Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
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| the effect of fungal ribosome inactivating proteins upon feeding choice in c. freemani, and indications of a mutualistic relationship with a. restrictus. environmental mycology. | carpophilus freemani beetles' feeding on the fungus aspergillus nidulans was substantially inhibited when a. nidulans was transformed and induced to secrete the ribosome inactivating protein, restrictocin (genetic source: aspergillus restrictus). no inhibition of feeding was observed when a. nidulans was transformed and induced to produce an inactive form of restrictocin with a single amino-acid substitution in the active site. similarly, there was no inhibition of feeding upon transgenic strain ... | 2001 | 11811644 |
| the oxpa5 mutation of aspergillus nidulans is an allele of adb, the gene encoding adenylosuccinate synthetase. | the oxpa5 mutation in aspergillus nidulans results in a pleiotropic phenotype, including resistance to oxypurinol and partial constitutivity of the enzymes of purine catabolism. here we show that the oxpa5 mutation is an allele of adb, the gene encoding adenylosuccinate synthetase (ass). cloning, sequencing and characterisation of the adb gene are reported in this paper. in vivo complementation tests indicate that the oxpa5 mutation is a partial loss-of-function mutation, and altered kinetic par ... | 2001 | 11810243 |
| aspergillus nidulans diga, a potential homolog of saccharomyces cerevisiae pep3 (vps18), is required for nuclear migration, mitochondrial morphology and polarized growth. | the fungal vacuole is an acidic organelle that is involved in a variety of physiological processes, such as protein turnover, ion and ph homeostasis and osmoregulation. the function of the vacuole largely depends on vesicle transport providing the organelle with enzymes and substrates. the process of vesicle transportation has been studied best in saccharomyces cerevisiae, where several proteins that are crucial for intracellular vesicle sorting have been identified. one such protein is pep3 (vp ... | 2001 | 11810240 |
| spontaneous second-site suppressors of the filamentation defect of prr1delta mutants define a critical domain of rim101p in candida albicans. | in response to changes in ambient ph the opportunistic pathogen candida albicans differentially expresses a number of genes. the response to ph affects morphological differentiation and virulence. the pathway controlling the ph response terminates in the zinc-finger containing transcription factor encoded by rim101/prr2. by analogy to the ph response pathway of aspergillus nidulans, prr1 of c. albicans encodes a protein that is presumably required to convert rim101p from an inactive to an active ... | 2001 | 11810234 |
| arca, the regulatory gene for the arginine catabolic pathway in aspergillus nidulans. | we have cloned and analysed the arca gene which encodes a transcriptional activator necessary for the high-level expression of two genes for enzymes of the arginine catabolic pathway in aspergillus nidulans: agaa (for arginase) and otaa (for ornithine transaminase, otase). here we present complete genomic and cdna sequences for, and describe the pattern of expression of, the arca gene. this gene contains one intron and encodes a polypeptide of 600 amino acids. the deduced protein belongs to the ... | 2001 | 11810230 |
| aspergillus nidulans septin aspb plays pre- and postmitotic roles in septum, branch, and conidiophore development. | members of the septin family of proteins act as organizational scaffolds in areas of cell division and new growth in a variety of organisms. herein, we show that in the filamentous fungus aspergillus nidulans, the septin aspb is important for cellular division, branching, and conidiation both pre- and postmitotically. aspb localizes postmitotically to the septation site with an underlying polarity that is evident as cytokinesis progresses. this localization at the septation site is dependent on ... | 2002 | 11809826 |
| mutations in sfda and sfdb suppress multiple developmental mutations in aspergillus nidulans. | conidiophore morphogenesis in aspergillus nidulans occurs in response to developmental signals that result in the activation of brla, a well-characterized gene that encodes a transcription factor that is central to asexual development. loss-of-function mutations in flbd and other fluffy loci have previously been shown to result in delayed development and reduced expression of brla. flbd message is detectable during both hyphal growth and conidiation, and its gene product is similar to the myb fa ... | 2002 | 11805053 |
| agrobacterium tumefaciens-mediated transformation of the plant pathogenic fungus, magnaporthe grisea. | an effective way to study the infection mechanisms of fungal pathogens is to disrupt their genes via transformation in both targeted and random manners. this isolates the mutants that exhibit altered virulence. in this paper, we report the successful transformation of magnaporthe grisea, the causal agent for rice blast, that is mediated by agrobacterium tumefaciens. employing the binary vector pbht2, which carries the bacterial hygromycin b phosphotransferase gene under the control of the asperg ... | 2001 | 11804343 |
| mouse skin passage of a streptococcus pyogenes tn917 mutant of saga/pel restores virulence, beta-hemolysis and saga/pel expression without altering the position or sequence of the transposon. | streptolysin s (sls), the oxygen-stable hemolysin of streptococcus pyogenes, has recently been shown to be encoded by the saga/pel gene. mutants lacking expression of this gene were less virulent in a dermonecrotic mouse infection model. inactivation of the saga/pel gene affect the expression of a variety of virulence factors in addition to the hemolysin. insertion of a tn917 transposon into the promoter region of the saga/pel gene of s. pyogenes isolate cs101 eliminated expression of sls, as we ... | 2001 | 11801184 |
| involvement of the fungal nuclear migration gene nudc human homolog in cell proliferation and mitotic spindle formation. | essential genes which are required for normal nuclear migration and play a role in developmental processes have been isolated from model genetic organisms. one such gene is nudc (nuclear distribution c), which is required for positioning nuclei in the cytoplasm of the filamentous fungus aspergillus nidulans and for normal colony growth. this gene is highly conserved, structurally and functionally, throughout evolution and the human homolog, hnudc, has been cloned. to study the function of nudc i ... | 2002 | 11795948 |
| transactivation of a target gene through feedforward loop activation in plants. | the expression of many genes encoding transcriptional activators in prokaryotes and eukaryotes is upregulated through positive feedback activation. during positive feedback activation, a transcriptional activator binds to its own promoter and thus increases its own expression as well as the expression of its target genes. in the simplest case, increased levels of the transcriptional activator can be directly correlated with increased expression of its target genes. in this study, we present a ge ... | 2000 | 11793220 |
| observation of egfp-visualized nuclei and distribution of vacuoles in aspergillus oryzae arpa null mutant. | the arpa gene encoding arp1 (actin-related protein) was previously cloned and characterized from aspergillus oryzae. phenotypes of the arpa null mutant indicate its requirement for normal nuclear distribution and morphology of conidiophores. in this study, we further characterized the function of the arpa gene in distribution of organelles. for further analysis of nuclear migration in living cells, an expression system consisting of a fusion protein of aspergillus nidulans histone h2b and egfp ( ... | 2002 | 11786257 |
