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the neurospora crassa genome opens up the world of filamentous fungi.the filamentous fungus neurospora crassa, which has played an important role in the development of modern genetics, has several unique genome-defense mechanisms, including a process called repeat-induced point mutation. the draft genome sequence has revealed several unusual features, which suggest that the evolution of n. crassa has been greatly influenced by these defense mechanisms.200312801405
analysis of two additional loci in neurospora crassa related to spore killer-2.two new loci found in one strain of neurospora crassa (p2604) collected in malaya are related to the meiotic drive system spore killer sk-2. sk-2 was found in neurospora intermedia and introgressed into n. crassa. p2604 showed high resistance to killing when crossed to sk-2. this resistance was found to be linked to, but not allelic to, resistance locus r(sk-2) on lgiiil. analysis showed that the high resistance phenotype of p2604 requires resistance alleles at two different loci on lgiiir. stra ...200312781673
cobalt-resistance in wall-less mutant (fz; sg; os-1) of neurospora crassa.a cobalt-resistant wall-less mutant (slime) of neurospora crassa was obtained by repeated sub-culturing of the sensitive wall-less mutant (w-sl) on agar medium containing toxic concentrations of cobalt. resistance was stable on culturing cor-sl on cobalt-free medium up to 15 weekly subcultures. cor-sl is 10-fold more resistant to cobalt when compared to w-sl. it is also cross-resistant to cu (10-fold) and ni (3-fold). cobalt accumulated by cor-sl during growth and in short-term uptake experiment ...200312779238
protonation of the neurospora crassa plasma membrane h+-atpase as a function of ph monitored by atr-ftir. 200312763847
synthesis and conformational characterization of peptides related to the neck domain of a fungal kinesin.the y362k mutation in the neck domain of conventional kinesin from neurospora crassa provokes a significant reduction of the rate of movement along microtubules. since the alpha-helical coiled-coil structure of the neck region is implicated in the mechanism of the processive movement of kinesins, a series of peptides related to the heptad region 338-379 of the wild-type and the variant fungal kinesinswere synthesized as monomers and as n-terminal disulfide dimers, crosslinked to favour self-asso ...200312725241
the internal alternative nadh dehydrogenase of neurospora crassa mitochondria.an open reading frame homologous with genes of non-proton-pumping nadh dehydrogenases was identified in the genome of neurospora crassa. the 57 kda nadh:ubiquinone oxidoreductase acts as internal (alternative) respiratory nadh dehydrogenase (ndi1) in the fungal mitochondria. the precursor polypeptide includes a pre-sequence of 31 amino acids, and the mature enzyme comprises one fad molecule as a prosthetic group. it catalyses specifically the oxidation of nadh. western blot analysis of fungal mi ...200312556227
rhythmic binding of a white collar-containing complex to the frequency promoter is inhibited by frequency.the biological clock of neurospora crassa includes interconnected transcriptional and translational feedback loops that cause both the transcript and protein encoded by the frequency gene (frq) to undergo the robust daily oscillations in abundance, which are essential for clock function. to understand better the mechanism generating rhythmic frq transcript, reporter constructs were used to show that the oscillation in frq message is transcriptionally regulated, and a single cis-acting element in ...200312714686
enzymes with extra talents: moonlighting functions and catalytic promiscuity.recent studies of moonlighting functions and catalytic promiscuity provide insights into the structural and mechanistic bases of these phenomena. moonlighting proteins that are highlighted include gephyrin, the neurospora crassa tyrosyl trna synthetase, phosphoglucose isomerase, and cytochrome c. new insights into catalytic promiscuity are provided by studies of aminoglycoside kinase (3') type iiia, tetrachlorohydroquinone dehalogenase, and aldolase antibody 38c2.200312714060
the methylated component of the neurospora crassa genome.cytosine methylation is common, but not ubiquitous, in eukaryotes. mammals and the fungus neurospora crassa have about 2-3% of cytosines methylated. in mammals, methylation is almost exclusively in the under-represented cpg dinucleotides, and most cpgs are methylated whereas in neurospora, methylation is not preferentially in cpg dinucleotides and the bulk of the genome is unmethylated. dna methylation is essential in mammals but is dispensable in neurospora, making this simple eukaryote a favou ...200312712205
characterization of neurospora crassa tom40-deficient mutants and effect of specific mutations on tom40 assembly.the tom complex (translocase of the outer mitochondrial membrane) is responsible for the recognition of mitochondrial preproteins synthesized in the cytosol and for their translocation across or into the outer mitochondrial membrane. tom40 is the major component of the tom complex and forms the translocation pore. we have created a tom40 mutant of neurospora crassa and have demonstrated that the gene is essential for the viability of the organism. mitochondria with reduced levels of tom40 were d ...200312399467
silencing of hygromycin phosphotransferase (hph) gene during sexual cycle and its reversible inactivation in heterokaryon of neurospora crassa.we transformed wild-type neurospora crassa with hph gene encoding hygromycin phosphotransferase to obtain hygromycin-resistant (hygr) transformants and studied their behavior in the vegetative and sexual phases of growth. during vegetative growth in the absence of hygromycin, the hph gene was stable for at least three successive transfers with conidia. on the other hand, the behavior of the transformants in the sexual phase was different. the segregation of hph gene in the meiotic progeny was in ...200314570273
isolation and characterization of neurospora crassa mutants resistant to antifungal plant defensins.twenty-five neurospora crassa mutants obtained by chemical mutagenesis were screened for increased resistance to various antifungal plant defensins. plant defensin-resistant n. crassa mutants were further tested for their cross-resistance towards other families of structurally different antimicrobial peptides. two n. crassa mutants, termed mut16 and mut24, displaying resistance towards all plant defensins tested but not to structurally different antimicrobial peptides were selected for further c ...200314516770
