Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| purification and characterization of mitochondrial ribonuclease p from aspergillus nidulans. | mitochondrial ribonuclease (rnase) p from aspergillus nidulans was purified to near homogeneity using whole-cell extract as the starting material. a 4400-fold purification with a yield of 5.2% was achieved by ammonium sulfate fractionation, heat treatment, and five types of column chromatography, including trna-affinity column chromatography. this enzyme, which has a molecular mass of 232 kda determined by glycerol gradient sedimentation analysis, appears to be composed of seven polypeptides and ... | 1996 | 8631344 |
| the rna component of mitochondrial ribonuclease p from aspergillus nidulans. | several rna molecules that copurified with aspergillus nidulans mitochondrial ribonuclease (rnase) p were identified [lee, y c., lee, b. j., hwang, d. s. & kang, h. s. (1996) eur j. biochem. 235, 289-296], and their partial sequences were determined. using an oligonucleotide probe, we cloned and mapped the gene encoding this putative rna component of rnase p (rnase p-rna), situated between urfa3 (unidentified reading frame a3) and coba (apocytochrome b) genes in the mitochondrial genome of a. ni ... | 1996 | 8631345 |
| twenty-five coregulated transcripts define a sterigmatocystin gene cluster in aspergillus nidulans. | sterigmatocystin (st) and the aflatoxins (afs), related fungal secondary metabolites, are among the most toxic, mutagenic, and carcinogenic natural products known. the st biosynthetic pathway in aspergillus nidulans is estimated to involve at least 15 enzymatic activities, while certain aspergillus parasiticus, aspergillus flavus, and aspergillus nomius strains contain additional activities that convert st to af. we have characterized a 60-kb region in the a. nidulans genome and find it contains ... | 1996 | 8643646 |
| wild chromosomal variants in aspergillus nidulans. | pulsed-field gel electrophoresis and a chromosome-specific cosmid dna library were used to determine the karyotypes of wild-type aspergillus nidulans isolates from around the world. overall, little structural variation was found, with a few major exceptions. one isolate possessed a non-essential b-chromosome of about 1.0 million base pairs (mb). another isolate had undergone a non-reciprocal translocation of about 1.6 mb of chromosome vi onto chromosome viii. other than these chromosomal differe ... | 1996 | 8595677 |
| domain structure and function within the quta protein of aspergillus nidulans: implications for the control of transcription. | quta is a positively acting regulatory protein that regulates the expression of the eight genes comprising the quinic acid utilization gene (qut) gene cluster in aspergillus nidulans. it has been proposed that the quta protein is composed of two domains that are related to the n-terminal two domains-dehydroquinate (dhq) synthase and 5-enolpyruvyl shikimate-3-phosphate (epsp) synthase-of the pentadomain arom protein. the arom protein is an enzyme catalysing five consecutive steps in the shikimate ... | 1996 | 8581174 |
| mutational analysis of the c-terminal region of area, the transcription factor mediating nitrogen metabolite repression in aspergillus nidulans. | in aspergillus nidulans the positive-acting, wide domain regulatory gene area mediates nitrogen metabolite repression. previous analysis demonstrated that the c-terminal 153 residues of the area product (area) are inessential for at least partial expression of most genes subject to regulation by area. paradoxically, arear2, a -1 frameshift replacing the wild-type 122 c-terminal residues with a mutant peptide of 117 amino acids, leads to general loss of function. to determine the basis for the ar ... | 1996 | 8569680 |
| a novel transporter involved in cobalt uptake. | cobalt is an essential component of a low molecular-mass nitrile hydratase (l-nhase) from rhodococcus rhodochrous j1. we have found a new gene, nhlf, in the dna region sandwiched between nhlba encoding l-nhase and amda encoding amidase, which are involved in the degradation of nitriles. the product of nhlf, nhlf, shows a significant sequence similarity with those of hoxn from alcaligenes eutrophus, hupn from bradyrhizobium japonicum, nixa from helicobacter pylori, and ureh from bacillus sp., whi ... | 1997 | 8990157 |
| the aspergillus nidulans genes chsa and chsd encode chitin synthases which have redundant functions in conidia formation [corrected and republished article originally appeared in mol gen genet 1996 jun; 251(4):442-50]. | we previously isolated three chitin synthase genes (chsa, chsb, and chsc) from aspergillus nidulans. in the present work, we describe the isolation and characterization of another chitin synthase gene, named chsd, from a. nidulans. its deduced amino acid sequence shows 56.7% and 55.9% amino acid identity, respectively, with cal1 of saccharomyces cerevisiae and chs3 of candida albicans. disruption of chsd caused no defect in cell growth or morphology during the asexual cycle and caused no decreas ... | 1997 | 9037115 |
| identification of amdx, a new cys-2-his-2 (c2h2) zinc-finger gene involved in the regulation of the amds gene of aspergillus nidulans. | the acetamidase-encoding amds gene of aspergillus nidulans has been shown to be controlled by multiple regulatory genes. a new gene, amdx, involved in amds regulation was identified during the characterization of a translocation affecting amds control. the amdx gene is predicted to encode a 1150-amino-acid polypeptide which contains two cys-2-his-2 (c2h2) zinc finger dna-binding motifs. insertional inactivation of amdx and the phenotypes of transformants containing multiple copies of the amdx ge ... | 1997 | 9044292 |
| characterization of the ph signal transduction pathway gene pala of aspergillus nidulans and identification of possible homologs. | we have cloned the pala gene of aspergillus nidulans, one of six genes participating in ambient ph signal transduction in a regulatory circuit mediating ph regulation of gene expression. the derived 798-residue pala protein is 29.4% identical over its entire length to a hypothetical protein from the nematode caenorhabditis elegans and also has possible yeast homologs. | 1997 | 9045850 |
| genetic and molecular analysis of a trna(leu) missense suppressor of nudc3, a mutation that blocks nuclear migration in aspergillus nidulans. | nudc encodes a protein of unknown biochemical function that is required for nuclear migration. in an attempt to define its function by identifying interacting proteins, a screen for extragenic suppressors of the temperature-sensitive nudc3 mutation was undertaken that identified nine snc genes. here we demonstrate that nudc3 has a missense mutation at amino acid 146 that causes leucine to be replaced by proline and that sncb69 encodes a mutant trna(leu) that corrects the mutation. the sncb69 mut ... | 1997 | 9055080 |
| spectrophotometric determination of homogentisate using aspergillus nidulans homogentisate dioxygenase. | the presence of homogentisic acid (hga) in urine is diagnostic for alkaptonuria, a classical example of a biochemical lesion resulting from a single gene trait. we describe here simple culture conditions which induce the synthesis of high levels of homogentisate dioxygenase activity in mycelia from the filamentous ascomycete aspergillus nidulans. crude enzyme preparations, showing an apparent km of 9 microm for homogentisate and an optimal ph of 6.5-7.0 are rather stable and highly specific for ... | 1997 | 9056215 |
