, as demonstrated using mutations in genes encoding xanthine dehydrogenase (hxa), urate oxidase (uaz), the transcription factor mediating regulation of ge ... | 2006 | 16963627 |
| evidence for novel ph-dependent regulation of candida albicans rim101, a direct transcriptional repressor of the cell wall beta-glycosidase phr2. | candida albicans is a commensal fungus of mucosal surfaces that can cause disease in susceptible hosts. one aspect of the success of c. albicans as both a commensal and a pathogen is its ability to adapt to diverse environmental conditions, including dramatic variations in environmental ph. the response to a neutral-to-alkaline ph change is controlled by the rim101 signal transduction pathway. in neutral-to-alkaline environments, the zinc finger transcription factor rim101 is activated by the pr ... | 2006 | 16963637 |
| secondary metabolic gene cluster silencing in aspergillus nidulans. | in contrast to most primary metabolism genes, the genes involved in secondary metabolism and certain nutrient utilization pathways are clustered in fungi. recently a nuclear protein, laea, was found to be required for the transcription of several secondary metabolite gene clusters in aspergillus nidulans. here we show that laea regulation does not extend to nutrient utilization or the spoc1 sporulation clusters. one of the secondary metabolite clusters regulated by laea contains the positive reg ... | 2006 | 16968230 |
| 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 |
| the aspergillus nidulans rcoa gene is required for vea-dependent sexual development. | the aspergillus nidulans rcoadelta mutant exhibits growth and developmental defects. we show that the rcoadelta mutant lacks cleistothecia and is self-sterile. in crosses with wild-type strains, rcoadelta nuclei do not contribute to the cleistothecial walls. furthermore, sexual development resulting from vea overexpression is rcoa dependent, indicating that rcoa lies downstream of vea in the sexual development pathway. | 2006 | 16980390 |
| calmodulin concentrates at the apex of growing hyphae and localizes to the spitzenkörper in aspergillus nidulans. | the calmodulin (cam) localization pattern in the growing hyphal tip of aspergillus nidulans was studied with the functional gfp::cam fusion protein. a faint tip-high gradient of cam was found in the growing hyphal tip, with cam highly localized in the region corresponding to the spitzenkörper forming a bright granule. the position of highly concentrated cam in the extreme apex seemed to determine the orientation of the hypha. the normal pattern of cam localization was also shown to be dependent ... | 2006 | 16983484 |
| the aspergillus fumigatus cellobiohydrolase b (cbhb) promoter is tightly regulated and can be exploited for controlled protein expression and rnai. | the utility of the aspergillus fumigatus cellobiohydrolase cbhb promoter for controlled gene expression has been investigated. cbhb message was present at high levels in the presence of carboxymethylcellulose and undetected in the presence of glucose. a reporter construct using the cbhb promoter showed similar behaviour and gave lower message levels than the aspergillus nidulans alca promoter under repressing conditions. an rnai construct driven by the cbhb promoter was used to down-regulate the ... | 2006 | 16984401 |
| systematic deletion and mitotic localization of the nuclear pore complex proteins of aspergillus nidulans. | to define the extent of the modification of the nuclear pore complex (npc) during aspergillus nidulans closed mitosis, a systematic analysis of nuclear transport genes has been completed. thirty genes have been deleted defining 12 nonessential and 18 essential genes. several of the nonessential deletions caused conditional phenotypes and self-sterility, whereas deletion of some essential genes caused defects in nuclear structure. live cell imaging of endogenously tagged npc proteins (nups) revea ... | 2006 | 16987955 |
| application of electron tomography to fungal ultrastructure studies. | access to structural information at the nanoscale enables fundamental insights into many complex biological systems. the development of the transmission electron microscope (tem) has vastly increased our understanding of multiple biological systems. however, when attempting to visualize and understand the organizational and functional complexities that are typical of cells and tissues, the standard 2-d analyses that tem affords often fall short. in recent years, high-resolution electron tomograp ... | 2006 | 16995909 |
| identification and comparative analysis of sixteen fungal peptidyl-prolyl cis/trans isomerase repertoires. | the peptidyl-prolyl cis/trans isomerase (ppiase) class of proteins is present in all known eukaryotes, prokaryotes, and archaea, and it is comprised of three member families that share the ability to catalyze the cis/trans isomerisation of a prolyl bond. some fungi have been used as model systems to investigate the role of ppiases within the cell, however how representative these repertoires are of other fungi or humans has not been fully investigated. | 2006 | 16995943 |
