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illuminating the diversity of aromatic polyketide synthases in aspergillus nidulans.genome sequencing has revealed that fungi have the ability to synthesize many more natural products (nps) than are currently known, but methods for obtaining suitable expression of nps have been inadequate. we have developed a successful strategy that bypasses normal regulatory mechanisms. by efficient gene targeting, we have replaced, en masse, the promoters of nonreducing polyketide synthase (nr-pks) genes, key genes in np biosynthetic pathways, and other genes necessary for nr-pks product for ...201222510154
identification and characterization of a novel diterpene gene cluster in aspergillus nidulans.fungal secondary metabolites are a rich source of medically useful compounds due to their pharmaceutical and toxic properties. sequencing of fungal genomes has revealed numerous secondary metabolite gene clusters, yet products of many of these biosynthetic pathways are unknown since the expression of the clustered genes usually remains silent in normal laboratory conditions. therefore, to discover new metabolites, it is important to find ways to induce the expression of genes in these otherwise ...201222506079
reprogramming of carbon metabolism by the transcriptional activators acuk and acum in aspergillus nidulans.the ability of fungi to use carbon sources metabolized via the tca cycle requires gluconeogenesis. in aspergillus nidulans the acuk and acum transcription factors regulate the expression of the gluconeogenic genes acuf, encoding phosphoenolpyruvate carboxykinase, and acug, encoding fructose-1,6-bisphosphatase. expressed proteins containing the acuk/acum n-terminal dna-binding domains bind together in vitro to motifs containing repeats of cgg separated by seven bases (ccgn7ccg) and the functional ...201222500966
functional and phylogenetic analysis of the aspergillus ochraceoroseus aflq (orda) gene ortholog.within the aspergillus parasiticus and a. flavus aflatoxin (af) biosynthetic gene cluster the aflq (orda) and aflp (omta) genes encode respectively an oxidoreductase and methyltransferase. these genes are required for the final steps in the conversion of sterigmatocystin (st) to aflatoxin b(1) (afb(1)). aspergillus nidulans harbors a gene cluster that produces st, as the aflq and aflp orthologs are either non-functional or absent in the genome. aspergillus ochraceoroseus produces both af and st, ...201222495451
aspergillus nidulans ckia is an essential casein kinase i required for delivery of amino acid transporters to the plasma membrane.type i casein kinases are highly conserved among eukaryotes. of the two aspergillus nidulans casein kinases i, ckia is related to the δ/ε mammalian kinases and to saccharomyces cerevisiae hrr25p. ckia is essential. three recessive ckia mutations leading to single residue substitutions, and downregulation using a repressible promoter, result in partial loss-of-function, which leads to a pleiotropic defect in amino acid utilization and resistance to toxic amino acid analogues. these phenotypes cor ...201222489878
allergens/antigens, toxins and polyketides of important aspergillus species.the medical, agricultural and biotechnological importance of the primitive eukaryotic microorganisms, the fungi was recognized way back in 1920. among various groups of fungi, the aspergillus species are studied in great detail using advances in genomics and proteomics to unravel biological and molecular mechanisms in these fungi. aspergillus fumigatus, aspergillus flavus, aspergillus niger, aspergillus parasiticus, aspergillus nidulans and aspergillus terreus are some of the important species r ...201122468035
endosomal maturation by rab conversion in aspergillus nidulans is coupled to dynein-mediated basipetal movement.we exploit the ease with which highly motile early endosomes are distinguished from static late endosomes in order to study aspergillus nidulans endosomal traffic. rabs(rab7) mediates homotypic fusion of late endosomes/vacuoles in a homotypic fusion- and vacuole protein sorting/vps41-dependent manner. progression across the endocytic pathway involves endosomal maturation because the end products of the pathway in the absence of rabs(rab7) are minivacuoles that are competent in multivesicular bod ...201222456509
[application of pcr combined with reverse line blot assay in detection and identification of common pathogenic aspergillus in fungal sinusitis].to evaluate the feasibility of pcr/reverse line blot hybridization (rlb) assay in the detection and identification of clinical pathogens in fungal sinusitis (fs).201222455842
methods for identifying lipoxygenase producing microorganisms on agar plates.plate assays for lipoxygenase producing microorganisms on agar plates have been developed. both potassium iodide-starch and indamine dye formation methods were effective for detecting soybean lipoxygenase activity on agar plates. a positive result was also achieved using the β-carotene bleaching method, but the sensitivity of this method was lower than the other two methods. the potassium iodide-starch and indamine dye formation methods were also applied for detecting lipoxygenase production by ...201222449314
fungal sensitivity to and enzymatic deglycosylation of ginsenosides.a ginseng pathogen, cylindrocarpon destructans, and five nonpathogens were tested for their sensitivity to a total ginsenoside fraction (t-gf), a protopanaxadiol-type ginsenoside fraction (ppd-gf) and a protopanaxatriol-type ginsenoside fraction (ppt-gf) from the roots of panax ginseng c.a. meyer. the results showed that t-gf inhibited growth of the five ginseng nonpathogens, while it promoted growth of the ginseng pathogen c. destructans. ppt-gf and ppd-gf both inhibited the growth of the five ...201222449289
identification of a permease gene involved in lactose utilisation in aspergillus nidulans.lactose is intracellularly hydrolysed by aspergillus nidulans. classical mutation mapping data and the physical characteristics of the previously purified glycosyl hydrolase facilitated identification of the clustered, divergently transcribed intracellular β-galactosidase (bgad) and lactose permease (lacpa) genes. at the transcript level, bgad and lacpa were coordinately expressed in response to d-galactose, lactose or l-arabinose, while no transcription was detectable in the additional presence ...201222445777
pcr detection of aflatoxin producing fungi and its limitations.unlike bacterial toxins that are primarily peptides and are therefore encoded by a single gene, fungal toxins such as the aflatoxins are multi-ring structures and therefore require a sequence of structural genes for their biological synthesis. there is therefore no specific pcr for any one of the four biologically produced aflatoxins. unfortunately, the structural genes presently in use for pcr detection of aflatoxin producing fungi are also involved in the synthesis of other fungal toxins such ...201222445201
gliotoxin effects on fungal growth: mechanisms and exploitation.although initially investigated for its antifungal properties, little is actually known about the effect of gliotoxin on aspergillus fumigatus and other fungi. we have observed that exposure of a. fumigatus to exogenous gliotoxin (14 μg/ml), under gliotoxin-limited growth conditions, results in significant alteration of the expression of 27 proteins (up- and down-regulated >1.9-fold; p<0.05) including de novo expression of cu, zn superoxide dismutase, up-regulated allergen asp f3 expression and ...201222405895