| salt sensitivity and arginase activity in aspergillus nidulans. | 1997 | 9056996 | |
| aspergillus nidulans maintains short telomeres throughout development. | we report the identification and cloning of the telomeres of the filamentous fungus,aspergillus nidulans. we have identified three classes of cloned chromosomal ends based on the telomere-associated sequences (tass) and demonstrated that the telomeric repeat sequence is ttaggg, identical to that found in vertebrates, including humans, and some lower eukaryotes. one category of telomere clones was found to contain internal, variant taaggg repeats. the a.nidulans telomeric tract length is striking ... | 1997 | 9060439 |
| molecular regulation of penicillin biosynthesis in aspergillus (emericella) nidulans. | the beta-lactam antibiotic penicillin is produced as end product by only some filamentous fungi, most notably by aspergillus nidulans and penicillium chrysogenum. the biosynthesis of this secondary metabolite is catalyzed by three enzymes which are encoded by the following three genes: acva (pcbab), ipna (pcbc) and aat (pende). the genes are organized into a gene cluster. in a. nidulans, several studies have indicated that the genes are controlled by a complex regulatory network. the wide-domain ... | 1997 | 9066103 |
| the phenylacetic acid uptake system of aspergillus nidulans is under a crea-independent model of catabolic repression which seems to be mediated by acetyl-coa. | the filamentous fungus aspergillus nidulans is able to grow on phenylacetic acid (phac) as the sole carbon source and has a highly specific phenylacetic acid transport system mediating the uptake of this aromatic compound. this transport system is also able to transport some phenoxyacetic acid (phoac), although less efficiently. maximal uptake rates were observed at 37 degrees c in 50 mm phosphate buffer (ph 7.0). under these conditions, uptake was linear for at least 1 minute, with k(m) values ... | 1997 | 9066765 |
| isolation of aspergillus nidulans mutants that overcome brla-induced growth arrest | the aspergillus nidulans brla gene is a primary regulator of development-specific gene expression during conidiation. forced activation of brla in vegetative cells leads to inappropriate induction of conidiophore formation and causes growth to stop. in fact, when conidia containing a nutritionally inducible brla gene fusion are placed on inducing medium, they fail to germinate. we used this phenotype to select 174 mutants that continue growing following such forced brla activation. forty-six of ... | 1997 | 9073485 |
| the glutamine ligand in the ferrous iron active site of isopenicillin n synthase of streptomyces jumonjinensis is not essential for catalysis. | isopenicillin n synthase (ipns) is a non-heme ferrous iron dependent dioxygenase that catalyses the ring closure of delta-(l-alpha-aminoadipoyl)-l-cysteinyl-d-valine (acv) to isopenicillin n. we previously used site-directed mutagenesis to identify in the ipns of streptomyces jumonjinensis two histidines and one aspartic acid that are essential for activity. the recent crystal structure of the ipns of aspergillus nidulans establishes that these amino acids are iron ligands and reveals that the f ... | 1997 | 9089285 |
| glutamine-330 is not essential for activity in isopenicillin n synthase from aspergillus nidulans. | the non-heme ferrous dependent oxidase isopenicillin n synthase (ipns) catalyses the biosynthesis of isopenicillin n from a tripeptide substrate. the crystal structure of aspergillus nidulans ipns complexed to manganese reveals a six co-ordinate metal ligated by two water molecules and four protein ligands: his-214, his-270, asp-216 and gln-330 (the penultimate c-terminal residue). modification of gln-330 to ala or leu, or deletion of 2 or 6 residues from the c-terminus resulted in lowering of s ... | 1997 | 9089289 |
| the role of gamma-tubulin in mitotic spindle formation and cell cycle progression in aspergillus nidulans. | gamma-tubulin has been hypothesized to be essential for the nucleation of the assembly of mitotic spindle microtubules, but some recent results suggest that this may not be the case. to clarify the role of gamma-tubulin in microtubule assembly and cell-cycle progression, we have developed a novel variation of the gene disruption/heterokaryon rescue technique of aspergillus nidulans. we have used temperature-sensitive cell-cycle mutations to synchronize germlings carrying a gamma-tubulin disrupti ... | 1997 | 9092944 |
| alkaptonuria: from humans to moulds and back. | 1997 | 9097720 | |
| cloning and characterization of the aspergillus nidulans cysb gene encoding cysteine synthase. | the cysb gene of a. nidulans was cloned by complementation of a cysb mutation. this is the first cloned eukaryotic genomic sequence coding for cysteine synthase. the gene contains one 71-bp intron and codes for a protein of 370 amino acids. its n-terminal region has characteristic features of transit peptides, suggesting mitochondrial localisation of the enzyme. the protein shows homology with bacterial and plant cysteine synthases among which it occupies a remote phylogenetic position and appar ... | 1997 | 9108143 |
| an aspergillus nidulans nuclear protein, ancp, involved in enhancement of taka-amylase a gene expression, binds to the ccaat-containing taag2, amds, and gata promoters. | using ancp (aspergillus nidulans ccaat-binding protein) as a ccaat-specific binding factor model, the possibility that one factor is able to recognize ccaat sequences in several different genes in a. nidulans was examined. dnase i protection analysis showed that ancp specifically bound to ccaat sequence-containing regions comprising 21 to 36 bp of the taa, amds and gata genes. furthermore, replacement of the ccaat sequence with cgtaa was found to abolish the binding of ancp and to have an inhibi ... | 1997 | 9108273 |
| the base analog 6-n-hydroxylaminopurine (hap) mutagenesis is dependent on the integrity of the uvse, uvsf and uvsb genes in aspergillus nidulans. | most of the available data in lower eukaryotes are consistent with the idea that base analogs-induced mutagenesis is due to the mis-pairing properties of these compounds, which, in turn, is due to a shift in the tautomeric equilibrium of the molecule. a tautomeric shift may in fact lead to mismatches which, at least in escherichia coli, can be repaired by genes involved in the post-replicative mismatch repair whose activity is necessary to control spontaneous mutagenesis. in filamentous fungi, s ... | 1997 | 9111919 |
| characterization of the aspergillus nidulans aspnd1 gene demonstrates that the aspnd1 antigen, which it encodes, and several aspergillus fumigatus immunodominant antigens belong to the same family. | for the first time, an immunodominant aspergillus nidulans antigen (aspnd1) consistently reactive with serum samples from aspergilloma patients has been purified and characterized, and its coding gene (aspnd1) has been cloned and sequenced. aspnd1 is a glycoprotein with four n-glycosidically-bound sugar chains (around 2.1 kda each) which are not necessary for reactivity with immune human sera. the polypeptide part is synthesized as a 277-amino-acid precursor of 30.6 kda that after cleavage of a ... | 1997 | 9119471 |