| nek2 localizes to multiple sites in mitotic cells, suggesting its involvement in multiple cellular functions during the cell cycle. | nek2 is a mammalian protein kinase that is structurally homologous to nima, a mitotic regulator in aspergillus nidulans. to understand the possible cellular processes in which nek2 participates during the cell cycle, we investigated the expression and subcellular localization of nek2 in mitotic cells. the nek2 protein levels were observed to be regulated in a cell cycle stage-specific manner in cultured cells. the cell cycle stage specificity of nek2 expression was also confirmed in cells underg ... | 2002 | 11785960 |
| 2,4-toluene diamines--their carcinogenicity, biodegradation, analytical techniques and an approach towards development of biosensors. | 2,4-toluene diamine (tda), a class a carcinogen, is a major raw material for the production of toluene diisocyanate (tdi), which is one of the precursors for the production of polyurethane foams (pu). this review deals with 2,4-toluene diamine's (tda) carcinogenicity, analytical techniques, biodegradation and use as a biosensor for biogenic and synthetic amines, emphasizing various carcinogenicity studies by 2,4-tda on animals and humans. this review reports some publications of the analysis of ... | 2001 | 11783783 |
| the aspergillus nidulans musn gene encodes a recq helicase that interacts with the pi-3k-related kinase uvsb. | in aspergillus nidulans, the uvsb gene encodes a member of the pi-3k-related kinase family of proteins. we have recently shown that uvsb is required for multiple aspects of the dna damage response. since the musn227 mutation is capable of partially suppressing defects caused by uvsb mutations, we sought to understand the mechanism underlying the suppression by cloning the musn gene. here, we report that musn encodes a recq helicase with homology to s. pombe rqh1, s. cerevisiae sgs1, and human bl ... | 2001 | 11779799 |
| ornithine decarboxylase knockout in tapesia yallundae abolishes infection plaque formation in vitro but does not reduce virulence toward wheat. | a knockout strain of tapesia yallundae lacking the single ornithine decarboxylase (odc) allele has been created by targeted gene replacement. a central region of the odc gene was isolated by polymerase chain reaction with degenerate oligonucleotides and used to probe a lambda genomic library. the gene was sequenced, and the encoded odc protein sequence was shown to be similar to those from other fungi. the functionality of the t. yallundae odc was confirmed by complementation of an aspergillus n ... | 2001 | 11763128 |
| no factors except for the hap complex increase the taka-amylase a gene expression by binding to the ccaat sequence in the promoter region. | to examine the possibility that factors different from the hap complex are involved in increasing taka-amylase a gene (taa) expression in aspergillus nidulans, either the authentic taa gene or the mutant taa gene with a replacement of the ccaat box was expressed in either a wild type strain or a mutant strain lacking the functional hap complex (hapcdelta). when the mutant taa was expressed in the hapcdelta strain, enzyme activity was as low as that of the hapcdelta strain transformed with the au ... | 2001 | 11758937 |
| sulphur amino acid synthesis in schizosaccharomyces pombe represents a specific variant of sulphur metabolism in fungi. | schizosaccharomyces pombe, in contrast to saccharomyces cerevisiae and aspergillus nidulans, lacks cystathionine beta-synthase and cystathionine gamma-lyase, two enzymes in the pathway from methionine to cysteine. as a consequence, methionine cannot serve as an efficient sulphur source for the fungus and does not bring about repression of sulphur assimilation, which is under control of the cysteine-mediated sulphur metabolite repression system. this system operates at the transcriptional level, ... | 2002 | 11754480 |
| [activity of itraconazole against clinical isolates of aspergillus spp. and fusarium spp. determined by the m38-p nccls method]. | the antifungal activity of itraconazole was studied in 101 clinical isolates of aspergillus fumigatus, a. flavus, a. niger, a. terreus, a. nidulans, a. candidus, a. glaucus, a. clavatus, fusarium solani, f. oxysporum and f. semitectum. the minimum inhibitory concentrations (mic) were determined according to the protocol of the m38-p national committee for laboratory standards (nccls) document using a microdilution method in 1640 rpmi liquid medium (visual reading at 48 and 72 h incubation). in g ... | 2001 | 11753450 |
| regulation of the acuf gene, encoding phosphoenolpyruvate carboxykinase in the filamentous fungus aspergillus nidulans. | phosphoenolpyruvate carboxykinase (pepck) is a key enzyme required for gluconeogenesis when microorganisms grow on carbon sources metabolized via the tricarboxylic acid (tca) cycle. aspergillus nidulans acuf mutants isolated by their inability to use acetate as a carbon source specifically lack pepck. the acuf gene has been cloned and shown to encode a protein with high similarity to pepck from bacteria, plants, and fungi. the regulation of acuf expression has been studied by northern blotting a ... | 2002 | 11741859 |
| nudc associates with lis1 and the dynein motor at the leading pole of neurons. | nudc is a highly conserved protein important for nuclear migration and viability in aspergillus nidulans. mammalian nudc interacts with lis1, a neuronal migration protein important during neocorticogenesis, suggesting a conserved mechanism of nuclear movement in a. nidulans and neuronal migration in the developing mammalian brain (s. m. morris et al., 1998). to further investigate this possibility, we show for the first time that nudc, lis1, and cytoplasmic dynein intermediate chain (cdic) coloc ... | 2001 | 11734602 |
| nudc expression during amphibian development. | to identify gene products important for gastrulation in the amphibian pleurodeles waltl, a screen for regional differences in new protein expression at the early gastrula stage was performed. a 45 kda protein whose synthesis was specific for progenitor endodermal cells was identified. microsequencing and cdna cloning showed that p45 is highly homologous to rat nudc, a protein suggested to play a role in nuclear migration. although pnudc can be detected in all regions of the embryo, its de novo s ... | 2001 | 11732844 |
| septum formation in aspergillus nidulans. | filamentous fungi form multicellular hyphae that are partitioned by septa. in a. nidulans, septum formation requires the assembly of a septal band following the completion of mitosis. recent observations show that this band is a dynamic structure composed of actin, a septin and a formin. in addition, assembly is dependent upon a conserved protein kinase cascade that regulates mitotic exit and septation in yeast. hyphal differentiation may reflect the regulation of this cascade by cyclin-dependen ... | 2001 | 11731327 |
| dna from aspergillus flavus contains 5-methylcytosine. | dna from aspergillus sp. has been reported not to contain 5-methylcytosine. however, it has been found that aspergillus nidulans responds to 5-azacytidine, a drug that is a strong inhibitor of dna methyltransferases. therefore, we have re-examined the occurrence of 5-methylcytosine in dna from aspergillus flavus by using a highly sensitive and specific method for detection of modified bases in genomic dna comprising high-performance liquid chromatography separation of nucleosides, labeling of th ... | 2001 | 11728730 |
| aspergillus nidulans alpha-1,3 glucanase (mutanase), muta, is expressed during sexual development and mobilizes mutan. | we established a subtractive cdna library of aspergillus nidulans to identify differentially expressed genes during sexual development. one of the clones displayed homology to fungal alpha-1,3 glucanases (mutanase). since alpha-1,3 glucan is considered the main reserve material accumulated during vegetative growth as a cell wall component and consumed during sexual development, we analyzed this gene in detail. the gene, muta, is disrupted by three introns and encodes a putative protein of 48 kda ... | 2001 | 11728159 |