transient and multivariate system for transformation of a fungal plant pathogen, rosellinia necatrix, using autonomously replicating vectors.rosellinia necatrix is a fungus that infects a wide range of host plants and ruins a variety of commercially important crops. dna fragments can be introduced into r. necatrix using conventional protoplast-peg transformation and genome-integrating vectors; however, transformation efficiency with this strategy is quite low. therefore, to establish a more effective transformation system for the studies of r. necatrix, an autonomously replicating vector was constructed using ama1 sequences derived f ...201222388868
improved biomass saccharification by trichoderma reesei through heterologous expression of laca gene from trametes sp. ah28-2.the trametes sp. ah28-2 laccase gene laca fused to cellobiohydrolase i signal peptide coding sequence was heterologously expressed in t. reesei. the laca cdna was under the control of the aspergillus nidulans glyceraldehyde-3-phosphate dehydrogenase promoter. native page analysis indicated that two transformants, l8 and l38, were able to secrete recombinant laccase a, and their laccase activities corresponding to abts oxidation reached 3.62 iuml(-1) and 1.50 iuml(-1) respectively. most of the ch ...201222387233
pali domain proteins of saccharomyces cerevisiae and candida albicans.the rim9/pali groups of proteins are members of the sur7 family, all of which contain a signal sequence and a block of three potential trans-membrane helices. multi-protein sequence comparisons among fungi suggest that there are two classes of rim9/pali proteins; longer proteins like pali that contain a sur7 domain and a c-terminal extension, and shorter proteins like rim9 that contain essentially only the sur7 domain. we have examined possible roles of the longer, pali-like proteins of both sac ...201222381911
xlnr-independent signaling pathway regulates both cellulase and xylanase genes in response to cellobiose in aspergillus aculeatus.the expression levels of the cellulase and xylanase genes between the host strain and an xlnr disruptant were compared by quantitative rt-pcr (qpcr) to identify the genes controlled by xlnr-independent signaling pathway. the cellulose induction of the fi-carboxymethyl cellulase (cmc1) and fib-xylanase (xynib) genes was controlled by xlnr; in contrast, the cellulose induction of the fiii-avicelase (cbhi), fii-carboxymethyl cellulase (cmc2), and fia-xylanase (xynia) genes was controlled by an xlnr ...201222371227
physiological characterization of recombinant saccharomyces cerevisiae expressing the aspergillus nidulans phosphoketolase pathway: validation of activity through 13c-based metabolic flux analysis.several bacterial species and filamentous fungi utilize the phosphoketolase pathway (phk) for glucose dissimilation as an alternative to the embden-meyerhof-parnas pathway. in aspergillus nidulans, the utilization of this metabolic pathway leads to increased carbon flow towards acetate and acetyl coa. in the first step of the phk, the pentose phosphate pathway intermediate xylulose-5-phosphate is converted into acetylphosphate and glyceraldehyde-3-phosphate through the action of xylulose-5-phosp ...201222367611
the aspergillus nidulans kinesin-3 tail is necessary and sufficient to recognize modified microtubules.posttranslational microtubule modifications (ptms) are numerous; however, the biochemical and cell biological roles of those modifications remain mostly an enigma. the aspergillus nidulans kinesin-3 unca uses preferably modified microtubules (mts) as tracks for vesicle transportation. here, we show that a positively charged region in the tail of unca (amino acids 1316 to 1402) is necessary for the recognition of modified mts. chimeric proteins composed of the kinesin-1 motor domain and the unca ...201222363525
disinfection efficacy of chlorine and peracetic acid alone or in combination against aspergillus spp. and candida albicans in drinking water.the aim of the present study was to evaluate the fungicidal activity of chlorine and peracetic acid in drinking water against various pathogenic aspergillus spp. and candida albicans strains. a. nidulans exhibited the greatest resistance, requiring 10 ppm of chlorine for 30 min contact time for a complete inactivation. under the same experimental conditions, peracetic acid was even less fungicidal. in this case, a. niger proved to be the most resistant species (50 ppm for 60 min for complete ina ...201222361698
the functions of myosin ii and myosin v homologs in tip growth and septation in aspergillus nidulans.because of the industrial and medical importance of members of the fungal genus aspergillus, there is considerable interest in the functions of cytoskeletal components in growth and secretion in these organisms. we have analyzed the genome of aspergillus nidulans and found that there are two previously unstudied myosin genes, a myosin ii homolog, myob (product = myob) and a myosin v homolog, myoe (product = myoe). deletions of either cause significant growth defects. myob localizes in strings th ...201222359575
l-rhamnose induction of aspergillus nidulans α-l-rhamnosidase genes is glucose repressed via a crea-independent mechanism acting at the level of inducer uptake.little is known about the structure and regulation of fungal α-l-rhamnosidase genes despite increasing interest in the biotechnological potential of the enzymes that they encode. whilst the paradigmatic filamentous fungus aspergillus nidulans growing on l-rhamnose produces an α-l-rhamnosidase suitable for oenological applications, at least eight genes encoding putative α-l-rhamnosidases have been found in its genome. in the current work we have identified the gene (rhae) encoding the former acti ...201222353731
effects of sterigmatocystin on tnf-α, il-6 and il-12 expression in murine peripheral blood mononuclear cells and peritoneal macrophages in vivo.sterigmatocystin (st) is a toxic metabolite mainly produced by the fungi aspergillus nidulans and aspergillus versicolor. st is considered a potent carcinogen, mutagen and teratogen. however, over the past few years, it has been demonstrated that it is less acutely toxic to rodents in vivo. in this study, we evaluated the putative effects of st on the expression of tumor necrosis factor-α (tnf-α), interleukin (il)-6 and il-12 at mrna levels in murine peripheral blood mononuclear cells (mpbmcs) a ...201222344519
an ordered pathway for the assembly of fungal escrt-containing ambient ph signalling complexes at the plasma membrane.the fungal pal/rim signalling pathway, which regulates gene expression in response to environmental ph involves, in addition to dedicated proteins, several components of escrt complexes, which suggested that ph signalling proteins assemble on endosomal platforms. in aspergillus nidulans, dedicated pal proteins include the plasma membrane receptor palh and its coupled arrestin, palf, which becomes ubiquitylated in alkaline ph conditions, and three potentially endosomal escrt-iii associates, inclu ...201222344261
the cop9 signalosome counteracts the accumulation of cullin scf ubiquitin e3 ring ligases during fungal development.defects in the cop9 signalosome (csn) impair multicellular development, including embryonic plant or animal death or a block in sexual development of the fungus aspergillus nidulans. csn deneddylates cullin-ring ligases (crls), which are activated by covalent linkage to ubiquitin-like nedd8. deneddylation allows crl disassembly for subsequent reassembly. an attractive hypothesis is a consecutive order of crls for development, which demands repeated cycles of neddylation and deneddylation for rea ...201222329854