nuclear dna degradation during heterokaryon incompatibility in neurospora crassa.many filamentous fungi are capable of undergoing conspecific hyphal fusion with a genetically different individual to form a heterokaryon. however, the viability of such heterokaryons is dependent upon vegetative (heterokaryon) incompatibility (het) loci. if two individuals undergo hyphal anastomosis, but differ in allelic specificity at one or more het loci, the fusion cell is usually compartmentalized and self-destructs. many of the microscopic features associated with vegetative incompatibili ...200314516765
roles for white collar-1 in circadian and general photoperception in neurospora crassa.the transcription factors white collar-1 (wc-1) and white collar-2 (wc-2) interact to form a heterodimeric complex (wcc) that is essential for most of the light-mediated processes in neurospora crassa. wcc also plays a distinct non-light-related role as the transcriptional activator in the frequency (frq)/wcc feedback loop that is central to the n. crassa circadian system. although an activator role was expected for wc-1, unanticipated phenotypes resulting from some wc-1 alleles prompted a close ...200312586700
detection of mutagenic activities of various pesticides in neurospora crassa. 200312478420
calcium gradient dependence of neurospora crassa hyphal growth.a tip-high cytoplasmic calcium gradient has been identified as a requirement for hyphal growth in the fungus neurospora crassa. the ca2+ gradient is less steep compared to wall vesicle, wall incorporation and vesicular ca2+ gradients, but this can be explained by ca2+ diffusion. analysis of the relation between the rate of hyphal growth and the spatial distribution of tip-localized calcium indicates that hyphal growth rates depend upon the tip-localized calcium concentration. it is not the steep ...200312949173
circadian rhythms in neurospora crassa: farnesol or geraniol allow expression of rhythmicity in the otherwise arrhythmic strains frq10, wc-1, and wc-2.in neurospora crassa, the circadian rhythm can be seen in the bd (band) strain as a series of "bands" or conidiation (spore-forming) regions on the surface of an agar medium. certain mutations at 3 different genes (frq, wc-1, or wc-2) lead to the loss of the circadian rhythm. in this study, it was found that the addition of 10(-4) to 10(-5) m of geraniol or farnesol restored rhythmic banding to strains that lack a circadian rhythm due to mutations in any 1 of these 3 genes. these 3 conditionally ...200312932081
a comparison of physical mapping algorithms based on the maximum likelihood model.physical mapping of chromosomes using the maximum likelihood (ml) model is a problem of high computational complexity entailing both discrete optimization to recover the optimal probe order as well as continuous optimization to recover the optimal inter-probe spacings. in this paper, two versions of the genetic algorithm (ga) are proposed, one with heuristic crossover and deterministic replacement and the other with heuristic crossover and stochastic replacement, for the physical mapping problem ...200312874040
genetic analysis of wild-isolated neurospora crassa strains identified as dominant suppressors of repeat-induced point mutation.repeat-induced point mutation (rip) in neurospora results in inactivation of duplicated dna sequences. rip is thought to provide protection against foreign elements such as retrotransposons, only one of which has been found in n. crassa. to examine the role of rip in nature, we have examined seven n. crassa strains, identified among 446 wild isolates scored for dominant suppression of rip. the test system involved a small duplication that targets rip to the easily scorable gene erg-3. we previou ...200312871906
the frequency gene is required for temperature-dependent regulation of many clock-controlled genes in neurospora crassa.the circadian clock of neurospora broadly regulates gene expression and is synchronized with the environment through molecular responses to changes in ambient light and temperature. it is generally understood that light entrainment of the clock depends on a functional circadian oscillator comprising the products of the wc-1 and wc-2 genes as well as those of the frq gene (the frq/wcc oscillator). however, various models have been advanced to explain temperature regulation. in nature, light and t ...200312871904
the genetic basis of cellular morphogenesis in the filamentous fungus neurospora crassa.cellular polarity is a fundamental property of every cell. due to their extremely fast growth rate (>/=1 microm/s) and their highly elongated form, filamentous fungi represent a prime example of polarized growth and are an attractive model for the analysis of fundamental mechanisms underlying cellular polarity. to identify the critical components that contribute to polarized growth, we developed a large-scale genetic screen for the isolation of conditional mutants defective in this process in th ...200312960438
photoreception in neurospora: a tale of two white collar proteins.neurospora crassa is the best-understood fungal organism in terms of the mechanism of light responses. all known neurospora photoresponses are mediated by blue light. two per-arnt-simdomain containing transcription factors, white collar-1 (wc-1) and wc-2, are essential components for almost all light responses. recently, wc-1was shown to be a blue-light photoreceptor. how light affects the dna binding of the wc proteins to the promoter of the circadian clock gene frequency was also demonstrated. ...200314618260
interaction of mutations affecting tip growth and branching in neurospora.there are at least 100 loci encoding products that influence tip growth and branching in neurospora crassa. the functional relationships between 38 of these loci were examined by an analysis of gene interaction in double mutants. a complex range of interactions was revealed. these have been grouped into full and partial epistasis, costasis, novel phenotypes, and synthetic lethality and sublethality. epistasis was used to construct the simplest "pathway" that accommodated the results; this pathwa ...200314599894
multiple oscillators regulate circadian gene expression in neurospora.high-density microarrays were used to profile circadian gene expression in neurospora crassa cultures grown in constant darkness. we identified 145 clock-controlled genes (ccgs). the ccgs peaked in mrna accumulation at all phases of the day, with the majority peaking in the late night to early morning. the predicted or known functions of the ccgs demonstrate that the clock contributes to a wide range of cellular processes, including cell signaling, development, metabolism, and stress responses. ...200314597725
