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isolation of a nitrogen response regulator gene (nrr1) from metarhizium anisopliae.attempts to improve the effectiveness of entomopathogenic fungi as biological control agents require a clear understanding of the pathogenicity determinants at both the biochemical and molecular level. proteases play a key role in entomopathogenicity, allowing the fungus to penetrate the insect cuticle and rapidly invade the host. the most extensively studied of these protease activities, pr1a and pr2, are both subject to nitrogen derepression. the metarhizium anisopliae nrr1 (nitrogen response ...19989852945
a highly conserved rna-binding protein for cytoplasmic mrna localization in vertebrates.cytoplasmic mrna localization is a widespread mechanism for restricting the translation of specific mrnas to distinct regions of eucaryotic cells. this process involves specific interactions between cellular factors and localization signals in the 3' untranslated regions of the localized mrna. because only a few of these cellular factors have been identified, it is not known whether common factors are utilized for the localization of different mrnas. we recently discovered vera, a protein that b ...19989560341
natural organic compounds that affect to microtubule functions.microtubules (mt), composed of a protein tubulin (tn) alpha,beta-heterodimer with concomitant other proteins, microtubule associated proteins (maps and tau), are known to be the main component of spindles in a mitotic apparatus of eucaryotic cells, and are also involved in many other basic and essential cell functions. there are a number of natural and synthetic compounds that interfere with mt function to cause the mitotic arrest of eucaryotic cells. such antimitotic agents show a broad biologi ...19989564789
bimaapc3, a component of the aspergillus anaphase promoting complex/cyclosome, is required for a g2 checkpoint blocking entry into mitosis in the absence of nima function.temperature sensitive (ts) nima mutants of aspergillus nidulans arrest at a unique point in g2 which is post activation of cdc2. here we show that this g2 arrest is due to loss of nima function and that it is dependent on bimaapc3, a component of the anaphase promoting complex/cyclosome (apc/c). whereas nima single mutants arrested in g2 with decondensed chromatin and interphase microtubule arrays, nima, bimaapc3 double mutants arrested growth with condensed chromatin and aster-like microtubule ...19989570762
altered specificity mutations define residues essential for substrate positioning in xanthine dehydrogenase.we describe the sequence changes of a number of mutations of the aspergillus nidulans xanthine dehydrogenase (xdh). we have located the amino acids affected by these changes in the three-dimensional (3d) structure of aldehyde oxido-reductase (mop) from desulfovibrio gigas, related to eukaryotic xdhs. of these, two are loss of function mutations, mapping, respectively, in the molybdenum-pterin co-factor (moco) domain and in the domain involved in substrate recognition. changes in two amino acids ...19989571062
virulence of catalase-deficient aspergillus nidulans in p47(phox)-/- mice. implications for fungal pathogenicity and host defense in chronic granulomatous disease.chronic granulomatous disease (cgd) is a rare genetic disorder in which phagocytes fail to produce superoxide because of defects in one of several components of the nadph oxidase complex. as a result, patients develop recurrent life-threatening bacterial and fungal infections. the organisms to which cgd patients are most susceptible produce catalase, regarded as an important factor for microbial pathogenicity in cgd. to test the role of pathogen-derived catalase in cgd directly, we have generate ...19989576747
[regulation of gene expression in aspergilli].the aspergillus oryzae taka-amylase a (taa) gene has been used as a model gene to characterize the regulatory mechanisms of gene expression in aspergilli. taa gene contained a typical eukaryotic promoter with a tata box and putative regulatory elements such as a ccaat sequence in its 5'-noncoding region. a nuclear protein designated ancp bound to the ccaat sequence. replacement of the ccaat sequence with cgtaa was found to abolish the binding of ancp and to have an inhibitory effect on taa promo ...19989580033
role of fungal dynein in hyphal growth, microtubule organization, spindle pole body motility and nuclear migration.cytoplasmic dynein is a microtubule-associated motor protein with several putative subcellular functions. sequencing of the gene (dhc1) for cytoplasmic dynein heavy chain of the filamentous ascomycete, nectria haematococca, revealed a 4,349-codon open reading frame (interrupted by two introns) with four highly conserved p-loop motifs, typical of cytoplasmic dynein heavy chains. the predicted amino acid sequence is 78.0% identical to the cytoplasmic dynein heavy chain of neurospora crassa, 70.2% ...19989580563
murine nima-related kinases are expressed in patterns suggesting distinct functions in gametogenesis and a role in the nervous system.nima protein kinase is a major regulator of progression into mitosis in aspergillus nidulans. dominant negative forms of nima protein prevent entrance into mitosis in hela cells, suggesting that mammals have a similar pathway. we have reported previously the isolation of a murine nima-related kinase, designated nek1, and more recently several additional nima-related human kinases have been cloned. the existence of several mammalian nima-related genes raises the questions of whether the different ...19989583679
a screen for dynein synthetic lethals in aspergillus nidulans identifies spindle assembly checkpoint genes and other genes involved in mitosis.cytoplasmic dynein is a ubiquitously expressed microtubule motor involved in vesicle transport, mitosis, nuclear migration, and spindle orientation. in the filamentous fungus aspergillus nidulans, inactivation of cytoplasmic dynein, although not lethal, severely impairs nuclear migration. the role of dynein in mitosis and vesicle transport in this organism is unclear. to investigate the complete range of dynein function in a. nidulans, we searched for synthetic lethal mutations that significantl ...19989584089
ribonucleic acid treatment alters gene expression in diploid strains of aspergillus nidulans.physical and chemical agents that promote dna damage can induce high levels of mitotic crossing-over in eukaryotic diploid cells. similarly, foreign dna segments introduced by transformation processes, in the cell genome, can also induce mitotic crossing-over as an outcome of the reactions leading to chromosomic balance or due to the mechanisms aiming at the integration of the exogenous dna. zucchi et al. have described a system showing that rna treatments are capable of inducing changes in the ...19989593581
the lissencephaly gene product lis1, a protein involved in neuronal migration, interacts with a nuclear movement protein, nudc.important clues to how the mammalian cerebral cortex develops are provided by the analysis of genetic diseases that cause cortical malformations [1-5]. people with miller-dieker syndrome (mds) or isolated lissencephaly sequence (ils) have a hemizygous deletion or mutation in the lis1 gene [3,6]; both conditions are characterized by a smooth cerebral surface, a thickened cortex with four abnormal layers, and misplaced neurons [7,8]. lis1 is highly expressed in the ventricular zone and the cortica ...19989601647