the role of flotillin floa and stomatin stoa in the maintenance of apical sterol-rich membrane domains and polarity in the filamentous fungus aspergillus nidulans.apical sterol-rich plasma membrane domains (srds), which can be viewed using the sterol-binding fluorescent dye filipin, are gaining attention for their important roles in polarized growth of filamentous fungi. the microdomain scaffolding protein flotillin/reggie and related stomatin were thought to be good candidates involved in the formation of srds. here, we show that the flotillin/reggie orthologue floa tagged with gfp localized as stable dots along the plasma membrane except hyphal tips. de ...201222329814
two separate gene clusters encode the biosynthetic pathway for the meroterpenoids austinol and dehydroaustinol in aspergillus nidulans.meroterpenoids are a class of fungal natural products that are produced from polyketide and terpenoid precursors. an understanding of meroterpenoid biosynthesis at the genetic level should facilitate engineering of second-generation molecules and increasing production of first-generation compounds. the filamentous fungus aspergillus nidulans has previously been found to produce two meroterpenoids, austinol and dehydroaustinol. using targeted deletions that we created, we have determined that, su ...201222329759
persistence versus escape: aspergillus terreus and aspergillus fumigatus employ different strategies during interactions with macrophages.invasive bronchopulmonary aspergillosis (ibpa) is a life-threatening disease in immunocompromised patients. although aspergillus terreus is frequently found in the environment, a. fumigatus is by far the main cause of ibpa. however, once a. terreus establishes infection in the host, disease is as fatal as a. fumigatus infections. thus, we hypothesized that the initial steps of disease establishment might be fundamentally different between these two species. since alveolar macrophages represent o ...201222319619
differential expression of silent polyketide biosynthesis gene clusters in chemostat cultures of aspergillus nidulans.the genome of the fungal model organism aspergillus nidulans harbors nearly 30 polyketide synthase genes, yet the majority of these genes remain silent in the absence of particular stimuli. in this study, environmental conditions such as low specific microbial growth rate as well as nitrate, orthophosphate and glucose limitations were simulated under a continuous cultivation regime to induce the expression of silent polyketide synthase genes. in addition to offline and online bioprocess paramete ...201222306112
genomic characteristics comparisons of 12 food-related filamentous fungi in trna gene set, codon usage and amino acid composition.filamentous fungi are widely exploited in food industry due to their abilities to secrete large amounts of enzymes and metabolites. the recent availability of fungal genome sequences has provided an opportunity to explore the genomic characteristics of these food-related filamentous fungi. in this paper, we selected 12 representative filamentous fungi in the areas of food processing and safety, which were aspergillus clavatus, a. flavus, a. fumigatus, a. nidulans, a. niger, a. oryzae, a. terreus ...201222305983
the gata factors area and areb together with the co-repressor nmra, negatively regulate arginine catabolism in aspergillus nidulans in response to nitrogen and carbon source.the filamentous fungus aspergillus nidulans can utilize arginine both as a nitrogen and carbon source. analysis of area and areb single and double mutants has shown that the two gata transcription factors area and areb negatively regulate the expression of arginine catabolism genes agaa and otaa under nitrogen repressing conditions. area is necessary for the ammonium repression of agaa and otaa under carbon repressing conditions, while areb is involved under carbon-limiting conditions. the abili ...201222300944
reengineering an azaphilone biosynthesis pathway in aspergillus nidulans to create lipoxygenase inhibitors.sclerotiorin, an azaphilone polyketide, is a bioactive natural product known to inhibit 15-lipoxygenase and many other biological targets. to readily access sclerotiorin and analogs, we developed a 2-3 step semisynthetic route to produce a variety of azaphilones starting from an advanced, putative azaphilone intermediate (5) overproduced by an engineered strain of aspergillus nidulans. the inhibitory activities of the semisynthetic azaphilones against 15-lipoxygenase were evaluated with several ...201222296232
effects of laea deletion on aspergillus flavus conidial development and hydrophobicity may contribute to loss of aflatoxin production.laea of aspergillus nidulans is a putative methyltransferase and a component of the velvet complex; it is thought to mainly affect expression of genes required for the production of secondary metabolites. we found that although aspergillus flavus ca14 laea deletion mutants showed no aflatoxin production, expression of some of the early genes involved in aflatoxin formation, but not the later genes, could still be detected. the mutants grown in minimal medium supplemented with simple sugars and o ...201122289775
an aspergillus nidulans bzip response pathway hardwired for defensive secondary metabolism operates through aflr.the eukaryotic bzip transcription factors are critical players in organismal response to environmental challenges. in fungi, the production of secondary metabolites (sms) is hypothesized as one of the responses to environmental insults, e.g. attack by fungivorous insects, yet little data to support this hypothesis exists. here we establish a mechanism of bzip regulation of sms through rsma, a recently discovered yap-like bzip protein. rsma greatly increases sm production by binding to two sites ...201222283524
functional analysis of fara transcription factor in the regulation of the genes encoding lipolytic enzymes and hydrophobic surface binding protein for the degradation of biodegradable plastics in aspergillus oryzae.fara is a zn(ii)(2)cys(6) transcription factor which upregulates genes required for growth on fatty acids in filamentous fungi like aspergillus nidulans. fara is also highly similar to the cutinase transcription factor ctf1α of fusarium solani which binds to the cutinase gene promoter in this plant pathogen. this study determines whether fara transcriptional factor also works in the regulation of genes responsible for the production of cutinase for the degradation of a biodegradable plastic, pol ...201222280964
comparison and characterization of α-amylase inducers in aspergillus nidulans based on nuclear localization of amyr.amyr, a fungal transcriptional activator responsible for induction of amylolytic genes in aspergillus nidulans, localizes to the nucleus in response to the physiological inducer isomaltose. maltose, kojibiose, and d: -glucose were also found to trigger the nuclear localization of gfp-amyr. isomaltose- and kojibiose-triggered nuclear localization was not inhibited by the glucosidase inhibitor, castanospermine, while maltose-triggered localization was inhibited. thus, maltose itself does not appea ...201222252265
the septin aspb in aspergillus nidulans forms bars and filaments and plays roles in growth emergence and conidiation.in yeast, septins form rings at the mother-bud neck and function as diffusion barriers. in animals, septins form filaments that can colocalize with other cytoskeletal elements. in the filamentous fungus aspergillus nidulans there are five septin genes, aspa (ortholog of s. cerevisiae cdc11), aspb (ortholog of s. cerevisiae cdc3), aspc (ortholog of s. cerevisiae cdc12), aspd (ortholog of s. cerevisiae cdc10), and aspe (found only in filamentous fungi). the aspb gene was previously reported to be ...201222247265