detection of unpaired dna at meiosis results in rna-mediated silencing.during meiosis, homologous chromosomes must pair in order to permit recombination and correct chromosome segregation to occur. two recent papers show that meiotic pairing is also important for correct gene expression during meiosis. they describe data for the filamentous fungus neurospora crassa that show that a lack of pairing generated by ectopic integration of genes can result in silencing of genes expressed during meiosis. this can result in aberrant meioses whose defects are specific to the ...200312539234
expression of protein phosphatase 1 during the asexual development of neurospora crassa.we cloned and sequenced the cdna and the gene encoding the catalytic subunit of protein phosphatase 1 from the filamentous fungus neurospora crassa. the gene, designated ppp-1 (phosphoprotein phosphatase 1), was mapped by restriction fragment length polymorphism to linkage group iii, in the vicinity of con-7 and trp-1. the expression of the gene was monitored by reverse transcriptase and polymerase chain reactions, by western blotting, and by protein phosphatase activity assays in synchronized c ...200312524044
a hex-1 crystal lattice required for woronin body function in neurospora crassa.the woronin body is a dense-core vesicle specific to filamentous ascomycetes (euascomycetes), where it functions to seal the septal pore in response to cellular damage. the hex-1 protein self-assembles to form this solid core of the vesicle. here, we solve the crystal structure of hex-1 at 1.8 a, which provides the structural basis of its self-assembly. the structure reveals the existence of three intermolecular interfaces that promote the formation of a three-dimensional protein lattice. consis ...200312640443
synthesis of signals for de novo dna methylation in neurospora crassa.most 5-methylcytosine in neurospora crassa occurs in a:t-rich sequences high in tpa dinucleotides, hallmarks of repeat-induced point mutation. to investigate how such sequences induce methylation, we developed a sensitive in vivo system. tests of various 25- to 100-bp synthetic dna sequences revealed that both t and a residues were required on a given strand to induce appreciable methylation. segments composed of (taaa)(n) or (ttaa)(n) were the most potent signals; 25-mers induced robust methyla ...200312640122
on the independence of barrage formation and heterokaryon incompatibility in neurospora crassa.a barrage is a line or zone of demarcation that may develop at the interface where genetically different fungi meet. barrage formation represents a type of nonself recognition that has often been attributed to the heterokaryon incompatibility system, which limits the co-occurrence of genetically different nuclei in the same cytoplasm during the asexual phase of the life cycle. while the genetic basis of the heterokaryon incompatibility system is well characterized in neurospora crassa, barrage f ...200312620257
role for antisense rna in regulating circadian clock function in neurospora crassa.the prevalence of antisense rna in eukaryotes is not known and only a few naturally occurring antisense transcripts have been assigned a function. however, the recent identification of a large number of putative antisense transcripts strengthens the view that antisense rnas might affect a wider variety of processes than previously thought. here we show that in the model organism neurospora crassa entrainment of the circadian clock, which is critical for the correct temporal expression of genes a ...200312607002
the qde-3 homologue recq-2 co-operates with qde-3 in dna repair in neurospora crassa.the post-transcriptional gene silencing mechanism in neurospora crassa, called quelling, was shown to involve the products of three genes termed quelling-defective. a homologue to the qde-3 gene encoding a putative recq-type dna helicase was isolated and was named recq-2. characterisation of the recq-2 gene has revealed that it is not involved in quelling, but may co-operate with the qde-3 gene product in a pathway that repairs damage to dna caused by the chemical mutagens methyl methanesulfonat ...200312589473
histone h1 is required for proper regulation of pyruvate decarboxylase gene expression in neurospora crassa.we show that neurospora crassa has a single histone h1 gene, hh1, which encodes a typical linker histone with highly basic n- and c-terminal tails and a central globular domain. a green fluorescent protein-tagged histone h1 chimeric protein was localized exclusively to nuclei. mutation of hh1 by repeat-induced point mutation (rip) did not result in detectable defects in morphology, dna methylation, mutagen sensitivity, dna repair, fertility, rip, chromosome pairing, or chromosome segregation. ne ...200312684383
trimethylated lysine 9 of histone h3 is a mark for dna methylation in neurospora crassa.besides serving to package nuclear dna, histones carry information in the form of a diverse array of post-translational modifications. methylation of histones h3 and h4 has been implicated in long-term epigenetic 'memory'. dimethylation or trimethylation of lys4 of histone h3 (h3 lys4) has been found in expressible euchromatin of yeasts and mammals. in contrast, methylation of lys9 of histone h3 (h3 lys9) has been implicated in establishing and maintaining the largely quiescent heterochromatin o ...200312679815
what's in the genome of a filamentous fungus? analysis of the neurospora genome sequence.the german neurospora genome project has assembled sequences from ordered cosmid and bac clones of linkage groups ii and v of the genome of neurospora crassa in 13 and 12 contigs, respectively. including additional sequences located on other linkage groups a total of 12 mb were subjected to a manual gene extraction and annotation process. the genome comprises a small number of repetitive elements, a low degree of segmental duplications and very few paralogous genes. the analysis of the 3218 iden ...200312655011
analysis of nutrient-dependent transcript variations in neurospora crassa.nutrient-dependent variations in transcript levels of the filamentous fungus neurospora crassa were studied on a microarray containing some 4700 cdnas. cells were grown in minimal and acetate medium. the isolated rna was analyzed in comparison to the results obtained upon the hybridization of samples prepared from the rna of cells grown in full medium. altogether, 160 cdna clones exhibited significant variations, falling into five distinct subgroups of very similar transcription profiles. this i ...200314599890
