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fgflbd regulates hyphal differentiation required for sexual and asexual reproduction in the ascomycete fungus fusarium graminearum.fusarium graminearum is a filamentous fungal plant pathogen that infects major cereal crops. the fungus produces both sexual and asexual spores in order to endure unfavorable environmental conditions and increase their numbers and distribution across plants. in a model filamentous fungus, aspergillus nidulans, early induction of conidiogenesis is orchestrated by the fluffy genes. the objectives of this study were to characterize fluffy gene homologs involved in conidiogenesis and their mechanism ...201425277408
gbf/gea mutant with a single substitution sustains fungal growth in the absence of big/sec7.golgi arf1-guanine nucleotide exchange factors (gefs) belong to two subfamilies: gbf/gea and big/sec7. both are conserved across eukaryotes, but the physiological role of each is not well understood. aspergillus nidulans has a single member of the early golgi gbf/gea-subfamily, geaa, and the late golgi big/sec7-subfamily, hypb. both geaa and hypb are essential. hypb5 conditionally blocks secretion. we sought extragenic hypb5 suppressors and obtained geaa1. geaa1 results in tyr1022cys within a co ...201425451223
trpac1, a ph response transcription regulator, is involved in cellulase gene expression in trichoderma reesei.fungi grow over a relatively wide ph range and adapt to extracellular ph through a genetic regulatory system mediated by a key component pacc, which is a ph transcription regulator. the cellulase production of the filamentous fungi trichoderma reesei is sensitive to ambient ph. to investigate the connection between cellulase expression regulation and ambient ph, an ortholog of aspergillus nidulans pacc, trpac1, was identified and functionally characterized using a target gene deletion strategy. ...201425442944
liaison alcaline: pals entice non-endosomal escrts to the plasma membrane for ph signaling.the alkaline ph-responsive pal/rim signal transduction pathway mediating regulation of gene expression by ambient ph has been extensively studied in aspergillus nidulans and saccharomyces cerevisiae. in a. nidulans, palh, pali, palf, palc, pala and palb are required for the proteolytic activation of the executing transcription factor pacc. although necessary, pal proteins are insufficient to transmit the signal, which additionally requires escrt-i, ii and vps20 with snf7 in escrt-iii. although t ...201425460796
crystallization and preliminary x-ray crystallographic analysis of ribosome assembly factors: the rpf2-rrs1 complex.rpf2 and rrs1 are essential proteins for ribosome biogenesis. these proteins form a complex (the rpf2-subcomplex) with 5s rrna and two ribosomal proteins (l5 and l11). this complex is recruited to the ribosome precursor (the 90s pre-ribosome). this recruitment is necessary for the maturation of 25s rrna. genetic depletion of rpf2 and rrs1 results in accumulation of the 25s rrna precursor. in this study, rpf2 and rrs1 from aspergillus nidulans were co-overexpressed in escherichia coli, purified a ...201425484219
nitrogen regulation of fungal secondary metabolism in fungi.fungi occupy diverse environments where they are constantly challenged by stressors such as extreme ph, temperature, uv exposure, and nutrient deprivation. nitrogen is an essential requirement for growth, and the ability to metabolize a wide variety of nitrogen sources enables fungi to colonize different environmental niches and survive nutrient limitations. favored nitrogen sources, particularly ammonium and glutamine, are used preferentially, while the expression of genes required for the use ...201425506342
standardization of functional reporter and antibiotic resistance cassettes to facilitate the genetic engineering of filamentous fungi.the unique physiological properties of fungi are useful for a myriad of applications, which could greatly benefit from increased control of native pathways and introduction of recombinant genes. however, fungal genetic engineering is still limited in scope and accessibility, largely due to lack of standardization. to help standardize the genetic engineering of filamentous fungi, we created biobricks of commonly used antibiotic resistance genes, neomycin phosphotransferase (nptii) and hygromycin ...201425524098
gene homozygosis and mitotic recombination induced by camptothecin and irinotecan in aspergillus nidulans diploid cells.mitotic recombination is a process involved in carcinogenesis which can lead to genetic loss through the loss of heterozygosity. the recombinogenic potentials of two anticancer drugs topoisomerase i inhibitors, camptothecin (cpt) and irinotecan (cpt-11), were evaluated in the present study. the homozygotization assay, which assess the induction of mitotic recombination and gene homozygosis, as well as the heterozygous a757//ut448 diploid strain of aspergillus nidulans were employed. the three no ...201425590709