ancut2, an extracellular cutinase from aspergillus nidulans induced by olive oil.cutinases are versatile carboxylic ester hydrolases with great potential in many biocatalytic processes, including biodiesel production. genome sequence analysis of the model organism aspergillus nidulans reveals four genes encoding putative cutinases. in this work, we purified and identified for the first time a cutinase (ancut2) produced by a. nidulans. ancut2 is a 29-kda protein which consists of 255 amino acid residues. comparison of the amino acid sequence of ancut2 with other microbial cut ...201222238011
signaling the induction of sporulation involves the interaction of two secondary metabolites in aspergillus nidulans.when growing aspergillus nidulans hyphae encounter the atmosphere, they initiate a morphogenetic program leading to the production of spores. mutants that are defective in the flug gene fail to undergo sporulation because they lack an endogenous diffusible factor that purportedly accumulates on aerial hyphae, thus signaling the initiation of development. in this study, the defect could be reversed by adding culture extracts from a wild-type strain onto a mutant colony. moreover, a bioassay-guide ...201222234162
functional characterization and oligomerization of a recombinant xyloglucan-specific endo-β-1,4-glucanase (gh12) from aspergillus niveus.xyloglucan is a major structural polysaccharide of the primary (growing) cell wall of higher plants. it consists of a cellulosic backbone (beta-1,4-linked glucosyl residues) that is frequently substituted with side chains. this report describes aspergillus nidulans strain a773 recombinant secretion of a dimeric xyloglucan-specific endo-β-1,4-glucanohydrolase (xega) cloned from aspergillus niveus. the orf of the a. niveus xega gene is comprised of 714 nucleotides, and encodes a 238 amino acid pro ...201122230786
the vea gene of the pine needle pathogen dothistroma septosporum regulates sporulation and secondary metabolism.fungi possess genetic systems to regulate the expression of genes involved in complex processes such as development and secondary metabolite biosynthesis. the product of the velvet gene vea, first identified and characterized in aspergillus nidulans, is a key player in the regulation of both of these processes. since its discovery and characterization in many aspergillus species, vea has been found to have similar functions in other fungi, including the dothideomycete mycosphaerella graminicola. ...201122227160
expression and characterization of an endo-1,4-β-galactanase from emericella nidulans in pichia pastoris for enzymatic design of potentially prebiotic oligosaccharides from potato galactans.potato pulp is a high-volume side-stream from industrial potato starch manufacturing. enzymatically solubilized β-1,4-galactan-rich potato pulp polysaccharides of molecular weights >100 kda (sppp) are highly bifidogenic in human fecal sample fermentations in vitro. the objective of the present study was to use potato β-1,4-galactan and the sppp as substrates for enzymatic production of potentially prebiotic compounds of lower and narrower molecular weight. a novel endo-1,4-β-galactanase from eme ...201122226198
AreA controls nitrogen source utilisation during both growth programs of the dimorphic fungus Penicillium marneffei.The opportunistic pathogen Penicillium marneffei displays a temperature-dependent dimorphic switching program with saprophytic hyphal growth at 25 °C and yeast growth at 37 °C. The areA gene of P. marneffei has been isolated and found to be required for the utilisation of nonpreferred nitrogen sources during both growth programs of P. marneffei, albeit to differing degrees. Based on this functional characterisation and high degree of sequence conservation with other fungal GATA factors, P. marne ...201222208609
Isolation and characterization of self-fertile suppressors from the sterile nsdD deletion mutant of Aspergillus nidulans.To identify downstream and/or interactive factors of the nsdD gene, which encodes a positive regulator of sexual development of Aspergillus nidulans, suppressor mutants displaying a self-fertile phenotype were isolated from a sterile nsdD deletion mutant. At least five different loci (sndA-E) were identified and genetically analyzed. In the nsdD (+) background, most of the suppressors showed a marked increment of sexual development, even under the stress conditions that n ...201122203574
studies on differential nuclear translocation mechanism and assembly of the three subunits of the arabidopsis thaliana transcription factor nf-y.the eukaryotic transcription factor nf-y consists of three subunits (a, b, and c), which are encoded in arabidopsis thaliana in multigene families consisting of 10, 13, and 13 genes, respectively. in principle, all potential combinations of the subunits are possible for the assembly of the heterotrimeric complex. we aimed at assessing the probability of each subunit to participate in the assembly of nf-y. the evaluation of physical interactions among all members of the nf-y subunit families indi ...201122199235
Aspergillus Myosin-v supports polarized growth in the absence of microtubule-based transport.In the filamentous fungus Aspergillus nidulans, both microtubules and actin filaments are important for polarized growth at the hyphal tip. Less clear is how different microtubule-based and actin-based motors work together to support this growth. Here we examined the role of myosin-V (MYOV) in hyphal growth. MYOV-depleted cells form elongated hyphae, but the rate of hyphal elongation is significantly reduced. In addition, although wild type cells without microtubules still undergo polarized grow ...201122194856
conserved and specific responses to hypoxia in aspergillus oryzae and aspergillus nidulans determined by comparative transcriptomics.hypoxia imposes stress on filamentous fungi that require oxygen to proliferate. global transcription analysis of aspergillus oryzae grown under hypoxic conditions found that the expression of about 50% of 4,244 affected genes was either induced or repressed more than 2-fold. a comparison of these genes with the hypoxically regulated genes of aspergillus nidulans based on their predicted amino acid sequences classified them as bi-directional best hit (bbh), one-way best hit (extra homolog, eh), a ...201122170104
structural analysis of fungal cerebrosides.of the ceramide monohexosides (cmhs), gluco- and galactosyl-ceramides are the main neutral glycosphingolipids expressed in fungal cells. their structural determination is greatly dependent on the use of mass spectrometric techniques, including fast atom bombardment-mass spectrometry, electrospray ionization, and energy collision-induced dissociation mass spectrometry. nuclear magnetic resonance has also been used successfully. such a combination of techniques, combined with classical analytical ...201122164155
Cloning and Expression of Hemicellulases from Aspergillus nidulans in Pichia pastoris.The methylotrophic yeast Pichia pastoris is increasingly used for heterologous expression of high quality proteins in laboratory-scale (milligram) quantities. Commercially available polysaccharide-active enzyme preparations have limited applications in plant cell wall research due to their heterogeneous mix of hydrolytic activities. P. pastoris provides an ideal in vitro expression system for producing monocomponent enzymes, since it lacks endogenous plant cell wall-active enzymes and can perfor ...201222160911