reduced models of the circadian oscillators in neurospora crassa and drosophila melanogaster illustrate mechanistic similarities.we have developed a reduced model representing feedback loops of transcriptional regulation underlying circadian rhythms in neurospora crassa. the model contains two delay differential equations that describe the dynamics of two core gene products, frq and wcc. in a negative feedback loop, frq protein represses frq transcription by binding the white-collar complex (wcc), which consists of the wc-1 and wc-2 proteins. in a positive feedback loop, wcc indirectly enhances its own formation. the mode ...200314683608
[a simple method to correct genetic distance between linked genes and a correction of calculating data in tetrad analysis in neurospora crassa].the present paper is dealing with a simple method to correct the distance of linked genes in tetrad analysis in neurospora crassa. it is suggested that the data of 4-thread double crossing over should be added in two single crossing over respectively in centromere maping when calculating crossover value of the two genes locating across the centromere.200315639882
[study on xylose fermentation by neurospora crassa].the influence of oxygen limitation and medium initial ph on xylose fermentation by neurospora crassa as 3.1602 was investigated. n. crassa as 3.1602 has high ability of xylose fermentation producing ethanol and xylitol. oxygen limitation has big influence on ethanol and xylitol production. the maximum conversion rate of ethanol was 63.2% obtained under semi-aerobic conditions. the maximum conversion rate of xylitol was 31.8% obtained under micro-aerobic conditions. xylitol accumulation is behind ...200316276921
transcripts and transcript-binding proteins in mitochondria of neurospora crassa.we analyzed expression elements of three disparate groups of mitochondrial genes in neurospora crassa, apocytochrome b (cob), cytochrome c oxidase 1 (cox1), and the clustered atp8-atp6-mtatp9-cox2. to identify promoter sequences we employed the published n. crassa consensus sequence for cob and rrna genes, and we found closely related sequences within the 5'-regions of both cox1 and the atp8-cox2 transcriptional units. we determined that the mature cox1 rna includes two flanking unassigned readi ...200316120332
effect of ph on the mutagenic and killing potencies of icr-170 in ad-3 tests of neurospora crassa. 20032579330
characterization of bc-hch, the botrytis cinerea homolog of the neurospora crassahet-c vegetative incompatibility locus, and its use as a population marker.the botrytis cinerea homolog (bc-hch) of nc-het-c and pa-hch (vegetative incompatibility loci of neurospora crassa and podospora anserina respectively) was cloned and sequenced. the gene structure of bc-hch is very close to those of nc-het-c and pa-hch. a pcr-rflp approach on a 1171 bp fragment was used to screen polymorphism at this locus among 117 natural isolates of b. cinerea. restriction patterns by the restriction enzyme hhai fell into two allelic types. moreover, haplotypes at the bc-hch ...200321156611
purification and characterization of epsilon-n-trimethyllysine l-amino oxidase from neurospora crassa.epsilon-n-trimethyllysine l-amino oxidase from neurospora crassa has been purified to electrophoretic homogeneity. a 1500-fold purification was obtained by centrifugation and successive column chromatography on ion-exchange and gel filtration supports. the enzyme has an estimated molecular weight of 160 000. it transforms epsilon-n-trimethyllysine into alpha-keto, epsilon-n-trimethylhexanoic acid by oxidative deamination. kinetic studies of this new enzyme are reported and its probable physiolog ...2003149561
biosynthesis of glycogen in neurospora crassa. kinetic mechanism of udp-glucose: glycogen 4-alpha-glucosyltransferase.the kinetic mechanism of glycogen synthase [udp-glucose: glycogen 4-alpha-glucosyltransferase, ec 2.4.1.11], glucose-6-p-dependent form, from neurospora crassa has been investigated by initial velocity experiments and studies with inhibitors in the presence of sufficient levels of glucose-6-p. the rate equation was different from those of common two-substrate systems because one of the substrates, glycogen, is also a product. the reaction rates were determined by varying the concentration of one ...2003153901
identification of a new chondropsin class of antitumor compound that selectively inhibits v-atpases.we identify a new naturally occurring class of inhibitor of vacuolar h+-atpases (v-atpases) isolated from vacuolar membranes of neurospora crassa and from chromaffin granule membranes of bos taurus. to date, the new class includes six chondropsins and poecillastrin a, large polyketide-derived macrolide lactams with 33-37 membered rings. in the national cancer institute's 60-cell screen the chondropsin class showed a tumor cell growth inhibitory fingerprint essentially indistinguishable from that ...200312944415
cloning, heterologous expression, and characterization of thielavia terrestris glucoamylase.thielavia terrestris is a soil-borne thermophilic fungus whose molecular/ cellular biology is poorly understood. only a few genes have been cloned from the thielavia genus. we detected an extracellular glucoamylase in culture filtrates of t. terrestris and cloned the corresponding glaa gene. the coding region contains five introns. based on the amino acid sequence, the glucoamylase was 65% identical to neurospora crassa glucoamylase. sequence comparisons suggested that the enzyme belongs to the ...200314665735
identification of a protective antigen of coccidioides immitis by expression library immunization.coccidioides immitis is a fungal pathogen of humans and is classified as a select agent. we have identified a new potential vaccine candidate for this pathogen using cdna expression library immunization (eli). a c. immitis spherule-phase cdna library containing 800-1000 genes was divided into 10 pools and each was tested for its protective capacity in balb/c mice against intraperitoneal challenge with 2500 arthroconidia of this dimorphic fungus. the most protective pool, designated pool 7, was f ...200314505918
active/de-active transition of respiratory complex i in bacteria, fungi, and animals.mammalian complex i (nadh:ubiquinone oxidoreductase) exists as a mixture of interconvertible active (a) and de-activated (d) forms. the a-form is capable of nadh:quinone-reductase catalysis, but not the d-form. complex i from the bacterium paracoccus denitrificans, by contrast, exists only in the a-form. this bacterial complex contains 32 fewer subunits than the mammalian complex. the question arises therefore if the structural complexity of complex i from higher organisms correlates with its ab ...200314507430
