| differences in composition of honey samples and their impact on the antimicrobial activities against drug multiresistant bacteria and pathogenic fungi. | antibiotic multiresistant microbes represent a challenging problem. because honey has a potent antibacterial property, the antimicrobial effects of different honey samples against multiresistant pathogens and their compositions were investigated. | 2013 | 23684665 |
| genetic bypass of aspergillus nidulans crza function in calcium homeostasis. | after dephosphorylation by the phosphatase calcineurin, the fungal transcription factor crza enters the nucleus and activates the transcription of genes responsible for calcium homeostasis and many other calcium-regulated activities. a lack of crza confers calcium-sensitivity to the filamentous fungus aspergillus nidulans. to further understand calcium signaling in filamentous fungi and to identify genes that interact genetically with crza, we selected for mutations that were able to suppress cr ... | 2013 | 23665873 |
| base composition and nucleosome density in exonic and intronic regions in genes of the filamentous ascomycetes aspergillus nidulans and aspergillus oryzae. | we sequenced nucleosomal dna fragments of the filamentous ascomycetes aspergillus nidulans and aspergillus oryzae and then mapped those sequences on their genomes. we compared the gc content and nucleosome density in the exonic and intronic regions in the genes of a. nidulans and a. oryzae. although the gc content and nucleosome density in the exonic regions tended to be higher than those in the intronic regions, the difference in the distribution of the gc content was more notable than that of ... | 2013 | 23664982 |
| identification of metabolic pathways influenced by the g-protein coupled receptors gprb and gprd in aspergillus nidulans. | heterotrimeric g-protein-mediated signaling pathways play a pivotal role in transmembrane signaling in eukaryotes. our main aim was to identify signaling pathways regulated by a. nidulans gprb and gprd g-protein coupled receptors (gpcrs). when these two null mutant strains were compared to the wild-type strain, the δgprb mutant showed an increased protein kinase a (pka) activity while growing in glucose 1% and during starvation. in contrast, the δgprd has a much lower pka activity upon starvatio ... | 2013 | 23658706 |
| conf and conj contribute to conidia germination and stress response in the filamentous fungus aspergillus nidulans. | light induces various responses in fungi including formation of asexual and sexual reproductive structures. the formation of conidia in the filamentous fungus aspergillus nidulans is regulated by red and blue light receptors. expression of conidia associated con genes, which are widely spread in the fungal kingdom, increases upon exposure to light. we have characterized the light-inducible conf and conj genes of a. nidulans which are homologs of con-6 and con-10 of neurospora crassa. con genes a ... | 2013 | 23644150 |
| β-glucan synthase gene overexpression and β-glucans overproduction in pleurotus ostreatus using promoter swapping. | mushroom β-glucans are potent immunological stimulators in medicine, but their productivities are very low. in this study, we successfully improved its production by promoter engineering in pleurotus ostreatus. the promoter for β-1,3-glucan synthase gene (gls) was replaced by the promoter of glyceraldehyde-3-phosphate dehydrogenase gene of aspergillus nidulans. the homologous recombination fragment for swapping gls promoter comprised five segments, which were fused by two rounds of combined touc ... | 2013 | 23637884 |
| pyrg is required for maintaining stable cellular uracil level and normal sporulation pattern under excess uracil stress in aspergillus nidulans. | tight control of the intracellular uracil level is believed to be important to reduce the occurrence of uracil incorporation into dna. the pyrg gene of aspergillus nidulans encodes orotidine 5'-phosphate decarboxylase, which catalyzes the conversion of orotidine monophosphate (omp) to uridine monophosphate (ump). in this study, we found that pyrg is critical for maintaining uracil at a low concentration in a. nidulans cells in the presence of exogenous uracil. excess uracil and its derivatives h ... | 2013 | 23633078 |
| an efficient system for heterologous expression of secondary metabolite genes in aspergillus nidulans. | fungal secondary metabolites (sms) are an important source of medically valuable compounds. genome projects have revealed that fungi have many sm biosynthetic gene clusters that are not normally expressed. to access these potentially valuable, cryptic clusters, we have developed a heterologous expression system in aspergillus nidulans . we have developed an efficient system for amplifying genes from a target fungus, placing them under control of a regulatable promoter, transferring them into a. ... | 2013 | 23621425 |
| comprehensive annotation of secondary metabolite biosynthetic genes and gene clusters of aspergillus nidulans, a. fumigatus, a. niger and a. oryzae. | secondary metabolite production, a hallmark of filamentous fungi, is an expanding area of research for the aspergilli. these compounds are potent chemicals, ranging from deadly toxins to therapeutic antibiotics to potential anti-cancer drugs. the genome sequences for multiple aspergilli have been determined, and provide a wealth of predictive information about secondary metabolite production. sequence analysis and gene overexpression strategies have enabled the discovery of novel secondary metab ... | 2013 | 23617571 |
| vertebral osteomyelitis and epidural abscess due to aspergillus nidulans resulting in spinal cord compression: case report and literature review. | vertebral osteomyelitis caused by aspergillus nidulans is rare and usually affects immunocompromised patients. this report presents a case of thoracic vertebral osteomyelitis with epidural abscesses due to a. nidulans in a 40-year-old immunocompetent female who presented with back pain, numbness and weakness of both lower limbs. magnetic resonance imaging demonstrated osteomyelitis involving the thoracic (t)1-t3 vertebral bodies with epidural abscesses, resulting in spinal compression. the patie ... | 2013 | 23569017 |
| water recycle as a must: decolorization of textile wastewaters by plant-associated fungi. | textile dye effluents are among the most problematic pollutants because of their toxicity on several organisms and ecosystems. low cost and ecocompatible bioremediation processes offer a promising alternative to the conventional and aspecific physico-chemical procedures adopted so far. here, microorganisms resident on three real textile dyeing effluent were isolated, characterized, and tested for their decolorizing performances. although able to survive on these real textile-dyeing wastewaters, ... | 2014 | 23553673 |
| western analysis of histone modifications (aspergillus nidulans). | western blotting allows for the specific detection of proteins and/or modifications of proteins by an antibody of interest. this protocol utilizes a crude nuclei extraction protocol for aspergillus nidulans to enrich for histones and other nuclear proteins prior to gel electrophoresis. post translational modifications of histones may then be easily detected. after electrophoresis, the selected antibodies are used to detect and quantify levels of the modifications of interest. | 2013 | 27275003 |
| a novel automethylation reaction in the aspergillus nidulans laea protein generates s-methylmethionine. | the filamentous fungi in the genus aspergillus are opportunistic plant and animal pathogens that can adapt to their environment by producing various secondary metabolites, including lovastatin, penicillin, and aflatoxin. the synthesis of these small molecules is dependent on gene clusters that are globally regulated by the laea protein. null mutants of laea in all pathogenic fungi examined to date show decreased virulence coupled with reduced secondary metabolism. although the amino acid sequenc ... | 2013 | 23532849 |