sporadic distribution of prion-forming ability of sup35p from yeasts and fungi.sup35p of saccharomyces cerevisiae can form the [psi+] prion, an infectious amyloid in which the protein is largely inactive. the part of sup35p that forms the amyloid is the region normally involved in control of mrna turnover. the formation of [psi+] by sup35p's from other yeasts has been interpreted to imply that the prion-forming ability of sup35p is conserved in evolution, and thus of survival/fitness/evolutionary value to these organisms. we surveyed a larger number of yeast and fungal spe ...201425081567
genome mining and functional genomics for siderophore production in aspergillus niger.iron is an essential metal for many organisms, but the biologically relevant form of iron is scarce because of rapid oxidation resulting in low solubility. simultaneously, excessive accumulation of iron is toxic. consequently, iron uptake is a highly controlled process. in most fungal species, siderophores play a central role in iron handling. siderophores are small iron-specific chelators that can be secreted to scavenge environmental iron or bind intracellular iron with high affinity. a second ...201425062661
isolation and identification of aspergillus spp. from brown kiwi (apteryx mantelli) nocturnal houses in new zealand.aspergillosis, a disease caused by infection with aspergillus spp., is a common cause of death in birds globally and is an irregular cause of mortality of captive kiwi (apteryx spp.). aspergillus spp. are often present in rotting plant material, including the litter and nesting material used for kiwi in captivity. the aim of this study was to survey nocturnal kiwi houses in new zealand to assess the levels of aspergillus currently present in leaf litter. samples were received from 11 nocturnal k ...201424758108
aspergillus nidulans cell wall composition and function change in response to hosting several aspergillus fumigatus udp-galactopyranose mutase activity mutants.deletion or repression of aspergillus nidulans ugma (anugma), involved in galactofuranose biosynthesis, impairs growth and increases sensitivity to caspofungin, a β-1,3-glucan synthesis antagonist. the a. fumigatus ugma (afugma) crystal structure has been determined. from that study, afugma mutants with altered enzyme activity were transformed into anugma▵ to assess their effect on growth and wall composition in a. nidulans. the complemented (anugma::wild type afugma) strain had wild type phenot ...201424454924
the aspergillus genome database: multispecies curation and incorporation of rna-seq data to improve structural gene annotations.the aspergillus genome database (aspgd; http://www.aspgd.org) is a freely available web-based resource that was designed for aspergillus researchers and is also a valuable source of information for the entire fungal research community. in addition to being a repository and central point of access to genome, transcriptome and polymorphism data, aspgd hosts a comprehensive comparative genomics toolbox that facilitates the exploration of precomputed orthologs among the 20 currently available asperg ...201424194595
conserved and varied dinucleotide sequences in the genomes of three aspergillus species.both guanine-cytosine content and nucleosome occupancy are higher in exons than in introns. in this study, the association between the frequencies of the dinucleotide sequences and the nucleosome occupancy of the exons and introns of the genes of aspergillus fumigatus, aspergillus nidulans, and aspergillus oryzae was studied. the frequency of the dinucleotide sequences aa (tt), at, and ta in the introns was more than that in the exons. in addition, the frequency of these sequences in the regions ...201425564023
heterologous expression of gaeumannomyces graminis lipoxygenase in aspergillus nidulans.aspergillus sp. contain ppo genes coding for ppo enzymes that produce oxylipins from polyunsaturated fatty acids. these oxylipins function as signal molecules in sporulation and influence the asexual to sexual ratio of aspergillus sp. fungi like aspergillus nidulans and aspergillus niger contain just ppo genes where the human pathogenic aspergillus flavus and aspergillus fumigatus contain ppo genes as well as lipoxygenases. lipoxygenases catalyze the synthesis of oxylipins and are hypothesized t ...201425401068
aspergillus fumigatus and related species.the genus aspergillus contains etiologic agents of aspergillosis. the clinical manifestations of the disease range from allergic reaction to invasive pulmonary infection. among the pathogenic aspergilli, aspergillus fumigatus is most ubiquitous in the environment and is the major cause of the disease, followed by aspergillus flavus, aspergillus niger, aspergillus terreus, aspergillus nidulans, and several species in the section fumigati that morphologically resemble a. fumigatus. patients that a ...201425377144
cytotoxic and antifungal activities of melleolide antibiotics follow dissimilar structure-activity relationships.the fungal genus armillaria is unique in that it is the only natural source of melleolide antibiotics, i.e., protoilludene alcohols esterified with orsellinic acid or its derivatives. this class of natural products is known to exert antimicrobial and cytotoxic effects. here, we present a refined relationship between the structure and the antimicrobial activity of the melleolides. using both agar diffusion and broth dilution assays, we identified the δ(2,4)-double bond of the protoilludene moiety ...201424906293