| novel mitogen-activated protein kinase mpkc of aspergillus fumigatus is required for utilization of polyalcohol sugars. | the genome of aspergillus fumigatus has four genes that encode mitogen-activated protein kinases (mapks), saka/hoga, mpka, mpkb, and mpkc. the functions of the mpkb and mpkc mapks are unknown for a. fumigatus and the closely related and genetically amenable species aspergillus nidulans. mpkc deletion mutants of a. fumigatus were made and their phenotypes characterized. the mpkc deletion mutants were viable and had normal conidial germination and hyphal growth on minimal or complete media. this i ... | 2006 | 16998074 |
| site-directed mutagenesis of selected residues at the active site of aryl-alcohol oxidase, an h2o2-producing ligninolytic enzyme. | aryl-alcohol oxidase provides h(2)o(2) for lignin biodegradation, a key process for carbon recycling in land ecosystems that is also of great biotechnological interest. however, little is known of the structural determinants of the catalytic activity of this fungal flavoenzyme, which oxidizes a variety of polyunsaturated alcohols. different alcohol substrates were docked on the aryl-alcohol oxidase molecular structure, and six amino acid residues surrounding the putative substrate-binding site w ... | 2006 | 16999821 |
| efficacy of caspofungin against aspergillus flavus, aspergillus terreus, and aspergillus nidulans. | the echinocandin caspofungin is a potent inhibitor of the activity of 1,3-beta-d-glucan synthase from aspergillus flavus, aspergillus terreus, and aspergillus nidulans. in murine models of disseminated infection, caspofungin prolonged survival and reduced the kidney fungal burden. caspofungin was at least as effective as amphotericin b against these filamentous fungi in vivo. | 2006 | 17015628 |
| glucose-mediated repression of autolysis and conidiogenesis in emericella nidulans. | glucose-mediated repression of autolysis and sporulation was studied in submerged emericellanidulans (anam. aspergillus nidulans) cultures. null mutation of the crea gene, which encodes the major carbon catabolite repressor crea in e. nidulans, resulted in a hyperautolytic phenotype characterized by increased extracellular hydrolase production and dry cell mass declination. interestingly, glucose, as well as the glucose antimetabolite 2-deoxy-d-glucose, repressed autolysis and sporulation in bot ... | 2006 | 17018254 |
| opposing signals differentially regulate transcript stability in aspergillus nidulans. | a good model for gene regulation, requiring the organism to monitor a complex and changing environment and respond in a precise and rapid way, is nitrogen metabolism in aspergillus nidulans. this involves co-ordinated expression of hundreds of genes, many dependent on the transcription factor area, which monitors the nitrogen state of the cell. area activity is in part modulated by differential degradation of its transcript in response to intracellular glutamine. here we report that glutamine tr ... | 2006 | 17020584 |
| 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 |
| a point mutation in the aspergillus nidulans sonbnup98 nuclear pore complex gene causes conditional dna damage sensitivity. | the nuclear pore complex (npc) is embedded in the nuclear envelope where it mediates transport between the cytoplasm and nucleus and helps to organize nuclear architecture. we previously isolated sonb1, a mutation encoding a single amino acid substitution within the aspergillus nidulans sonbnnup98 npc protein (nucleoporin). here we demonstrate that this mutation causes marked dna damage sensitivity at 42 degrees . although sonbnnup98 has roles in the g2 transition, we demonstrate that the g2 dna ... | 2006 | 17028324 |
| upstream and downstream regulation of asexual development in aspergillus fumigatus. | the opportunistic human pathogen aspergillus fumigatus produces a large quantity of asexual spores (conidia), which are the primary agent causing invasive aspergillosis in immunocompromised patients. we investigated the mechanisms controlling asexual sporulation (conidiation) in a. fumigatus via examining functions of four key regulators, gpaa (galpha), afflba (rgs), afflug, and afbrla, previously studied in aspergillus nidulans. expression analyses of gpaa, afflba, afflug, afbrla, and afweta th ... | 2006 | 17030990 |
| the intracellular siderophore ferricrocin is involved in iron storage, oxidative-stress resistance, germination, and sexual development in aspergillus nidulans. | iron is required by most organisms, but an excess of this metal is potentially toxic. consequently, uptake and intracellular storage of iron are tightly controlled. the filamentous fungus a. nidulans lacks the iron storage compound ferritin but possesses an intracellular siderophore, which is accumulated in a highly regulated manner as iron-free desferri-ferricrocin or iron-containing ferricrocin via transcriptional regulation of the nonribosomal peptide synthetase sidc. biosynthesis of desferri ... | 2006 | 17030991 |