| lammer kinase lkha plays multiple roles in the vegetative growth and asexual and sexual development of aspergillus nidulans. | lammer kinase plays pivotal roles in various physiological processes in eukaryotes; however, its function in filamentous fungi is not known. we performed molecular studies on the function of the aspergillus nidulans lammer kinase, lkha, and report its involvement in multiple developmental processes. the gene for lkha was highly expressed during reproductive organ development, such as that of conidiophores and cleistothecia. during vegetative growth, the patterns of germ tube emergence and hyphal ... | 2013 | 23516554 |
| functional analysis of the aspergillus nidulans kinome. | the filamentous fungi are an ecologically important group of organisms which also have important industrial applications but devastating effects as pathogens and agents of food spoilage. protein kinases have been implicated in the regulation of virtually all biological processes but how they regulate filamentous fungal specific processes is not understood. the filamentous fungus aspergillus nidulans has long been utilized as a powerful molecular genetic system and recent technical advances have ... | 2013 | 23505451 |
| the arrestin-like protein arta is essential for ubiquitination and endocytosis of the uapa transporter in response to both broad-range and specific signals. | we investigated the role of all arrestin-like proteins of aspergillus nidulans in respect to growth, morphology, sensitivity to drugs and specifically for the endocytosis and turnover of the uric acid-xanthine transporter uapa. a single arrestin-like protein, arta, is essential for hula(rsp) (5) -dependent ubiquitination and endocytosis of uapa in response to ammonium or substrates. mutational analysis showed that residues 545-563 of the uapa c-terminal region are required for efficient uapa end ... | 2013 | 23490137 |
| effect of cell wall integrity stress and rlma transcription factor on asexual development and autolysis in aspergillus nidulans. | the cell wall integrity (cwi) signaling pathway is responsible for cell wall remodeling and reinforcement upon cell wall stress, which is proposed to be universal in fungal cultures. in aspergillus nidulans, both the deletion of rlma encoding the rlma transcription factor in cwi signaling and low concentrations of the cell wall polymer intercalating agent congo red caused significant physiological changes. the gene deletion mutant δrlma strain showed decreased cwi and oxidative stress resistance ... | 2013 | 23485399 |
| aspergillus nidulans translationally controlled tumor protein has a role in the balance between asexual and sexual differentiation and normal hyphal branching. | translationally controlled tumor protein (tctp) is a highly conserved and ubiquitously expressed protein present in all eukaryotes. cellular functions of tctp include growth promoting, allergic response and responses to various cellular stresses, but the functions in filamentous fungi have not been reported. in this report, we characterized an aspergillus nidulans tctp (tcpa) with high similarity to tctp. the level of tcpa mrna was relatively high, both during vegetative growth stage and at earl ... | 2013 | 23480775 |
| functional characterization of aspergillus nidulans ypka, a homologue of the mammalian kinase sgk. | the serum- and glucocorticoid-regulated protein kinase (sgk) is an agc kinase involved in signal cascades regulated by glucocorticoid hormones and serum in mammals. the saccharomyces cerevisiae ypk1 and ypk2 genes were identified as sgk homologues and ypk1 was shown to regulate the balance of sphingolipids between the inner and outer plasma membrane. this investigation characterized the aspergillus nidulans ypk1 homologue, ypka, representing the first filamentous fungal ypk1 homologue. two condi ... | 2013 | 23472095 |
| modelling the activation of alkaline ph response transcription factor pacc in aspergillus nidulans: involvement of a negative feedback loop. | alkaline ph adaptation represents an important environmental stress response in aspergillus nidulans. it is mediated by the pal signalling pathway and the pacc transcription factor. although studied extensively experimentally, the activation mechanism of pacc has not been quantified, and it is not clear how this activation is regulated. here, by constructing mathematical models, we first show that the pattern of pacc activation observed in previously published experiments cannot be explained bas ... | 2013 | 23458440 |
| improved polyhydroxybutyrate production by saccharomyces cerevisiae through the use of the phosphoketolase pathway. | the metabolic pathways of the central carbon metabolism in saccharomyces cerevisiae are well studied and consequently s. cerevisiae has been widely evaluated as a cell factory for many industrial biological products. in this study, we investigated the effect of engineering the supply of precursor, acetyl-coa, and cofactor, nadph, on the biosynthesis of the bacterial biopolymer polyhydroxybutyrate (phb), in s. cerevisiae. supply of acetyl-coa was engineered by over-expression of genes from the et ... | 2013 | 23456608 |
| pseudo-constitutivity of nitrate-responsive genes in nitrate reductase mutants. | in fungi, transcriptional activation of genes involved in no3(-) assimilation requires the presence of an inducer (nitrate or nitrite) and low intracellular concentrations of the pathway products ammonium or glutamine. in aspergillus nidulans, the two transcription factors nira and area act synergistically to mediate nitrate/nitrite induction and nitrogen metabolite derepression, respectively. in all studied fungi and in plants, mutants lacking nitrate reductase (nr) activity express nitrate-met ... | 2013 | 23454548 |
| reconstitution of the early steps of gliotoxin biosynthesis in aspergillus nidulans reveals the role of the monooxygenase glic. | the gliotoxin, a member of the epipolythiodioxopiperazine (etp), has received considerable attention from the scientific community for its wide range of biological activity. despite the identification of gliotoxin cluster, however, the sequence of steps in the gliotoxin biosynthesis has remained elusive. as an alternative to the gene knock-out and biochemical approaches used so far, here we report using a heterologous expression approach to determine the sequence of the early steps of gliotoxin ... | 2013 | 23434416 |
| control of multicellular development by the physically interacting deneddylases den1/dena and cop9 signalosome. | deneddylases remove the ubiquitin-like protein nedd8 from modified proteins. an increased deneddylase activity has been associated with various human cancers. in contrast, we show here that a mutant strain of the model fungus aspergillus nidulans deficient in two deneddylases is viable but can only grow as a filament and is highly impaired for multicellular development. the den1/dena and the cop9 signalosome (csn) deneddylases physically interact in a. nidulans as well as in human cells, and csn ... | 2013 | 23408908 |
| eisosome distribution and localization in the meiotic progeny of aspergillus nidulans. | in the model filamentous fungus aspergillus nidulans, pila and pilb, two homologues of the saccharomyces cerevisiae eisosome proteins pil1/lsp1, and surg, a strict orthologue of sur7, are assembled and form tightly packed structures in conidiospores. as a. nidulans differs in its reproduction pattern from the saccharomycotina in that it has the ability to reproduce through two different types of spores, conidiospores and ascospores, the products of the asexual and the sexual cycle respectively, ... | 2013 | 23395641 |