aspergillosis of bones and joints - a review from 2002 until today.poor clinical outcome and complicated neurological complications illustrate the severity of bone and joint infections with aspergillus species. host predisposing conditions are immunosuppression, intravenous drug use, a variety of chronic underlying diseases and prior surgical interventions. nosocomial infections may originate from contaminated air ventilation systems or water pipes. most common causative pathogen is aspergillus fumigatus, followed by aspergillus flavus and aspergillus nidulans. ...201424397460
osteomyelitis caused by aspergillus species: a review of 310 reported cases.aspergillus osteomyelitis is a rare infection. we reviewed 310 individual cases reported in the literature from 1936 to 2013. the median age of patients was 43 years (range, 0-86 years), and 59% were males. comorbidities associated with this infection included chronic granulomatous disease (19%), haematological malignancies (11%), transplantation (11%), diabetes (6%), pulmonary disease (4%), steroid therapy (4%), and human immunodeficiency virus infection (4%). sites of infection included the sp ...201424303995
understanding transporter specificity and the discrete appearance of channel-like gating domains in transporters.transporters are ubiquitous proteins mediating the translocation of solutes across cell membranes, a biological process involved in nutrition, signaling, neurotransmission, cell communication and drug uptake or efflux. similarly to enzymes, most transporters have a single substrate binding-site and thus their activity follows michaelis-menten kinetics. substrate binding elicits a series of structural changes, which produce a transporter conformer open toward the side opposite to the one from whe ...201425309439
alternaria alternata transcription factor cmra controls melanization and spore development.melanin is a black pigment widely distributed across the kingdoms, from bacterial to human. the filamentous fungus alternaria alternata is a typical 'black fungus', which produces melanin in its hyphal and especially its asexual spore cell walls. its biosynthesis follows the dihydroxynaphthalene (dhn) pathway with 1,8-dhn as an intermediate. two genes, encoding a polyketide synthase (pksa) and a 1,3,8-trihydroxynaphthalene (thn) reductase (brm2), along with a putative transcription factor, cmra, ...201424972701
targeting fungal genes by diced sirnas: a rapid tool to decipher gene function in aspergillus nidulans.gene silencing triggered by chemically synthesized small interfering rnas (sirnas) has become a powerful tool for deciphering gene function in many eukaryotes. however, prediction and validation of a single sirna duplex specific to a target gene is often ineffective. rna interference (rnai) with synthetic sirna suffers from lower silencing efficacy, off-target effects and is cost-intensive, especially for functional genomic studies. with the explosion of fungal genomic information, there is an i ...201324130711
arabidopsis and brachypodium distachyon transgenic plants expressing aspergillus nidulans acetylesterases have decreased degree of polysaccharide acetylation and increased resistance to pathogens.the plant cell wall has many significant structural and physiological roles, but the contributions of the various components to these roles remain unclear. modification of cell wall properties can affect key agronomic traits such as disease resistance and plant growth. the plant cell wall is composed of diverse polysaccharides often decorated with methyl, acetyl, and feruloyl groups linked to the sugar subunits. in this study, we examined the effect of perturbing cell wall acetylation by making ...201323463782
aspergillus flavus velb acts distinctly from vea in conidiation and may coordinate with flug to modulate sclerotial production.the proteins vea, velb and laea of aspergillus nidulans form a heterotrimeric complex (the velvet complex) in the dark to coordinate sexual development and production of some secondary metabolites. vea and velb of a. nidulans and aspergillus fumigatus also are repressors of conidiation, but vea of aspergillus flavus in studied strains acts positively on conidiation. in the present study, we show via yeast-two hybrid assays that interactions among a. flavus vea, velb, and laea are conserved as in ...201323994319
determination of isavuconazole susceptibility of aspergillus and candida species by the eucast method.isavuconazole is a novel expanded-spectrum triazole, which has recently been approved by the fda as an orphan drug to treat invasive aspergillosis and is currently being studied in phase iii clinical trials for invasive candidiasis. the susceptibility of relatively few clinical isolates has been reported. in this study, the isavuconazole susceptibilities of 1,237 aspergillus and 2,010 candida geographically diverse clinical isolates were determined by eucast methodology at four european mycology ...201323959309