| transcriptome analysis of aspergillus nidulans exposed to camptothecin-induced dna damage. | we have used an aspergillus nidulans macroarray carrying sequences of 2,787 genes from this fungus to monitor gene expression of both wild-type and uvsb(atr) (the homologue of the atr gene) deletion mutant strains in a time course exposure to camptothecin (cpt). the results revealed a total of 1,512 and 1,700 genes in the wild-type and uvsb(atr) deletion mutant strains that displayed a statistically significant difference at at least one experimental time point. we characterized six genes that h ... | 2006 | 17030995 |
| expression profile of amylolytic genes in aspergillus nidulans. | aspergillus nidulans possessed 16 putative amylolytic genes consisting of 7 alpha-glucosidase (agda-f), 7 alpha-amylase (amya-f), and 2 glucoamylase (glaa and b) genes on the genome. among them, the agda, agdb, agde, agdf, amya, amyb, amyf, and glab genes were induced by isomaltose. amyr, a zn(ii)(2)cys(6) transcription factor, was required for the induction. the isomaltose-inducible genes possessed at least one consensus sequence for amyr binding, 5'-cggn(8)cgg, on each promoter region. none of ... | 2006 | 17031028 |
| discovery of aspoquinolones a-d, prenylated quinoline-2-one alkaloids from aspergillus nidulans, motivated by genome mining. | motivated by the observation that the aspergillus nidulans genome bears multiple anthranilic acid synthase gene copies, the fungal metabolome was reinvestigated under various fermentation conditions, resulting in the discovery of novel prenylated quinolin-2-one alkaloids, two of which bear unprecedented terpenoid side chains. | 2006 | 17036148 |
| isolation of cell wall mutants in aspergillus nidulans by screening for hypersensitivity to calcofluor white. | as a first step toward identifying novel genes of wall metabolism in filamentous fungi, we have screened a collection of aspergillus nidulans mutants for strains exhibiting hypersensitivity toward the chitin binding agent calcofluor white (cfw). this strategy has been used previously to identify cell wall mutants in saccharomyces cerevisiae. we have identified 10 mutants representing eight loci, designated cala through calh, for calcofluor hypersensitivity. all cal mutants are impaired for sporu ... | 2006 | 17040069 |
| 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 |
| fvve1 regulates filamentous growth, the ratio of microconidia to macroconidia and cell wall formation in fusarium verticillioides. | the velvet gene, vea, co-ordinates asexual and sexual development in the homothallic fungal species aspergillus nidulans. studies in aspergillus parasiticus and aspergillus fumigatus demonstrated that vea also regulates morphological differentiation in these species. whether vea has the same role in morphogenesis in other fungal genera has not been investigated. in this work, we studied the role of the vea homologue, fvve1, in the heterothallic fungus fusarium verticillioides. deletion of fvve1 ... | 2006 | 17054442 |
| 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 |
| metabolic network driven analysis of genome-wide transcription data from aspergillus nidulans. | aspergillus nidulans (the asexual form of emericella nidulans) is a model organism for aspergilli, which are an important group of filamentous fungi that encompasses human and plant pathogens as well as industrial cell factories. aspergilli have a highly diversified metabolism and, because of their medical, agricultural and biotechnological importance, it would be valuable to have an understanding of how their metabolism is regulated. we therefore conducted a genome-wide transcription analysis o ... | 2006 | 17107606 |
| 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 |
| effects of mutations in the ganb/rgsa g protein mediated signalling on the autolysis of aspergillus nidulans. | physiological changes taking place in carbon-starved, autolysing cultures of aspergillus (emericella) nidulans strains with mutations in the ganb/rgsa heterotrimeric g protein signalling pathway were studied and compared. deletion of the ganb, rgsa or both genes did not alter markedly either the autolytic loss of biomass or the extracellular chitinase production. however, they caused a significant decrease in the proteinase formation, which was detected by measuring both extracellular enzyme act ... | 2006 | 17139616 |