the photolyase gene from the plant pathogen fusarium oxysporum f. sp. lycopersici is induced by visible light and alpha-tomatine from tomato plant.survival of irradiated spores from fusarium oxysporum with ultraviolet radiation (uv) was increased following exposition to visible light, indicating that this phytopathogenic fungus has a mechanism of photoreactivation able to counteract the lethal effects of uv. a genomic sequence containing the complete photolyase gene (phr1) from f. oxysporum was isolated by heterologous hybridisation with the neurospora crassa photolyase gene. the f. oxysporum phr1 cdna was isolated and expressed in a photo ...200314516768
purification, characterization and functional cloning of inositol oxygenase from cryptococcus.the enzyme inositol oxygenase (myo-inositol : oxygen oxidoreductase; e.c. 1.13.99.1) is a monooxygenase that converts inositol into glucuronic acid in the presence of molecular oxygen. this enzyme is integrated into a pathway leading to either degradation and energy production or the biosynthesis of precursors for polysaccharides. the enzyme was purified from the yeast cryptococcus lactativorus by a five-step chromatography procedure. the purified enzyme shows a molecular mass of 37 kda on sds-p ...200314663824
analysis of expressed sequence tags from gibberella zeae (anamorph fusarium graminearum).gibberella zeae is a broad host range pathogen that infects many crop plants, including wheat and barley, and causes head blight and rot diseases throughout the world. to better understand fungal development and pathogenicity, we have generated 7996 ests from three cdna libraries. two libraries were generated from carbon-(c-) and nitrogen- (n-) starved mycelia and one library was generated from cultures of maturing perithecia (p). in other fungal pathogens, starvation conditions have been shown ...200312620255
a novel binding protein for a member of cyp40-type cyclophilins: n.crassa cypbp37, a growth and thiamine regulated protein homolog to yeast thi4p.cyclophilins belong to the family of peptidyl-prolyl cis/trans isomerases (ppiases), which are ubiquitous and highly conserved enzymes capable of cis/trans isomerizing xaa-pro peptide bonds. members of the cyp40-type cyclophilins have originally been described as components of hormone receptor complexes. here, we describe nccyp41, a cyp40 ortholog from neurospora crassa, its expression in escherichia coli and subsequent purification. characterization of nccyp41 reveals that it is a heat shock pr ...200314568539
analysis of loss of pathogenicity mutants reveals that repeat-induced point mutations can occur in the dothideomycete leptosphaeria maculans.restriction enzyme mediated insertional mutagenesis using a plasmid, pucatph, that confers hygromycin resistance, generated loss-of-pathogenicity mutants of leptosphaeria maculans, the fungus that causes blackleg disease of brassica napus. of 516 l. maculans transformants analysed, 12 were pathogenicity mutants. when eight of these mutants were crossed to an isolate that attacks b. napus, cosegregation of pucatph sequences and loss of pathogenicity was not observed, suggesting that these mutatio ...200312742061
the 9.8 kda subunit of complex i, related to bacterial na(+)-translocating nadh dehydrogenases, is required for enzyme assembly and function in neurospora crassa.a nuclear gene encoding a 9.8 kda subunit of complex i, the homologue of mammalian mwfe protein, was identified in the genome of neurospora crassa. the gene was cloned and inactivated in vivo by the generation of repeat-induced point mutations. fungal mutant strains lacking the 9.8 kda polypeptide were subsequently isolated. analyses of mitochondrial proteins from mutant nuo9.8 indicate that the membrane and peripheral arms of complex i fail to assemble. respiration of mutant mitochondria on mat ...200312758076
mapping and characterization of polymorphism in mtdna of cryphonectria parasitica: evidence of the presence of an optional intron.the mitochondrial dna (mtdna) of the filamentous ascomycete cryphonectria parasitica is large and polymorphic so, to better understand the nature of the polymorphisms within populations, a small collection of italian strains of the fungus was examined. known mtdna polymorphisms were mapped and found to cluster in four regions of the mtdna molecule, particularly in the rflp region 2 where five different mtdna haplotypes out of 13 strains were identified. this region included an area of 8.4kbp whi ...200314599889
two divergent plasma membrane syntaxin-like snares, nsyn1 and nsyn2, contribute to hyphal tip growth and other developmental processes in neurospora crassa.highly polarized exocytosis of vesicles at hyphal apices is an essential requirement of tip growth. this requirement may be met by the localization and/or activation of an apical snare-based machinery. we have cloned nsyn1 and nsyn2, snares predicted to function at the plasma membrane in neurospora crassa. transformation of extra copies of nsyn1 into wild-type strains displayed effects consistent with quelling of nsyn1 expression, which was lethal in most transformants. all surviving transforman ...200314599895
time series analysis demonstrates the absence of pulsatile hyphal growth.hyphal tip growth has been previously reported as pulsatile, defined as regularly alternating fast and slow rates of extension. the growth of pollen tubes, and hyphae of neurospora crassa and saprolegnia ferax were analysed using high spatial and temporal resolution. by using long (100-500 s) records of growth rate, sampled every second, it was possible to apply rigorous statistical analysis of the time series. as previously demonstrated, pollen tubes can show pulsatile growth, detectable with t ...200314600223
asexual development is increased in neurospora crassa cat-3-null mutant strains.we use asexual development of neurospora crassa as a model system with which to determine the causes of cell differentiation. air exposure of a mycelial mat induces hyphal adhesion, and adherent hyphae grow aerial hyphae that, in turn, form conidia. previous work indicated the development of a hyperoxidant state at the start of these morphogenetic transitions and a large increase in catalase activity during conidiation. catalase 3 (cat-3) increases at the end of exponential growth and is induced ...200312912899
an ordered collection of expressed sequences from cryphonectria parasitica and evidence of genomic microsynteny with neurospora crassa and magnaporthe grisea.cryphonectria parasitica, the causative agent of chestnut blight, has proven to be a tractable experimental system for studying fungal pathogenesis. moreover, the development of infectious cdna clones of c. parasitica hypoviruses, capable of attenuating fungal virulence, has provided the opportunity to examine molecular aspects of fungal plant pathogenesis in the context of biological control. in order to establish a genomic base for future studies of c. parasitica, the authors have analysed a c ...200312949163