| characterization of the gdha gene from the phytopathogen botrytis cinerea. | a 3.48-kb dna region containing the gdha gene, which codifies the nadp-dependent glutamate dehydrogenase enzyme from botrytis cinerea, has been cloned and characterized. a fragment of 2351 nucleotides was sequenced and found to contain an orf of 1350 bp that encodes a protein of 450 amino acids. the gene, containing two introns that showed polymorphic size between them, was located by pulsed-field gel electrophoresis in chromosome x in seven strains, which were isolated from several hosts and ha ... | 2001 | 11728157 |
| lipid peroxidation as a possible secondary mechanism of sterigmatocystin toxicity. | sterigmatocystin (stg), a major secondary metabolite of aspergillus versicolor and a. nidulans, is the precursor of aflatoxin b1. in this study, male albino rats were treated with stg-contaminated diet for 30 days, resulting in reduced levels of glutathione, ascorbic acid, and alpha-tocopherol. the activity of catalase in liver was reduced, whereas an increase in the activities of superoxide dismutase and glutathione peroxidase was observed. the levels of cytochrome p450, cytochrome b5, cytochro ... | 2001 | 11727790 |
| the structure of the negative transcriptional regulator nmra reveals a structural superfamily which includes the short-chain dehydrogenase/reductases. | nmra is a negative transcriptional regulator involved in the post-translational modulation of the gata-type transcription factor area, forming part of a system controlling nitrogen metabolite repression in various fungi. x-ray structures of two nmra crystal forms, both to 1.8 a resolution, show nmra consists of two domains, including a rossmann fold. nmra shows an unexpected similarity to the short-chain dehydrogenase/reductase (sdr) family, with the closest relationship to udp-galactose 4-epime ... | 2001 | 11726498 |
| comparison of spectrophotometric and visual readings of nccls method and evaluation of a colorimetric method based on reduction of a soluble tetrazolium salt, 2,3-bis [2-methoxy-4-nitro-5-[(sulfenylamino) carbonyl]-2h-tetrazolium-hydroxide], for antifungal susceptibility testing of aspergillus species. | the susceptibilities of 25 clinical isolates of various aspergillus species (aspergillus fumigatus, a. flavus, a. terreus, a. ustus, and a. nidulans) to itraconazole (itc) and amphotericin b (amb) were determined using the standard proposed by nccls for antifungal susceptibility testing of[filamentous fungi, a modification of this method using spectrophotometric readings, and a colorimetric method using the tetrazolium salt 2,3-bis [2-methoxy-4-nitro-5-[(sulfenylamino) carbonyl]-2h-tetrazolium-h ... | 2001 | 11724829 |
| characterization of the ethanol-inducible alc gene-expression system in arabidopsis thaliana. | controlled expression of transgenes in plants is key to the characterization of gene function and the regulated manipulation of growth and development. the alc gene-expression system, derived from the filamentous fungus aspergillus nidulans, has previously been used successfully in both tobacco and potato, and has potential for use in agriculture. its value to fundamental research is largely dependent on its utility in arabidopsis thaliana. we have undertaken a detailed function analysis of the ... | 2001 | 11722766 |
| aspergillus species cystitis in a cat. | a persian male cat with a history of lower urinary tract disease was presented because of polydipsia, polyuria, constipation and nasal discharge. ten weeks before admission, the cat had been treated for lower urinary tract disease by catheterisation and flushing of the bladder. the animal was thin, dehydrated, anaemic and azotaemic. urine culture revealed aspergillus species cystitis. antibodies against aspergillus nidulans were identified in serum. fluconazole was administered orally (7.5 mg/kg ... | 2001 | 11716628 |
| genetic and cytological characterization of a developmental mutant of aspergillus nidulans induced by 5-azacytidine. | an analysis of a new medusa mutant of aspergillus nidulans obtained by 5-azacytidine-treatment and named b116 is provided. the b116 mutant was phenotypically characterized by the production of conidiophores with reduced pigmentation and vesicles bearing multiple tiers of sterigmata. a single nuclear gene located on chromosome i is responsible for phenotypical changes in the mutant. the 5-azacytidine-altered locus, designated meda102, is recessive in heterozygous diploid and the medusa mutant is ... | 2001 | 11715212 |
| effect of macerating enzymes on red wine aroma at laboratory scale: exogenous addition or expression by transgenic wine yeasts. | the effects of a trichoderma longibrachiatum endoglucanase and an aspergillus nidulans endoxylanase on the concentration of free and bound volatiles, color, and phenolics during maceration in red wine vinification has been studied. two different approaches have been considered for the utilization of these enzymes: (i) direct addition of the enzymes to must and (ii) inoculation of must with recombinant wine yeasts overexpressing these activities. an experimental design based on a taguchi orthogon ... | 2001 | 11714353 |
| deletion of the cnxe gene encoding the gephyrin-like protein involved in the final stages of molybdenum cofactor biosynthesis in aspergillus nidulans. | the aspergillus nidulans cnxe gene, required for molybdenum cofactor biosynthesis, was isolated by functional complementation of an escherichia coli moga mutant strain. the deduced cnxe polypeptide consists of two domains which display similarity to the e. coli proteins moea and moga, respectively, separated by a putative hinge region of around 58 amino acid residues which is notably histidine rich. a deletion mutant lacking the entire cnxe gene, including both moea-like and moga-like domains, w ... | 2001 | 11713674 |
| purification and properties of pi-repressible acid phosphatases from aspergillus nidulans. | two forms of the paca-encoded acid phosphatase (designated acid phosphatases i and ii) secreted by the mold aspergillus nidulans grown in low-pi medium at 37 degrees, ph5.0, were purified to apparent homogeneity by page. the m(r) of the purified enzyme forms were ca 115000 (60000) and 113000 (62000) respectively for forms i and ii secreted by strain bia1 and ca 118000 (60000) and 121000 (61000) respectively for forms i and ii secreted by strain bia1 paca1, as determined by exclusion chromatograp ... | 1998 | 11711060 |
| microbial, chemical and physical aspects of citrus waste composting. | citrus waste supplemented with calcium hydroxide and with a c/n ratio of 24:1, ph of 6.3 and moisture content of 60% was composted by piling under shelter. with regular turning over of the pile and replenishment of moisture, the thermic phase lasted for 65-70 days and composting was completed after 3 months. compost thus prepared had an air-filled porosity of 14%, water-holding capacity of 590 ml l(-1), bulk density of 1.05 g cm(-3) and conductivity of 480 ms m(-1). phosphorus content (in mg l(- ... | 2002 | 11708757 |
| apparent genetic redundancy facilitates ecological plasticity for nitrate transport. | aspergillus nidulans possesses two high-affinity nitrate transporters, encoded by the nrta and the nrtb genes. mutants expressing either gene grew normally on 1-10 mm nitrate as sole nitrogen source, whereas the double mutant failed to grow on nitrate concentrations up to 200 mm. these genes appear to be regulated coordinately in all growth conditions, growth stages and regulatory genetic backgrounds studied. flux analysis of single gene mutants using 13no3(-) revealed that k(m) values for the n ... | 2001 | 11707396 |
| wdchs2p, a class i chitin synthase, together with wdchs3p (class iii) contributes to virulence in wangiella (exophiala) dermatitidis. | the chitin synthase structural gene wdchs2 was isolated by screening a subgenomic dna library of wangiella dermatitidis by using a 0.6-kb pcr product of the gene as a probe. the nucleotide sequence revealed a 2,784-bp open reading frame, which encoded 928 amino acids, with a 59-bp intron near its 5' end. derived protein sequences showed highest amino acid identities with those derived from the cichs1 gene of coccidioides immitis and the anchsc gene of aspergillus nidulans. the derived sequence a ... | 2001 | 11705928 |