isolation of the aspergillus nidulans sudd gene and its human homologue.we have been studying the heat-sensitive bimd6 mutation of aspergillus nidulans. at a restrictive temperature, the chromosomes of bimd6 mutant strains fail to attach properly to the spindle microtubules, and the mutant also displays a high rate of chromosome loss. we previously cloned the suda gene, an extragenic suppressor of the heat-sensitive bimd6 mutation and showed that it coded for a da-box or smc protein. smc proteins have been demonstrated to function in chromosome condensation, segrega ...19989602165
successful treatment with voriconazole of invasive aspergillosis in chronic granulomatous disease.a 5-year-old boy with chronic granulomatous disease (cgd) was treated with amphotericin b for an invasive pulmonary aspergillus nidulans infection. the infection progressed during 6 wk of treatment despite the addition of interferon-gamma (ifn-gamma), filgrastim, and transfusions with donor granulocytes. treatment with a novel antifungal triazole, voriconazole, resulted in an excellent clinical response.19989603157
transcriptional activation of the aspergillus nidulans gpda promoter by osmotic signals.a differentially expressed gpda cdna clone was isolated from nacl-adapted aspergillus nidulans (fgsc359) and identified as glyceraldehyde-3-phosphate dehydrogenase (gpda) on the basis of its nucleotide sequence. the level of gpda rna substantially increased in cultures gradually adapted to nacl but was greatly reduced in cultures exposed briefly to a high concentration of nacl. a pyrg auxotroph of a. nidulans (a773) was cotransformed with a gpda-uida construct and a plasmid containing the neuros ...19989603839
culture conditions control expression of the genes for aflatoxin and sterigmatocystin biosynthesis in aspergillus parasiticus and a. nidulans.high temperature and nitrate supported gene expression for sterigmatocystin biosynthesis in aspergillus nidulans; ammonium did not. homologous genes for aflatoxin biosynthesis in a. parasiticus showed the opposite transcript expression pattern, suggesting that the two mycotoxins are regulated differently. the aflr gene is postulated to require additional genetic elements to effect its own activation by the different culture conditions. a patulin polyketide synthase (pks) gene was found to be reg ...19989603849
constitutive activation of endocytosis by mutation of myoa, the myosin i gene of aspergillus nidulans.class i myosins function in cell motility, intracellular vesicle trafficking and endocytosis. recently, it was shown that class i myosins are phosphorylated by a member of the p21-activated kinase (pak) family. pak phosphorylates a conserved serine or threonine residue in the myosin heavy chain. phosphorylation at this site is required for maximal activation of the actin-activated mg2+-atpase activity in vitro. this serine or threonine residue is conserved in all known class i myosins of microbi ...19989603982
increased transformation frequency and tagging of developmental genes in aspergillus nidulans by restriction enzyme-mediated integration (remi).we have used a plasmid containing the argb gene to transform an aspergillus nidulans argb-deleted strain in the presence of restriction enzymes and show a 20- to 60-fold increase in transformation frequency via restriction enzyme-mediated integration (remi). this procedure was used to try to tag new genes involved in the asexual development of this fungus. more than 2000 transformants isolated following electroporation of conidia and approximately 3700 transformants recovered following protoplas ...19989613576
the aspergillus nidulans cnxf gene and its involvement in molybdopterin biosynthesis. molecular characterization and analysis of in vivo generated mutants.the product of the aspergillus nidulans cnxf gene was found by biochemical analysis of cnxf mutants to be involved in the conversion of precursor z to molybdopterin. mutants cnxf1242 and cnxf8 accumulate precursor z, while the level of molybdopterin is undetectable. the dna sequence of the cnxf gene was determined, and the inferred protein of 560 amino acids was found to contain a central region (residues around 157 to 396) similar in sequence to the prokaryotic proteins moeb, which is thought t ...19989614089
secretion, purification, and characterisation of barley alpha-amylase produced by heterologous gene expression in aspergillus niger.efficient production of recombinant barley alpha-amylase has been achieved in aspergillus niger. the cdna encoding alpha-amylase isozyme 1 (amy1) and its signal peptide was placed under the control of the aspergillus nidulans glyceraldehyde-3-phosphate dehydrogenase (gpd) promoter and the a. nidulans trpc gene terminator. secretion yields up to 60 mg/l were obtained in media optimised for alpha-amylase activity and low protease activity. the recombinant amy1 (reamy1) was purified to homogeneity ...19989615479
development of a homologous transformation system for the human pathogenic fungus aspergillus fumigatus based on the pyrg gene encoding orotidine 5'-monophosphate decarboxylase.a homologous transformation system for the opportunistic fungal pathogen aspergillus fumigatus was developed. it is based on the a. fumigatus pyrg gene, encoding orotidine 5'-monophosphate decarboxylase, which was cloned and sequenced. transformation of both aspergillus (emericella) nidulans and a. fumigatus pyrg mutant strains by the use of protoplasts or electroporation established the functionality of the cloned gene. dna sequencing of the a. fumigatus pyrg1 mutant allele revealed that it enc ...19989618589
sequence, exon-intron organization, transcription and mutational analysis of prna, the gene encoding the transcriptional activator of the prn gene cluster in aspergillus nidulans.the prna gene codes for a transcriptional activator that mediates proline induction of four other genes involved in proline utilization as a nitrogen and/or carbon source in aspergillus nidulans. in this paper, we present the genomic and cdna sequence and the transcript map of prna. the prna protein belongs to the zn binuclear cluster family of transcriptional activators. the gene shows a striking intron-exon organization, with the putative nuclear localization sequence and the zn cluster domain ...19989622360
susceptibility of aspergillus strains from culture collections to amphotericin b and itraconazole.susceptibility testing of 27 aspergillus reference strains belonging to five species was performed using the microdilution broth method with yeast nitrogen broth and rpmi-1640. similar results were found using the two media. the strains of aspergillus fumigatus (n = 8) and aspergillus niger (n = 4) had mics of amphotericin b in the range 0.125-0.5 mg/l. in contrast, nine out of 13 strains of aspergillus flavus and aspergillus nidulans had mics in the range 2-16 mg/l. all strains had mics of itra ...19989630411
stress protein of cyanobacteria cp36: interaction with photoactive complexes and formation of supramolecular structurescyanobacterium anacystis nidulans r2, synechocystis sp. pcc 6803 (wild-type strain and mutants delta2 and delta3 lacking psii and psi, respectively), and synechocystis sp. bo 9201 synthesize the pigment--protein complex cp36 (cpiv-4, cp43') under iron deficiency in the medium. accumulation of cp36 is accompanied by structural reorganizations in the photosynthetic membranes. integrating mean times of excitation relaxation (quenching) are 2.2 nsec (cp36), 1 nsec (psi), and 420 psec (psii in fm sta ...19989632897