| identification of a novel gene, ure2, that functionally complements a urease-negative clinical strain of cryptococcus neoformans. | a urease-negative serotype a strain of cryptococcus neoformans (b-4587) was isolated from the cerebrospinal fluid of an immunocompetent patient with a central nervous system infection. the ure1 gene encoding urease failed to complement the mutant phenotype. urease-positive clones of b-4587 obtained by complementing with a genomic library of strain h99 harboured an episomal plasmid containing dna inserts with homology to the suda gene of aspergillus nidulans. the gene harboured by these plasmids ... | 2006 | 17159224 |
| 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 |
| application of molecular modeling to analysis of inhibition of kinesin motor proteins of the bimc subfamily by monastrol and related compounds. | application of molecular modeling approaches has potential to contribute to rational drug design. these approaches may be especially useful when attempting to elucidate the structural features associated with novel drug targets. in this study, molecular docking and molecular dynamics were applied to studies of inhibition of the human motor protein denoted hseg5 and other homologues in the bimc subfamily. these proteins are essential for mitosis, so compounds that inhibit their activity may have ... | 2005 | 17191952 |
| 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 |
| differential expression of genes involved in iron metabolism in aspergillus fumigatus. | the ability of fungi to survive in many environments is linked to their capacity to acquire essential nutrients. iron is generally complexed and available in very limited amounts. like bacteria, fungi have evolved highly specific systems for iron acquisition. production and uptake of iron-chelating siderophores has been shown to be important for certain human bacterial pathogens, as well as in fungal pathogens such as cryptococcus neoformans and fusarium graminearum. this system also enables the ... | 2006 | 17236162 |
| 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 |
| mitochondrial four-point crosses in aspergillus nidulans : mapping of a suppressor of a mitochondrially inherited cold-sensitive mutation. | four-point mitochondrial crosses were conducted in heterokaryons of aspergillus nidulans. the mutations used were (olia1), conferring resistance to oligomycin, (cama112), conferring resistance to chloramphenicol; (cs-67), conferring cold-sensitivity, and ( sumd16), a suppressor of (cs-67). initially, the crosses were conducted by observing the segregation of extranuclear markers in heterokaryotic sectors emerging from the original point of heterokaryosis. this showed that (cama112), (cs-67) and ... | 1983 | 17246113 |
| induced somatic segregation in aspergillus nidulans. | | 1960 | 17247964 |
| induction of mitotic crossing-over in aspergillus nidulans by bifunctional alkylating agents. | | 1963 | 17248183 |
| 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 |
| 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 |
| oxylipins as developmental and host-fungal communication signals. | pathogenic microbes and their hosts have acquired complex signalling mechanisms to appraise themselves of the environmental milieu in the ongoing battle for survival. several recent studies have implicated oxylipins as a novel class of host-microbe signalling molecules. oxylipins represent a vast and diverse family of secondary metabolites that originate from the oxidation or further conversion of polyunsaturated fatty acids. among the microbial oxylipins, the fungal oxylipins are best character ... | 2007 | 17276068 |
| phosphopantetheinyl transferase cfwa/npga is required for aspergillus nidulans secondary metabolism and asexual development. | polyketide synthases (pkss) and/or nonribosomal peptide synthetases (nrpss) are central components of secondary metabolism in bacteria, plants, and fungi. in filamentous fungi, diverse pkss and nrpss participate in the biosynthesis of secondary metabolites such as pigments, antibiotics, siderophores, and mycotoxins. however, many secondary metabolites as well as the enzymes involved in their production are yet to be discovered. both pkss and nrpss require activation by enzyme members of the 4'-p ... | 2007 | 17277172 |
| accurate prediction of the aspergillus nidulans terrequinone gene cluster boundaries using the transcriptional regulator laea. | laea is a regulatory protein of the genus aspergillus which controls global expression of secondary metabolism gene clusters. during a previous genome-wide transcriptional profiling screen, numerous novel gene clusters were found to be regulated by laea including a cluster required for the production of the antitumor agent terrequinone a. beginnings and ends of secondary metabolite gene clusters are difficult to predict by gene sequence alone, but sharp demarcation of transcriptional control by ... | 2007 | 17291795 |