| identification and assignment of the human nima-related protein kinase 7 gene (nek7) to human chromosome 1q31.3. | neks (nima-related kinase) are a group of protein kinases sharing high amino acid sequence identity with nima which controls initiation of mitosis in aspergillus nidulans. we have identified and characterized human nek7, a novel human gene structurally related to nima. its open reading frame encodes a 302-amino acid protein and is 77% identical to human nek6 protein. phylogenetic analysis suggests that nek6, nek7, and caenorhabditis elegans f19h6.1 constitute a subfamily within the nima family o ... | 2001 | 11701951 |
| yeast pala/aip1/alix homolog rim20p associates with a pest-like region and is required for its proteolytic cleavage. | the saccharomyces cerevisiae zinc finger protein rim101p is activated by cleavage of its c-terminal region, which resembles pest regions that confer susceptibility to proteolysis. here we report that rim20p, a member of the broadly conserved pala/aip1/alix family, is required for rim101p cleavage. two-hybrid and coimmunoprecipitation assays indicate that rim20p binds to rim101p, and a two-hybrid assay shows that the rim101p pest-like region is sufficient for rim20p binding. rim101p-rim20p intera ... | 2001 | 11698381 |
| substitution f569s converts uapa, a specific uric acid-xanthine transporter, into a broad specificity transporter for purine-related solutes. | uapa, a highly specific uric acid-xanthine transporter in aspergillus nidulans, is a member of a large family of nucleobase-ascorbate transporters conserved in all domains of life. we have investigated structure-function relationships in uapa, by studying chimeric transporters and missense mutations, and showed that specific polar or charged amino acid residues (e412, e414, q449, n450, t457) on either side of an amphipathic alpha-helical transmembrane segment (tms10) are critical for purine bind ... | 2001 | 11697902 |
| physiological characterisation of recombinant aspergillus nidulans strains with different crea genotypes expressing a. oryzae alpha-amylase. | the physiology of three strains of aspergillus nidulans was examined--a crea deletion strain, a wild type crea genotype and a strain containing extra copies of the crea gene, all producing aspergillus oryzae alpha-amylase. the strains were cultured in batch and continuous cultivations and the biomass formation and alpha-amylase production was characterised. overexpression of the crea gene resulted in a lower maximum specific growth rate and a slightly higher repression of the alpha-amylase produ ... | 2002 | 11689252 |
| biomass production and secretion of hydrolytic enzymes are influenced by the structural complexity of the nitrogen source in fusarium oxysporum and aspergillus nidulans. | the structural complexity of the nitrogen sources strongly affects biomass production and secretion of hydrolytic enzymes in filamentous fungi. fusarium oxysporum and aspergillus nidulans were grown in media containing glucose or starch, and supplemented with a nitrogen source varying from a single ammonium salt (ammonium sulfate) to free amino acids (casamino acids), peptides (peptone) and protein (gelatin). in glucose, when the initial ph was adjusted to 5.0, for both microorganisms, higher bi ... | 2001 | 11688213 |
| identification of aspergillus nidulans genes essential for the accumulation of sterigmatocystin. | the fungus aspergillus nidulans (emericella nidulans) was used as a genetic model for the identification of genes required for efficient accumulation of sterigmatocystin (st). the required gene for sterigmatocystin expression was stc, which is an intermediate penultimate product in the aflatoxin biosynthetic pathway. genetic analysis included studies of the sexual and parasexual cycles. the allelic segregation rates and recombination frequencies between linked and nonlinked genetic markers were ... | 2001 | 11686675 |
| evolutionarily conserved nuclear migration genes required for early embryonic development in caenorhabditis elegans. | the nudf and nudc genes of the fungus aspergillus nidulans encode proteins that are members of two evolutionarily conserved families. in a. nidulans these proteins mediate nuclear migration along the hyphae. the human ortholog of nudf is lis1, a gene essential for neuronal migration in the developing cerebral cortex. the mammalian ortholog of nudc encodes a protein that interacts with lis1. we have identified orthologs of nudc and lis1 from the nematode caenorhabditis elegans. heterologous expre ... | 2001 | 11685578 |
| riboflavin, overproduced during sporulation of ashbya gossypii, protects its hyaline spores against ultraviolet light. | riboflavin (vitamin b2), essential in tiny amounts as a precursor for oxidoreductase coenzymes, is a yellow pigment. although it causes cytotoxicity via photoinduced damage of macromolecules, several microorganisms are striking overproducers. a question, unanswered for decades, is whether riboflavin overproducers can benefit from this property. here, we report an ultraviolet (uv) protective effect of riboflavin. the spores of ashbya gossypii, a riboflavin-overproducing fungus, are more sensitive ... | 2001 | 11683864 |
| complex control of the developmental regulatory locus brla in aspergillus nidulans. | brla is a primary regulator of asexual development in aspergillus nidulans. activation of brla is necessary and sufficient for conidiophore development. it is known that brla produces two overlapping transcripts, designated brlaalpha and brlabeta. we found that expression of brla is subject to complex regulation, in that activation of the two brla transcripts is regulated at different levels. while brlaalpha is regulated at the transcriptional level, brlabeta is regulated at both the transcripti ... | 2001 | 11683268 |
| cloning and sequence analysis of cnaa gene encoding the catalytic subunit of calcineurin from aspergillus oryzae. | calcineurin has been implicated in ion-homeostasis, stress adaptation in yeast and for hyphal growth in filamentous fungi. genomic dna and cdna encoding the catalytic subunit of calcineurin (cnaa) were isolated from aspergillus oryzae. the cnaa open reading frame extended to 1727 bp and encoded a putative protein of 514 amino acids. comparative analysis of the nucleotide sequence of cnaa genomic dna and cdna confirmed the presence of three introns and a highly conserved calmodulin binding domain ... | 2001 | 11682197 |
| agrobacterium tumefaciens-mediated genetic transformation of the phytopathogenic ascomycete calonectria morganii. | conidia of the phytopathogenic fungus calonectria morganii were transformed to hygromycin b resistance using the hph gene of escherichia coli as the selective trait, governed by a heterologous fungal promoter and the aspergillus nidulans trpc terminator. agrobacterium tumefaciens-mediated transformation yielded stable hygromycin b-resistant clones (average number (106 per 10(7)) [corrected] conidia). putative transformants appeared to be mitotically and meiotically stable. the presence of the hp ... | 2001 | 11680825 |
| transcriptional regulation of the nitrate reductase gene in chlorella vulgaris: identification of regulatory elements controlling expression. | nitrate reductase (nr), the rate-limiting and primary control point of the nitrate assimilation pathway, is regulated at transcriptional and post-transcriptional levels. to better understand how nr is regulated at the transcriptional level in chlorella vulgaris, studies were performed to identify the factors regulating nr expression. sequence analysis of the nr promoter identified a number of potential sites that were investigated by mobility shift assays. of the protein-binding sites found, sev ... | 2001 | 11680822 |