genome-wide analysis of the zn(ii)₂cys₆ zinc cluster-encoding gene family in aspergillus flavus.proteins with a zn(ii)₂cys₆ domain, cys-x₂-cys-x₆-cys-x₅₋₁₂-cys-x₂-cys-x₆₋₉-cys (hereafter, referred to as the c6 domain), form a subclass of zinc finger proteins found exclusively in fungi and yeast. genome sequence databases of saccharomyces cerevisiae and candida albicans have provided an overview of this family of genes. annotation of this gene family in most fungal genomes is still far from perfect and refined bioinformatic algorithms are urgently needed. aspergillus flavus is a saprophytic ...201323563886
investigation of the antimicrobial effect of neosartorya fischeri antifungal protein (nfap) after heterologous expression in aspergillus nidulans.neosartorya fischeri antifungal protein (nfap) is a β-defensin-like peptide produced by the n. fischeri nrrl 181 isolate. in this study, we investigated the manifestation of the antimicrobial effect of nfap via heterologous expression of the nfap gene in an nfap-sensitive fungus, aspergillus nidulans. heterologous expression of the nfap gene was carried out in a. nidulans cs2902 using a pama1-based autonomous replicative vector construct. the effect of the produced nfap on the germination of a. ...201323197172
bioaugmented composting of jatropha de-oiled cake and vegetable waste under aerobic and partial anaerobic conditions.this study was conducted to assess the effect of microbial inoculation in jatropha cake composting with different vegetable waste. the microbial inoculums composed of fungal strains (aspergillus awamori, aspergillus nidulans, trichoderma viride, phanerochaete chrysosporium) and bacterial inoculums (pseudomonas striata as phosphorus solublizer and azotobacter chroococcum as nitrogen fixer) were added to the compost mixture after the thermophilic phase was over for bioaugmenting of jatropha cake u ...201322736484
aspergillus collagen-like genes (acl): identification, sequence polymorphism, and assessment for pcr-based pathogen detection.the genus aspergillus is a burden to public health due to its ubiquitous presence in the environment, its production of allergens, and wide demographic susceptibility among cystic fibrosis, asthmatic, and immunosuppressed patients. current methods of detection of aspergillus colonization and infection rely on lengthy morphological characterization or nonstandardized serological assays that are restricted to identifying a fungal etiology. collagen-like genes have been shown to exhibit species-spe ...201324123732
gfsa encodes a novel galactofuranosyltransferase involved in biosynthesis of galactofuranose antigen of o-glycan in aspergillus nidulans and aspergillus fumigatus.the cells walls of filamentous fungi in the genus aspergillus have galactofuranose (galf)-containing polysaccharides and glycoconjugates, including o-glycans, n-glycans, fungal-type galactomannan and glycosylinositolphosphoceramide, which are important for cell wall integrity. here, we attempted to identify galactofuranosyltransferases that couple galf monomers onto other wall components in aspergillus nidulans. using reverse-genetic and biochemical approaches, we identified that the an8677 gene ...201324118544
gβ-like cpcb plays a crucial role for growth and development of aspergillus nidulans and aspergillus fumigatus.growth, development, virulence and secondary metabolism in fungi are governed by heterotrimeric g proteins (g proteins). a gβ-like protein called gib2 has been shown to function as an atypical gβ in gpa1-camp signaling in cryptococcus neoformans. we found that the previously reported cpcb (cross pathway control b) protein is the ortholog of gib2 in aspergillus nidulans and aspergillus fumigatus. in this report, we further characterize the roles of cpcb in governing growth, development and toxige ...201323936193
discovery of cryptic polyketide metabolites from dermatophytes using heterologous expression in aspergillus nidulans.dermatophytes belonging to the trichophyton and arthroderma genera cause skin infections in humans and animals. from genome sequencing data, we mined a conserved gene cluster among dermatophytes that are homologous to one that produces an immunosuppressive polyketide in aspergillus fumigatus. using a recombination-based cloning strategy in yeast, we constructed fungal heterologous expression vectors that encode the cryptic clusters. when integrated into the model aspergillus nidulans host, a str ...201323758576
genetic and structural validation of aspergillus fumigatus udp-n-acetylglucosamine pyrophosphorylase as an antifungal target.the sugar nucleotide udp-n-acetylglucosamine (udp-glcnac) is an essential metabolite in both prokaryotes and eukaryotes. in fungi, it is the precursor for the synthesis of chitin, an essential component of the fungal cell wall. udp-n-acetylglucosamine pyrophosphorylase (uap) is the final enzyme in eukaryotic udp-glcnac biosynthesis, converting utp and n-acetylglucosamine-1-phosphate (glcnac-1p) to udp-glcnac. as such, this enzyme may provide an attractive target against pathogenic fungi. here, w ...201323750903