| genotoxicity (mitotic recombination) of the cancer chemotherapeutic agents cisplatin and cytosine arabinoside in aspergillus nidulans. | cisplatin (cis-diamminedichloroplatinum, cis-ddp) and cytosine arabinoside (ara-c) are anticancer drugs used in the treatment of human cancer. the two chemotherapeutic drugs were tested in current research for their recombinogenic potential in diploid cells of aspergillus nidulans. non-cytotoxic concentrations of ara-c (0.4 and 0.8 microm) and cis-ddp (1.5, 3.0 and 6.0 microm) were strong recombinagens in a. nidulans ut448//a757 diploid strain, which induced homozygosis of recessive genetic mark ... | 2007 | 17306432 |
| small molecule inhibitors of histone arginine methyltransferases: homology modeling, molecular docking, binding mode analysis, and biological evaluations. | the screening of the inhibition capabilities of dye-like small molecules from a focused library against both human prmt1 and aspergillus nidulans rmta is reported as well as molecular modeling studies (homology modeling, molecular docking, and 3-d qsar) of the catalytic domain of the prmt1 fungal homologue rmta. the good correlation between computational and biological results makes rmta a reliable tool for screening arginine methyltransferase inhibitors. in addition, the binding mode analyses o ... | 2007 | 17323938 |
| the evolutionary history of cytochrome p450 genes in four filamentous ascomycetes. | the cytochrome p450 system is important in fungal evolution for adapting to novel ecological niches. to elucidate the evolutionary process of cytochrome p450 genes in fungi with different life styles, we studied the patterns of gene gains and losses in the genomes of four filamentous ascomycetes, including two saprotrophs (aspergillus nidulans (an) and neurospora crassa (nc)) and two plant pathogens (fusarium graminearum (fg) and magnaporthe grisea (mg)). | 2007 | 17324274 |
| transcriptional control of gluconeogenesis in aspergillus nidulans. | aspergillus nidulans can utilize carbon sources that result in the production of tca cycle intermediates, thereby requiring gluconeogenesis. we have cloned the acug gene encoding fructose-1,6 bisphosphatase and found that expression of this gene is regulated by carbon catabolite repression as well as by induction by a tca cycle intermediate similar to the induction of the previously studied acuf gene encoding phosphoenolpyruvate carboxykinase. the acun356 mutation results in loss of growth on gl ... | 2007 | 17339216 |
| characterization of the nika histidine kinase implicated in the phosphorelay signal transduction of aspergillus nidulans, with special reference to fungicide responses. | we recently compiled a complete list of phosphorelay signal transduction components in the model filamentous fungus aspergillus nidulans. in this study, we characterized a histidine protein kinase (designated nika) that is found in many fungi, with special reference to responses to potent fungicides (iprodione and fludioxonil). we provided evidence that not only nika, but also two downstream response regulators (sska and srra) are crucially implicated in the mode of action of these fungicides, a ... | 2007 | 17341812 |
| genomics of aspergillus oryzae. | the genome sequence of aspergillus oryzae, a fungus used in the production of the traditional japanese fermentation foods sake (rice wine), shoyu (soy sauce), and miso (soybean paste), has revealed prominent features in its gene composition as compared to those of saccharomyces cerevisiae and neurospora crassa. the a. oryzae genome is extremely enriched with genes involved in biomass degradation, primary and secondary metabolism, transcriptional regulation, and cell signaling. even compared to t ... | 2007 | 17341818 |
| the proline permease of aspergillus nidulans: functional replacement of the native cysteine residues and properties of a cysteine-less transporter. | the major proline transporter (prnb) of aspergillus nidulans belongs to the amino acid polyamine organocation (apc) transporter superfamily. members of this family have not been subjected to systematic structure-function relationship studies. in this report, we examine the functional replacement of the three native cys residues (cys54, cys352 and cys530) of prnb and the properties of an engineered cys-less prnb protein, as background for employing a cys-scanning mutagenesis approach. we show tha ... | 2007 | 17350864 |
| the tightly regulated promoter of the xana gene of aspergillus nidulans is included in a helitron. | in aspergillus nidulans the xana gene codes for a xanthine alpha-ketoglutarate-dependent dioxygenase, an enzyme only present in the fungal kingdom. the 5' region of this gene, including its putative promoter and the first 54 codons of the open reading frame, together with the first intron is duplicated in the genome. this duplication corresponds to a helitron, a eukaryotic element proposed to transpose replicatively by the rolling circle mechanism. we show that the regulation of xana conforms to ... | 2007 | 17367381 |