| expression, purification and crystallization of aspergillus nidulans nmra, a negative regulatory protein involved in nitrogen-metabolite repression. | the nmra repressor protein of aspergillus nidulans was overproduced in escherichia coli and purified to homogeneity. gel-exclusion chromatography showed that nmra was monomeric in solution under the buffer conditions used. the protein was crystallized in three forms, belonging to trigonal, monoclinic and hexagonal space groups. two of these crystal forms (a and b) diffract to high resolution and thus appear suitable for structure determination. crystal form a belongs to space group p3((1))21, wi ... | 2001 | 11679757 |
| characterization of nitrogen metabolite signalling in aspergillus via the regulated degradation of area mrna. | area is the principal transcription factor involved in determining nitrogen utilization in aspergillus nidulans. nh4+ and gln are utilized preferentially but in their absence, area acts to facilitate the expression of genes involved in metabolizing alternative nitrogen sources. it is crucial to the function of area that its expression is tightly modulated by the quality and availability of nitrogen sources. one signalling mechanism involves regulated degradation of the area transcript in respons ... | 2001 | 11679084 |
| mutation of luxs affects growth and virulence factor expression in streptococcus pyogenes. | adaptive responses of bacteria that involve sensing the presence of other bacteria are often critical for proliferation and the expression of virulence characteristics. the autoinducer ii (ai-2) pathway has recently been shown to be a mechanism for sensing other bacteria that is highly conserved among diverse bacterial species, including gram-positive pathogens. however, a role for this pathway in the regulation of virulence factors in gram-positive pathogens has yet to be established. in this s ... | 2001 | 11679074 |
| genetic evidence for a microtubule-destabilizing effect of conventional kinesin and analysis of its consequences for the control of nuclear distribution in aspergillus nidulans. | conventional kinesin is a microtubule-dependent motor protein believed to be involved in a variety of intracellular transport processes. in filamentous fungi, conventional kinesin has been implicated in different processes, such as vesicle migration, polarized growth, nuclear distribution, mitochondrial movement and vacuole formation. to gain further insights into the functions of this kinesin motor, we identified and characterized the conventional kinesin gene, kina, of the established model or ... | 2001 | 11679072 |
| seph, a cdc7p orthologue from aspergillus nidulans, functions upstream of actin ring formation during cytokinesis. | in the filamentous fungus, aspergillus nidulans, multiple rounds of nuclear division occur before cytokinesis, allowing an unambiguous identification of genes required specifically for cytokinesis. as in animal cells, both an intact microtubule cytoskeleton and progression through mitosis are required for actin ring formation and contraction. the seph gene from a. nidulans was discovered in a screen for temperature-sensitive cytokinesis mutants. sequence analysis showed that seph is 42% identica ... | 2001 | 11679062 |
| an inhibitor-resistant histone deacetylase in the plant pathogenic fungus cochliobolus carbonum. | we have partially purified and characterized histone deacetylases of the plant pathogenic fungus cochliobolus carbonum. depending on growth conditions, this fungus produces hc-toxin, a specific histone deacetylase inhibitor. purified enzymes were analyzed by immunoblotting, by immunoprecipitation, and for toxin sensitivity. the results demonstrate the existence of at least two distinct histone deacetylase activities. a high molecular weight complex (430,000) is sensitive to hc-toxin and trichost ... | 2001 | 11669622 |
| the aspergillus nidulans snt genes are required for the regulation of septum formation and cell cycle checkpoints. | in aspergillus nidulans, germinating conidia undergo multiple rounds of nuclear division before forming a septum. previous genetic results suggest that the ability to separate nuclear division and septum formation depends upon a threshold level of activity of the cyclin-dependent kinase nimx(cdk1). mutations in nimx and nimt, the gene encoding the nimx(cdk1)-activating phosphatase, have revealed that tyr-15 phosphorylation is important for determining the timing of the formation of the first sep ... | 2001 | 11606533 |
| stable transformation of pleurotus ostreatus to hygromycin b resistance using lentinus edodes gpd expression signals. | it was reported that pleurotus ostreatus was transformed unstably using recombinant plasmids containing a hygromycin b phosphotransferase gene (hph) under the control of aspergillus nidulans expression signals, and that the plasmids were maintained extrachromosomally in the transformants. here we report a stable and integrative transformation of the fungus to hygromycin b resistance, using a recombinant hph fused with lentinus edodes glyceraldehyde-3-phosphate dehydrogenase expression signals. r ... | 2001 | 11601618 |
| gamma-tubulin and the c-terminal motor domain kinesin-like protein, klpa, function in the establishment of spindle bipolarity in aspergillus nidulans. | previous research has found that a gamma-tubulin mutation in schizosaccharomyces pombe is synthetically lethal with a deletion of the c-terminal motor domain kinesin-like protein gene pkl1, but the lethality of the double mutant prevents a phenotypic analysis of the synthetic interaction. we have investigated interactions between klpa1, a deletion of an aspergillus nidulans homolog of pkl1, and mutations in the mipa, gamma-tubulin gene. we find that klpa1 dramatically increases the cold sensitiv ... | 2001 | 11598200 |
| the hypocrea jecorina hap 2/3/5 protein complex binds to the inverted ccaat-box (attgg) within the cbh2 (cellobiohydrolase ii-gene) activating element. | the 5' regulatory region of the chh2 gene, encoding cellobiohydrolase ii, of the filamentous fungus hypocrea jecorina contains the cbh2 activating element (cae) which is essential for cbh2 expression. the cae consists of two separate, adjacent motifs, a ccaat box on the template strand (attgg) and a gtaata box on the coding strand, which co-operate in the induction of the gene by cellulose or sophorose. emsa supershift experiments using an antibody against aspergillus nidulans hapc suggested tha ... | 2001 | 11589578 |
| cytochrome c is not essential for viability of the fungus aspergillus nidulans. | the filamentous fungus aspergillus nidulans is an obligate aerobe, which is capable of anaerobic survival, but not anaerobic growth. since cytochrome c forms an essential part of the oxidative respiratory pathway it was expected that mutants lacking this component would be non-viable. gene replacement of one homologue of the cyca (cytochrome c) gene was carried out in a diploid strain. benomyl-induced haploidisation of this diploid yielded all cyca+ haploid colonies, initially suggesting that lo ... | 2001 | 11589577 |
| isolation of uv-induced mutations in the area nitrogen regulatory gene of aspergillus niger, and construction of a disruption mutant. | the area gene of filamentous fungi encodes a positive-acting transcriptional factor required for the expression of genes involved in the utilisation of nitrogen sources other than ammonium and glutamine. in aspergillus niger we have isolated three uv-induced area mutants and constructed a well-defined disruption allele of the area gene. the area gene was genetically localised on linkage group iii, 3.6 map units (m.u.) from bioa1 and 4.5 m.u. from lysa7. analysis of the expression of the nitrate ... | 2001 | 11589576 |