multicenter study of isavuconazole mic distributions and epidemiological cutoff values for aspergillus spp. for the clsi m38-a2 broth microdilution method.epidemiological cutoff values (ecvs) were established for the new triazole isavuconazole and aspergillus species wild-type (wt) mic distributions (organisms in a species-drug combination with no detectable acquired resistance mechanisms) that were defined with 855 aspergillus fumigatus, 444 a. flavus, 106 a. nidulans, 207 a. niger, 384 a. terreus, and 75 a. versicolor species complex isolates; 22 aspergillus section usti isolates were also included. clsi broth microdilution mic data gathered in ...201323716059
rsma regulates aspergillus fumigatus gliotoxin cluster metabolites including cyclo(l-phe-l-ser), a potential new diagnostic marker for invasive aspergillosis.dimeric basic leucine zipper (bzip) proteins are conserved transcriptional enhancers found in all eukaryotes. a recently reported and novel function for bzips is association of these proteins with secondary metabolite production in filamentous fungi. in particular a yap-like bzip termed rsma (restorer of secondary metabolism a) was identified in aspergillus nidulans that positively regulates the carcinogen sterigmatocystin. to assess for conserved function for rsma, we examined a role of this pr ...201323671611
invasive fungal infections in patients with chronic granulomatous disease.invasive fungal infections are a major threat for chronic granulomatous disease (cgd) patients. the present study provides a comprehensive overview of published invasive fungal infections in the cgd host through an extensive review of epidemiological, clinical, diagnostic and therapeutic data. in addition to the often mild clinical presentation, the currently used diagnostics for invasive aspergillosis have low sensitivity in cgd patients and cannot be easily translated to this non-neutropenic h ...201323654055
loss of ccla, required for histone 3 lysine 4 methylation, decreases growth but increases secondary metabolite production in aspergillus fumigatus.secondary metabolite (sm) production in filamentous fungi is mechanistically associated with chromatin remodeling of specific sm clusters. one locus recently shown to be involved in sm suppression in aspergillus nidulans was ccla, a member of the histone 3 lysine 4 methylating compass complex. here we examine loss of ccla and a putative h3k4 demethylase, hdma, in the human pathogen aspergillus fumigatus. although deletion of hdma showed no phenotype under the conditions tested, the ccla deletant ...201323638376
light sensing in aspergillus fumigatus highlights the case for establishing new models for fungal photobiology.microbes inhabit diverse environmental locations, and many species need to shift their physiology between different niches. to do this effectively requires the accurate sensing of and response to the environment. for pathogens, exposure to light is one major change between a free-living saprophyte lifestyle and causation of disease within the host. however, how light may act as a signal to influence pathogenesis, on the side of either the host or the pathogen, is poorly understood. research duri ...201323631920
fungal siderophore biosynthesis is partially localized in peroxisomes.siderophores play a central role in iron metabolism and virulence of most fungi. both aspergillus fumigatus and aspergillus nidulans excrete the siderophore triacetylfusarinine c (tafc) for iron acquisition. in a. fumigatus, green fluorescence protein-tagging revealed peroxisomal localization of the tafc biosynthetic enzymes sidi (mevalonyl-coa ligase), sidh (mevalonyl-coa hydratase) and sidf (anhydromevalonyl-coa transferase), while elimination of the peroxisomal targeting signal (pts) impaired ...201323617799
chloroquine modulates the fungal immune response in phagocytic cells from patients with chronic granulomatous disease.invasive aspergillosis is a major threat to patients with chronic granulomatous disease (cgd). fungal pathogenesis is the result of a diminished antifungal capacity and dysregulated inflammation. a deficient nadph-oxidase complex results in defective phagolysosomal alkalization. to investigate the contribution of defective ph regulation in phagocytes among patients with cgd during fungal pathogenesis, we evaluated the effect of the acidotropic, antimalarial drug chloroquine (cq) on the antifunga ...201323482646
partial reconstruction of the ergot alkaloid pathway by heterologous gene expression in aspergillus nidulans.ergot alkaloids are pharmaceutically and agriculturally important secondary metabolites produced by several species of fungi. ergot alkaloid pathways vary among different fungal lineages, but the pathway intermediate chanoclavine-i is evolutionarily conserved among ergot alkaloid producers. at least four genes, dmaw, easf, ease, and easc, are necessary for pathway steps prior to chanoclavine-i; however, the sufficiency of these genes for chanoclavine-i synthesis has not been established. a fragm ...201323435153