c-nap1, a novel centrosomal coiled-coil protein and candidate substrate of the cell cycle-regulated protein kinase nek2.nek2 (for nima-related kinase 2) is a mammalian cell cycle-regulated kinase structurally related to the mitotic regulator nima of aspergillus nidulans. in human cells, nek2 associates with centrosomes, and overexpression of active nek2 has drastic consequences for centrosome structure. here, we describe the molecular characterization of a novel human centrosomal protein, c-nap1 (for centrosomal nek2-associated protein 1), first identified as a nek2-interacting protein in a yeast two-hybrid scree ...19989647649
a role for nima in the nuclear localization of cyclin b in aspergillus nidulans.nima promotes entry into mitosis in late g2 by some mechanism that is after activation of the aspergillus nidulans g2 cyclin-dependent kinase, nimxcdc2/nimecyclin b. here we present two independent lines of evidence which indicate that this mechanism involves control of nimxcdc2/nimecyclin b localization. first, we found that nimecyclin b localized to the nucleus and the nucleus-associated organelle, the spindle pole body, in a nima-dependent manner. analysis of cells from asynchronous cultures, ...19989647650
the role of the aspergillus fumigatus area gene in invasive pulmonary aspergillosis.the area gene of aspergillus nidulans is a positive-acting transcriptional factor required for the expression of genes involved in the utilization of a broad range of nitrogen sources other than ammonium and glutamine. we have investigated the role in pathogenesis of the corresponding gene (afarea) of aspergillus fumigatus, a causative agent of invasive pulmonary aspergillosis. stable and unstable afarea- strains were constructed and tested for altered virulence in mice on the basis of host surv ...19989669338
chimeric purine transporters of aspergillus nidulans define a domain critical for function and specificity conserved in bacterial, plant and metazoan homologues.in aspergillus nidulans, purine uptake is mediated by three transporter proteins: uapa, uapc and azga. uapa and uapc have partially overlapping functions, are 62% identical and have nearly identical predicted topologies. their structural similarity is associated with overlapping substrate specificities; uapa is a high-affinity, high-capacity specific xanthine/uric acid transporter. uapc is a low/moderate-capacity general purine transporter. we constructed and characterized uapa/uapc, uapc/uapa a ...19989670000
complementation of the mpg1 mutant phenotype in magnaporthe grisea reveals functional relationships between fungal hydrophobins.the functional relationship between fungal hydrophobins was studied by complementation analysis of an mpg1(-) gene disruption mutant in magnaporthe grisea. mpg1 encodes a hydrophobin required for full pathogenicity of the fungus, efficient elaboration of its infection structures and conidial rodlet protein production. seven heterologous hydrophobin genes were selected which play distinct roles in conidiogenesis, fruit body development, aerial hyphae formation and infection structure elaboration ...19989670001
a cyclin-dependent kinase family member (phoa) is required to link developmental fate to environmental conditions in aspergillus nidulans.we addressed the question of whether aspergillus nidulans has more than one cyclin-dependent kinase gene and identified such a gene, phoa, encoding two pstaire-containing kinases (phoam1 and phoam47) that probably result from alternative pre-mrna splicing. phoam47 is 66% identical to saccharomyces cerevisiae pho85. the function of this gene was studied using phoa null mutants. it functions in a developmental response to phosphorus-limited growth but has no effect on the regulation of enzymes inv ...19989670015
the uvsi gene of aspergillus nidulans required for uv-mutagenesis encodes a homolog to rev3, a subunit of the dna polymerase zeta of yeast involved in translesion dna synthesis.defects in the uvsi gene of aspergillus nidulans resulted in high uv sensitivity and reductions of spontaneous and uv-induced reversion of certain alleles, uvsl;uvsa double mutants exhibited high methyl methane sulfonate (mms)-sensitivity in contrast to the slight sensitivity of the component single mutants. using such a double mutant as recipient, a clone complementing uvsi501 has been isolated from a chromosome iii specific library. the deduced amino acid sequence from the 1.1-kb sequenced reg ...19989675845
sequence-specific binding by aspergillus nidulans aflr, a c6 zinc cluster protein regulating mycotoxin biosynthesis.the aspergillus nidulans aflr gene is found within a 60 kb gene cluster that includes approximately 24 other genes that putatively function in the production of the aflatoxin-related mycotoxin sterigmatocystin. previous work showed that aflr is a c6 zinc binuclear cluster protein that is conserved across aspergillus spp. and functions as a pathway-specific transcription factor in activating expression of other cluster genes. in this report, we demonstrate that a. nidulans aflr (anaflr) is a 45kd ...19989680223
plant-adapted green fluorescent protein is a versatile vital reporter for gene expression, protein localization and mitosis in the filamentous fungus, aspergillus nidulans.green fluorescent protein (gfp) is a useful reporter to follow the in vivo behaviour of proteins, but the wild-type gfp gene does not function in many organisms, including many plants and filamentous fungi. we show that codon-modified forms of gfp, produced for use in plants, function effectively in aspergillus nidulans both as gene expression reporters and as vital reporters for protein location. to demonstrate the use of these modified gfps as reporter genes we have used fluorescence to follow ...19989466261
expression of rnudc, a potential nuclear movement protein, in mammalian cells: localization to the golgi apparatus.prolactin and other cytokines regulate lymphocyte proliferation through the activation of a number of genes, one of which was identified as rnudc from a prolactin-dependent rat t cell line, nb2. rnudc encodes a 45-kda protein whose carboxy terminal 94 amino acids are similar to the carboxy terminus of the aspergillus nidulans nuclear movement protein nudc. in nb2 t cells, rnudc protein levels are induced two- to threefold by prolactin stimulation. this prolactin-inducible increase in rnudc prote ...19989457053
identification and analysis of a class 2 alpha-mannosidase from aspergillus nidulans.a class 2 alpha-mannosidase gene was cloned and sequenced from the filamentous fungus aspergillus nidulans. a portion of the gene was amplified using degenerate oligonucleotide primers which were designed based on similarity between the saccharomyces cerevisiae vacuolar and rat er/cytosolic class 2 protein sequences. the pcr amplification product was used to isolate the full length gene, and dna sequencing revealed a 3383 bp coding region containing three introns. the predicted 1049 amino acid r ...19989451011
cloning of a thermostable ascorbate oxidase gene from acremonium sp. hi-25 and modification of the azide sensitivity of the enzyme by site-directed mutagenesis.a gene encoding a thermostable ascorbate oxidase (asom) was cloned from acremonium sp. hi-25 and sequenced. the gene comprised 1709 bp and was interrupted by a single intron of 57 bp. asom consisted of 551 amino acids including a signal peptide with a molecular mass of 61200, and contained four histidine-rich regions with high sequence homology to the corresponding regions of other multicopper oxidases. the asom gene was expressed in aspergillus nidulans under the aspergillus oryzae taka-amylase ...19989858779