| myosin motor-like domain of class vi chitin synthase csmb of aspergillus nidulans is not functionally equivalent to that of class v chitin synthase csma. | chitin is a major cell wall component of many filamentous fungi. among the eight chitin synthase genes of aspergillus nidulans, csma and csmb encode a myosin motor-like domain (mmd) and a chitin synthase domain (csd) at their n- and c-termini respectively. in our previous reports, we suggested that csma and csmb play compensatory roles essential for polarized hyphal growth although their functions do not completely overlap, and that their mmds are essential for their functions. in the present st ... | 2013 | 23391938 |
| functional analyses of trichoderma reesei lae1 reveal conserved and contrasting roles of this regulator. | the putative methyltransferase laea is a global regulator that affects the expression of multiple secondary metabolite gene clusters in several fungi, and it can modify heterochromatin structure in aspergillus nidulans. we have recently shown that the laea ortholog of trichoderma reesei (lae1), a fungus that is an industrial producer of cellulase and hemicellulase enzymes, regulates the expression of cellulases and polysaccharide hydrolases. to learn more about the function of lae1 in t. reesei, ... | 2013 | 23390613 |
| light inhibits spore germination through phytochrome in aspergillus nidulans. | aspergillus nidulans responds to light in several aspects. the balance between sexual and asexual development as well as the amount of secondary metabolites produced is controlled by light. here, we show that germination is largely delayed by blue (450 nm), red (700 nm), and far-red light (740 nm). the largest effect was observed with far-red light. whereas 60 % of the conidia produced a germ tube after 20 h in the dark, less than 5 % of the conidia germinated under far-red light conditions. bec ... | 2013 | 23385948 |
| sr-like rna-binding protein slr1 affects candida albicans filamentation and virulence. | candida albicans causes both mucosal and disseminated infections, and its capacity to grow as both yeast and hyphae is a key virulence factor. hyphal formation is a type of polarized growth, and members of the sr (serine-arginine) family of rna-binding proteins influence polarized growth of both saccharomyces cerevisiae and aspergillus nidulans. therefore, we investigated whether sr-like proteins affect filamentous growth and virulence of c. albicans. blast searches with s. cerevisiae sr-like pr ... | 2013 | 23381995 |
| functional analysis of the α-1,3-glucan synthase genes agsa and agsb in aspergillus nidulans: agsb is the major α-1,3-glucan synthase in this fungus. | although α-1,3-glucan is one of the major cell wall polysaccharides in filamentous fungi, the physiological roles of α-1,3-glucan remain unclear. the model fungus aspergillus nidulans possesses two α-1,3-glucan synthase (ags) genes, agsa and agsb. for functional analysis of these genes, we constructed several mutant strains in a. nidulans: agsa disruption, agsb disruption, and double-disruption strains. we also constructed several cagsb strains in which agsb expression was controlled by the indu ... | 2013 | 23365684 |
| invasive pulmonary aspergillosis due to emericella nidulans var. echinulata, successfully cured by voriconazole and micafungin. | a 78-year-old male who was undergoing prolonged glucocorticoid treatment experienced cough and expectoration for 2 weeks. galactomannan antigen analysis and a chest computed tomography (ct) scan suggested a diagnosis of invasive pulmonary aspergillosis. dna sequencing indicated that emericella nidulans var. echinulata was the causative agent. a combination of voriconazole and micafungin successfully treated the illness. | 2013 | 23363828 |
| overproduction of polygalacturonase by penicillium griseoroseum recombinant strains and functional analysis by targeted disruption of the pgg2 gene. | inactivation of the pgg2 gene, a polygalacturonase-encoding gene from penicillium griseoroseum, reduced the total activity of polygalacturonase (pg) by 90 % in wild-type p. griseoroseum, which indicates that the pgg2 gene is the major gene responsible for pg production in this species. to increase pg production, the coding region of the pgg2 gene was cloned under the control of the glyceraldehyde 3-phosphate dehydrogenase (gpd) promoter and the terminator region of the tryptophan synthase (trpc) ... | 2013 | 23354503 |
| secondary metabolism and development is mediated by llmf control of vea subcellular localization in aspergillus nidulans. | secondary metabolism and development are linked in aspergillus through the conserved regulatory velvet complex composed of vea, velb, and laea. the founding member of the velvet complex, vea, shuttles between the cytoplasm and nucleus in response to alterations in light. here we describe a new interaction partner of vea identified through a reverse genetics screen looking for laea-like methyltransferases in aspergillus nidulans. one of the putative laea-like methyltransferases identified, llmf, ... | 2013 | 23341778 |
| novel sexual-cycle-specific gene silencing in aspergillus nidulans. | we report a novel sexual-cycle-specific gene-silencing system in the genetic model aspergillus nidulans. duplication of the mating type mata(hmg) gene in this haploid organism triggers mat-induced silencing (matis) of both endogenous and transgenic mata genes, eliminates function of the encoded sry structural ortholog, and results in formation of barren fruiting bodies. matis is spatiotemporally restricted to the prezygotic stage of the sexual cycle and does not interfere with vegetative growth, ... | 2013 | 23341415 |
| regulation of cellulolytic genes by mcma, the srf-mads box protein in aspergillus nidulans. | cellobiose triggers the production of two endoglucanases, egla and eglb, in aspergillus nidulans. the cellulose responsive element (cere) cis-element that is essential for induction has been identified on the egla promoter, but transcription factors that bind to cere have not yet been identified. cere contained a consensus sequence cc(a/t)6gg for binding of the srf-type mads box proteins. introduction of a missense mutation into mcma, encoding for the sole srf-mads protein in a. nidulans, caused ... | 2013 | 23337500 |
| evaluation of strategies to improve the production of alkaline protease prta from aspergillus nidulans. | aspergillus nidulans produces several proteases. the prta gene encodes a major protease, and two approaches were explored to achieve the overproduction of this enzyme. molecular cloning of the mature form of this enzyme in pichia pastoris resulted in the production of an inactive form. in addition, the presence of this enzyme was toxic for the host and resulted in cell lysis. the modification of the culture medium constituents resulted in a 6.4-fold increase in enzyme production. the main effect ... | 2013 | 23334783 |
| amdsym, a new dominant recyclable marker cassette for saccharomyces cerevisiae. | despite the large collection of selectable marker genes available for saccharomyces cerevisiae, marker availability can still present a hurdle when dozens of genetic manipulations are required. recyclable markers, counterselectable cassettes that can be removed from the targeted genome after use, are therefore valuable assets in ambitious metabolic engineering programs. in the present work, the new recyclable dominant marker cassette amdsym, formed by the ashbya gossypii tef2 promoter and termin ... | 2013 | 23253382 |