| the amda regulatory gene of aspergillus nidulans: characterization of gain-of-function mutations and identification of binding sites for the gene product. | genetic evidence suggests that the amda gene of aspergillus nidulans encodes a protein which controls the expression of the amds and acia structural genes. the amd166 and amd1666 mutations in the 5' regulatory region of amds lead to higher levels of amda-dependent amds expression. we show here that the putative dna binding domain of amda is capable of binding specific regions of the amds and acia promoters in vitro and this region includes sequences duplicated and triplicated in the amd166 and a ... | 1997 | 9126617 |
| the aspergillus nidulans septin encoding gene, aspb, is essential for growth. | septins are a highly conserved family of presumed cytoskeletal proteins involved in cytokinesis and morphogenesis in saccharomyces cerevisiae and drosophila melanogaster. to investigate the role of septins in filamentous fungi, we have identified presumptive septin homologues in aspergillus nidulans. one of these septins, aspb, is expressed during vegetative growth and asexual sporulation. based on cdna and genomic sequences, the predicted aspb protein shares a p-loop motif and coiled coil regio ... | 1997 | 9126618 |
| isolation of aspergillus nidulans mutants that overcome brla-induced growth arrest. | the aspergillus nidulans brla gene is a primary regulator of development-specific gene expression during conidiation. forced activation of brla in vegetative cells leads to inappropriate induction of conidiophore formation and causes growth to stop. in fact, when conidia containing a nutritionally inducible brla gene fusion are placed on inducing medium, they fail to germinate. we used this phenotype to select 174 mutants that continue growing following such forced brla activation. forty-six of ... | 1997 | 9126620 |
| aspergillus fumigatus chse: a gene related to chs3 of saccharomyces cerevisiae and important for hyphal growth and conidiophore development but not pathogenicity. | the aspergillus fumigatus chse (afchse) gene was isolated from an a. fumigatus dna library on the basis of hybridization to a segment of saccharomyces cerevisiae chs3 (scchs3). the amino acid sequence derived from afchse is 28% identical with scchs3 and 80% identical with the product of aspergillus nidulans chsd (anchsd). a mutant strain constructed by disruption of afchse has reduced levels of mycelial chitin, periodic swellings along the length of hyphae, and a block in conidiation that can be ... | 1997 | 9126623 |
| beta-xylosidase activity, encoded by xlnd, is essential for complete hydrolysis of xylan by aspergillus niger but not for induction of the xylanolytic enzyme spectrum. | two proteins exhibiting beta-d-xylosidase activity were identified upon fractionation and purification of a culture filtrate of an arabinoxylan-grown aspergillus niger. a single band of 110 kda by sds/page was obtained in both cases and these were active on xylo-oligosaccharides and on xylan. partial xlnd cdna clones were immunochemically identified and isolated from a lambda cdna expression library. sequence analysis showed that all cdna clones correspond to a single gene. a genomic clone was i ... | 1997 | 9128738 |
| cloning of cutinase transcription factor 1, a transactivating protein containing cys6zn2 binuclear cluster dna-binding motif. | hydroxy fatty acids from plant cutin were shown previously to induce the expression of the cutinase gene via a palindromic sequence located at -159 base pairs of the cutinase gene in fusarium solani f. sp. pisi (nectria hematococca mating type vi). of the two overlapping palindromes in this sequence, palindrome 2 was found to be essential for the inducibility of cutinase by hydroxy fatty acids. screening of a phage expression library with the concatenated palindrome 2 as probe detected a distinc ... | 1997 | 9139694 |
| the gene encoding the major proline transporter of aspergillus nidulans is upregulated during conidiospore germination and in response to proline induction and amino acid starvation. | in aspergillus nidulans a highly specific l-proline transporter is encoded by the prnb gene which is tightly linked to all other genes involved in proline catabolism. in mycelia, the expression of the prn structural genes is finely co-regulated in response to proline induction and nitrogen/carbon catabolite repression. in this study we establish that prnb expression is also activated during germination of conidiospores. this activation persists until the development of 6 h-old mycelia and it is ... | 1997 | 9140969 |
| molecular characterization of the aspergillus nidulans trea gene encoding an acid trehalase required for growth on trehalose. | aspergillus nidulans conidiospores contain high levels of the non-reducing disaccharide trehalose. we show that upon induction of conidiospore germination, the trehalose pool is rapidly degraded and a glycerol pool is transiently accumulated. a trehalase with an acidic ph optimum was purified from conidiospores. characterization of the trea gene encoding this trehalase shows that it is homologous to saccharomyces cerevisiae vacuolar acid trehalase, the product of the ath1 gene, and to two relate ... | 1997 | 9140977 |
| properties of yeast expressed aspergillus nidulans chitin synthase b which is essential for hyphal growth. | a complementary dna of the aspergillus nidulans chsb gene encoding chitin synthase, an essential gene for hyphal growth, was obtained by rt-pcr and expressed in saccharomyces cerevisiae by using the gal1 promoter in a multicopy plasmid. the biochemical characteristics of chitin synthase b (chsb) expressed in s. cerevisiae were examined. the chitin synthase b produced in galactose medium showed zymogenicity due to activation by trypsin treatment and required mg2+ ion to exert maximal activity. it ... | 1997 | 9141670 |
| the tbp gene from aspergillus nidulans-structure and expression in saccharomyces cerevisiae. | the genomic and cdna copy of the tata-binding protein (tbp) gene from the filamentous fungus aspergillus nidulans have been cloned. the gene is interrupted by four introns, one of which is in the long 5' untranslated region of 615 bp. the transcription initiation site was established and the levels of mrna were analysed under diverse growth conditions and found to vary severalfold. the gene encodes a protein of 268 amino acids composed of an n-terminal domain of 88 amino acids with no significan ... | 1997 | 9141689 |
| purification and characterization of the precursor trna 3'-end processing nuclease from aspergillus nidulans. | the precursor-trna 3'-end processing nuclease activity was purified homogeneously about 15,300 fold from the heat-treated fraction. the precursor-trna 3'-end processing nuclease was a single polypeptide of 160,000 da. this nuclease generates a mature 3'-end of nuclear trna(asp) of aspergillus nidulans by the endonuclease activity and prefers the 5'-end processed trna(asp) rather than primary precursor-trna(asp) as a substrate. however, this enzyme did not process both primary mitochondrial precu ... | 1997 | 9144538 |
| two divergent catalase genes are differentially regulated during aspergillus nidulans development and oxidative stress. | catalases are ubiquitous hydrogen peroxide-detoxifying enzymes that are central to the cellular antioxidant response. of two catalase activities detected in the fungus aspergillus nidulans, the cata gene encodes the spore-specific catalase a (cata). here we characterize a second catalase gene, identified after probing a genomic library with cata, and demonstrate that it encodes catalase b. this gene, designated catb, predicts a 721-amino-acid polypeptide (catb) showing 78% identity to an aspergi ... | 1997 | 9150225 |