nuclear migration, nucleokinesis and lissencephaly.during the past 20 years, biologists have become used to finding that proteins first identified in simple, genetically manipulable eukaryotic organisms are conserved in higher eukaryotes. this article draws attention to the similarity between nudf protein, which is required for nuclear migration in the filamentous fungus aspergillus nidulans, and a mammalian homologue, lis1, whose malfunction causes lissencephaly, a neuronal migration disease. the authors suggest that there might be an underlyin ...19989861667
in vivo linearization and autonomous replication of plasmids containing human telomeric dna in aspergillus nidulans.plasmids containing two inverted 0.6-kb stretches of human telomeric repeats transform aspergillus nidulans at frequencies characteristic of autonomously replicating vectors. transformation frequency is not affected when the plasmids are linearized in vitro prior to transformation by cutting between the inverted repeats. southern analysis reveals the presence of a homogeneous pool of linear plasmid molecules in mycelium of transformants. addition of the ama1 plasmid replicator to the telomere-co ...19989862467
repression of the expression of genes encoding xylanolytic enzymes in aspergillus oryzae by introduction of multiple copies of the xynf1 promoter.a xylanase gene, xynf1, was cloned and characterized from a shoyu koji mould aspergillus oryzae kbn616. the xynf1 gene was found to be comprised of 1484 bp with ten introns. the deduced amino acid sequence encodes a protein consisting of 327 amino acids (35,402 da) which is very similar to the fungal family f xylanases such as aspergillus nidulans xlnc, aspergillus kawachii xyna and penicillium chrysogenum xylp. the intron/exon organization of xynf1 is very similar to that of the fungal family f ...19989866173
isolation and characterisation of the acetyl-coa carboxylase gene from aspergillus nidulans.the putative gene encoding acetyl-coa carboxylase, acca, has been isolated from aspergillus nidulans. this single-copy gene has an open reading frame (orf) of 6864 bp and contains two small introns near the 5'-end. a short orf upstream of the atg start codon has been identified in this gene by rt-pcr. based on sequence homology to acetyl-coa carboxylases from other organisms, putative biotin-, atp-, hco3-- and acetyl-coa- binding sites have been assigned. northern data and acc enzyme-activity me ...19989871120
the use of cryopreserved apical protoplasts from curvularia lunata for electrotransformation.an electroporation method, utilizing cryopreserved protoplasts, has been developed for the steroid 11-hydroxylating fungus curvularia lunata strain im 2901. protoplasts released from the apical parts of 24- and 48-h-old mycelia were suspended in cryopreservation buffer and stored at -75 degrees c for several weeks. the thawed and freshly prepared (control) protoplasts were electroporated with pan 7-1 plasmid carrying the escherichia coli hygromycin b resistance gene (hph) under the control of as ...19989871997
the myosin i sh3 domain and teds rule phosphorylation site are required for in vivo function.the class i myosins play important roles in controlling many different types of actin-based cell movements. dictyostelium cells either lacking or overexpressing amoeboid myosin is have significant defects in cortical activities such as pseudopod extension, cell migration, and macropinocytosis. the existence of dictyostelium null mutants with strong phenotypic defects permits complementation analysis as a means of exploring important functional features of the myosin i heavy chain. mutant dictyos ...19989436992
direct sulfhydrylation for methionine biosynthesis in leptospira meyeri.a gene library of the leptospira meyeri serovar semaranga strain veldrat s.173 dna has been constructed in a mobilizable cosmid with inserts of up to 40 kb. it was demonstrated that a leptospira dna fragment carrying mety complemented escherichia coli strains carrying mutations in metb. the latter gene encodes cystathionine gamma-synthase, an enzyme which catalyzes the second step of the methionine biosynthetic pathway. the mety gene is 1,304 bp long and encodes a 443-amino-acid protein with a m ...19989440513
integrity of a zn finger-like domain in samb is crucial for morphogenesis in ascomycetous fungi.genetic features determine the site of polarized growth in filamentous fungi and lead to hyphal tip extension or subapical branching. we have isolated the samb gene (suppressor of anucleate metulae) of aspergillus nidulans which encodes a 66 kda protein carrying an atypical cys4 and an additional cys2/his/cys zn finger motif at the carboxy-terminus. such novel zn finger-like domains have recently been found in several other developmental regulators in organisms ranging from yeast to man. deletio ...19989427754
a centrosomal function for the human nek2 protein kinase, a member of the nima family of cell cycle regulators.nek2, a mammalian protein kinase of unknown function, is closely related to the mitotic regulator nima of aspergillus nidulans. here we show by both immunofluorescence microscopy and biochemical fractionation that human nek2 localizes to the centrosome. centrosome association occurs throughout the cell cycle, including all stages of mitosis, and is independent of microtubules. overexpression of active nek2 induces a striking splitting of centrosomes, whereas prolonged expression of either active ...19989430639
intra- and interspecies virus transfer in aspergilli via protoplast fusion.intra- and interspecies transfer of dsrna viruses between black aspergilli and aspergillus nidulans strains has been investigated using protoplast fusion. we found interspecies transfer of virus in all combinations of black aspergillus and a. nidulans strains and vice versa. using the same conditions, intraspecies virus transfer among heterokaryon incompatible strains was also tested. whereas such transfer was always found among a. nidulans strains, transfer among black aspergilli was frequently ...19989917371
fate of transforming dna in pathogenic fungi.genetic engineering is an important tool in helping us to define the molecular basis of pathogenicity and is also useful in helping us to identify new therapeutic targets in pathogenic fungi. molecular genetic manipulation of micro-organisms requires the development of plasmid-mediated transformation systems that include: (i) infusion of exogenous dna into recipient cells, (ii) expression of genes present on the incoming dna, and (iii) stable maintenance and replication of the inserted dna leadi ...19989988490
coordinate control of secondary metabolite production and asexual sporulation in aspergillus nidulans.microbial secondary metabolite production is frequently associated with developmental processes such as sporulation, but there are few cases where this correlation is understood. recent work with the filamentous fungus aspergillus nidulans has provided new insights into the mechanisms coordinating production of the toxic secondary metabolite sterigmatocystin with asexual sporulation. these processes have been shown to be linked through a common need to inactivate a heterotrimeric g protein depen ...199810066549