| accurate prediction of secondary metabolite gene clusters in filamentous fungi. | biosynthetic pathways of secondary metabolites from fungi are currently subject to an intense effort to elucidate the genetic basis for these compounds due to their large potential within pharmaceutics and synthetic biochemistry. the preferred method is methodical gene deletions to identify supporting enzymes for key synthases one cluster at a time. in this study, we design and apply a dna expression array for aspergillus nidulans in combination with legacy data to form a comprehensive gene expr ... | 2013 | 23248299 |
| modelling colony population growth in the filamentous fungus aspergillus nidulans. | filamentous fungi are ubiquitous in nature and have high societal significance, being both major (food-borne) pathogens and important industrial organisms in the production of antibiotics and enzymes. in addition, fungi are important model organisms for fundamental research, such as studies in genetics and evolutionary biology. however, mechanistic models for population growth that would help understand fungal biology and fundamental processes are almost entirely missing. here we present such a ... | 2013 | 23246716 |
| characterization of a tannase from emericella nidulans immobilized on ionic and covalent supports for propyl gallate synthesis. | the extracellular tannase from emericela nidulans was immobilized on different ionic and covalent supports. the derivatives obtained using deae-sepharose and q-sepharose were thermally stable from 60 to 75 °c, with a half life (t50) >24 h at 80 °c at ph 5.0. the glyoxyl-agarose and amino-glyoxyl derivatives showed a thermal stability which was lower than that observed for ionic supports. however, when the stability to ph was considered, the derivatives obtained from covalent supports were more s ... | 2013 | 23242498 |
| identification of a novel site in the tail of dynein heavy chain important for dynein function in vivo. | the minus end-directed microtubule motor cytoplasmic dynein is responsible for the intracellular movements of many organelles, including nuclei and endosomes. the dynein heavy chain contains a c-terminal motor domain and an n-terminal tail domain. the tail binds other dynein subunits and the cargo-interacting dynactin complex but is dispensable for movement of single dynein molecules in vitro. here, we identified a mutation in the aspergillus nidulans heavy chain tail domain, nuda(f208v), which ... | 2013 | 23212922 |
| involvement of protein kinase c in the suppression of apoptosis and in polarity establishment in aspergillus nidulans under conditions of heat stress. | the pkca gene, which encodes a protein kinase c (pkc) in the filamentous fungus aspergillus nidulans, is essential for its viability. however, little is known about its functions. to address this issue, we constructed and characterized temperature-sensitive mutants of pkca. the conidia of these mutants swelled slightly and exhibited apoptotic phenotypes at 42°c. the apoptotic phenotypes were suppressed by an osmotic stabilizer. under these conditions, the conidia swelled extensively and did not ... | 2012 | 23209763 |
| proteome-based profiling of hypercellulase-producing strains developed through interspecific protoplast fusion between aspergillus nidulans and aspergillus tubingensis. | thirty heterokaryons, formed by protoplast fusion of aspergillus nidulans and aspergillus tubingensis, were selected on the basis of their ability to grow on 2-deoxyglucose (0.2 %, w/v) and intermediate spore color. these heterokaryons were studied for cellulase production using shake flask and solid substrate cultures at 40 °c. fusants 51 and 28 exhibited appreciably higher levels of endoglucanase, cellobiohydrolase, β-glucosidase, and fpase activities when compared with parental strains. emplo ... | 2013 | 23197346 |
| multivariate phenotypic divergence due to the fixation of beneficial mutations in experimentally evolved lineages of a filamentous fungus. | the potential for evolutionary change is limited by the availability of genetic variation. mutations are the ultimate source of new alleles, yet there have been few experimental investigations of the role of novel mutations in multivariate phenotypic evolution. here, we evaluated the degree of multivariate phenotypic divergence observed in a long-term evolution experiment whereby replicate lineages of the filamentous fungus aspergillus nidulans were derived from a single genotype and allowed to ... | 2012 | 23185601 |
| morphological changes induced by class iii chitin synthase gene silencing could enhance penicillin production of penicillium chrysogenum. | chitin synthases catalyze the formation of β-(1,4)-glycosidic bonds between n-acetylglucosamine residues to form the unbranched polysaccharide chitin, which is the major component of cell walls in most filamentous fungi. several studies have shown that chitin synthases are structurally and functionally divergent and play crucial roles in the growth and morphogenesis of the genus aspergillus although little research on this topic has been done in penicillium chrysogenum. we used blast to find the ... | 2013 | 23179625 |
| saga complex components and acetate repression in aspergillus nidulans. | alongside the well-established carbon catabolite repression by glucose and other sugars, acetate causes repression in aspergillus nidulans. mutations in crea, encoding the transcriptional repressor involved in glucose repression, also affect acetate repression, but mutations in creb or crec, encoding components of a deubiquitination system, do not. to understand the effects of acetate, we used a mutational screen that was similar to screens that uncovered mutations in crea, creb, and crec, excep ... | 2012 | 23173087 |
| transcriptome changes initiated by carbon starvation in aspergillus nidulans. | carbon starvation is a common stress for micro-organisms both in nature and in industry. the carbon starvation stress response (cssr) involves the regulation of several important processes including programmed cell death and reproduction of fungi, secondary metabolite production and extracellular hydrolase formation. to gain insight into the physiological events of cssr, dna microarray analyses supplemented with real-time rt-pcr (rrt-pcr) experiments on 99 selected genes were performed. these da ... | 2013 | 23154970 |
| bzip transcription factors affecting secondary metabolism, sexual development and stress responses in aspergillus nidulans. | the eukaryotic basic leucine zipper (bzip) transcription factors play critical roles in the organismal response to the environment. recently, a novel yap-like bzip, restorer of secondary metabolism a (rsma), was found in a suppressor screen of an aspergillus nidulans secondary metabolism (sm) mutant in which overexpression of rsma was found to partially remediate loss of sm in velvet complex mutants. the velvet complex is a conserved fungal transcriptional heteromer that couples sm with sexual d ... | 2013 | 23154967 |
| new insights into the biosynthesis of prenylated xanthones: xptb from aspergillus nidulans catalyses an o-prenylation of xanthones. | gene-inactivation experiments have indicated that the putative prenyltransferase xptb from aspergillus nidulans was likely to be responsible for the prenylation of 1,7-dihydroxy-6-methyl-8-hydroxymethylxanthone. recently, it was suggested that this enzyme might also accept as substrate the benzophenone arugosin h, which is assumed to be a precursor of prenylated xanthones. in this study, five benzophenones and ten xanthones were incubated with purified recombinant xptb in the presence of dimethy ... | 2012 | 23150454 |
| involvement of bcvea and bcvelb in regulating conidiation, pigmentation and virulence in botrytis cinerea. | the heterotrimeric velvet complex vea/velb/laea is involved in the regulation of diverse cellular processes in aspergillus nidulans. in this work, we investigated functions of two velvet-like genes bcvea and bcvelb in botrytis cinerea. morphological characterization of bcvea and bcvelb deletion mutants showed that the deletion of bcvea and bcvelb led to increased conidiation and melanin biosynthesis. bcvea and bcvelb deletion mutants also showed increased sensitivity to oxidative stress. pathoge ... | 2013 | 23147398 |