| efg1p, an essential regulator of morphogenesis of the human pathogen candida albicans, is a member of a conserved class of bhlh proteins regulating morphogenetic processes in fungi. | we identified a gene of the fungal pathogen candida albicans, designated efg1, whose high-level expression stimulates pseudohyphal morphogenesis in the yeast saccharomyces cerevisiae. in a central region the deduced efg1 protein is highly homologous to the stua and phd1/sok2 proteins that regulate morphogenesis of aspergillus nidulans and s. cerevisiae, respectively. the core of the conserved region is homologous to the basic helix-loop-helix (bhlh) motif of eukaryotic transcription factors, spe ... | 1997 | 9155024 |
| [a nidulans bronchial aspergillosis after treatment of low-grade lymphoma with fludarabine]. | pulmonary aspergillosis is a common complication in neutropenic patients. the most important fungus is aspergillus fumigatus. we report a case of invasive pulmonary aspergillosis due to aspergillus nidulans secondary to fludarabine therapy. there are few cases of pulmonary aspergillosis due to aspergillus nidulans (one chronic necrotizing pulmonary aspergillosis, one aspergilloma). fludarabine induces a marked decreased of cd4 lymphocyte count responsible for opportunistic infections. it is the ... | 1997 | 9161576 |
| identification of putative phosphoinositide-specific phospholipase c genes in filamentous fungi. | five putative phosphoinositide-specific phospholipases c (plc) genes were identified in three species of filamentous fungi. using polymerase chain reaction with degenerate oligonucleotide primers, gene fragments encoding amino acid sequences homologous to plcs of mammals and other organisms were amplified: one sequence from botryotinia fuckeliana, one from aspergillus nidulans, and three from neurospora crassa. the molecular cloning and sequencing of a putative plc gene (bcplc1) from b. fuckelia ... | 1997 | 9163731 |
| cloning of an e. coli reca and yeast rad51 homolog, rada, an allele of the uvsc in aspergillus nidulans and its mutator effects. | an e. coli reca and yeast rad51 homolog from aspergillus nidulans, rada, has been cloned by screening genomic and cdna libraries with a pcr-amplified probe. this probe was generated using primers carrying the conserved sequences of eukaryotic reca homologs. the deduced amino acid sequence revealed two conserved walker-a and -b type nucleotide-binding domains and exhibited 88%, 60%, and 53% identity with mei-3 of neurospora crassa, rhp51+ of schizosaccharomyces pombe, and rad51 of saccharomyces c ... | 1997 | 9163746 |
| cloning and characterization of the cita gene encoding the mitochondrial citrate synthase of aspergillus nidulans. | we isolated a citrate synthase gene (cita) from aspergillus nidulans. by analysis of the protein coding region, cita was shown to encode a citrate synthase (cita) of 52.2 kda consisting of 474 amino acid residues that were interrupted by seven introns. also, the precursor cita protein was revealed to have an n-terminal mitochondrial targeting signal of 35 amino acid residues containing an r-3 cleavage motif, r(32)-c-y decreases s(35), which supports the fact that cita encodes the mitochondrial f ... | 1997 | 9163747 |
| expression of a synthetic protein-based polymer (elastomer) gene in aspergillus nidulans. | a gene for a synthetic protein-based polymer, g-(vpgvg)119-vpgv, coding for the eg-120mer (elastomer), was cloned into a fungal expression vector to allow constitutive expression of the polymer controlled by the gpda (glyceraldehyde-3-phosphate dehydrogenase) promoter sequence of aspergillus nidulans. stable transformants of a. nidulans showed plasmid integration with varying copy number when analyzed by southern-blot hybridization. expression of the synthetic gene was demonstrated by northern-b ... | 1997 | 9163950 |
| factors affecting the spread of double-stranded rna viruses in aspergillus nidulans. | viruses are common in asexual aspergilli but not in sexual aspergilli. we found no viruses in 112 isolates of the sexual aspergillus nidulans. we have investigated factors that could play a role in preventing the spread of mycoviruses through populations of a. nidulans. experiments were performed with a. nidulans strains infected with viruses originating from a. niger. horizontal virus transmission was restricted but not prevented by somatic incompatibility. viruses were transmitted vertically v ... | 1997 | 9164170 |
| cloning and sequencing of an alpha-glucosidase gene from aspergillus niger and its expression in a. nidulans. | we have cloned an extracellular alpha-glucosidase gene from aspergillus niger with oligonucleotide probes synthesized on the basis of the determined peptide sequences. the nucleotide sequence revealed an open reading frame of 985 amino acids split with three introns, and the deduced amino acid sequence was nearly identical to that of the alpha-glucosidase previously determined. the cloned gene was introduced into aspergillus nidulans, and its expression in the transformants was shown to be regul ... | 1997 | 9165762 |
| differential poisoning of human and aspergillus nidulans dna topoisomerase i by bi- and terbenzimidazoles. | dna topoisomerase i has been partially purified from aspergillus nidulans. the purified enzyme is most likely the major nuclear dna topoisomerase i on the basis of the following findings. (1) purified dna topoisomerase i can relax both positively and negatively supercoiled dna. (2) neither an energy cofactor nor mg(ii) is required for the relaxation or the cleavage reaction of the enzyme. on the basis of a phosphate-transfer experiment, the aspergillus topoisomerase i was shown to have a molecul ... | 1997 | 9174366 |
| multidrug resistance in aspergillus nidulans involves novel atp-binding cassette transporters. | two single-copy genes, designated atra and atrb (atp-binding cassette transporter a and b), were cloned from the filamentous fungus aspergillus nidulans and sequenced. based on the presence of conserved motifs and on hydropathy analysis, the products encoded by atra and atrb can be regarded as novel members of the atp-binding cassette (abc) superfamily of membrane transporters. both products share the same topology as the abc transporters pdr5 and snq2 from saccharomyces cerevisiae and cdr1 from ... | 1997 | 9180695 |
| in vitro recognition of specific dna targets by alcr, a zinc binuclear cluster activator different from the other proteins of this class. | alcr is the transactivator mediating transcriptional induction of the alc gene cluster in aspergillus nidulans. the alcr dna-binding domain consists of a zinc binuclear cluster different from the other members of the zn2cys6 family by several features. in particular, it is able to bind to symmetric and asymmetric sites with the same affinity, with both sites being functional in a. nidulans. here, we show that unlike the other proteins of the zn2cys6 binuclear cluster family, alcr binds most prob ... | 1997 | 9182587 |
| the integration of nitrogen and carbon catabolite repression in aspergillus nidulans requires the gata factor area and an additional positive-acting element, ada. | the expression of the structural genes of the proline utilization cluster of aspergillus nidulans is repressed efficiently only when both repressing carbon and nitrogen sources are present. two hypotheses can account for this fact. one is a direct or indirect competition mechanism between the positive-acting area gata factor, mediating nitrogen metabolite repression, and the negative-acting crea protein, mediating carbon catabolite repression. the second is to propose that crea prevents the bind ... | 1997 | 9184237 |