| a fungal perspective on human inborn errors of metabolism: alkaptonuria and beyond. | crucial for the establishment and development of biochemical genetics as a self-standing discipline was beadle and tatum's choice of neurospora crassa as experimental organism some 60 years ago. although garrod's insights on biochemical genetics and his astonishingly modern concepts of biochemical individuality and susceptibility to disease had been ignored by their contemporaries, beadle acknowledged on several occasions how close garrod had come to the "one-gene-one-enzyme" hypothesis. in an u ... | 2001 | 11567547 |
| role of ntcb in activation of nitrate assimilation genes in the cyanobacterium synechocystis sp. strain pcc 6803. | in synechocystis sp. strain pcc 6803, the genes encoding the proteins involved in nitrate assimilation are organized into two transcription units, nrtabcd-narb and nira, the expression of which was repressed by ammonium and induced by inhibition of ammonium assimilation, suggesting involvement of ntca in the transcriptional regulation. under inducing conditions, expression of the two transcription units was enhanced by nitrite, suggesting regulation by ntcb, the nitrite-responsive transcriptiona ... | 2001 | 11566981 |
| role of glutamine synthetase in nitrogen metabolite repression in aspergillus nidulans. | glutamine synthetase (gs), ec 6.3.1.2, is a central enzyme in the assimilation of nitrogen and the biosynthesis of glutamine. we have isolated the aspergillus nidulans glna gene encoding gs and have shown that glna encodes a highly expressed but not highly regulated mrna. inactivation of glna results in an absolute glutamine requirement, indicating that gs is responsible for the synthesis of this essential amino acid. even when supplemented with high levels of glutamine, strains lacking a functi ... | 2001 | 11566979 |
| the solution structure of an alcr-dna complex sheds light onto the unique tight and monomeric dna binding of a zn(2)cys(6) protein. | in aspergillus nidulans, the transcription activator alcr mediates specific induction of a number of the genes of the alc cluster. this cluster includes genes involved in the oxidation of ethanol and other alcohols to acetate. the pattern of binding and of transactivation of alcr is unique within the zn(2)cys(6) family. the structural bases for these specificities have not been analyzed at the atomic level until now. | 2001 | 11566132 |
| molecular cloning of kpca gene encoding a kex2p-like endoprotease from aspergillus nidulans. | we cloned and sequenced a gene, kpca (kex2p-like proprotein convertase a), from a genomic library of aspergillus nidulans. the kpca gene encodes an 820-residue protein, named kpca, which contains a putative subtilisin-like catalytic domain (residues 136-466) homologous to that of the subtilisin serine protease family. kpca shows 56, 73, and 47% amino acid identities with saccharomyces cerevisiae kex2p, aspergillus niger kexb, and mouse furin within the subtilisin-like catalytic domain, respectiv ... | 2001 | 11561725 |
| srea is involved in regulation of siderophore biosynthesis, utilization and uptake in aspergillus nidulans. | under conditions of low iron availability, most fungi excrete siderophores in order to mobilize extracellular iron. we show that lack of the gata-type transcription factor srea in aspergillus nidulans not only leads to derepression of siderophore biosynthesis but also to deregulation of siderophore-bound iron uptake and ornithine esterase expression. furthermore, srea deficiency causes increased accumulation of ferricrocin, the siderophore responsible for intracellular iron storage. in srea dele ... | 2001 | 11555288 |
| transcriptional autoregulation and inhibition of mrna translation of amino acid regulator gene cpca of filamentous fungus aspergillus nidulans. | the cpca protein of the filamentous fungus aspergillus nidulans is a member of the c-jun-like transcriptional activator family. it acts as central transcription factor of the cross-pathway regulatory network of amino acid biosynthesis and is functionally exchangeable for the general control transcriptional activator gcn4p of saccharomyces cerevisiae. in contrast to gcn4, expression of cpca is strongly regulated by two equally important mechanisms with additive effects that lead to a fivefold inc ... | 2001 | 11553722 |
| ethanol catabolism in aspergillus nidulans: a model system for studying gene regulation. | this article reviews our knowledge of the ethanol utilization pathway (alc system) in the hyphal fungus aspergillus nidulans. we discuss the progress made over the past decade in elucidating the two regulatory circuits controlling ethanol catabolism at the level of transcription, specific induction, and carbon catabolite repression, and show how their interplay modulates the utilization of nutrient carbon sources. the mechanisms featuring in this regulation are presented and their modes of actio ... | 2001 | 11550794 |
| a new class of glutaminase from aspergillus oryzae. | the koji mold aspergillus oryzae is able to produce glutaminase which converts glutamine to glutamic acid, one of the most important flavor components in soy sauce. we present here the isolation and the complete nucleotide sequence of the glutaminase- encoding gene from a. oryzae u212, an industrial strain used in thailand. n-terminal and internal amino acid sequences were determined from purified glutaminase. a 700-bp fragment was amplified by pcr using oligonucleotide primers designed from par ... | 2001 | 11545278 |
| reduced function of a phenylacetate-oxidizing cytochrome p450 caused strong genetic improvement in early phylogeny of penicillin-producing strains. | the single-copy paha gene from penicillium chrysogenum encodes a phenylacetate 2-hydroxylase that catalyzes the first step of phenylacetate catabolism, an oxidative route that decreases the precursor availability for penicillin g biosynthesis. paha protein is homologous to cytochrome p450 monooxygenases involved in the detoxification of xenobiotic compounds, with 84% identity to the aspergillus nidulans homologue phaca. expression level of paha displays an inverse correlation with the penicillin ... | 2001 | 11544206 |
| the structure and domain organization of escherichia coli isocitrate lyase. | enzymes of the glyoxylate-bypass pathway are potential targets for the control of many human diseases caused by such pathogens as mycobacteria and leishmania. isocitrate lyase catalyses the first committed step in this pathway and the structure of this tetrameric enzyme from escherichia coli has been determined at 2.1 a resolution. e. coli isocitrate lyase, like the enzyme from other prokaryotes, is located in the cytoplasm, whereas in plants, protozoa, algae and fungi this enzyme is found local ... | 2001 | 11526312 |
| colorimetric assay for antifungal susceptibility testing of aspergillus species. | a colorimetric assay for antifungal susceptibility testing of aspergillus species (aspergillus fumigatus, aspergillus flavus, aspergillus terreus, aspergillus nidulans, and aspergillus ustus) is described based on the reduction of the tetrazolium salt 2,3-bis(2-methoxy-4-nitro-5-[(sulphenylamino)carbonyl]-2h-tetrazolium-hydroxide (xtt) in the presence of menadione as an electron-coupling agent. the combination of 200 microg of xtt/ml with 25 microm menadione resulted in a high production of form ... | 2001 | 11526191 |
| induction of jlba mrna synthesis for a putative bzip protein of aspergillus nidulans by amino acid starvation. | the jlba (jun-like hzip) gene of aspergillus nidulans was isolated. the deduced amino acid motif of the c-terminal region of jlha encodes a putative dna-binding site composed of a basic amino acid domain and an adjacent leucine zipper motif. this region shares highest similarities to the c-terminal dna-binding domain and the basic zipper (bzip)-motifs of transcription factors like cpca from a. niger, gcn4p from saccharomyces cerevisiae, human junb and c-jun. the putative jlba protein contains a ... | 2001 | 11525406 |