| analysis of the structure and conformational states of dewa gives insight into the assembly of the fungal hydrophobins. | the hydrophobin dewa from the fungus aspergillus nidulans is a highly surface-active protein that spontaneously self-assembles into amphipathic monolayers at hydrophobic:hydrophilic interfaces. these monolayers are composed of fibrils that are a form of functional amyloid. while there has been significant interest in the use of dewa for a variety of surface coatings and as an emulsifier in biotechnological applications, little is understood about the structure of the protein or the mechanism of ... | 2013 | 23137797 |
| cell cycle regulation by the nek family of protein kinases. | genetic screens for cell division cycle mutants in the filamentous fungus aspergillus nidulans led to the discovery of never-in-mitosis a (nima), a serine/threonine kinase that is required for mitotic entry. since that discovery, nima-related kinases, or neks, have been identified in most eukaryotes, including humans where eleven genetically distinct proteins named nek1 to nek11 are expressed. although there is no evidence that human neks are essential for mitotic entry, it is clear that several ... | 2012 | 23132929 |
| improvement of gene targeting in aspergillus nidulans with excess non-homologous fragments. | efficiency of gene targeting was increased more than 10-fold when an excess molar ratio of non-homologous fragments was added in the transformation of aspergillus nidulans. in the targeted transformants, integration of such fragments into the host chromosome was a rare event. hence, our approach proved practical in terms of producing successful targeting events without disturbing the host chromosomes. | 2012 | 23132572 |
| microtubule-based transport in filamentous fungi. | defects in microtubule-based transport are implicated in many neuropathologies. the filamentous fungi aspergillus nidulans and ustilago maydis are valuable models for studying transport owing to their yeast-like genetic and biochemical tractability and metazoan-like dependence on microtubule-based transport for cellular trafficking. in these organisms the role of microtubules in nuclear positioning is well studied, but recent work has expanded the range of cargos to include endosomes, messenger ... | 2012 | 23127389 |
| antifungal activity of extracellular hydrolases produced by autolysing aspergillus nidulans cultures. | carbon-starving aspergillus nidulans cultures produce high activities of versatile hydrolytic enzymes and, among these, chib endochitinase and enga β-1,3-endoglucanase showed significant antifungal activity against various fungal species. double deletion of enga and chib diminished the antifungal activity of the fermentation broths and increased conidiogenesis and long-term viability of a. nidulans, but decreased the growth rate on culture media containing weak carbon sources. production of chib ... | 2012 | 23124755 |
| intracellular trehalase activity is required for development, germination and heat-stress resistance of aspergillus niger conidia. | the disaccharide trehalose is known as a stress protectant in several kinds of organisms, including fungi, where it is a major carbohydrate in resting structures, e.g. asexual conidia. the gene encoding the enzyme responsible for degradation of intracellular trehalose, treb, was deleted and the phenotype was analyzed in terms of morphology, trehalose content during conidial outgrowth and stress tolerance. the mutant conidiophores produced fewer and less viable spores, and during early stages of ... | 2013 | 23116628 |
| evidence that two pcl-like cyclins control cdk9 activity during cell differentiation in aspergillus nidulans asexual development. | cyclin-dependent protein kinases (cdks) are usually involved in cell cycle regulation. however, cdk9 is an exception and promotes rna synthesis through phosphorylation of the carboxy-terminal domain (ctd) of the largest subunit of rna polymerase ii (rnapii). the ctd is comprised of repeating heptapeptides, in which serine residues at positions 2, 5, and 7 are of crucial importance. ser5 phosphorylation causes transcription initiation and promoter escape. however, rnapii pauses 20 to 50 bp downst ... | 2013 | 23104571 |
| genetic control of asexual sporulation in filamentous fungi. | asexual sporulation (conidiation) in the ascomycetous filamentous fungi involves the formation of conidia, formed on specialized structures called conidiophores. conidiation in filamentous fungi involves many common themes including spatial and temporal regulation of gene expression, specialized cellular differentiation, intra-/inter-cellular communications, and response to environmental factors. the commencement, progression and completion of conidiation are regulated by multiple positive and n ... | 2012 | 23092920 |
| genetic analysis of the arabidopsis protein kinases map3kε1 and map3kε2 indicates roles in cell expansion and embryo development. | map3kε1 and map3kε2 are a pair of arabidopsis thaliana genes that encode protein kinases related to cdc7p from saccharomyces cerevisiae. we have previously shown that the map3kε1;map3kε2 double-mutant combination causes pollen lethality. in this study, we have used an ethanol-inducible promoter construct to rescue this lethal phenotype and create map3kε1(-/-);map3kε2(-/-) double-mutant plants in order to examine the function of these genes in the sporophyte. these rescued double-mutant plants ca ... | 2012 | 23087695 |
| a pericentrin-related protein homolog in aspergillus nidulans plays important roles in nucleus positioning and cell polarity by affecting microtubule organization. | pericentrin is a large coiled-coil protein in mammalian centrosomes that serves as a multifunctional scaffold for anchoring numerous proteins. recent studies have linked numerous human disorders with mutated or elevated levels of pericentrin, suggesting unrecognized contributions of pericentrin-related proteins to the development of these disorders. in this study, we characterized anpcpa, a putative homolog of pericentrin-related protein in the model filamentous fungus aspergillus nidulans, and ... | 2012 | 23087372 |
| enhanced enzymatic cellulose degradation by cellobiohydrolases via product removal. | product inhibition by cellobiose decreases the rate of enzymatic cellulose degradation. the optimal reaction conditions for two emericella (aspergillus) nidulans-derived cellobiohydrolases i and ii produced in pichia pastoris were identified as cbhi: 52 °c, ph 4.5-6.5, and cbhii: 46 °c, ph 4.8. the optimum in a mixture of the two was 50 °c, ph 4.9. an almost fourfold increase in enzymatic hydrolysis yield was achieved with intermittent product removal of cellobiose with membrane filtration (2 kd ... | 2013 | 23076365 |
| putative calcium channels ccha and mida play the important roles in conidiation, hyphal polarity and cell wall components in aspergillus nidulans. | although the high affinity ca(2+) channel, cch1, and its subunit mid1 have been investigated and evaluated in yeast and some of filamentous fungi, little is known about the function of their homologs in the aspergilli. here, we have functionally characterized the yeast homologs, ccha and mida, in aspergillus nidulans using conditional and null deletion mutants. ccha and mida not only have functional benefits of fast growth, which is consistent with cch1 and mid1 in yeast, but also have unique an ... | 2012 | 23071589 |