characterization of the major woronin body protein hexa of the human pathogenic mold aspergillus fumigatus.in filamentous fungi, the septal pore controls the exchange between neighbouring hyphal compartments. woronin bodies are fungal-specific organelles that plug the pore in case of physical damage. the hex protein is their major and essential component. hex proteins of different size are predicted in the data base for pathogenic and non-pathogenic aspergillus species. however, using specific monoclonal antibodies, we identified 2 dominant hexa protein species of 20 and 25kda in a. fumigatus, a. ter ...201323332467
inhibition of nitric oxide and tumour necrosis factor-α production in peritoneal macrophages by aspergillus nidulans melanin.the naturally occurring pigment, melanin is found in organisms of all phylogenetic kingdoms, including fungi, and exhibits a wide range of biological activities. our objective was to investigate the effects of melanin extracted from the fungus aspergillus nidulans on the production of the pro-inflammatory mediators nitric oxide (no) and tumour necrosis factor-α (tnf-α) in peritoneal macrophages and on the viability of mccoy mouse fibroblasts. the results showed that a. nidulans melanin did not s ...201324432378
sensitivity of aspergillus nidulans to the cellulose synthase inhibitor dichlobenil: insights from wall-related genes' expression and ultrastructural hyphal morphologies.the fungal cell wall constitutes an important target for the development of antifungal drugs, because of its central role in morphogenesis, development and determination of fungal-specific molecular features. fungal walls are characterized by a network of interconnected glycoproteins and polysaccharides, namely α-, β-glucans and chitin. cell walls promptly and dynamically respond to environmental stimuli by a signaling mechanism, which triggers, among other responses, modulations in wall biosynt ...201324312197
intestinal retransplant in a patient after fungal sepsis: considerations and issues.an adolescent female received an isolated intestinal transplant. she developed severe exfoliative rejection and required complete enterectomy. the patient developed a septic hip and lung lesions with biopsy-proven aspergillus nidulans and was treated with caspofungin, ambiosome, and voriconizole. after completing a year of treatment and extensive physical therapy, the patient requested retransplant. the case was presented to the ethics committee, which determined that the patient demonstrated un ...201324311401
a p53-like transcription factor similar to ndt80 controls the response to nutrient stress in the filamentous fungus, aspergillus nidulans.the aspergillus nidulans xprg gene encodes a putative transcriptional activator that is a member of the ndt80 family in the p53-like superfamily of proteins. previous studies have shown that xprg controls the production of extracellular proteases in response to starvation. we undertook transcriptional profiling to investigate whether xprg has a wider role as a global regulator of the carbon nutrient stress response. our microarray data showed that the expression of a large number of genes, inclu ...201324358888
assessing the effects of light on differentiation and virulence of the plant pathogen botrytis cinerea: characterization of the white collar complex.organisms are exposed to a tough environment, where acute daily challenges, like light, can strongly affect several aspects of an individual's physiology, including pathogenesis. while several fungal models have been widely employed to understand the physiological and molecular events associated with light perception, various other agricultural-relevant fungi still remain, in terms of their responsiveness to light, in the dark. the fungus botrytis cinerea is an aggressive pathogen able to cause ...201324391918
a putative apses transcription factor is necessary for normal growth and development of aspergillus nidulans.the nsdd gene encoding a gata type transcription factor positively controls sexual development in aspergillus nidulans. according to microarray data, 20 genes that were upregulated by deleting nsdd during various life cycle stages were randomly selected and deleted for functional analysis. none of the mutants showed apparent changes in growth or development compared with those of the wild-type except the an3154 gene that encodes a putative apses transcription factor and is an ortholog of sacchar ...201324385358
development of a pyrg mutant of aspergillus oryzae strain s1 as a host for the production of heterologous proteins.the ease with which auxotrophic strains and genes that complement them can be manipulated, as well as the stability of auxotrophic selection systems, are amongst the advantages of using auxotrophic markers to produce heterologous proteins. most auxotrophic markers in aspergillus oryzae originate from chemical or physical mutagenesis that may yield undesirable mutations along with the mutation of interest. an auxotrophic a. oryzae strain s1 was generated by deleting the orotidine-5'-monophosphate ...201324381522