| genomics-driven discovery of pks-nrps hybrid metabolites from aspergillus nidulans. | in the postgenomic era it has become increasingly apparent that the vast number of predicted biosynthesis genes of microorganisms is not reflected by the metabolic profile observed under standard fermentation conditions. in the absence of a particular (in most cases unknown) trigger these gene loci remain silent. because these cryptic gene clusters may code for the biosynthesis of important virulence factors, toxins, or even drug candidates, new strategies for their activation are urgently neede ... | 2007 | 17369821 |
| the light-dependent regulator velvet a of aspergillus nidulans acts as a repressor of the penicillin biosynthesis. | the biosynthesis of the beta-lactam antibiotic penicillin in aspergillus nidulans is catalysed by three enzymes that are encoded by the genes acva, ipna and aata. several studies have indicated that these genes are controlled by a complex regulatory network, including a variety of cis-acting dna elements and regulatory factors. until now, however, relatively little information is available on external signals and their transmission influencing the expression of the structural genes. here, we sho ... | 2007 | 17375284 |
| a regulator of a g protein signalling (rgs) gene, cag8, from the insect-pathogenic fungus metarhizium anisopliae is involved in conidiation, virulence and hydrophobin synthesis. | regulators of the g protein signalling (rgs) pathway have been implicated in the control of a diverse array of cellular functions, including conidiation in filamentous fungi. however, the regulatory processes involved in conidiation in insect-pathogenic fungi are poorly understood. since conidia are the infective propagules in these fungi, an understanding of the regulatory processes involved in conidiation is essential to the development of an effective biocontrol fungus. here, the cloning and ... | 2007 | 17379711 |
| interactions of isopenicillin n synthase with cyclopropyl-containing substrate analogues reveal new mechanistic insight. | isopenicillin n synthase (ipns), a non-heme iron oxidase central to penicillin and cephalosporin biosynthesis, catalyzes an energetically demanding chemical transformation to produce isopenicillin n from the tripeptide delta-(l-alpha-aminoadipoyl)-l-cysteinyl-d-valine (acv). we describe the synthesis of two cyclopropyl-containing tripeptide analogues, delta-(l-alpha-aminoadipoyl)-l-cysteinyl-beta-methyl-d-cyclopropylglycine and delta-(l-alpha-aminoadipoyl)-l-cysteinyl-d-cyclopropylglycine, desig ... | 2007 | 17397141 |
| a homologue of the aspergillus velvet gene regulates both cephalosporin c biosynthesis and hyphal fragmentation in acremonium chrysogenum. | the aspergillus nidulans velvet (vea) gene encodes a global regulator of gene expression controlling sexual development as well as secondary metabolism. we have identified the vea homologue acvea from acremonium chrysogenum, the major producer of the beta-lactam antibiotic cephalosporin c. two different disruption strains as well as the corresponding complements were generated as a prelude to detailed functional analysis. northern hybridization and quantitative real-time pcr clearly indicate tha ... | 2007 | 17400783 |
| identification and analysis of essential aspergillus nidulans genes using the heterokaryon rescue technique. | in the heterokaryon rescue technique, gene deletions are carried out using the pyrg nutritional marker to replace the coding region of target genes via homologous recombination in aspergillus nidulans. if an essential gene is deleted, the null allele is maintained in spontaneously generated heterokaryons that consist of two genetically distinct types of nuclei. one nuclear type has the essential gene deleted but has a functional pyrg allele (pyrg+). the other has the wild-type allele of the esse ... | 2006 | 17406500 |
| fusion pcr and gene targeting in aspergillus nidulans. | we describe a rapid method for the production of fusion pcr products that can be used, generally without band purification, to transform aspergillus nidulans. this technique can be used to replace genes; tag genes with fluorescent moeties or epitope tags; or replace endogenous promoters with regulatable promoters, by introducing an appropriate selective cassette (e.g., fluorescent protein + selectable marker). the relevant genomic fragments and cassette are first amplified separately by pcr usin ... | 2006 | 17406574 |
| the aspergillus nidulans pkca gene is involved in polarized growth, morphogenesis and maintenance of cell wall integrity. | the protein kinase c (pkc) family participates in maintaining integrity and growth of fungal cell walls. however, the precise molecular role of these proteins in the filamentous fungi remains unknown. in this work, pkca, the gene encoding the pkc homolog in the filamentous fungus aspergillus nidulans, was cloned and its function analyzed using a conditional alca-pkc mutant strain. repression of pkca expression resulted in increased conidial swelling, decreased rates of hyphal growth, changes in ... | 2007 | 17406869 |