| characterization of gamma-tubulin complexes in aspergillus nidulans and detection of putative gamma-tubulin interacting proteins. | gamma-tubulin is central to the nucleation of microtubule assembly in vivo. although it is most obviously located at microtubule organizing centers, it is also found in soluble cytoplasmic complexes. characterizing these complexes and identifying proteins that interact with gamma-tubulin in vivo will be necessary if gamma-tubulin function is to be understood fully. we have begun to investigate soluble complexes of gamma-tubulin in aspergillus nidulans, the organism in which gamma-tubulin was dis ... | 1997 | 9186012 |
| the aspergillus nidulans transcription factor alcr forms a stable complex with its half-site dna: a nmr study. | the aspergillus nidulans transcription factor alcr is shown by nmr and gel retardation assay to form a stable complex with oligonucleotide sequences comprising the consensus half-site 5'-tgcgg-3'. apparent microm dissociation constants are evaluated by both methods. the measured lifetime of the complex is 74+/-7 ms at 20 degrees c with the following dna sequence: 5'-c1g2t3g4c5g6g7a8t9c10-3'. the major chemical shift variations upon binding involve both the two adjacent gc pairs (g6 and g7) and, ... | 1997 | 9187374 |
| the acetate regulatory gene facb of aspergillus nidulans encodes a zn(ii)2cys6 transcriptional activator. | genetic studies have indicated that the facb gene of aspergillus nidulans is a major regulatory gene involved in acetamide and acetate utilisation. sequencing of the facb gene revealed that it encodes a protein that contains an n-terminal gal4-like zn(ii)2cys6 (or c6 zinc) binuclear cluster for dna binding, leucine zipper-like heptad repeat motifs and central and c-terminal acidic alpha-helical regions, consistent with a function as a dna-binding transcriptional activator. the zn(ii)2cys6 cluste ... | 1997 | 9197408 |
| genetic analysis of regulatory mutants affecting synthesis of extracellular proteinases in the yeast yarrowia lipolytica: identification of a rim101/pacc homolog. | depending on the ph of the growth medium, the yeast yarrowia lipolytica secretes both an acidic proteinase and an alkaline proteinase, the synthesis of which is also controlled by carbon, nitrogen, and sulfur availability, as well as by the presence of extracellular proteins. recessive mutations at four unlinked loci, named pal1 to pal4, were isolated which prevent alkaline proteinase derepression under conditions of carbon and nitrogen limitation at ph 6.8. these mutations markedly affect matin ... | 1997 | 9199331 |
| two uvs genes of aspergillus nidulans with different functions in error-prone repair: uvsi, active in mutation-specific reversion, and uvsc, a reca homolog, required for all uv mutagenesis. | two genes of aspergillus nidulans are known to function in uv mutagenesis, but have been assigned to different epistasis groups: uvsc, which is also required for meiosis and mitotic recombination, and uvsi, which may have no other function. to clarify their role in error-prone repair and to investigate their interaction, uvsi and uvsc single and uvsi;uvsc double mutant strains were further tested for mutagen sensitivities and characterized for effects on mutation. spontaneous and induced frequen ... | 1997 | 9202380 |
| cloning, sequencing, disruption and phenotypic analysis of uvsc, an aspergillus nidulans homologue of yeast rad51. | we have cloned the uvsc gene of aspergillus nidulans by complementation of the a. nidulans uvsc114 mutant. the predicted protein uvsc shows 67.4% sequence identity to the saccharomyces cerevisiae rad51 protein and 27.4% sequence identity to the escherichia coli reca protein. transcription of uvsc is induced by methyl-methane sulphonate (mms), as is transcription of rad51 of yeast. similar levels of uvsc transcription were observed after mms induction in a uvsc+ strain and the uvsc114 mutant. the ... | 1997 | 9202381 |
| adaptation of proteases and carbohydrates of saprophytic, phytopathogenic and entomopathogenic fungi to the requirements of their ecological niches. | the abilities of isolates of saprophytes (neurospora crassa, aspergillus nidulans), an opportunistic human pathogen (aspergillus fumigatus), an opportunistic insect pathogen (aspergillus flavus), plant pathogens (verticillium albo-atrum, verticillium dahliae, nectria haematococca), a mushroom pathogen (verticillium fungicola) and entomopathogens (verticillium lecanii, beauveria bassiana, metarhizium anisopliae) to utilize plant cell walls and insect cuticle components in different nutrient media ... | 1997 | 9202474 |
| pcr-identification of a nicotiana plumbaginifolia cdna homologous to the high-affinity nitrate transporters of the crna family. | a family of high-affinity nitrate transporters has been identified in aspergillus nidulans and chlamydomonas reinhardtii, and recently homologues of this family have been cloned from a higher plant (barley). based on six of the peptide sequences most strongly conserved between the barley and c. reinhardtii polypeptides, a set of degenerate primers was designed to permit amplification of the corresponding genes from other plant species. the utility of these primers was demonstrated by rt-pcr with ... | 1997 | 9207842 |
| a kinesin-like mechanoenzyme from the zygomycete syncephalastrum racemosum shares biochemical similarities with conventional kinesin from neurospora crassa. | the kinesin superfamily consists of mechanoenzymes that convert chemical energy, stored in nucleoside triphosphates, into movement along microtubules. the founding member of this protein superfamily, the so-called conventional kinesin, was only known from animal sources until the recent description of kinesin from the filamentous fungus neurospora crassa (g. steinberg, m. schliwa, mol. biol. cell 6, 1605-1618 (1995)). to determine whether similar motors with comparable features are common in oth ... | 1997 | 9208225 |
| cloning of the candida albicans homolog of saccharomyces cerevisiae gsc1/fks1 and its involvement in beta-1,3-glucan synthesis. | saccharomyces cerevisiae gsc1 (also called fks1) and gsc2 (also called fks2) have been identified as the genes for putative catalytic subunits of beta-1,3-glucan synthase. we have cloned three candida albicans genes, gsc1, gsl1, and gsl2, that have significant sequence homologies with s. cerevisiae gsc1/fks1, gsc2/fks2, and the recently identified fksa of aspergillus nidulans at both nucleotide and amino acid levels. like s. cerevisiae gsc/fks proteins, none of the predicted products of c. albic ... | 1997 | 9209021 |
| pyruvate decarboxylase and anaerobic survival in aspergillus nidulans. | the presence of pyruvate decarboxylase activity has been demonstrated in aspergillus nidulans, and a gene encoding a pyruvate decarboxylase has been isolated from this organism and physically characterized. the isolation of the pdca gene in a. nidulans confirms the existence of the alcoholic fermentation pathway in this fungus, despite it being an obligate aerobic organism. southern analysis showed that it is most probably a single copy gene. several potential binding sites for a gatar-binding p ... | 1997 | 9210590 |
| carbon regulation of the cuticle-degrading enzyme pr1 from metarhizium anisopliae may involve a trans-acting dna-binding protein crr1, a functional equivalent of the aspergillus nidulans crea protein. | the pr1 gene of the entomopathogenic fungus metarhizium anisopliae encodes a serine protease that is highly active towards the insect cuticle and whose synthesis is subject to both carbon and nitrogen repression. the pr1 promoter region was sequenced revealing the presence of putative crea- and area-binding sites. in vitro bandshift experiments demonstrated that an aspergillus nidulans gst-crea fusion protein was capable of binding to two of the three putative crea sites. using a pcr-based strat ... | 1997 | 9211795 |