identification of the galactitol dehydrogenase, ladb, that is part of the oxido-reductive d-galactose catabolic pathway in aspergillus niger.for the catabolism of d-galactose three different metabolic pathways have been described in filamentous fungi. apart from the leloir pathway and the oxidative pathway, there is an alternative oxido-reductive pathway. this oxido-reductive pathway has similarities to the metabolic pathway of l-arabinose, and in trichoderma reesei (hypocrea jecorina) and aspergillus nidulans the same enzyme is employed for the oxidation of l-arabitol and galactitol. here we show evidence that in aspergillus nigerl- ...201122155165
engineering hydrophobin dewa to generate surfaces that enhance adhesion of human but not bacterial cells.hydrophobins are fungal proteins with the ability to form immunologically inert membranes of high stability, properties that makes them attractive candidates for orthopaedic implant coatings. cell adhesion on the surface of such implants is necessary for better integration with the neighbouring tissue; however, hydrophobin surfaces do not mediate cell adhesion. the aim of this project was therefore to investigate whether the class i hydrophobin dewa from aspergillus nidulans can be functionalize ...201122154865
Critical cellulase and hemicellulase activities for hydrolysis of ionic liquid pretreated biomass.Critical cellulase and hemicellulase activities are identified for hydrolysis of ionic liquid (IL) pretreated poplar and switchgrass; hemicellulase rich substrates with largely amorphous cellulose. Enzymes from Aspergillus nidulans were expressed and purified: an endoglucanase (EG) a cellobiohydrolase (CBH), an endoxylanase (EX) and an acetylxylan esterase (AXE). ß-Xylosidase (ßX) from Selenomonas ruminantium and a commercial ß-glucosidase (ßG) from Novozyme 188 were admixed with the A. nidulans ...201222154300
molecular characterization of the aspergillus nidulans fbxa encoding an f-box protein involved in xylanase induction.the filamentous fungus aspergillus nidulans has been used as a fungal model system to study the regulation of xylanase production. these genes are activated at transcriptional level by the master regulator the transcriptional factor xlnr and repressed by carbon catabolite repression (ccr) mediated by the wide-domain repressor crea. here, we screened a collection of 42 a. nidulans f-box deletion mutants grown either in xylose or xylan as the single carbon source in the presence of the glucose ana ...201122142781
the polo-like kinase plka in aspergillus nidulans is not essential, but plays important roles during vegetative growth and development.the polo-like kinases (plks) are conserved, multi-functional cell cycle regulators that are induced in many forms of cancer, and play additional roles in metazoan development. we previously identified plka in aspergillus nidulans, the only plk investigated in filamentous fungi to date, and partially characterized its function through overexpression. here, we report the plka null phenotype. surprisingly, plka was not essential, unlike plks in other organisms that contain a single homologue. a sub ...201122140227
rescue of aspergillus nidulans severely debilitating null mutations in escrt-0, i, ii and iii genes by inactivation of a salt-tolerance pathway allows examination of escrt gene roles in ph signalling.the aspergillus pal pathway hijacks escrt proteins into ambient ph signalling complexes. we show that components of escrt-0, escrt-i, escrt-ii and escrt-iii are nearly essential for growth, precluding assessment of null mutants for ph signalling or trafficking. this severely debilitating effect is rescued by loss-of-function mutations in two cation tolerance genes, one of which, slta, encodes a transcription factor whose inactivation promotes hypervacuolation. exploiting a conditional expression ...201122135362
the anisin1 gene encodes a defensin-like protein and supports the fitness of aspergillus nidulans.in the genome of aspergillus nidulans, a defensin-like protein, anisin1, was annotated with high homology to the mosquito defensin aadefa1. so far, no studies exist on defensins from filamentous ascomycetes. therefore, we characterized the anisin1 gene in a. nidulans and generated a deletion mutant, which suffered from a defect in mitospore development and produced less conidia at 42°c compared to the reference strain. in surface cultures of a. nidulans wild type, the anisin1 expression correlat ...201122113351
constitutive expression, purification and characterization of a phosphoglucomutase from fusarium oxysporum.the phosphoglucomutase gene from a wild type fusarium oxysporum strain (f3), was homologously expressed, under the control of the constitutive promoter of gpda of aspergillus nidulans. the transformant produced elevated levels of phosphoglucomutase activity compared to the wild type, a fact that facilitated the subsequent purification procedure. the enzyme (fopgm) was purified to homogeneity applying three anion exchange and one gel filtration chromatography steps. the native enzyme revealed a m ...201122112903
definition and characterization of enzymes for maximal biocatalytic solubilization of prebiotic polysaccharides from potato pulp.potato pulp is a high-volume co-processing product resulting from industrial potato starch manufacturing. potato pulp is particularly rich in pectin, notably galactan branched rhamnogalacturonan i polysaccharides, which are highly bifidogenic when solubilized. the objective of the present study was to characterize and compare four homogalacturonan degrading enzymes capable of catalyzing the required solubilization of these pectinaceous polysaccharides from potato pulp in a 1 min reaction. an add ...201122112514
A strong promoter, PMagpd, provides a tool for high gene expression in entomopathogenic fungus, Metarhizium acridum.A glyceraldehyde-3-phosphate dehydrogenase gene (gpd) promoter (PMagpd) was obtained from Metarhizium acridum and its active region analyzed by 5'-deletion strategy using ß-glucuronidase (GUS) as a reporter. Sequence analysis revealed that typical regulatory elements of PMagpd were included in the 1.7 kb region upstream of the start codon of the Magpd gene. Deletion of the region from -1,691 bp to -1,463 bp, where the gpd box is harbored, did not significantly affect the PMagpd activity. Deletio ...201122109936
in vivo roles of the basic domain of dynactin p150 in microtubule plus-end tracking and dynein function.microtubule (mt) plus-end-tracking proteins accumulate at mt plus ends for various cellular functions, but their targeting mechanisms are not fully understood (akhmanova a and steinmetz mo. tracking the ends: a dynamic protein network controls the fate of microtubule tips. nat rev mol cell biol 2008;9:309-322.). here, we tested in the filamentous fungus aspergillus nidulans the requirement for plus-end localization of dynactin p150, a protein essential for dynein function. deletion of the n-term ...201122106867
association between indoor fungi in delhi homes and sensitization in children with respiratory allergy.indoor fungi are potential sensitizing agents in children and their detection and quantification in indoor air are important in the diagnosis and environmental management of fungal allergies. the objective of this investigation was to assess the prevalence of fungal allergies in children in delhi and to study the association between mold counts in the homes of children and their sensitization to respective fungal extracts. fungal concentrations and seasonality were studied at two-week intervals ...201122103346