increased nuclear traffic chaos in hyphae of aspergillus nidulans: molecular characterization of apsb and in vivo observation of nuclear behaviour.filamentous fungi are model microorganisms for studying nuclear migration in eukaryotic cells. two genes, apsa and apsb (=anucleate primary sterigmata), were identified in aspergillus nidulans that affect nuclear distribution in hyphae and specifically block conidiophore development at the metula stage when mutant. here we describe the cloning, sequencing and molecular analysis of apsb. the gene encodes a 121 kda coiled-coil, hydrophilic protein that was localized in the cytoplasm. no protein-pr ...199810094631
genetic analysis of aspergillus nidulans unstable transformants obtained by the biolistic process.mitotically unstable aspergillus nidulans argb+ transformants obtained by the biolistic process were studied in the present work. hybridization signals from undigested dna and pulsed-field chromosomal bands of the transformants suggested the introduced plasmid occurred as free concatenated molecules. fifteen vigorous growth sectors released from the transformants were analysed in order to understand the mechanisms involved in their formation. all sectors showed the integration of exogenous genes ...199810347861
the gene that determines resistance to tioconazole and to acridine derivatives in aspergillus nidulans may have a corresponding gene in trichophyton rubrum.understanding the genetic mechanisms involved in resistance to antifungal agents is important in the fight against pathogenic fungi. in the present investigation we studied a strain of the model fungus aspergillus nidulans which presents resistance to tioconazole and behaves as the wild strain in the presence of other azole derivatives. genetic analysis revealed that this resistance is due to a mutation in a single gene located on chromosome ii, closely linked to the allele responsible for resis ...199810205888
isolation of the crea gene from the cellulolytic fungus humicola grisea and analysis of crea binding sites upstream from the cellulase genes.a carbon catabolite repressor gene, crea, was isolated from the cellulolytic fungus humicola grisea by using a portion of the trichoderma reesei cre1 gene as a probe. the deduced amino acid sequence predicts a zinc finger protein of 419 amino acids in length, and its zinc finger regions show high similarity with those of aspergillus creas, t. reesei cre1, and saccharomyces cerevisiae mig1. northern blot analysis showed that the h. grisea crea gene was highly transcribed when the mycelia were gro ...19989972263
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 ...199811711060
isolation and characterisation of cycloheximide-sensitive mutants of aspergillus nidulans.aspergillus nidulans is a non-pathogenic fungus with well-developed genetics which provides an excellent model system for studying different aspects of drug resistance in filamentous fungi. as a preliminary step to characterizing genes that confer pleiotropic drug resistance in aspergillus, we isolated cycloheximide-sensitive mutants of a. nidulans, which is normally resistant to this drug. the rationale for this approach is to identify genes whose products are important for drug resistance by a ...19989472081
conservation of the active site motif in aspergillus niger (ficuum) ph 6.0 optimum acid phosphatase and kidney bean purple acid phosphatase.aspergillus niger (ficuum) and the kidney bean purple acid phosphatases retained all the essential amino acids in the active site despite a low degree of total sequence homology. this high degree of homology in the sequence motif of a. niger fungal acid phosphatase (apase6) active site with kidney bean metallo phosphoesterase (kbpap) and the absence of the rhg-xrxp sequence motif indicates apase6 to be a metallophosphoesterase rather than a histidine acid phosphatase.19989480832
an intoxicating switch for plant transgene expression. 19989487515
an ethanol inducible gene switch for plants used to manipulate carbon metabolism.many transgenic plant studies use constitutive promoters to express transgenes. for certain genes, deleterious effects arise from constant expression in all tissues throughout development. we describe a chemically inducible plant gene expression system, with negligible background activity, that obviates this problem. we demonstrate its potential by showing inducible manipulation of carbon metabolism in transgenic plants. upon rapid induction of yeast cytosolic invertase, a marked phenotype appea ...19989487526
the regulator of nitrate assimilation in ascomycetes is a dimer which binds a nonrepeated, asymmetrical sequence.the regulation of nitrate assimilation seems to follow the same pattern in all ascomycetes where this process has been studied. we show here by in vitro binding studies and a number of protection and interference techniques that the transcription factor mediating nitrate induction in aspergillus nidulans, a protein containing a binuclear zinc cluster dna binding domain, recognizes an asymmetrical sequence of the form ctcc ghgg. we further show that the protein binds to its consensus site as a di ...19989488449
the penicillin regulator penr1 of aspergillus nidulans is a hap-like transcriptional complex.in aspergillus nidulans, a dna-binding complex, penr1, was shown to bind to two ccaat-box-containing dna elements located in the promoter regions of the bidirectionally oriented penicillin biosynthesis genes acva and ipna, and of the aat promoter. here, partial purification of penr1 and western blotting using anti-hapc sera indicated that the previously identified hapc protein, which was suggested to be part of the ccaat-binding complex ancf, is also part of penr1. this was confirmed by band shi ...19989490049
mutations in the bimc box of cut7 indicate divergence of regulation within the bimc family of kinesin related proteins.members of the bimc family of kinesin related proteins (krps) play vital roles in the formation and function of the mitotic spindle. although they share little amino acid homology outside the highly conserved microtubule motor domain, several family members do contain a 'bimc box', a sequence motif around a p34(cdc2) consensus phosphorylation site in their carboxy-terminal 'tail' region. one family member, eg5, requires phosphorylation at this site for association with the mitotic spindle. we sh ...19989490630
a nima homologue promotes chromatin condensation in fission yeast.entry into mitosis requires p34(cdc2), which activates downstream mitotic events through phosphorylation of key target proteins. in aspergillus nidulans, the nima protein kinase has been identified as a potential downstream target and plays a role in regulating chromatin condensation at mitosis. nima- mutants arrest in a state that physically resembles interphase even though p34(cdc2) is fully active. despite evidence for the existence of nima-like activities in a variety of cell types, the only ...19989490640
purification and characterization of the nuclear ribonuclease p of aspergillus nidulans.in aspergillus nidulans, the nuclear ribonuclease p was separated from its mitochondrial counterpart by q-sepharose chromatography, and a precursor-trna(his) processing assay system was used to discriminate nuclear ribonuclease p activity from the mitochondrial counterpart. the nuclear ribonuclease p was purified to near homogeneity from whole-cell extracts. a 2150-fold purification with a yield of 2.3% was achieved by five types of chromatography including trna affinity chromatography and glyce ...19989492290