| the uvsf gene region in aspergillus nidulans codes for a protein with homology to dna replication factor c. | the uv-sensitive mutant uvsf201 of aspergillus nidulans shows increased spontaneous and uv-induced mutation and generally resembles mutants defective in nucleotide excision repair (ner). fully-complementing uvsf clones were isolated from cosmid and cdna libraries for sequencing. the uvsf gene is approximately 3.75 kb long and codes for a predicted polypeptide of 1092 amino acids (aa). three small introns are clustered early in the coding region of the protein. a major part of the sequence shows ... | 1997 | 9218714 |
| mutations in a dispensable region of the uay transcription factor of aspergillus nidulans differentially affect the expression of structural genes. | the uay gene encodes a transcriptional activator mediating uric acid induction of at least nine genes of the purine-utilization pathway. in this article, we characterize a loss-of-function mutation, uay205, as a 16 bp deletion that results in premature translation termination, and substitutes the c-terminal 63 amino acids for 13 amino acid residues. reversion analysis demonstrates that the c-terminal 63 amino acid residues are unnecessary for uay function, and that the loss-of-function phenotype ... | 1997 | 9218768 |
| the aspergillus nidulans sepa gene encodes an fh1/2 protein involved in cytokinesis and the maintenance of cellular polarity. | cytokinesis (septation) in the fungus aspergillus nidulans occurs through the formation of a transient actin ring at the incipient division site. temperature-sensitive mutations in the sepa gene prevent septation and cause defects in the maintenance of cellular polarity, without affecting growth and nuclear division. the sepa gene encodes a member of the growing family of fh1/2 proteins, which appear to have roles in morphogenesis and cytokinesis in organisms such as yeast and drosophila. result ... | 1997 | 9218790 |
| a novel fungal gene encoding chitin synthase with a myosin motor-like domain. | a csma gene that encodes chitin synthase with a myosin motor-like domain was isolated from the filamentous fungus aspergillus nidulans. initially, we obtained the csma as a homolog of the aspergillus fumigatus chse-partial fragment. a large open reading frame encoding a polypeptide of 1,852 a.a. was identified by determining the cdna sequences. the chitin synthase conserved region was situated at the c-terminus and classified into class v as reported previously. on the other hand, the n-terminal ... | 1997 | 9223429 |
| carbon repression in aspergilli. | many microorganisms prefer easily metabolizable carbon sources over alternative, less readily metabolized carbon sources. one of the mechanisms to achieve this is repression of the synthesis of enzymes related to catabolism of the alternative carbon sources, i.e. carbon repression. it is now clear that in aspergillus nidulans and aspergillus niger the repressor protein crea plays a major role in carbon repression. crea inhibits transcription of many target genes by binding to specific sequences ... | 1997 | 9228741 |
| cloning and analysis of an actin-encoding cdna from the dimorphic pathogenic fungus histoplasma capsulatum. | we have cloned an actin-encoding cdna from the dimorphic fungus histoplasma capsulatum, an important pathogen of humans. the predicted amino acid sequence as well as the general codon pattern of histoplasma actin revealed the highest degree of similarity to the actin of the filamentous ascomycete aspergillus nidulans. southern blot analysis determined that actin was encoded by a single copy in the histoplasma genome. northern blot analysis showed a single 1700 nt transcript in yeast and mould ce ... | 1997 | 9229331 |
| new evidence for old detective work. | 1997 | 9229524 | |
| subtle hydrophobic interactions between the seventh residue of the zinc finger loop and the first base of an hgatar sequence determine promoter-specific recognition by the aspergillus nidulans gata factor area. | a change of a universally conserved leucine to valine in the dna-binding domain of the gata factor area results in inability to activate some area-dependent promoters, including that of the uapa gene encoding a specific urate-xanthine permease. some other area-dependent promoters become able to function more efficiently than in the wild-type context. a methionine in the same position results in a less extreme, but opposite effect. suppressors of the area(val) mutation mapping in the uapa promote ... | 1997 | 9233807 |
| mutations in the heavy chain of cytoplasmic dynein suppress the nudf nuclear migration mutation of aspergillus nidulans. | to identify proteins that interact directly or indirectly with the nudf protein, which is required for nuclear migration in aspergillus nidulans, we initiated a screen for extragenic suppressors of the heat-sensitive nudf6 mutation. suppressor mutations in at least five genes, designated snfa-snfe, caused improved growth and nuclear migration at high temperatures compared to the nudf6 parent. two snfc mutations mapped near the nuda gene, which encodes the cytoplasmic dyncin heavy chain, and coul ... | 1997 | 9236777 |
| gene targeting is locus dependent in the filamentous fungus aspergillus nidulans. | the effect of altering the conditions of transformation on the efficiency of gene targeting in filamentous fungi was studied using aspergillus nidulans as a model organism. the niad and amds genes of a. nidulans, which are both involved in nitrogen source utilisation, were selected as target loci. homologous recombination of transforming dna at these loci resulted in niad and amds mutants with an impaired ability to utilise nitrate or acetamide as the sole nitrogen source, respectively. vectors ... | 1997 | 9236780 |
| involvement of ntcb, a lysr family transcription factor, in nitrite activation of the nitrate assimilation operon in the cyanobacterium synechococcus sp. strain pcc 7942. | nitrite, either exogenously supplied or endogenously generated by nitrate reduction, activates transcription of the nitrate assimilation operon (nira-nrtabcd-narb) in synechococcus sp. strain pcc 7942 cells treated with l-methionine-dl-sulfoximine (an inhibitor of glutamine synthetase), in which there is no negative feedback resulting from fixation of the ammonium generated by nitrite reduction (kikuchi et al., j. bacteriol. 178:5822-5825, 1996). other transcription units related to nitrogen ass ... | 1997 | 9244251 |
| monoclonal antibodies as probes for fungal wall structure during morphogenesis. | three monoclonal antibodies (mabs), s4d1, s3b3 and s1e5, were produced from hybridoma cell lines raised from mice immunized with hyphal walls of neurospora crassa and one (pax-1) from mice immunized with hyphal walls of paxillus involutus. in immunofluorescence studies, the three n. crassa mabs recognized epitopes with different patterns of distribution at the hyphal surface of n. crassa. s4d1 recognized an epitope which was present on the surface of both conidia and hyphae; s3b3 recognized an e ... | 1997 | 9245814 |