Heterochromatin influences the secondary metabolite profile in the plant pathogen Fusarium graminearum.Chromatin modifications and heterochromatic marks have been shown to be involved in the regulation of secondary metabolism gene clusters in the fungal model system Aspergillus nidulans. We examine here the role of HEP1, the heterochromatin protein homolog of Fusarium graminearum, for the production of secondary metabolites. Deletion of Hep1 in a PH-1 background strongly influences expression of genes required for the production of aurofusarin and the main tricothecene metabolite DON. In the Hep1 ...201122100541
sexual development and cryptic sexuality in fungi: insights from aspergillus species.major insights into sexual development and cryptic sexuality within filamentous fungi have been gained from investigations using aspergillus species. here, an overview is first given into sexual morphogenesis in the aspergilli, describing the different types of sexual structures formed and how their production is influenced by a variety of environmental and nutritional factors. it is argued that the formation of cleistothecia and accessory tissues, such as hülle cells and sclerotia, should be vi ...201222091779
heterologous expression system in aspergillus oryzae for fungal biosynthetic gene clusters of secondary metabolites.fungal secondary metabolites have been considered promising resources in the search for novel bioactive compounds. given the high potential of fungi as genetic resources, it is essential to find an efficient way to link biosynthetic genes to the product in a heterologous system, because many genes for the secondary metabolite in the original strain are silent under standard laboratory conditions. in a previous study, we constructed a heterologous expression system for a biosynthetic gene cluster ...201122083274
The Aspergillus Genome Database (AspGD): recent developments in comprehensive multispecies curation, comparative genomics and community resources.The Aspergillus Genome Database (AspGD; http://www.aspgd.org) is a freely available, web-based resource for researchers studying fungi of the genus Aspergillus, which includes organisms of clinical, agricultural and industrial importance. AspGD curators have now completed comprehensive review of the entire published literature about Aspergillus nidulans and Aspergillus fumigatus, and this annotation is provided with streamlined, ortholog-based navigation of the multispecies information. AspGD fa ...201222080559
Invasive mold infections in chronic granulomatous disease: a 25-year retrospective survey.Invasive fungal infection (IFI) represents a life-threatening condition for patients with chronic granulomatous disease (CGD) and causes one-third of deaths in this population. This study offers a descriptive review of invasive mold infection (mIFI) in children with CGD over an extended period of time.201122080130
[general epidemiology of invasive fungal disease.]invasive mycoses associated with high morbidity and mortality rates are increasing among immunocompromised or severely ill patients. candida, cryptococcus, pneumocystis and aspergillus are most prevalent agents with varying distribution as regards geography, patient condition and hospital units. the latest multicentre candidaemia survey conducted in spain, showed c. albicans as the most frequently isolated species followed by c. parapsilosis, c. glabrata, c. tropicalis and c. krusei in contrast ...201122079232
Disruption of Trichoderma reesei cre2, encoding an ubiquitin C-terminal hydrolase, results in increased cellulase activity.ABSTRACT:201122070776
Heme-Biosynthetic Porphobilinogen Deaminase Protects Aspergillus nidulans from Nitrosative Stress.Microorganisms have developed mechanisms to combat reactive nitrogen species (RNS); however, only a few of the fungal genes involved have been characterized. Here we screened RNS-resistant Aspergillus nidulans strains from fungal transformants obtained by introducing a genomic DNA library constructed in a multicopy vector. We found that the AN0121.3 gene (hemC) encodes a protein similar to the heme biosynthesis enzyme porphobilinogen deaminase (PBG-D) and facilitates RNS-tolerant fungal growth. ...201222038601
the length of adaptive walks is insensitive to starting fitness in aspergillus nidulans.adaptation involves the successive substitution of beneficial mutations by selection, a process known as an adaptive walk. gradualist models of adaptation, which assume that all mutations are small relative to the distance to a fitness optimum, predict that adaptive walks should be longer when the founding genotype is less well adapted. more recent work modeling adaptation as a sequence of moves in phenotype or genotype space predicts, by contrast, much shorter adaptive walks irrespective of the ...201122023575
Physiological and Biochemical Characterization of AnNitA, the Aspergillus nidulans High-Affinity Nitrite Transporter.High-affinity nitrite influx into mycelia of Aspergillus nidulans has been characterized by use of (13)NO(2)(-), giving average K(m) and V(max) values of 48 ± 8 µM and 228 ± 49 nmol mg(-1) dry weight (DW) h(-1), respectively. Kinetic analysis of a plot that included an additional large number of low-concentration fluxes gave an excellent monophasic fit (r(2) = 0.96), with no indication of sigmoidal kinetics. Two-dimensional (2D) and three-dimensional (3D) models of AnNitA are presented, and the ...201122021238
the velvet gene, fgve1, affects fungal development and positively regulates trichothecene biosynthesis and pathogenicity in fusarium graminearum.trichothecenes are a group of toxic secondary metabolites produced mainly by fusarium graminearum (teleomorph: gibberella zeae) during the infection of crop plants, including wheat, maize, barley, oats, rye and rice. some fungal genes involved in trichothecene biosynthesis have been shown to encode regulatory proteins. however, the global regulation of toxin biosynthesis is still enigmatic. in addition to the production of secondary metabolites belonging to the trichothecene family, f. graminear ...201122013911
Involvement of a helix-loop-helix transcription factor CHC-1 in CO(2)-mediated conidiation suppression in Neurospora crassa.The morphological switch from vegetative growth to conidiation in filamentous fungi is highly regulated, but the understanding of the regulatory mechanisms is limited. In this study, by screening a set of knock-out mutants corresponding to 103 transcription factor encoding genes in Neurospora crassa, a mutant was found to produce abundant conidia in race tubes in which conidiation in the wild-type strain was suppressed. The corresponding gene NCU00749 encodes a protein containing a helix-loop-he ...201122001287
Analysis of phytochemical constituents of Eucalyptus citriodora L. responsible for antifungal activity against post-harvest fungi.In vitro antifungal activity and phytochemical constituents of essential oil, aqueous, methanol and chloroform extract of Eucalyptus citriodora Hook leaves were investigated. A qualitative phytochemical analysis was performed for the detection of alkaloids, cardiac glycosides, flavonoids, saponins, sterols, tannins and phenols. Methanolic extract holds all identified biochemical constituents except for the tannin. While these biochemical constituents were found to be absent in essential oil, aqu ...201121999598