the recombinant antigen aspnd1r from aspergillus nidulans is specifically recognized by sera from patients with aspergilloma.a 996 bp aspergillus nidulans cdna encoding the aspnd1 immunodominant antigen was cloned and expressed in escherichia coli as a fusion protein with the enzyme glutathione s-transferase (gst) from schistosoma japonicum. the gst-aspnd1 fusion protein was purified from isolated bacterial inclusion bodies by preparative sds-page. after cleavage with thrombin, the aspnd1 recombinant antigen (aspnd1r) and the gst protein were separated by sds-page and immunoblotted with a number of different human ser ...19989493392
quantitative immuno-slot blot assay to measure acmpk protein in cell extracts of aspergillus nidulans. 19989494720
opposite patterns of expression of two aspergillus nidulans xylanase genes with respect to ambient ph.the aspergillus nidulans xylanase genes xlna and xlnb are subject to regulation by ambient ph via the zinc finger transcription factor pacc. in the presence of d-xylose, xlna is expressed under conditions of alkaline ambient ph while xlnb is expressed at acidic ambient ph. these data have been confirmed for acidity- and alkalinity-mimicking a. nidulans mutants.19989495775
the crea repressor is the sole dna-binding protein responsible for carbon catabolite repression of the alca gene in aspergillus nidulans via its binding to a couple of specific sites.carbon catabolite repression is mediated in aspergillus nidulans by the negative acting protein crea. the crea repressor plays a major role in the control of the expression of the alc regulon, encoding proteins required for the ethanol utilization pathway. it represses directly, at the transcriptional level, the specific transacting gene alcr, the two structural genes alca and alda, and other alc genes in all physiological growth conditions. among the seven putative crea sites identified in the ...19989497366
regulation of the aspergillus nidulans penicillin biosynthesis gene acva (pcbab) by amino acids: implication for involvement of transcription factor pacc.the beta-lactam antibiotic penicillin is produced as an end product by some filamentous fungi only. it is synthesized from the amino acid precursors l-alpha-aminoadipic acid, l-cysteine, and l-valine. previous data suggested that certain amino acids play a role in the regulation of its biosynthesis. therefore, in this study the effects of externally added amino acids on both aspergillus (emericella) nidulans penicillin production and expression of the bidirectionally oriented biosynthesis genes ...19989501424
cloning and characterization of a chitinase-encoding gene (chia) from aspergillus nidulans, disruption of which decreases germination frequency and hyphal growth.we cloned a chitinase-encoding gene from aspergillus nidulans by polymerase chain reaction using degenerated oligonucleotide primers designed from the conserved amino acid sequences among chitinases from yeasts and rhizopus spp. the cloned gene, named chia, encoded a polypeptide consisting of 660 amino acids. disruption of chia had no effect on hyphal or conidiophore morphology, but germination frequency and hyphal growth rate decreased substantially. expression of chia was investigated using es ...19989501518
hyp loci control cell pattern formation in the vegetative mycelium of aspergillus nidulans.aspergillus nidulans grows by apical extension of multinucleate cells called hyphae that are subdivided by the insertion of crosswalls called septa. apical cells vary in length and number of nuclei, whereas subapical cells are typically 40 microm long with three to four nuclei. apical cells have active mitotic cycles, whereas subapical cells are arrested for growth and mitosis until branch formation reinitiates tip growth and nuclear divisions. this multicellular growth pattern requires coordina ...19989504915
structure and regulation of cysd, the homocysteine synthase gene of aspergillus nidulans.the a. nidulans cysd gene encoding homocysteine synthase (o-acetyl-l-homoserine sulphydrylase) has been isolated by functional complementation of a cysd11 mutation. the gene contains five short introns and codes for a protein of 437 amino acids. the protein shows homology with bacterial and yeast o-acetyl- and o-succinyl-homoserine sulphydrylases, particularly from schizosaccharomyces pombe, saccharomyces cerevisiae and kluyveromyces lactis. the cysd cdna is able to complement a s. cerevisiae mu ...19989506902
genetic analysis of resistance to fenpropimorph in aspergillus niger.resistance to the morpholine-fungicide fenpropimorph was studied in aspergillus niger and a. nidulans. mass selection of conidia of a. nidulans on agar amended with the fungicide at different concentrations did not yield of resistant mutants, even after uv-treatment of the conidia. in contrast, similar experiments with a. niger generated many fenpropimorph-resistant mutants. the mutants displayed cross-resistance to fenpropidin and generally showed wild-type sensitivity to the unrelated toxicant ...19989506903
mapping of the nitrate-assimilation gene cluster (crna-niia-niad) and characterization of the nitrite reductase gene (niia) in the opportunistic fungal pathogen aspergillus fumigatus.this study reports the molecular characterization of the nitrate-assimilation gene cluster from the opportunistic fungal pathogen aspergillus fumigatus. a genomic fragment was isolated which contained the entire structural gene encoding nitrite reductase (niia), plus segments of the nitrate reductase (niad) and the nitrate transporter (crna) genes. nitrate-assimilation genes in a. fumigatus are physically linked and transcribed in the same direction as in a. nidulans. the nitrate-assimilation ge ...19989508795
the aspergillus nidulans sulphur regulatory gene sconb encodes a protein with wd40 repeats and an f-box.the aspergillus nidulans gene sconb, one of the four identified genes controlling sulphur metabolite repression, was cloned and analysed. it encodes a polypeptide of 678 amino acids containing seven wd repeats characteristic of the large wd40 family of eukaryotic regulatory proteins. the sconb protein has nuclear localisation signals and is very similar to the neurospora crassa scon2 and saccharomyces cerevisiae met30 proteins, both of which are involved in the regulation of sulphur metabolism. ...19989520259
the role of the dynactin complex in intracellular motility.dynactin is a multisubunit complex that binds to the minus-end-directed microtubule motor cytoplasmic dynein and may provide a link between the motor and its cargo. results from genetic studies in saccharomyces cerevisiae, neurospora crassa, aspergillus nidulans, and drosophila have suggested that cytoplasmic dynein and dynactin function in the same cellular pathways. p150glued, a vertebrate homologue of the drosophila gene glued, is the largest polypeptide in the dynactin complex with multiple ...19989522459
facb, the aspergillus nidulans activator of acetate utilization genes, binds dissimilar dna sequences.the facb gene is required for acetate induction of acetamidase (amds) and the acetate utilization enzymes acetyl-coa synthase (faca), isocitrate lyase (acud) and malate synthase (acue) in aspergillus nidulans. the facb gene encodes a transcriptional activator with a gal4-type zn(ii)2cys6 zinc binuclear cluster dna-binding domain which is shown to be required for dna binding. in vitro dna-binding sites for facb in the 5' regions of the amds, faca, acud and acue genes have been identified. mutatio ...19989524126