vivid is a flavoprotein and serves as a fungal blue light photoreceptor for photoadaptation.blue light regulates many physiological and developmental processes in fungi. most of the blue light responses in the ascomycete neurospora crassa are dependent on the two blue light regulatory proteins white collar (wc)-1 and -2. wc-1 has recently been shown to be the first fungal blue light photoreceptor. in the present study, we characterize the neurospora protein vivid. vivid shows a partial sequence similarity with plant blue light photoreceptors. in addition, we found that vivid non-covale ...200312970196
characterization and expression of the neurospora crassa nmt-1 gene.the neurospora crassa homologue of the yeast no message in thiamine ( nmt-1) gene was characterized. the deduced 342-amino-acid gene product has more than 60% identity with other fungal homologues and 42% similarity to a putative bacterial permease. in addition to three introns disrupting the coding sequence, a differentially spliced intron in the 5' untranslated region was also detected. unlike other fungi, the n. crassa nmt-1 gene is repressed only 6- to 8-fold by exogenous thiamine concentrat ...200313680155
single fungal kinesin motor molecules move processively along microtubules.conventional kinesins are two-headed molecular motors that move as single molecules micrometer-long distances on microtubules by using energy derived from atp hydrolysis. the presence of two heads is a prerequisite for this processive motility, but other interacting domains, like the neck and k-loop, influence the processivity and are implicated in allowing some single-headed kinesins to move processively. neurospora kinesin (nkin) is a phylogenetically distant, dimeric kinesin from neurospora c ...200312609885
deletion of mdmb impairs mitochondrial distribution and morphology in aspergillus nidulans.mitochondria form a dynamic network of interconnected tubes in the cells of saccharomyces cerevisiae or filamentous fungi such as aspergillus nidulans, neurospora crassa, or podospora anserina. the dynamics depends on the separation of mitochondrial fragments, their movement throughout the cell, and their subsequent fusion with the other parts of the organelle. interestingly, the microtubule network is required for the distribution in n. crassa and s. pombe, while s. cerevisiae and a. nidulans a ...200312740872
isolation and genetic characterization of the neurospora crassa rev1 and rev7 homologs: evidence for involvement in damage-induced mutagenesis.in a previous paper, we reported that the neurospora crassa upr-1 gene is a homolog of the yeast gene rev3, which encodes the catalytic subunit of dna polymerase zeta (polzeta). characterization of the upr-1 mutant indicated that the upr1 protein plays a role in dna repair and mutagenesis. to help understand the mechanisms of mutagenic dna repair in the n. crassa more extensively, we identified n. crassa homologs of yeast rev1 and rev7 and obtained mutants ncrev1 or ncrev7, which had similar phe ...200312547396
production and characterization of the talaromyces stipitatus feruloyl esterase faec in pichia pastoris: identification of the nucleophilic serine.feruloyl esterases constitute an interesting group of enzymes that have the potential for use over a broad range of applications in the agri-food industries. we report the over-expression and characterization of a novel feruloyl esterase exhibiting broad substrate specificity from talaromyces stipitatus (faec) in pichia pastoris. using various gene constructions, we have investigated the use of alternative signal peptides to produce an authentic feruloyl esterase featuring the n-terminal sequenc ...200312767807
alternative oxidase expression in neurospora crassa.when electron flow through the cytochrome-mediated electron transport chain is blocked by inhibitors or mutations, the mitochondria of neurospora crassa contain a kcn-insensitive alternative oxidase, encoded by the aod-1 gene, that transfers electrons directly from the ubiquinone pool to oxygen. the mechanism by which the enzyme is induced is unknown. comparison of the sequence upstream of the n. crassa aod-1 gene with the corresponding region of gelasinospora spp. and aspergillus nidulans revea ...200312781676
selectivity of 4,5,6,7-tetrabromobenzimidazole as an atp-competitive potent inhibitor of protein kinase ck2 from various sources.like the previously reported 4,5,6,7-tetrabromobenzotriazole (tbbt), the structurally related 4,5,6,7-tetrabromobenzimidazole (tbbz) is a selective atp-competitive inhibitor of protein kinase ck2 from such divergent sources as yeast, rat liver, neurospora crassa and candida tropicalis, with k(i) values in the range 0.5-1 microm. it is virtually inactive vs. pka, pkc, and a very weak inhibitor of protein kinase ck1. the corresponding tetrachlorobenzimidazole (tcbz) is a much weaker inhibitor of c ...200312788077
verification of a new gene on saccharomyces cerevisiae chromosome iii.we present verification of the existence of a previously unannotated, intron-containing gene of 134 amino acids (predicted molecular weight approximately 15.5 kda) located on chromosome iii of saccharomyces cerevisiae. strains carrying a deletion of this gene, which we have called ycl012c, reveal no apparent phenotype. orthologues of ycl012c are present in related species s. bayanus, s. paradoxus and ashbya gossypii. comparison with other fungal sequences reveals that orthologues of this gene ar ...200312794934
a blumeria graminis gene family encoding proteins with a c-terminal variable region with homologues in pathogenic fungi.in a study aimed at characterising, at the molecular level, the obligate biotrophic fungus blumeria graminis f. sp. hordei (bgh), we have identified a novel group of genes, the egh16h genes, and shown that two of these are up-regulated during primary infection of barley leaves. the genes have partial homology to a previously characterised bgh gene family, egh16. egh16 and egh16h are subfamilies of a larger multigene family with presently about 15 members identified in bgh. egh16h has about ten m ...200312853153