| a family of dna repeats in aspergillus nidulans has assimilated degenerated retrotransposons. | in the course of a chromosomal walk towards the centromere of chromosome iv of aspergillus nidulans, several cross-hybridizing genomic cosmid clones were isolated. restriction mapping of two such clones revealed that their restriction patterns were similar in a region of at least 15 kb, indicating the presence of a large repeat. the nature of the repeat was further investigated by sequencing and southern analysis. the study revealed a family of long dispersed repeats with a high degree of sequen ... | 2001 | 11523805 |
| in vivo and in vitro analyses of the amyr binding site of the aspergillus nidulans agda promoter; requirement of the cgg direct repeat for induction and high affinity binding of amyr. | the alpha-glucosidase gene (agda) of aspergillus nidulans has a single cggn8cgg type amyr binding site in its promoter region. the binding site is functional in vivo as a cis-element responsible for induction by starch, and mutational studies indicated that both the cgg triplets are required for high-level induction. a part of amyr (residues 1-411; amyr(1-411)), which was produced as a male fusion protein in e. coli, bound to the cggn8cgg site of the agda promoter. dna binding profiles to the mu ... | 2001 | 11515540 |
| visualization of nuclei in aspergillus oryzae with egfp and analysis of the number of nuclei in each conidium by facs. | aspergillus oryzae has been reported to form conidia with multinuclei. in order to analyze nuclei in living cells, we developed an expression system of the a. nidutans histone h2b protein tagged by egfp (h2b::egfp). in both a. oryzae niad300 and a. nidulans fgsc89 transformants expressing h2b::egfp, fluorescence was detected in nuclear regions of hyphae and conidia. while a conidium contained only one fluorescent spot in the a. nidulans transformant, approximately 66% of conidia had two, 24% had ... | 2001 | 11515532 |
| cell cycle progression and cell polarity require sphingolipid biosynthesis in aspergillus nidulans. | sphingolipids are major components of the plasma membrane of eukaryotic cells and were once thought of merely as structural components of the membrane. we have investigated effects of inhibiting sphingolipid biosynthesis, both in germinating spores and growing hyphae of aspergillus nidulans. in germinating spores, genetic or pharmacological inactivation of inositol phosphorylceramide (ipc) synthase arrests the cell cycle in g(1) and also prevents polarized growth during spore germination. howeve ... | 2001 | 11509663 |
| the lis1-related protein nudf of aspergillus nidulans and its interaction partner nude bind directly to specific subunits of dynein and dynactin and to alpha- and gamma-tubulin. | the nudf protein of aspergillus nidulans, which is required for nuclear migration through the fungal mycelium, closely resembles the lis1 protein required for migration of neurons to the cerebral cortex in humans. genetic experiments suggested that nudf influences nuclear migration by affecting cytoplasmic dynein. nudf interacts with another protein, nude, which also affects nuclear migration in a. nidulans. interactions among lis1, nude, dynein, and gamma-tubulin have been demonstrated in anima ... | 2001 | 11509576 |
| the nsdd gene encodes a putative gata-type transcription factor necessary for sexual development of aspergillus nidulans. | the ability to reproduce both sexually and asexually is one of the characteristics of the homothalic ascomycete aspergillus nidulans. unlike the other aspergillus species, a. nidulans undergoes sexual development that seems to be regulated by internal and external stimuli. to begin to understand the sexual reproduction of a. nidulans we previously isolated and characterized several nsd (never in sexual development) mutants that failed to produce any sexual reproductive organs, and identified fou ... | 2001 | 11489119 |
| a single gene produces mitochondrial, cytoplasmic, and peroxisomal nadp-dependent isocitrate dehydrogenase in aspergillus nidulans. | nadp-dependent isocitrate dehydrogenase enzymes catalyze the decarboxylation of isocitrate to 2-oxoglutarate accompanied by the production of nadph. in mammals two different genes encode mitochondrial and cytoplasmic/peroxisomal located enzymes, whereas in saccharomyces cerevisiae three separate genes specify compartment specific enzymes. we have identified a single gene, idpa, in the filamentous fungus aspergillus nidulans that specifies a protein with a high degree of identity to mammalian and ... | 2001 | 11483612 |
| development of a homologous transformation system for the opportunistic human pathogen aspergillus fumigatus based on the sc gene encoding atp sulfurylase. | the development of a homologous transformation system for the opportunistic human pathogenic fungus aspergillus fumigatus is described. the system is based on the sc gene encoding atp sulfurylase. several a. fumigatus sc mutant strains were readily isolated by strong selection for selenate resistance. the coding region plus upstream and downstream regulatory sequences of the a. fumigatus sc gene were cloned by inverse pcr and then sequenced. sequencing of the sc cdna revealed the presence of fiv ... | 2001 | 11479709 |
| the aspergillus nidulans carnitine carrier encoded by the acuh gene is exclusively located in the mitochondria. | the location of the aspergillus nidulans carnitine/acyl-carnitine carrier (acuh) was studied. acuh with a his-tag at its n-terminus was over-expressed in escherichia coli and purified by ni(2+) affinity chromatography. the purified protein was utilised to raise polyclonal antibodies which were characterised by western blotting. for localisation studies a. nidulans t1 strain, that contains the acuh gene under control of the strong promoter alca(p), was derived. results obtained demonstrate the ex ... | 2001 | 11470361 |
| myosin i mutants with only 1% of wild-type actin-activated mgatpase activity retain essential in vivo function(s). | the single class i myosin (myoa) of aspergillus nidulans is essential for hyphal growth. it is generally assumed that the functions of all myosins depend on their actin-activated mgatpase activity. here we show that myoa mutants with no more than 1% of the actin-activated mgatpase activity of wild-type myoa in vitro and no detectable in vitro motility activity can support fungal cell growth, albeit with a delay in germination time and a reduction in hyphal elongation. from these and other data, ... | 2001 | 11459943 |
| functional analysis of tama, a coactivator of nitrogen-regulated gene expression in aspergillus nidulans. | the tam a gene of aspergillus nidulans encodes a 739-amino acid protein with similarity to uga35p/dal81p/durlp of saccharomyces cerevisiae. it has been proposed that tama functions as a co-activator of area, the major nitrogen regulatory protein in a. nidulans. because area functions as a transcriptional activator under nitrogen-limiting conditions, we investigated whether tama was also present in the nucleus. we found that a gfp-tama fusion protein was predominantly localised to the nucleus in ... | 2001 | 11459183 |
| functional expression and cellular localization of a green fluorescent protein-tagged proline transporter in aspergillus nidulans. | the prnb protein is a highly specific proline transporter that belongs to an amino acid transporter family conserved in both prokaryotes and eukaryotes. in this work, we detected and analyzed the cellular localization of prnb in vivo by means of green fluorescent protein (gfp) fusions. several prnb-gfp gene fusions, driven by prnb native promoter sequences, were constructed and targeted to the genomic locus of a prnb null mutant. chimeric proteins containing gfp fused to the c terminus of prnb t ... | 2001 | 11456464 |
| characterization of the role of the flug protein in asexual development of aspergillus nidulans. | we showed previously that a deltaflug mutation results in a block in aspergillus nidulans asexual sporulation and that overexpression of flug activates sporulation in liquid-submerged culture, a condition that does not normally support sporulation of wild-type strains. here we demonstrate that the entire n-terminal region of flug ( approximately 400 amino acids) can be deleted without affecting sporulation, indicating that flug activity resides in the c-terminal half of the protein, which bears ... | 2001 | 11454752 |