cytoplasmic dynamics of the general nuclear import machinery in apically growing syncytial cells.karyopherins are transporters involved in the bidirectional, selective and active transport of macromolecules through nuclear pores. importin-β1 is the paradigm of karyopherins and, together with its cargo-adapter importin-α, mediates the general nuclear import pathway. here we show the existence of different cellular pools of both importin-α and -β1 homologues, kapa and kapb, in the coenocytic ascomycete aspergillus nidulans. fluorescence analysis of haploid and diploid strains expressing kapb: ...201324376868
an acidic thermostable recombinant aspergillus nidulans endoglucanase is active towards distinct agriculture residues.aspergillus nidulans is poorly exploited as a source of enzymes for lignocellulosic residues degradation for biotechnological purposes. this work describes the a. nidulans endoglucanase a heterologous expression in pichia pastoris, the purification and biochemical characterization of the recombinant enzyme. active recombinant endoglucanase a (reg a) was efficiently secreted as a 35 kda protein which was purified through a two-step chromatography procedure. the highest enzyme activity was detecte ...201323936633
light regulation on growth, development, and secondary metabolism of marine-derived filamentous fungi.effects of different light conditions on development, growth, and secondary metabolism of three marine-derived filamentous fungi were investigated. darkness irritated sexual development of aspergillus glaucus hb1-19, while white, red, and blue lights improved its asexual behavior. the red and blue lights improved asexual stroma formation of xylaria sp. (no. 2508), but the darkness and white light inhibited it. differently, development of halorosellinia sp. (no. 1403) turned out to be insensitive ...201323546832
current understanding of hog-mapk pathway in aspergillus fumigatus.aspergillus fumigatus is an important opportunistic fungal pathogen that causes lethal systemic invasive aspergillosis. it must be able to adapt to stress in the microenvironment during host invasion and systemic spread. the high-osmolarity glycerol (hog) mitogen-activated protein kinase (mapk) signaling pathway is a key element that controls adaptation to environmental stress. it plays a critical role in the virulence of several fungal pathogens. in this review, we summarize the current knowled ...201323161019
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.201327275003
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 ...201323532849
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 ...201323516554
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 ...201323505451
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 ...201323490137
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 ...201323485399
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 ...201323480775
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 ...201323472095
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 ...201323458440
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 ...201323456608
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 ...201323454548
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 ...201323434416
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 ...201323408908
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, ...201323395641
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 ...201323391938
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, ...201323390613
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 ...201323385948
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 ...201323381995
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 ...201323365684
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.201323363828
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) ...201323354503
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, ...201323341778
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, ...201323341415
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 ...201323337500
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 ...201323334783
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 ...201323253382
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 ...201323248299
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 ...201323246716
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 ...201323242498
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 ...201323212922
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 ...201323076365
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 ...201323197346
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 ...201323179625
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 ...201323147398
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 ...201323137797
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 ...201323116628
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 ...201323104571
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 ...201323154970