electrotransformation and expression of bacterial genes encoding hygromycin phosphotransferase and beta-galactosidase in the pathogenic fungus histoplasma capsulatum.we developed an efficient electrotransformation system for the pathogenic fungus histoplasma capsulatum and used it to examine the effects of features of the transforming dna on transformation efficiency and fate of the transforming dna and to demonstrate fungal expression of two recombinant escherichia coli genes, hph and lacz. linearized dna and plasmids containing histoplasma telomeric sequences showed the greatest transformation efficiencies, while the plasmid vector had no significant effec ...19989529100
the aspergillus nidulans ccaat-binding factor ancp/ancf is a heteromeric protein analogous to the hap complex of saccharomyces cerevisiae.the aspergillus nidulans hapc gene was expressed as a fusion protein with male or glutathione-s-transferase (gst) in escherichia coli, and used for the purification of hapc and the preparation of anti-hapc antiserum. the ccaat-binding factor ancp/ancf contains a component with an approximate molecular mass of 32 kda that cross-reacts with the antibody. the male-hapc fusion protein was able to replace authentic hapc in ancp when incubated under appropriate conditions. furthermore, reconstitution ...19989529521
asexual sporulation in aspergillus nidulans.the formation of mitotically derived spores, called conidia, is a common reproductive mode in filamentous fungi, particularly among the large fungal class ascomycetes. asexual sporulation strategies are nearly as varied as fungal species; however, the formation of conidiophores, specialized multicellular reproductive structures, by the filamentous fungus aspergillus nidulans has emerged as the leading model for understanding the mechanisms that control fungal sporulation. initiation of a. nidula ...19989529886
group specific antibodies against the putative amp-binding domain signature sgttgxpkg in peptide synthetases and related enzymes.the superfamily of adenylate forming enzymes including peptide synthetases, acyl-coa synthetases and insect luciferases is readily identified by the signature sequence sgttgxpkg. this sequence including an invariant lysyl residue is located in a disordered loop region and was predicted to be of significant antigenicity. antibodies were generated employing ytsgttgrpkgc attached to bovine serum albumin and have been successfully used to identify respective enzymes and adenylate forming domains in ...19989530507
the solution structure of a fungal area protein-dna complex: an alternative binding mode for the basic carboxyl tail of gata factors.the solution structure of a complex between the dna binding domain of a fungal gata factor and a 13 base-pair oligonucleotide containing its physiologically relevant cgatag target sequence has been determined by multidimensional nuclear magnetic resonance spectroscopy. the area dna binding domain, from aspergillus nidulans, possesses a single cys2-cys2 zinc finger module and a basic c-terminal tail, which recognize the cgatag element via an extensive network of hydrophobic interactions with the ...19989533883
the solution structure of the leu22-->val mutant area dna binding domain complexed with a tgatag core element defines a role for hydrophobic packing in the determination of specificity.the seemingly innocuous leucine-to-valine mutation at position 22 of the area dna binding domain results in dramatic changes in the in vivo expression profile of genes controlled by this gata transcription factor. this is associated with a preference of the leu22-->val mutant for tgatag sites over (a/c)gatag sites. quantitative gel retardation assays confirm this observation and show that the leu22-->val mutant area dna binding domain has a approximately 30-fold lower affinity than the wild-type ...19989533884
isolation and characterization of an invertase and its repressor genes from schizosaccharomyces pombe.pcr was used to isolate an invertase homolog gene from the fission yeast schizosaccharomyces pombe. the cloned inv1(+) gene encodes a protein of 581 amino acids with 16 potential asparagine-linked glycosylation sites, and has 39% and 38% identity to the schwanniomyces occidentalis and saccharomyces cerevisiae suc2 invertases. when the inv1(+) gene was disrupted, s. pombe strains lacked detectable invertase activity. this result showed that the inv1(+) gene encodes only one active invertase in s. ...19989535817
characterization of the aspergillus nidulans nmra gene involved in nitrogen metabolite repression.the gene nmra of aspergillus nidulans has been isolated and found to be a homolog of the neurospora crassa gene nmr-1, involved in nitrogen metabolite repression. deletion of nmra results in partial derepression of activities subject to nitrogen repression similar to phenotypes observed for certain mutations in the positively acting area gene.19989537404
effect of cytochalasin a on apical growth, actin cytoskeleton organization and enzyme secretion in aspergillus nidulans.the role of actin in apical growth and enzyme secretion in the filamentous fungus aspergillus nidulans was studied by treating the hyphae with cytochalasin a (ca), which inhibits actin polymerization. indirect immunofluorescence microscopy revealed actin at the tips of main hyphae and branches, and at the site of developing septa. ca inhibited the growth of the fungus and changed the growth pattern of hyphal tips from cylindrical tubes to spherical beads. the regions with swellings showed no act ...19989537763
the neurospora rca-1 gene complements an aspergillus flbd sporulation mutant but has no identifiable role in neurospora sporulation.the aspergillus nidulans flbd gene encodes a protein with a myb-like dna-binding domain that is proposed to act in concert with other developmental regulators to control initiation of conidiophore development. we have identified a neurospora crassa gene called rca-1 (regulator of conidiation in aspergillus) based on its sequence similarity to flbd. we found that n. crassa rca-1 can complement the conidiation defect of an a. nidulans flbd mutant and that induced expression of rca-1 caused conidia ...19989539422
regulation of septum formation in aspergillus nidulans by a dna damage checkpoint pathway.in aspergillus nidulans, germinating conidia undergo multiple rounds of nuclear division before the formation of the first septum. previous characterization of temperature-sensitive sepb and sepj mutations showed that although they block septation, they also cause moderate defects in chromosomal dna metabolism. results presented here demonstrate that a variety of other perturbations of chromosomal dna metabolism also delay septum formation, suggesting that this is a general cellular response to ...19989539424
specific recombinogenic activity of a new polyene antibiotic.a new antibiotic from streptomyces sp., tetrapol a159, active against various fungi, a promising compound for the control of plant diseases, was studied for its genotoxic effects. it was produced at the institute of microbiological preparations for agriculture, sofia, bulgaria. the chemical was tested in three different test systems: a bacterial system, the ames test for point mutations, the micronucleus test in bone marrow cells of rats for chromosomal aberrations and the fungal system of asper ...19989539955