| aspergillus nidulans infection in a patient with chronic granulomatous disease. | aspergillus nidulans is one of the several species of aspergillus with low pathogenicity. the significant infections of a. nidulans in human have rarely been reported, almost exclusively in patients with chronic granulomatous disease (cgd). cgd is a primary immunodeficiency disease which results from the absence of the nadph oxidase in the phagocytic cells, leading to recurrent pyogenic infection and granuloma and abscess formation. here we report a fatal case a. nidulans infection in a six-year ... | 1997 | 9250922 |
| characterization of nima protein kinase in aspergillus nidulans. | 1997 | 9251045 | |
| fungal microflora biodiversity as a function of pollution in oued sebou (morocco). | an inventory of the fungal microflora present in sediments collected at 11 sites along oued sebou has been established. the influence of some climatic parameters (temperature, rainfall) and of pollution on the composition of the fungal communities has been questioned. emericella nidulans, eurotium amstelodami, neosartotya fisheri var. glabrum (ascomycetes), dreschslera biseptata (dematiaceae), penicillium citrinum (mucedinaceae) and phoma sp. (sphaeropsidale) can be considered as strains sensiti ... | 1997 | 9253167 |
| evolution of transcription-regulating proteins: caveat lector! | the paper of hawkins et al. [gene 146 (1994) 145-158] reports incorrect descriptions of mutant phenotypes, omits mention of the absence of a highly relevant glutamine-binding site and contains sequence alignments which might mislead the reader. extensive sequence analysis reveals as untenable a central hypothesis of the paper concerning a possible evolutionary relationship between anthranilate synthetases and the transcription factors mediating nitrogen metabolite repression in fungi. | 1997 | 9253382 |
| a protein encoded by a group i intron in aspergillus nidulans directly assists rna splicing and is a dna endonuclease. | some group i introns self-splice in vitro, but almost all are thought to be assisted by proteins in vivo. mutational analysis has shown that the splicing of certain group i introns depends upon a maturase protein encoded by the intron itself. however the effect of a protein on splicing can be indirect. we now provide evidence that a mitochondrial intron-encoded protein from aspergillus nidulans directly facilitates splicing in vitro. this demonstrates that a maturase is an rna splicing protein. ... | 1997 | 9256423 |
| mycological and some physiological studies of keratinophilic and other moulds associated with sheep wool. | wool samples of 50 healthy sheep collected from different localities at ar' ar in saudi arabia were examined for the presence of keratinophilic and other fungi using the hair plate technique. forty-eight species and 2 varieties belonging to 20 genera were isolated on sabouraud's dextrose agar at 25 degrees c. two species of true dermatophytes were isolated: trichophyton terrestre and t. rubrum in low frequency of occurrence. chrysosporium, a well-know keratinophilic genus, was the predominant ge ... | 1997 | 9265769 |
| acv synthetase: expression of amino acid activating domains of the penicillium chrysogenum enzyme in aspergillus nidulans. | fragments of acv synthetase of penicillium chrysogenum carrying partial activities of amino acid activation were expressed under the alca promoter in an acva-deletion mutant of aspergillus nidulans. the 210 kda domain a-beta-galactosidase fusion protein was partially cleaved to fragments of 200 and 97 kda. the domain a fragment and the 312 kda domain bc construct were identified by peptide specific antibodies and shown to catalyze alpha-aminoadipate-, cysteine-, and valine-dependent atp/[32p]ppi ... | 1997 | 9266851 |
| the aspergillus nidulans lysf gene encodes homoaconitase, an enzyme involved in the fungus-specific lysine biosynthesis pathway. | in filamentous fungi, lysine is synthesized via the alpha-aminoadipate pathway. in order to gain insight into this fungus-specific pathway (to date, no genes for enzymes of this pathway in filamentous fungi have been cloned) the lysine auxotrophic mutant lysf88 of aspergillus nidulans was studied. hplc and 1h-nmr analyses revealed that lysf88 accumulated homocitric acid in the culture supernatant. in addition, both the lysf88 mutant strain and lysf deletion strain (lysfko) described here showed ... | 1997 | 9268014 |
| the bimc family of kinesins: essential bipolar mitotic motors driving centrosome separation. | 1997 | 9268050 | |
| the sequence of palf, an environmental ph response gene in aspergillus nidulans. | to molecularly characterize the influence of external ph in the secretion of enzymes by filamentous fungi, we have cloned and sequenced the palf gene of aspergillus nidulans (an). an an wild-type (wt) chromosome vii-specific cosmid library was used to transform a palf15 mutant strain. selection for complementation was done on medium containing beta-glycerolphosphate as the sole pi source. two cosmids were identified (w2g08 and w4g12) and further subcloning of one cosmid (w2g08) defined a 5-kb ps ... | 1997 | 9272857 |
| the zinc binuclear cluster activator alcr is able to bind to single sites but requires multiple repeated sites for synergistic activation of the alca gene in aspergillus nidulans. | the alca gene which is part of the recently identified ethanol regulon, is one of the most strongly inducible genes in aspergillus nidulans. its transcriptional activation is mediated by the alcr transactivator which contains a dna-binding domain belonging to the c6 zinc binuclear cluster family. alcr differs from the other members of this family by several features, the most striking characteristic being its binding to both symmetric and asymmetric dna sites with the same apparent affinity. how ... | 1997 | 9278448 |
| evolution of transcription-regulating proteins: a brief, critical appraisal. | 1997 | 9280733 | |
| lipases in autolysed cultures of filamentous fungi. | fifty-one fungi from different genera and strains were checked in plate to determine lipase activity in protein precipitates from their autolysed cultures. each of them was then analysed at 3.5, 6.5 and 9.2 ph units and, as a consequence, basic lipases with high activity at 9.2 ph were found after 1 h of incubation. only 25% of the studied fungi showed this lipase activity, among them the best producers were fungi from genus fusarium (47% of fungi had lipase activity). in addition to lipase acti ... | 1997 | 9281862 |
| biotransformation of the flavonoid tiliroside to 7-methylether tiliroside: bioactivity of this metabolite and of its acetylated derivative. | incubation of kaempferol-3-o-beta-d-(6"-e-p-coumaroyl)-glucopyranoside (tiliroside) (1) with aspergillus nidulans gives the 7-methyl ether of tiliroside (2) which is a new compound. its structure is determined by spectroscopic methods. cytotoxic studies of 2 and of its acetylated derivative 2a were carried out in vitro against fourteen human leukemic cell lines. results clearly show that compound 2 is ineffective against all leukemic cell lines tested. on the contrary, compound 2a exhibited cyto ... | 1997 | 9284960 |
| role of four major cellulases in triggering of cellulase gene expression by cellulose in trichoderma reesei. | the relative contributions of four major cellulases of trichoderma reesei (1,4-beta-d-glucan cellobiohydrolase i [cbh i], cbh ii, endo-1,4-beta-d-glucanase i [eg i], and eg ii) to the generation of the cellulase inducer from cellulose were studied with isogenic strains in which the corresponding genes (cbh1, cbh2, egl1, and egl2) had been deleted by insertion of the aspergillus nidulans amds marker gene. during growth on lactose (a soluble carbon source provoking cellulase gene expression), thes ... | 1997 | 9286982 |