| investigation of in vivo protein interactions in aspergillus spores. | understanding in vivo protein-protein interactions is critical to dissect precise functions of the regulatory proteins of fungal secondary metabolites. as many fungi differentially produce a diverse array of secondary metabolites during their lifecycle, it is important to understand the cell-type specific regulation of secondary metabolism. however, due to the difficulty of sample preparation of biologically active proteins in fungal spores, protein-protein interaction studies have been generall ... | 2012 | 23065622 |
| identification of protein complexes from filamentous fungi with tandem affinity purification. | fungal molecular biology has benefited from the enormous advances in understanding protein-protein interactions in prokaryotic or eukaryotic organisms of the past decade. tandem affinity purification (tap) allows the enrichment of native protein complexes from cell extracts under mild conditions. we codon-optimized tags and established tap, previously not applicable to filamentous fungi, for the model organism aspergillus nidulans. we could identify by this method the trimeric velvet complex vel ... | 2012 | 23065618 |
| multi-copy genetic screen in aspergillus nidulans. | with the completion of genomes of various aspergillus species, large-scale genome-wide expression studies can be carried out. genomics, however, is more powerful and efficient when combined with genetics. a multi-copy-based gain-of-function screen is a complementary method to loss-of-function genetic screen and can identify novel genes that may not be easily identifiable through loss-of-function-type screens. particularly, gain-of-function genetic screens would identify novel activators or repre ... | 2012 | 23065617 |
| tools for manipulation of secondary metabolism pathways: rapid promoter replacements and gene deletions in aspergillus nidulans. | targeted gene deletions and promoter replacements are proving to be a valuable tool for awakening and analyzing silent secondary metabolism gene clusters in aspergillus nidulans and, as molecular genetic methods for manipulating the genomes of other fungi are developed, they will likely be as valuable in those organisms. here we describe procedures for constructing dna fragments by pcr that can be used to replace genes or promoters quickly and on a large scale. we also describe transformation pr ... | 2012 | 23065614 |
| the chemical identification and analysis of aspergillus nidulans secondary metabolites. | filamentous fungi have long been recognized to be a rich source of secondary metabolites with potential medicinal applications. the recent genomic sequencing of several aspergillus species has revealed that many secondary metabolite gene clusters are apparently silent under standard laboratory conditions. several successful approaches have been utilized to upregulate these genes and unearth the corresponding natural products. a straightforward, reliable method to purify and characterize new meta ... | 2012 | 23065610 |
| galx regulates the d-galactose oxido-reductive pathway in aspergillus niger. | galactose catabolism in aspergillus nidulans is regulated by at least two regulators, galr and galx. in aspergillus niger only galx is present, and its role in d-galactose catabolism in this fungus was investigated. phenotypic and gene expression analysis of a wild type and a galx disruptant revealed that galx regulates the d-galactose oxido-reductive pathway, but not the leloir pathway in a. niger. | 2012 | 23063944 |
| the role, interaction and regulation of the velvet regulator velb in aspergillus nidulans. | the multifunctional regulator velb physically interacts with other velvet regulators and the resulting complexes govern development and secondary metabolism in the filamentous fungus aspergillus nidulans. here, we further characterize velb's role in governing asexual development and conidiogenesis in a. nidulans. in asexual spore formation, velb deletion strains show reduced number of conidia, and decreased and delayed mrna accumulation of the key asexual regulatory genes brla, abaa, and vosa. o ... | 2012 | 23049895 |
| high abundance of serine/threonine-rich regions predicted to be hyper-o-glycosylated in the secretory proteins coded by eight fungal genomes. | o-glycosylation of secretory proteins has been found to be an important factor in fungal biology and virulence. it consists in the addition of short glycosidic chains to ser or thr residues in the protein backbone via o-glycosidic bonds. secretory proteins in fungi frequently display ser/thr rich regions that could be sites of extensive o-glycosylation. we have analyzed in silico the complete sets of putatively secretory proteins coded by eight fungal genomes (botrytis cinerea, magnaporthe grise ... | 2012 | 22994653 |
| phosphoribosyl pyrophosphate synthetase, as a suppressor of the seph mutation in aspergillus nidulans, is required for the proper timing of septation. | timely cytokinesis/septation is essential for hyphal growth and conidiation in aspergillus nidulans. genetic analyses have identified that a. nidulans has components of the septum initiation network (sin) pathway; one of these, seph, is a key player for early events during cytokinesis. however, little is known about how the seph kinase cascade is regulated by other components. here, we demonstrate that the phosphoribosyl pyrophosphate synthetase family acts antagonistically against the sin so th ... | 2012 | 22994198 |
| modeling, substrate docking, and mutational analysis identify residues essential for the function and specificity of a eukaryotic purine-cytosine ncs1 transporter. | the recent elucidation of crystal structures of a bacterial member of the ncs1 family, the mhp1 benzyl-hydantoin permease from microbacterium liquefaciens, allowed us to construct and validate a three-dimensional model of the aspergillus nidulans purine-cytosine/h(+) fcyb symporter. the model consists of 12 transmembrane α-helical, segments (tmss) and cytoplasmic n- and c-tails. a distinct core of 10 tmss is made of two intertwined inverted repeats (tms1-5 and tms6-10) that are followed by two a ... | 2012 | 22969088 |
| invasive fungal infection in chronic granulomatous disease: insights into pathogenesis and management. | invasive fungal infections (ifis) remain a major cause of death in patients with chronic granulomatous disease (cgd). we discuss the new insights into the pathogenesis, diagnosis, prevention, and management of invasive fungal infections in patients with cgd. | 2012 | 22964947 |
| ambient ph controls glycogen levels by regulating glycogen synthase gene expression in neurospora crassa. new insights into the ph signaling pathway. | glycogen is a polysaccharide widely distributed in microorganisms and animal cells and its metabolism is under intricate regulation. its accumulation in a specific situation results from the balance between glycogen synthase and glycogen phosphorylase activities that control synthesis and degradation, respectively. these enzymes are highly regulated at transcriptional and post-translational levels. the existence of a dna motif for the aspergillus nidulans ph responsive transcription factor pacc ... | 2012 | 22952943 |
| γ-tubulin plays a key role in inactivating apc/c(cdh1) at the g(1)-s boundary. | a γ-tubulin mutation in aspergillus nidulans, mipa-d159, causes failure of inactivation of the anaphase-promoting complex/cyclosome (apc/c) in interphase, resulting in failure of cyclin b (cb) accumulation and removal of nuclei from the cell cycle. we have investigated the role of cdha, the a. nidulans homologue of the apc/c activator protein cdh1, in γ-tubulin-dependent inactivation of the apc/c. cdha was not essential, but it targeted cb for destruction in g(1), and apc/c(cdha) had to be inact ... | 2012 | 22927465 |