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 ...201323154967
stabilizing the heterologously expressed uric acid-xanthine transporter uapa from the lower eukaryote aspergillus nidulans.despite detailed genetic and mutagenic analysis and a recent high-resolution structure of a bacterial member of the nucleobase-ascorbate transporter (nat) family, understanding of the mechanism of action of eukaryotic nats is limited. preliminary studies successfully expressed and purified wild-type uapa to high homogeneity; however, the protein was extremely unstable, degrading almost completely after 48 h at 4°c. in an attempt to increase uapa stability we generated a number of single point mu ...201322694048
distinct amino acids of histone h3 control secondary metabolism in aspergillus nidulans.chromatin remodelling events play an important role in the secondary metabolism of filamentous fungi. previously, we showed that a bacterium, streptomyces rapamycinicus, is able to reprogram the histone-modifying spt-ada-gcn5-acetyltransferase/ada (saga/ada) complex of the model fungus aspergillus nidulans. consequently, the histone h3 amino acids lysine 9 and lysine 14 at distinct secondary metabolism genes were specifically acetylated during the bacterial fungal interaction, which, furthermore ...201323892751
aniquinazolines a-d, four new quinazolinone alkaloids from marine-derived endophytic fungus aspergillus nidulans.four new quinazolinone alkaloids, namely, aniquinazolines a-d (1-4), were isolated and identified from the culture of aspergillus nidulans ma-143, an endophytic fungus obtained from the leaves of marine mangrove plant rhizophora stylosa. the structures of the new compounds were elucidated by spectroscopic analysis, and their absolute configurations were determined on the basis of chiral hplc analysis of the acidic hydrolysates. the structure for 1 was confirmed by single-crystal x-ray diffractio ...201323880937
new interfacial microtubule inhibitors of marine origin, pm050489/pm060184, with potent antitumor activity and a distinct mechanism.we have investigated the target and mechanism of action of a new family of cytotoxic small molecules of marine origin. pm050489 and its dechlorinated analogue pm060184 inhibit the growth of relevant cancer cell lines at subnanomolar concentrations. we found that they are highly potent microtubule inhibitors that impair mitosis with a distinct molecular mechanism. they bind with nanomolar affinity to unassembled αβ-tubulin dimers, and pm050489 binding is inhibited by known vinca domain ligands. n ...201323859655
deleterious effects of recombination and possible nonrecombinatorial advantages of sex in a fungal model.why sexual reproduction is so prevalent in nature remains a major question in evolutionary biology. most of the proposed advantages of sex rely on the benefits obtained from recombination. however, it is still unclear whether the conditions under which these recombinatorial benefits would be sufficient to maintain sex in the short term are met in nature. our study addresses a largely overlooked hypothesis, proposing that sex could be maintained in the short term by advantages due to functions li ...201323848947
vea and mvla repression of the cryptic orsellinic acid gene cluster in aspergillus nidulans involves histone 3 acetylation.a perplexing aspect of fungal secondary metabolite gene clusters is that most clusters remain 'silent' under common laboratory growth conditions where activation is obtained through gene manipulation or encounters with environmental signals. few proteins have been found involved in repression of silent clusters. through multicopy suppressor mutagenesis, we have identified a novel cluster suppressor in aspergillus nidulans, mvla (modulator of vea loss). genetic assessment of mvla mutants revealed ...201323841751
rrma regulates the stability of specific transcripts in response to both nitrogen source and oxidative stress.differential regulation of transcript stability is an effective means by which an organism can modulate gene expression. a well-characterized example is glutamine signalled degradation of specific transcripts in aspergillus nidulans. in the case of area, which encodes a wide-domain transcription factor mediating nitrogen metabolite repression, the signal is mediated through a highly conserved region of the 3' utr. utilizing this rna sequence we isolated rrma, an rna recognition motif protein. di ...201323841692
role of the zinc finger transcription factor slta in morphogenesis and sterigmatocystin biosynthesis in the fungus aspergillus nidulans.potassium, a widely accepted macronutrient, is vital for many physiological processes such as regulation of cell volume, maintenance of intracellular ph, synthesis of proteins and activation of enzymes in filamentous fungi. another cation, calcium, plays an essential role in many signaling processes from lower to higher eukaryotes. imbalance in the intracellular ionic levels of potassium or calcium causes adverse effects on cell growth, morphology and development, and eventually death. previous ...201323840895
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