contributions of the peroxisome and β-oxidation cycle to biotin synthesis in fungi.the first step in the synthesis of the bicyclic rings of d-biotin is mediated by 8-amino-7-oxononanoate (aon) synthase, which catalyzes the decarboxylative condensation of l-alanine and pimelate thioester. we found that the aspergillus nidulans aon synthase, encoded by the biof gene, is a peroxisomal enzyme with a type 1 peroxisomal targeting sequence (pts1). localization of aon to the peroxisome was essential for biotin synthesis because expression of a cytosolic aon variant or deletion of pexe ...201121998305
Culture-positive invasive aspergillosis in a medical center in Taiwan, 2000-2009.We reviewed 776 patients who were culture positive for Aspergillus species at the hospital from 2000 to 2009. The isolates were collected for species identification by oligonucleotide hybridization and sequence analysis. A total of 96 cases of proven or probable IA were identified according to published criteria. The incidence of IA has increased significantly during the study period. Aspergillus fumigatus and A. flavus (41.7% each) were equally prevalent causative species. IA due to unusual spe ...201121997774
Transcription of Aspergillus nidulans pacC is modulated by alternative RNA splicing of palB.Fungi have evolved elaborate signal transduction networks for remodeling metabolic pathways to scavenge nutrients, including the secretion of nutritional enzymes. This adaptive response involves the conserved PacC/Pal signal transduction pathway, which mediates the transcriptional response to ambient pH. In this study, we show that transcription of the gene for PacC is modulated in response to nutrient changes, phosphate and carbon sources, and pH. In addition, we show that transcription of pacC ...201121985967
new resources for functional analysis of omics data for the genus aspergillus.detailed and comprehensive genome annotation can be considered a prerequisite for effective analysis and interpretation of omics data. as such, gene ontology (go) annotation has become a well accepted framework for functional annotation. the genus aspergillus comprises fungal species that are important model organisms, plant and human pathogens as well as industrial workhorses. however, go annotation based on both computational predictions and extended manual curation has so far only been availa ...201121974739
heterologous expression and biochemical characterization of novel pyranose 2-oxidases from the ascomycetes aspergillus nidulans and aspergillus oryzae.a gene encoding a pyranose 2-oxidase (pox; pyranose/oxygen 2-oxidoreductase; glucose 2-oxidase; ec 1.1.3.10) was identified in the genome of the ascomycete aspergillus nidulans. attempts to isolate pox directly from a. nidulans cultures or to homologously overexpress the native pox (under control of the constitutive gpda promoter) in a. nidulans were unsuccessful. cdna encoding pox was synthesized from mrna and expressed in escherichia coli, and the enzyme was subsequently purified and character ...201121968652
extracellular proteinase formation in carbon starving aspergillus nidulans cultures--physiological function and regulation.extracellular proteinase formation in carbon depleted cultures of the model filamentous fungus aspergillus nidulans was studied to elucidate its regulation and possible physiological function. as demonstrated by gene deletion, culture optimization, microbial physiological and enzymological experiments, the prta and pepj proteinases of a. nidulans did not appear to play a decisive role in the autolytic decomposition of fungal cells under the conditions we tested. however, carbon starvation induce ...201121953444
The Aspergillus giganteus antifungal protein AFPNN5353 activates the cell wall integrity pathway and perturbs calcium homeostasis.The antifungal protein AFPNN5353 is a defensin-like protein of Aspergillus giganteus. It belongs to a group of secretory proteins with low molecular mass, cationic character and a high content of cysteine residues. The protein inhibits the germination and growth of filamentous ascomycetes, including important human and plant pathogens and the model organsims Aspergillus nidulans and Aspergillus niger.201121943024
farnesol-induced cell death in the filamentous fungus aspergillus nidulans.foh (farnesol), a non-sterol isoprenoid produced by dephosphorylation of farnesyl pyrophosphate, has been shown to inhibit proliferation and induce apoptosis. we have been using aspergillus nidulans and foh as a model system and cell death stimulus, respectively, aiming to understand by which means filamentous fungi are driven towards cell death. here, we review some of our findings about foh-induced cell death in a. nidulans.201121936849
Putative stress sensors WscA and WscB are involved in hypo-osmotic and acidic pH stress tolerance in Aspergillus nidulans.Wsc proteins have been identified in fungi and are believed to be stress sensors in the cell wall integrity (CWI) signaling pathway. In this study, we characterized the sensor orthologs WscA and WscB in Aspergillus nidulans. Using hemagglutinin-tagged WscA and WscB, we showed both Wsc proteins to be N- and O-glycosylated and localized in the cell wall and membrane, implying that they are potential cell surface sensors. The wscA disruptant (?wscA) strain was characterized by reduced colony and co ...201121926329
a new class of imp dehydrogenase with a role in self-resistance of mycophenolic acid producing fungi.many secondary metabolites produced by filamentous fungi have potent biological activities, to which the producer organism must be resistant. an example of pharmaceutical interest is mycophenolic acid (mpa), an immunosuppressant molecule produced by several penicillium species. the target of mpa is inosine-5'-monophosphate dehydrogenase (impdh), which catalyses the rate limiting step in the synthesis of guanine nucleotides. the recent discovery of the mpa biosynthetic gene cluster from penicilli ...201121923907
Monitoring and assessment of airborne fungi in Kolkata, India, by viable and non-viable air sampling methods.The composition and variability of airborne fungal spores were studied using two complementary sampling methods in an outdoor environment in Kolkata suburb for 2 years, from November 2002 to October 2004. For monitoring the total fungal spore burden in the air, Burkard 7-day volumetric sampler was used, whereas Andersen two-sage viable sampler was used for isolating the cultivable airborne fungi. Among the 37 fungal spore types identified in the air samples, the predominant ones were Cladosporiu ...201121915605
cytotoxic pheofungins from an engineered fungus impaired in posttranslational protein modification. 201121913294
Post-synthetic modification of plant cell walls by expression of microbial hydrolases in the apoplast.The systematic creation of defined cell wall modifications in the model plant Arabidopsis thaliana by expression of microbial hydrolases with known specific activities is a promising approach to examine the impacts of cell wall composition and structure on both plant fitness and cell wall recalcitrance. Moreover, this approach allows the direct evaluation in living plants of hydrolase specificity, which can differ from in vitro specificity. To express genes encoding microbial hydrolases in A. th ...201121910026
nuclear transporters in a multinucleated organism: functional and localization analyses in aspergillus nidulans.nuclear transporters mediate bidirectional macromolecule traffic through the nuclear pore complex (npc), thus participating in vital processes of eukaryotic cells. a systematic functional analysis in aspergillus nidulans permitted the identification of 4 essential nuclear transport pathways of a hypothetical number of 14. the absence of phenotypes for most deletants indicates redundant roles for these nuclear receptors. subcellular distribution studies of these carriers show three main distribut ...201121880896