| dna minor groove sensing and widening by the ccaat-binding complex. | the ccaat box is a frequent element of eukaryotic promoters, and its specific recognition by the conserved heterotrimeric ccaat-binding complex (cbc) constitutes a key step in promoter organization and regulation of transcription. here, we report the crystal structures of the cbc from aspergillus nidulans in the absence and in complex with double-stranded dna at 1.8 å resolution. the histone-like subunits hapc and hape induce nucleosome-like dna bending by interacting with the sugar-phosphate ba ... | 2012 | 22902862 |
| proof-of-principle for sers imaging of aspergillus nidulans hyphae using in vivo synthesis of gold nanoparticles. | high spatial resolution methods to assess the physiology of growing cells should permit analysis of fungal biochemical composition. whole colony methods cannot capture the details of physiology and organism-environment interaction, in part because the structure, function and composition of fungal hyphae vary within individual cells depending on their distance from the growing apex. surface enhanced raman scattering (sers) can provide chemical information on materials that are in close contact wi ... | 2012 | 22900260 |
| overexpression of the aspergillus nidulans histone 4 acetyltransferase esaa increases activation of secondary metabolite production. | regulation of secondary metabolite (sm) gene clusters in aspergillus nidulans has been shown to occur through cluster-specific transcription factors or through global regulators of chromatin structure such as histone methyltransferases, histone deacetylases, or the putative methyltransferase laea. a multicopy suppressor screen for genes capable of returning sm production to the sm deficient δlaea mutant resulted in identification of the essential histone acetyltransferase esaa, able to complemen ... | 2012 | 22882998 |
| induced mitotic homologous recombination by the babesicide imidocarb dipropionate in aspergillus nidulans diploid cells. | imidocarb dipropionate (imd) is a chemotherapeutic agent prescribed for the treatment and control of babesiosis; it is known to be a nucleic acid synthesis inhibitor. although it is an effective babesicide, there are reports of persistent imd residues retained at high levels in edible tissues of cattle, swine and sheep, raising concerns about potential effects on humans. since the carcinogenic potential of a chemical compound can be assessed through its effect on the homologous recombination, we ... | 2012 | 22869537 |
| cis- and trans-acting localization determinants of ph response regulator rim13 in saccharomyces cerevisiae. | the rim101/pacc pathway governs adaptation to alkaline ph in many fungi. output of the pathway is mediated by transcription factors of the rim101/pacc family, which are activated by proteolytic cleavage. the proteolytic complex includes scaffold protein rim20 and endosome-associated subunits of the endosomal sorting complex required for transport (escrt). we provide here evidence that saccharomyces cerevisiae rim13, the protease that is implicated in rim101 cleavage, is associated with the rim20 ... | 2012 | 22865500 |
| motor-driven motility of fungal nuclear pores organizes chromosomes and fosters nucleocytoplasmic transport. | exchange between the nucleus and the cytoplasm is controlled by nuclear pore complexes (npcs). in animals, npcs are anchored by the nuclear lamina, which ensures their even distribution and proper organization of chromosomes. fungi do not possess a lamina and how they arrange their chromosomes and npcs is unknown. here, we show that motor-driven motility of npcs organizes the fungal nucleus. in ustilago maydis, aspergillus nidulans, and saccharomyces cerevisiae fluorescently labeled npcs showed ... | 2012 | 22851316 |
| identification of the substrate recognition and transport pathway in a eukaryotic member of the nucleobase-ascorbate transporter (nat) family. | using the crystal structure of the uracil transporter uraa of escherichia coli, we constructed a 3d model of the aspergillus nidulans uric acid-xanthine/h(+) symporter uapa, which is a prototype member of the nucleobase-ascorbate transporter (nat) family. the model consists of 14 transmembrane segments (tmss) divided into a core and a gate domain, the later being distinctly different from that of uraa. by implementing molecular mechanics (mm) simulations and quantitative structure-activity relat ... | 2012 | 22848666 |
| identification and molecular genetic analysis of the cichorine gene cluster in aspergillus nidulans. | we recently demonstrated that the phytotoxin cichorine is produced by aspergillus nidulans. through a set of targeted deletions, we have found a cluster of seven genes that are required for its biosynthesis. two of the deletions yielded molecules that give information about the biosynthesis of this metabolite. | 2012 | 24244835 |
| vea1 is required for cleistothecial formation and virulence in histoplasma capsulatum. | histoplasma capsulatum is a pathogenic fungus dependent on dimorphism for virulence. among the four described velvet family genes, two of them, ryp2 and ryp3, have been shown to be required for dimorphism. it is known that velvet a (vea) is necessary for sexual development and toxin production in aspergillus nidulans. however, the role of the vea ortholog in h. capsulatum has not yet been explored. vea1, h. capsulatum homolog of vea, was studied to determine its role in cleistothecial formation, ... | 2012 | 22841690 |
| the aspergillus nidulans mapk module anste11-ste50-ste7-fus3 controls development and secondary metabolism. | the sexual fus3 map kinase module of yeast is highly conserved in eukaryotes and transmits external signals from the plasma membrane to the nucleus. we show here that the module of the filamentous fungus aspergillus nidulans (an) consists of the anfus3 map kinase, the upstream kinases anste7 and anste11, and the anste50 adaptor. the fungal mapk module controls the coordination of fungal development and secondary metabolite production. it lacks the membrane docking yeast ste5 scaffold homolog; bu ... | 2012 | 22829779 |
| aspergillus nidulans and chronic granulomatous disease: a unique host-pathogen interaction. | invasive fungal infections are a major threat for patients suffering from chronic granulomatous disease (cgd), a primary immunodeficiency caused by a defect in the nicotinamide adenine dinucleotide phosphate (nadph)-oxidase. interestingly, aspergillus (emericella) nidulans is the second most encountered mold in cgd patients, causing almost exclusively invasive infections in this specific host, and is characterized by its aggressive behavior. a proper diagnosis is complicated by the often mild cl ... | 2012 | 22829648 |
| increasing oxidative stress tolerance and subculturing stability of cordyceps militaris by overexpression of a glutathione peroxidase gene. | like other filamentous fungi, the medicinal ascomycete cordyceps militaris frequently degenerates during continuous maintenance in culture by showing loss of the ability to reproduce sexually or asexually. degeneration of fungal cultures has been related with cellular accumulation of reactive oxygen species (ros). in this study, an antioxidant glutathione peroxidase (gpx) gene from aspergillus nidulans was engineered into two c. militaris strains, i.e., the cm01 strain which can fruit normally a ... | 2013 | 22828981 |
| putative cell wall integrity sensor proteins in aspergillus nidulans. | the cell wall integrity (cwi) signal transduction pathway, which has been well-studied in the yeast saccharomyces cerevisiae, plays an important role in the regulation of cell wall biogenesis. recently, we characterized the cwi stress sensor orthologs wsca and wscb in the filamentous fungus aspergillus nidulans. disruption of the wsca and wscb genes causes a change in the transcriptional levels of agsa and agsb, which encode α-1,3-glucan synthase, resulting in an increase in alkaline soluble cel ... | 2012 | 22808335 |