| the isda gene is necessary for sexual development inhibition by a salt in aspergillus nidulans. | using one of 17 expressed sequence tags (ests) previously identified as specific to the late sexual developmental (lsd) stage of aspergillus nidulans, a gene for the subject est was isolated. the determined dna sequences revealed an open reading frame encoding a 356 amino acid polypeptide which does not share a sequence similarity to previously identified genes or proteins. the isolated gene was named lsda (late sexual development), since it was expressed abundantly at the lsd stage. the lsda ge ... | 2001 | 11453253 |
| alanine-scanning mutagenesis of aspergillus gamma-tubulin yields diverse and novel phenotypes. | we have created 41 clustered charged-to-alanine scanning mutations of the mipa, gamma-tubulin, gene of aspergillus nidulans and have created strains carrying these mutations by two-step gene replacement and by a new procedure, heterokaryon gene replacement. most mutant alleles confer a wild-type phenotype, but others are lethal or conditionally lethal. the conditionally lethal alleles exhibit a variety of phenotypes under restrictive conditions. most have robust but highly abnormal mitotic spind ... | 2001 | 11452008 |
| carbon catabolite repression in aspergillus nidulans involves deubiquitination. | the best studied role of ubiquitination is to mark proteins for destruction by the proteasome but, in addition, it has recently been shown to promote macromolecular assembly and function, and alter protein function, thus playing a regulatory role distinct from protein degradation. deubiquinating enzymes, the ubiquitin-processing proteases (ubps) and the ubiquitin carboxy-terminal hydrolases (uchs), remove ubiquitin from ubiquitinated substrates. we show here that the creb gene involved in carbon ... | 2001 | 11442830 |
| cloning and characterization of the cpya gene encoding intracellular carboxypeptidase from aspergillus nidulans. | carboxypeptidase y (cpy) has been used as a maker enzyme for investigations on intracellular transport of vacuolar proteins and on vacuolar biogenesis in saccharomyces cerevisiae. we describe the cloning and characterization of the cpy homologue encoding gene (cpya) from the filamentous fungus aspergillus nidulans. the cpya gene has one intron and encodes a protein with 552 amino acids containing a putative signal sequence and pro-sequence. the predicted cpya protein is highly similar in sequenc ... | 2001 | 11440134 |
| trehalose is required for the acquisition of tolerance to a variety of stresses in the filamentous fungus aspergillus nidulans. | trehalose is a non-reducing disaccharide found at high concentrations in aspergillus nidulans conidia and rapidly degraded upon induction of conidial germination. furthermore, trehalose is accumulated in response to a heat shock or to an oxidative shock. the authors have characterized the a. nidulans tpsa gene encoding trehalose-6-phosphate synthase, which catalyses the first step in trehalose biosynthesis. expression of tpsa in a saccharomyces cerevisiae tps1 mutant revealed that the tpsa gene ... | 2001 | 11429462 |
| identification of two different 14-alpha sterol demethylase-related genes (cyp51a and cyp51b) in aspergillus fumigatus and other aspergillus species. | two cyp51-related genes (cyp51a and cyp51b) encoding 14-alpha sterol demethylase-like enzymes were identified in the opportunistic human pathogen aspergillus fumigatus. pcr amplification using degenerate oligonucleotides based on conserved areas of cytochrome p450 demethylases of other filamentous fungi and yeasts allowed the cloning and sequencing of two different homologue genes in a. fumigatus. southern analysis confirmed that both genes hybridized to distinct genomic loci and that both are r ... | 2001 | 11427550 |
| 2-methylisocitrate lyases from the bacterium escherichia coli and the filamentous fungus aspergillus nidulans: characterization and comparison of both enzymes. | in escherichia coli and aspergillus nidulans, propionate is oxidized to pyruvate via the methylcitrate cycle. the last step of this cycle, the cleavage of 2-methylisocitrate to succinate and pyruvate is catalysed by 2-methylisocitrate lyase. the enzymes from both organisms were assayed with chemically synthesized threo-2-methylisocitrate; the erythro-diastereomer was not active. 2-methylisocitrate lyase from e. coli corresponds to the prpb protein of the prp operon involved in propionate oxidati ... | 2001 | 11422389 |
| site-directed mutagenesis of proline-285 to leucine in cephalosporium acremonium isopenicillin-n-synthase affects catalysis and increases soluble expression at higher temperatures. | the conversion of delta-(l-alpha-aminoadipyl)-l-cysteinyl-d-valine (acv) to isopenicillin n is dependant on the catalytic action of isopenicillin n-synthase (ipns), an important enzyme in the penicillin and cephalosporin biosynthetic pathway. one of the amino acid residues suggested by the aspergillus nidulans ipns crystal structure for interaction with the valine isopropyl group of acv is proline-283. site-directed mutagenesis of the corresponding proline-285 to leucine in cephalosporium acremo ... | 2001 | 11421458 |
| resistance to itraconazole in aspergillus nidulans and aspergillus fumigatus is conferred by extra copies of the a. nidulans p-450 14alpha-demethylase gene, pdma. | triazoles selectively inhibit the cytochrome p-450-dependent c-14 lanosterol alpha-demethylase (p-450 14 alpha dm), a key enzyme in ergosterol biosynthesis in fungi. to investigate mechanisms of triazole resistance in a mould, we used aspergillus nidulans, a genetically amenable model fungus closely related to more pathogenic members of the genus. we selected for genes that would give resistance to itraconazole following transformation with a high copy genomic library of a. nidulans. in all the ... | 2001 | 11418514 |
| phenotypic and genotypic characterization of reference strains of the genus aspergillus. | twenty-five culture collection strains from four aspergillus species (a. fumigatus n = 8, a. flavus n = 8, a. niger n = 4, a. nidulans n = 5) were characterized by four methods: (i) determination of patterns in an assimilation assay; (ii) protein pattern of whole mycelial cell lysates in the sodium dodecyl sulphate (sds)-polyacrylamide gel electrophoresis (page); (iii) reactivity of a pool serum obtained from cystic fibrosis patients with mycelial lysates in the immunoblot; and (iv) random ampli ... | 2001 | 11413925 |
| aohapb, aohapc and aohape, subunits of the aspergillus oryzae ccaat-binding complex, are functionally interchangeable with the corresponding subunits in aspergillus nidulans. | two genes, aohapb and aohape, encoding subunits of the aspergillus oryzae ccaat-binding complex were cloned and sequenced. the polypeptides encoded by aohapb and aohape were expressed in escherichia coli and used to reconstitute a dna-binding complex with recombinant aohapc. the dna-binding activity was observed only in the presence of all three subunits, indicating that aohapb, aohape and aohapc are essential for ccaat-binding. furthermore, introduction of the aohapb, aohapc and aohape genes in ... | 2001 | 11409179 |
| isolation and characterization of sexual sporulation mutants of aspergillus nidulans. | for the genetic dissection of sexual sporulation in aspergillus nidulans, we started a collection of ascosporeless mutants. after mutagenization of conidiospores with high doses of uv, we isolated 20 mutants with defects in ascospore formation. we crossed these mutants in two successive rounds with the wild-type strain. eighteen of the 20 isolated mutants produced progeny with the original mutant phenotype in these crosses, and these mutants were further analyzed. all 18 analyzed mutations were ... | 2001 | 11407883 |