mcp1 encodes the molybdenum cofactor carrier protein in chlamydomonas reinhardtii and participates in protection, binding, and storage functions of the cofactor.the molybdenum cofactor (moco) is essential for the activity of all molybdoenzymes except nitrogenase. the cdna for the moco carrier protein (mococp) of chlamydomonas reinhardtii has been cloned by reverse transcription pcr approaches with primers designed from microsequenced peptides of this protein. the c. reinhardtii mococp has been expressed in escherichia coli. the recombinant protein has been purified to electrophoretic homogeneity and is found assembled into a homotetramer when moco is no ...200312519777
arabidopsis ndk1 is a component of ros signaling by interacting with three catalases.plants sense various environmental stimuli and have specific signaling pathways to respond to these cues. we focused on light responsive components and found that ndks were phosphorylated specifically after red light irradiation in pisum sativum [tanaka et al. (1998) j. photochem. photobiol. b 45: 113] and after blue light irradiation in neurospora crassa [oda and hasunuma (1997) mol. gen. genet. 256: 593, ogura et al. (2001) j. biol. chem. 276: 21228]. we performed yeast two-hybrid screening us ...200314581623
whole-genome analysis of two-component signal transduction genes in fungal pathogens.two-component phosphorelay systems are minimally comprised of a histidine kinase (hk) component, which autophosphorylates in response to an environmental stimulus, and a response regulator (rr) component, which transmits the signal, resulting in an output such as activation of transcription, or of a mitogen-activated protein kinase cascade. the genomes of the yeasts saccharomyces cerevisiae, schizosaccharomyces pombe, and candida albicans encode one, three, and three hks, respectively. in contra ...200314665450
suv39h-mediated histone h3 lysine 9 methylation directs dna methylation to major satellite repeats at pericentric heterochromatin.histone h3 lysine 9 (h3-k9) methylation and dna methylation are characteristic hallmarks of mammalian heterochromatin. h3-k9 methylation was recently shown to be a prerequisite for dna methylation in neurospora crassa and arabidopsis thaliana. currently, it is unknown whether a similar dependence exists in mammalian organisms.200312867029
gene organization and molecular modeling of copper amine oxidase from aspergillus niger: re-evaluation of the cofactor structure.amine oxidase ao-i from aspergillus niger aku 3302 has been reported to contain topa quinone (tpq) as a cofactor; however, analysis of the p-nitrophenylhydrazine-derivatized enzyme and purified active site peptides showed the presence of a carboxylate ester linkage of tpq to a glutamate. the catalytic functionality of such a cross-linked cofactor has recently been shown unlikely by spectroscopic and voltammetric studies on synthesized model compounds. we have obtained resonance raman spectra of ...200314669988
the aspergillus nidulans metr gene encodes a bzip protein which activates transcription of sulphur metabolism genes.the identification, isolation and characterization of a new aspergillus nidulans positive-acting gene metr, which encodes a transcriptional activator of sulphur metabolism, is reported. metr mutants are tight auxotrophs requiring methionine or homocysteine for growth. mutations in the metr gene are epistatic to mutations in the negative-acting sulphur regulatory scon genes. the metr coding sequence is interrupted by a single intron of 492 bp which is unusually long for fungi. aspergillus nidulan ...200312890030
characterization of the genomic organization of the region bordering the centromere of chromosome v of podospora anserina by direct sequencing.a podospora anserina bac library of 4800 clones has been constructed in the vector pbhyg allowing direct selection in fungi. screening of the bac collection for centromeric sequences of chromosome v allowed the recovery of clones localized on either sides of the centromere, but no bac clone was found to contain the centromere. seven bac clones containing 322,195 and 156,244bp from either sides of the centromeric region were sequenced and annotated. one 5s rrna gene, 5 trna genes, and 163 putativ ...200312892638
the ph-induced glycosylation of secreted phosphatases is mediated in aspergillus nidulans by the regulatory gene pacc-dependent pathway.in this communication, we show that the pacc(c)14 mutation drastically reduced the mannose and n-acetylglycosamine content of the paca-encoded acid phosphatase secreted by the fungus aspergillus nidulans when grown at 22 degrees c, ph 5.0, compared to a control strain. the staining after page was not observed for the paca-encoded acid phosphatase, while the pald-encoded pi-repressible alkaline phosphatase had an altered electrophoretic mobility. in addition, the secreted acid phosphatase also ha ...200312892641
environmental suppression of neurospora crassa cot-1 hyperbranching: a link between cot1 kinase and stress sensing.cot-1 mutants belong to a class of neurospora crassa colonial temperature-sensitive (cot) mutants that exhibit abnormal polar extension and branching patterns when grown at restrictive temperatures. cot-1 encodes a ser/thr protein kinase that is structurally related to the human myotonic dystrophy kinase which, when impaired, confers a disease that involves changes in cytoarchitecture and ion homeostasis. when grown under restrictive conditions, cot-1 cultures exhibited enhanced medium acidifica ...200312912889
circadian and light-induced expression of luciferase in neurospora crassa.we have constructed a plasmid vector for expressing firefly luciferase in neurospora crassa under control of the light- and clock-regulated ccg-2 (eas) promoter. the sequence of the luciferase gene in the vector has been modified to reflect the n. crassa codon bias. both light-induced activity and circadian activity are demonstrated. expression of luciferase in strains carrying mutant frequency alleles shows appropriate period length alterations. these data demonstrate that luciferase is a sensi ...200312684022
identification of a high-affinity phosphate transporter gene in a prasinophyte alga, tetraselmis chui, and its expression under nutrient limitation.a high-affinity phosphate transporter gene, tcpho, was isolated from a growth-dependent subtracted cdna library of the marine unicellular alga tetraselmis chui. the full-length cdna of tcpho obtained by 5' and 3' rapid amplification of cdna ends was 1,993 bp long and encoded an open reading frame consisting of 610 amino acids. the deduced amino acid sequence of tcpho exhibited 51.6 and 49.8% similarity to the amino acid sequences of pho89 from saccharomyces cerevisiae and pho4 from neurospora cr ...200312570992