identification, cloning and sequence of the aspergillus niger area wide domain regulatory gene controlling nitrogen utilisation.the gene encoding the positive-acting regulator of nitrogen metabolite repression (area) has been cloned and characterised from the industrially important filamentous fungus aspergillus niger. the deduced amino acid sequence has an overall level of identity with its homologues from other fungal species which varies between 32 and 72%. this gene (areanig) complements the a. nidulans arear-18 loss-of-function mutation. sequences upstream of the structural gene contain several putative gata-type zi ...19989540832
unusual gene arrangement of the bidirectional hydrogenase and functional analysis of its diaphorase subunit hoxu in respiration of the unicellular cyanobacterium anacystis nidulansthe bidirectional, nad+-dependent hydrogenase from cyanobacteria is encoded by the structural genes hoxfuyh, which have been found to be clustered, though interspersed with different open reading frames (orfs), in the heterocystous, n2-fixing anabaena variabilis and in the unicellular synechocystis pcc 6803. in another unicellular, non n2-fixing cyanobacterium, anacystis nidulans, hoxf has now been identified as being separated by at least 16 kb from the residual structural genes hoxuyh. an orf ...19989541559
analysis of the conversion of delta-(l-alpha-aminoadipoyl)-l-cysteinyl-d-alpha-aminobutyrate by active-site mutants of aspergillus nidulans isopenicillin n synthase.penicillins and cephalosporins constitute a major class of clinically useful antibiotics. a key step in their biosynthesis involves the oxidative cyclisation of delta-(lalpha-aminoadipoyl)-l-cysteinyl-d-valine to isopenicillin n by isopenicillin n synthase (ipns). this chemically remarkable transformation has been extensively studied using substrate analogues. the conversion of an analogue in which the valine is replaced by alpha-aminobutyrate results in three products, two epimeric penams and a ...19989545433
covasiam: an image analysis method that allows detection of confluent microbial colonies and colonies of various sizes for automated counting.in this work we introduce the confluent and various sizes image analysis method (covasiam), an automated colony count technique that uses digital imaging technology for detection and separation of confluent microbial colonies and colonies of various sizes growing on petri dishes. the proposed method takes advantage of the optical properties of the surfaces of most microbial colonies. colonies in the petri dish are epi-illuminated in order to direct the reflection of concentrated light coming fro ...19989546177
molecular cloning and transcriptional regulation of the aspergillus nidulans xlnd gene encoding a beta-xylosidase.the xlnd gene encoding the 85-kda beta-xylosidase was cloned from aspergillus nidulans. the deduced primary structure of the protein exhibits considerable similarity to the primary structures of the aspergillus niger and trichoderma reesei beta-xylosidases and some similarity to the primary structures of the class 3 beta-glucosidases. xlnd is regulated at the transcriptional level; it is induced by xylan and d-xylose and is repressed by d-glucose. glucose repression is mediated by the product of ...19989546179
characterization of a fungal maleylacetoacetate isomerase gene and identification of its human homologue.we have previously used aspergillus nidulans as a fungal model for human phenylalanine catabolism. this model was crucial for our characterization of the human gene involved in alcaptonuria. we use here an identical approach to characterize at the cdna level the human gene for maleylacetoacetate isomerase (maai, ec 5.2.1.2), the only as yet unidentified structural gene of the phenylalanine catabolic pathway. we report here the first characterization of a gene encoding a maai enzyme from any orga ...19989417084
onychomycosis in malaysia.the common etiological agents of onychomycosis are dermatophytes, molds and yeasts. a mycological nail investigation of onychomycosis using direct microscopy and culture was conducted by the mycology unit, department of medical microbiology, university of malaya from march 1996 to november 1998. the study involved 878 nail clippings or subungal scrapings from subjects with onychomycosis. on direct microscopy examination, 50% of the specimens were negative for fungal elements. on culture, 373 spe ...199910872513
interaction between developmental and cell cycle regulators is required for morphogenesis in aspergillus nidulans.in aspergillus nidulans, mutation of the transcriptional regulator brla arrests formation of asexual spore-forming structures called conidiophores but does not hinder vegetative hyphal growth. during conidiophore development a 6-fold, brla-dependent increase in the kinase activities of nimx(cdc2) and nima occurs. a similar level of kinase induction was promoted by ectopic expression of brla. northern and western analysis revealed marked induction of nimx(cdc2) mrna after ectopic expression of br ...199910601021
prr1, a homolog of aspergillus nidulans palf, controls ph-dependent gene expression and filamentation in candida albicans.the ph of the environment has been implicated in controlling the yeast-hypha transition and pathogenesis of candida albicans. several c. albicans genes, including phr1 and phr2, are ph dependent in their expression. to investigate the mechanism of ph-dependent expression, we have cloned and characterized prr1 (for ph response regulator). prr1 is homologous to palf, a component of the ph response pathway in aspergillus nidulans. expression of prr1 was itself ph dependent, being maximal at acid ph ...199910601209
effect of environmental ph on morphological development of candida albicans is mediated via the pacc-related transcription factor encoded by prr2.the ability to respond to ambient ph is critical to the growth and virulence of the fungal pathogen candida albicans. this response entails the differential expression of several genes affecting morphogenesis. to investigate the mechanism of ph-dependent gene expression, the c. albicans homolog of pacc, designated prr2 (for ph response regulator), was identified and cloned. pacc encodes a zinc finger-containing transcription factor that mediates ph-dependent gene expression in aspergillus nidula ...199910601210
[aortic rupture in invasive pulmonary aspergillosis in a neutropenic patient]. 199910605483
role of water mobility on mold spore germination.a sugar transport defected strain of aspergillus nidulans (bia-1 sora-2) was tested for spore germination in nutrient media containing various water activity (a(w)) values and varying amounts of non-nutritive, nontoxic carbohydrates (l-sorbose and cellulose). freeze-dried media [containing the same nutrient level but different in sorbose/cellulose (s:c) ratio] were adjusted to 0.75-0.97a(w) at 25 degrees c before inoculation. minimum a(w) for germination varied with s:c ratio. because both sorbo ...199910606561
refined structures of oxidized flavodoxin from anacystis nidulans.flavodoxin from anacystis nidulans (synechococcus pcc 7942) was the first member of the flavodoxin family to be characterized, and is the structural prototype for the "long-chain" flavodoxins that have molecular masses of approximately 20 kda. crystal structure analyses and refinements of three orthorhombic forms of oxidized a. nidulans flavodoxin are reported, and salient features of the fold and the fmn binding site are compared with other flavodoxins. the structure of form i (wild-type: p2121 ...199910610791
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