wild-type mic distributions and epidemiological cutoff values for amphotericin b and aspergillus spp. for the clsi broth microdilution method (m38-a2 document).although clinical breakpoints have not been established for mold testing, epidemiological cutoff values (ecvs) are available for aspergillus spp. versus the triazoles and caspofungin. wild-type (wt) mic distributions (organisms in a species-drug combination with no acquired resistance mechanisms) were defined in order to establish ecvs for six aspergillus spp. and amphotericin b. two sets (clsi/eucast broth microdilution) of available mics were evaluated: those for a. fumigatus (3,988/833), a. f ...201121876047
complex mechanisms regulate developmental expression of the mata (hmg) mating type gene in homothallic aspergillus nidulans.sexual reproduction is a fundamental developmental process that allows for genetic diversity through the control of zygote formation, recombination, and gametogenesis. the correct regulation of these events is paramount. sexual reproduction in filamentous fungi, including mating strategy (self-fertilization/homothallism or outcrossing/heterothallism), is determined by the expression of mating type genes at mat loci. aspergillus nidulans mata encodes a critical regulator that is a fungal ortholog ...201121868608
recombinant production and characterisation of two related gh5 endo-β-1,4-mannanases from aspergillus nidulans fgsc a4 showing distinctly different transglycosylation capacity.the glycoside hydrolase family 5 (gh5) endo-β-1,4-mannanases mana and manc from aspergillus nidulans fgsc a4 were produced in pichia pastoris x33 and purified in high yields of 120 and 145mg/l, respectively, from the culture supernatants. both enzymes showed increasing catalytic efficiency (k(cat)/k(m)) towards β-1,4 manno-oligosaccharides with the degree of polymerisation (dp) from 4 to 6 and also hydrolysed konjac glucomannan, guar gum and locust bean gum galactomannans. manc had up to two-fol ...201121867780
Polyphasic characterization of "Aspergillus nidulans var. roseus" ATCC 58397.Polyphasic characterization of the echinocandin B producer Aspergillus nidulans var. roseus ATCC 58397 strain was carried out to elucidate its taxonomical status. According to its carbon source utilization and secondary metabolite spectrum as well as the partial ß-tubulin, calmodulin, and ?-actin gene sequences, A. nidulans var. roseus belongs to the Emericella rugulosa species. Auxotroph mutants of A. nidulans var. roseus ATCC 58397 and E. rugulosa CBS 171.71 and CBS 133.60 formed stable hetero ...201121858538
backbone and sidechain (1)h, (13)c and (15)n chemical shift assignments of the hydrophobin dewa from aspergillus nidulans.hydrophobins are proteins secreted by filamentous fungi that are able to self-assemble into monolayers at hydrophobic:hydrophilic interfaces. the layers are amphipathic and can reverse the wettability of surfaces. hydrophobins have several roles in fungal development, including the formation of coatings on fungal structures to render them hydrophobic. here we report the backbone and sidechain assignments for the class i hydrophobin dewa from the fungus aspergillus nidulans.201121845363
bacteria-induced natural product formation in the fungus aspergillus nidulans requires saga/ada-mediated histone acetylation.sequence analyses of fungal genomes have revealed that the potential of fungi to produce secondary metabolites is greatly underestimated. in fact, most gene clusters coding for the biosynthesis of antibiotics, toxins, or pigments are silent under standard laboratory conditions. hence, it is one of the major challenges in microbiology to uncover the mechanisms required for pathway activation. recently, we discovered that intimate physical interaction of the important model fungus aspergillus nidu ...201121825172
Preliminary X-ray crystallographic studies of UDP-glucose-4-epimerase from Aspergillus nidulans.UDP-glucose-4-epimerase (GALE) from Aspergillus nidulans was overexpressed in Escherichia coli, purified via His-tag affinity chromatography and cocrystallized with UDP-galactose using the microbatch method. The crystals diffracted to 2.4ÔÇà+à resolution using synchrotron radiation on the Canadian Light Source 08ID-1 beamline. Examination of the data with d*TREK revealed nonmerohedral twinning, from which a single lattice was ultimately extracted for processing. The final space group was found t ...201121821886
a unique regulatory mechanism for d-galactose utilization in aspergillus nidulans.this study describes two novel regulators, galx and galr, that control d-galactose utilization in aspergillus nidulans. this system is unique for a. nidulans since no galr homologs were found in other ascomycetes. galr, but not galx, shares significant sequence identity with the arabinanolytic and xylanolytic regulators arar and xlnr, but galx is more distantly related.201121821745
Engineering of an "Unnatural" Natural Product by Swapping Polyketide Synthase Domains in Aspergillus nidulans.An StcA-AfoE hybrid polyketide synthase (PKS), generated by swapping the AfoE (asperfuranone biosynthesis) SAT domain with the StcA (sterigmatocystin biosynthesis) SAT domian, produced a major new metabolite with the same chain length as the native AfoE product. Structure elucidation allowed us to propose a likely pathway, and feeding studies supported the hypothesis that the chain length of PKS metabolites may be under precise control of KS and PT domains.201121815681
microtubule dynamics in mitosis in aspergillus nidulans.mitosis in aspergillus nidulans is very rapid, requiring less than 5min at 37°c in germlings (bergen and morris, 1983). in this time the cytoplasmic microtubules (mts) must disassemble, the mitotic spindle assemble, function and disassemble, and cytoplasmic mts reassemble. it follows that cytoplasmic mts must be extremely dynamic in this period and we were interested, in particular, in examining the processes of mt disassembly in prophase and reassembly in anaphase and telophase. we observed a d ...201121807107
dynamics and mechanism of cyclobutane pyrimidine dimer repair by dna photolyase.photolyase uses blue light to restore the major ultraviolet (uv)-induced dna damage, the cyclobutane pyrimidine dimer (cpd), to two normal bases by splitting the cyclobutane ring. our earlier studies showed that the overall repair is completed in 700 ps through a cyclic electron-transfer radical mechanism. however, the two fundamental processes, electron-tunneling pathways and cyclobutane ring splitting, were not resolved. here, we use ultrafast uv absorption spectroscopy to show that the cpd sp ...201121804035
the aspergillus nidulans cenp-e kinesin kipa is able to dimerize and to move processively along microtubules.kinesin molecular motors serve a variety of cellular functions usually in dynamic processes. one characteristic feature of many kinesins is their atp-dependent processive movement along polymerized microtubules. however, many kinesins work as stationary polymerases or depolymerases. therefore, it needs to be determined for each motor, whether it moves processively along microtubules or not. the schizosaccharomyces pombe kinesin-7, tea2, has been shown to be involved in cell end marker transporta ...201121785949
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