| hydrolase controls cellular nad, sirtuin, and secondary metabolites. | cellular levels of nad(+) and nadh are thought to be controlled by de novo and salvage mechanisms, although evidence has not yet indicated that they are regulated by nad(+) degradation. here we show that the conserved nudix hydrolase isozyme ndxa hydrolyzes and decreases cellular nad(+) and nadh in aspergillus nidulans. the ndxa-deficient fungus accumulated more nad(+) during the stationary growth phase, indicating that ndxa maintains cellular nad(+)/nadh homeostasis. the deficient strain also g ... | 2012 | 22801369 |
| flbd, a myb transcription factor of aspergillus nidulans, is uniquely involved in both asexual and sexual differentiation. | in the fungus aspergillus nidulans, inactivation of the flba to -e, flug, fluf, and tmpa genes results in similar phenotypes, characterized by a delay in conidiophore and asexual spore production. flbb to -d encode transcription factors needed for proper expression of the brla gene, which is essential for asexual development. however, recent evidence indicates that flbb and flbe also have nontranscriptional functions. here we show that fluf1 is an allele of flbd which results in an r47p substitu ... | 2012 | 22798393 |
| comprehensive analysis of the dna-binding specificity of an aspergillus nidulans transcription factor, amyr, using a bead display system. | the in vitro dna binding profile of aspergillus nidulans transcription factor amyr was analyzed by a novel approach employing a genetic library of beads and flow cytometry analysis. an artificial library with 22 randomized nucleotides was constructed and subjected to a protein-dna binding reaction with male-tagged amyr. dna fragments with potential amyr-binding sites were labeled with fluorescence-conjugated antibody to be enriched by flow cytometry through 5 rounds of successive selection. fina ... | 2012 | 22790934 |
| vea-dependent rna-pol ii transcription elongation factor-like protein, rtfa, is associated with secondary metabolism and morphological development in aspergillus nidulans. | in aspergillus nidulans the global regulatory gene vea is necessary for the biosynthesis of several secondary metabolites, including the mycotoxin sterigmatocystin (st). in order to identify additional vea-dependent genetic elements involved in regulating st production, we performed a mutagenesis on a deletion vea (δvea) strain to obtain revertant mutants (rm) that regained the capability to produce toxin. genetic analysis and molecular characterization of one of the revertant mutants, rm3, reve ... | 2012 | 22783880 |
| ph response pathways in fungi: adapting to host-derived and environmental signals. | microorganisms are significantly affected when the ambient ph of their environment changes. they must therefore be able to sense and respond to these changes in order to survive. previous investigators have studied various fungal species to define conserved ph-responsive signaling pathways. one of these pathways, known as the pal/rim pathway, is activated in response to alkaline ph signals, ultimately targeting the pacc/rim101 transcription factor. although the central signaling components are c ... | 2011 | 22783112 |
| product patterns of a feruloyl esterase from aspergillus nidulans on large feruloyl-arabino-xylo-oligosaccharides from wheat bran. | a purified feruloyl esterase (ec 3.1.1.73) from aspergillus nidulans produced in pichia pastoris was used to study the de-esterification of large feruloyl oligosaccharides consisting of 4 to 20 pentose residues and (xylose plus arabinose) and one ferulic acid residue. the feruloyl oligosaccharides were prepared from total oligosaccharidic hydrolysates from wheat bran treated with a purified endoxylanase from thermobacillus xylanilyticus. the feruloyl esterase showed similar specific activity but ... | 2012 | 22770893 |
| mutations in the basic loop of the zn binuclear cluster of the uay transcriptional activator suppress mutations in the dimerisation domain. | uay is the specific znii(2)cys(6) transcriptional activator of the purine utilisation pathway in aspergillus nidulans. previous work has determined the consensus binding sequence by emsa and foot-printing. we determine here that it binds as a dimer to its cognate cgg-n(6)-ccg sites. we identify the uay109 mutation, which has been shown to affect differentially the expression of a number of uay-regulated genes, as a f112i substitution in the dna-binding motif dimerisation domain. we isolated back ... | 2012 | 22760060 |
| model and test in a fungus of the probability that beneficial mutations survive drift. | determining the probability of fixation of beneficial mutations is critically important for building predictive models of adaptive evolution. despite considerable theoretical work, models of fixation probability have stood untested for nearly a century. however, recent advances in experimental and theoretical techniques permit the development of models with testable predictions. we developed a new model for the probability of surviving genetic drift, a major component of fixation probability, fo ... | 2013 | 22740642 |
| alanine scanning mutagenesis of a high-affinity nitrate transporter highlights the requirement for glycine and asparagine residues in the two nitrate signature motifs. | common to all of the nitrate nitrite porter family are two conserved motifs in transmembrane helices 5 and 11 termed ns (nitrate signature) 1 and ns2. although perfectly conserved substrate-interacting arginine residues have been described in transmembrane helices 2 and 8, the role of nss has not been investigated. in the present study, a combination of structural modelling of nrta (nitrate transporter from aspergillus nidulans) with alanine scanning mutagenesis of residues within and around the ... | 2012 | 22738143 |
| genetic and biosynthetic studies of the fungal prenylated xanthone shamixanthone and related metabolites in aspergillus spp. revisited. | biosynthetic genes for the prenylated xanthone shamixanthone have been identified in the aspergillus nidulans genome; based on assignment of putative functions from sequence analyses and selected gene deletions, a pathway was proposed leading from the anthraquinone emodin via the benzophenone carboxylic acid monodictyphenone and the xanthone emericellin to shamixanthone. several aspects of this proposed pathway are inconsistent with previously identified biosynthetic intermediates: the anthraqui ... | 2012 | 22730213 |
| lae1 regulates expression of multiple secondary metabolite gene clusters in fusarium verticillioides. | the filamentous fungus fusarium verticillioides can cause disease of maize and is capable of producing fumonisins, a family of toxic secondary metabolites linked to esophageal cancer and neural tube defects in humans and lung edema in swine and leukoencephalomalacia in equines. the expression of fumonisin biosynthetic genes is influenced by broad-domain transcription factors (global regulators) and fum21, a pathway-specific transcription factor. laea is a global regulator that in aspergillus nid ... | 2012 | 22713715 |
| fgvelb is associated with vegetative differentiation, secondary metabolism and virulence in fusarium graminearum. | the velvet complex containing vea, velb and laea has been showed to play critical roles in the regulation of secondary metabolism and diverse cellular processes in aspergillus spp. in this study, we identified fgvelb, a homolog of aspergillus nidulans velb, from fusarium graminearum using the blastp program. disruption of fgvelb gene led to several phenotypic defects, including suppression of aerial hyphae formation, reduced hyphal hydrophobicity and highly increased conidiation. the mutant show ... | 2012 | 22713714 |