| the design of pooling experiments for screening a clone map. | we consider nonadaptive pooling designs for unique-sequence screening of a 1530-clone map of aspergillus nidulans. the map has the properties that the clones are, with possibly a few exceptions, ordered and no more than 2 of them cover any point on the genome. we propose two subdesigns of the steiner system s(3, 5, 65), one with 65 pools and approximately 118 clones per pool, the other with 54 pools and about 142 clones per pool. each design allows 1 or 2 positive clones to be detected, even in ... | 1997 | 9290242 |
| multicellular ascomycetous fungal genomes contain more than 8000 genes. | fungi comprise a large monophyletic group of uni- and multicellular eukaryotic organisms in which many species are of economic or medical importance. fungal genomes are variable in size (13-42 mb), and multicellular species support true spatial and temporal cell-type-specific regulation of gene expression. in a 38.8-kb aspergillus nidulans contiguous genomic dna region, a transposable element and 12 potential genes were identified, 7 similar to genes in other organisms. this observation is consi ... | 1997 | 9290249 |
| autonomous plasmid replication in aspergillus nidulans: ama1 and mate elements. | with few exceptions, in eukaryotic organisms the presence of a chromosomal replicator on a circular vector molecule is not sufficient to confer on it the ability to persist and replicate extrachromosomally. however, it is possible to isolate from genomes of some filamentous fungi dna fragments which can provide extrachromosomal maintenance of plasmids. in aspergillus nidulans, two functional classes of such sequences can be distinguished: effective plasmid replicators (e.g., ama1) and transforma ... | 1997 | 9290250 |
| the validity of the aspergillus nidulans linkage map. | the aspergillus nidulans linkage map is reviewed as a background to physical mapping by cosmid cross-hybridization and genome sequencing. dna-based methods depend on contiguity, so that the resulting maps are only as good as the weakest link, whereas each new marker added to a linkage map can provide independent confirmation of the positions of its neighbors. for all eight chromosomes of a. nidulans a reliable framework has been provided by analysis of mitotic crossing over, in many cases substa ... | 1997 | 9299197 |
| aspergillus sporulation and mycotoxin production both require inactivation of the fada g alpha protein-dependent signaling pathway. | the filamentous fungus aspergillus nidulans contains a cluster of 25 genes that encode enzymes required to synthesize a toxic and carcinogenic secondary metabolite called sterigmatocystin (st), a precursor of the better known fungal toxin aflatoxin (af). one st cluster (stc) gene, aflr, functions as a pathway-specific transcriptional regulator for activation of other genes in the st pathway. however, the mechanisms controlling activation of aflr and synthesis of st and af are not understood. her ... | 1997 | 9305634 |
| deletion of nudc, a nuclear migration gene of aspergillus nidulans, causes morphological and cell wall abnormalities and is lethal. | nuclear migration is required for normal development in both higher and lower eukaryotes. in fungi this process is mediated by cytoplasmic dynein. it is believed that this motor protein is anchored to the cell membrane and moves nuclei by capturing and pulling on spindle pole body microtubules. to date, four genes have been identified and shown to be required for this process in aspergillus nidulans. the nuda and nudg genes, respectively, encode the heavy and light chains of cytoplasmic dynein, ... | 1997 | 9307970 |
| isolation of aspergillus niger crea mutants and effects of the mutations on expression of arabinases and l-arabinose catabolic enzymes. | aspergillus niger mutants relieved of carbon repression were isolated from an area parental strain by selection of colonies that exhibited improved growth on a combination of 4-aminobutanoic acid (gaba) and d-glucose. in addition to derepression of the utilization of gaba as a nitrogen source in the presence of d-glucose, three of the four mutants also showed derepression of l-alanine and l-proline utilization. transformation of the mutants with the a. niger crea gene, encoding the repressor pro ... | 1997 | 9308182 |
| stuap is a sequence-specific transcription factor that regulates developmental complexity in aspergillus nidulans. | the aspergillus nidulans stunted protein (stuap) regulates multicellular complexity during asexual reproduction by moderating the core developmental program that directs differentiation of uninucleate, terminally differentiated spores from multinucleate, vegetative hyphae. stuap is also required for ascosporogenesis and multicellular development during sexual reproduction. stuap is a member of a family of fungal transcription factors that regulate development or cell cycle progression. further, ... | 1997 | 9312029 |
| aspergillus asexual reproduction and sexual reproduction are differentially affected by transcriptional and translational mechanisms regulating stunted gene expression. | the stunted protein (stuap) is a member of a family of transcription factors that regulate fungal development and cell cycle progression. regulated stua gene expression is required for correct cell pattern formation during asexual reproduction (conidiation) and for initiation of the sexual reproductive cycle in aspergillus nidulans. transcriptional initiation from two different promoters yields overlapping mrnas (stua alpha and stuabeta) that upon translation yield the same protein. here we show ... | 1997 | 9315680 |
| unusual lack of internal mobility and fast overall tumbling in oxidized flavodoxin from anacystis nidulans. | anacystis nidulans flavodoxin, an electron-transfer protein containing a flavin mononucleotide (fmn) molecule as its prosthetic group, has a redox potential for the oxidized/semiquinone equilibrium close to that of free flavin. whereas the redox potential for the semiquinone/hydroquinone equilibrium is more negative. to gain an understanding of the contribution of mobility to redox potential modulation, we studied the backbone mobility of the oxidized a. nidulans flavodoxin at ph 6.6, 303 k by 1 ... | 1997 | 9325102 |
| a model for the combined effects of temperature and salt concentration on growth rate of food spoilage molds. | we modeled mold growth on a solid culture medium at various temperatures and nacl concentrations by using five common food spoilage molds (penicillium roqueforti, trichoderma harzianum, paecilomyces variotii, aspergillus niger, and emericella nidulans). for the description of the growth rate (expressed as the increase in colony diameter per unit of time) as a function of temperature and nacl concentration, a six-parameter model has been developed. the model combines either the rosso-type or the ... | 1997 | 9327540 |
| studies on cellulases of aspergillus nidulans mutants. | mutants were characterized as to their morphology, auxotrophy and cellulase production. no apparent correlation was evident among these characters. the degree of repression or enhancement of the three components of the cellulase enzyme in the mutants varied considerably, indicating their separate genetic control. considerable variations in the enzyme profiles of the mutants were observed as compared to the wild type. enzyme production was also found to be related to development. | 1997 | 9330668 |