tim50, a novel component of the tim23 preprotein translocase of mitochondria.the preprotein translocase of the inner membrane of mitochondria (tim23 complex) is the main entry gate for proteins of the matrix and the inner membrane. we isolated the tim23 complex of neurospora crassa. besides tim23 and tim17, it contained a novel component, referred to as tim50. tim50 spans the inner membrane with a single transmembrane segment and exposes a large hydrophilic domain in the intermembrane space. tim50 is essential for viability of yeast. mitochondria from cells depleted of t ...200312574118
antifungal properties of novel n- and alpha,beta-substituted succinimides against dermatophytes.the synthesis and antifungal properties of a series of new n-aryl alpha,beta-substituted succinimides against a panel of dermatophytes of clinical relevance are reported. among those compounds possessing a n-phenyl substituent, 7-thia-2-azabicyclo[2,2,1]hept-2-en-3-amine[5,6-c]succinimide was the better inhibitor of trichophyton rubrum, the major ethiological agent of all infections produced by dermatophytes. in contrast, succinimides containing a n-(p-sulfonylphenyl) substituent, only inhibited ...200312785125
the n-acetylglutamate synthase/n-acetylglutamate kinase metabolon of saccharomyces cerevisiae allows co-ordinated feedback regulation of the first two steps in arginine biosynthesis.in saccharomyces cerevisiae, which uses the nonlinear pathway of arginine biosynthesis, the first two enzymes, n-acetylglutamate synthase (nags) and n-acetylglutamate kinase (nagk), are controlled by feedback inhibition. we have previously shown that nags and nagk associate in a complex, essential to synthase activity and protein level [abadjieva, a., pauwels, k., hilven, p. & crabeel, m. (2001) j. biol. chem.276, 42869-42880]. the nagks of ascomycetes possess, in addition to the catalytic domai ...200312603335
inhibition of dna methylation and reactivation of silenced genes by zebularine.gene silencing by abnormal methylation of promoter regions of regulatory genes is commonly associated with cancer. silenced tumor suppressor genes are obvious targets for reactivation by methylation inhibitors such as 5-azacytidine (5-aza-cr) and 5-aza-2'-deoxycytidine (5-aza-cdr). however, both compounds are chemically unstable and toxic and neither can be given orally. we characterized a new demethylating agent, zebularine [1-(beta-d-ribofuranosyl)-1,2-dihydropyrimidin-2-one], which is a chemi ...200312618505
the mapkk kinase stec regulates conidiophore morphology and is essential for heterokaryon formation and sexual development in the homothallic fungus aspergillus nidulans.environmental signals can be transduced into intracellular responses by the action of map kinase cascades. sequential phosphorylation results in the transient activation of a map kinase, which in turn activates certain transcription factors and thus a set of pathway-specific genes. many steps in this cascade are conserved, and homologues have been discovered from yeast to human. we have characterized the mapkk kinase, stec, a homologue of saccharomyces cerevisiae ste11, in the filamentous fungus ...200312622813
mmm1p spans both the outer and inner mitochondrial membranes and contains distinct domains for targeting and foci formation.in the yeast saccharomyces cerevisiae, the integral membrane protein mmm1p is required for maintenance of mitochondrial morphology and retention of mitochondrial dna (mtdna). mmm1p localizes to discrete foci on mitochondria that are adjacent to mtdna nucleoids in the matrix, raising the possibility that this protein plays a direct role in organizing, replicating, or segregating mtdna. although mmm1p has been shown to cross the outer membrane with its c terminus facing the cytoplasm, the location ...200312972421
interaction of the mitotic inhibitor monastrol with human kinesin eg5.the microtubule-dependent kinesin-like protein eg5 from homo sapiens is involved in the assembly of the mitotic spindle. it shows a three-domain structure with an n-terminal motor domain, a central coiled coil, and a c-terminal tail domain. in vivo hseg5 is reversibly inhibited by monastrol, a small cell-permeable molecule that causes cells to be arrested in mitosis. both monomeric and dimeric eg5 constructs have been examined in order to define the minimal monastrol binding domain on hseg5. nmr ...200312525161
pex7p and pex20p of neurospora crassa function together in pts2-dependent protein import into peroxisomes.recruiting matrix proteins with a peroxisomal targeting signal type 2 (pts2) to the peroxisomal membrane requires species-specific factors. in saccharomyces cerevisiae, the pts2 receptor pex7p acts in concert with the redundant pex18p/pex21p, whereas in yarrowia lipolytica, pex20p might unite the function of both s. cerevisiae peroxins. herein, the genome of the filamentous fungus neurospora crassa was analyzed for peroxin-encoding genes. we identified a set of 18 peroxins that resembles that of ...200312589072
the transition between active and de-activated forms of nadh:ubiquinone oxidoreductase (complex i) in the mitochondrial membrane of neurospora crassa.the mammalian mitochondrial nadh:ubiquinone oxidoreductase (complex i) has been shown to exist in two kinetically and structurally distinct slowly interconvertible forms, active (a) and de-activated (d) [vinogradov and grivennikova (2001) iubmb life 52, 129-134]. this work was undertaken to investigate the putative complex i a-d transition in the mitochondrial membrane of the lower eukaryote neurospora crassa and in plasma membrane of the prokaryote paracoccus denitrificans, organisms that are e ...200312379145
primary structure of cytochrome c gene from the white root rot fungus rosellinia necatrix.the nucleotide sequence of the cytochrome c (cytc) gene of the white root rot fungus rosellinia necatrix was analyzed. the structure of this gene, which had three introns in the coding region, was similar to that of aspergillus nidulans. the second intron of the r. necatrix cytc gene was not present in neurospora crassa or fusarium oxysporum. however, the amino acid sequence of r. necatrix was most similar to that of neurospora crassa. thus, it seemed that the second intron of the r. necatrix cy ...200312619691
putative homologs of ssk22 mapkk kinase and pbs2 mapk kinase of saccharomyces cerevisiae encoded by os-4 and os-5 genes for osmotic sensitivity and fungicide resistance in neurospora crassa.we cloned and characterized neurospora ncssk22 and ncpbs2 genes, similar to yeast ssk22 mitogen-activated protein (map) kinase kinase kinase and the pbs2 map kinase kinase genes, respectively. disruptants of the ncssk22 gene were sensitive to osmotic stress and resistant to iprodione and fludioxonil. their phenotypes were similar to those of osmotic-sensitive (os) mutants os-1, os-2, os-4, and os-5. the os-4 mutant strain transformed with the wild-type ncssk22 gene grew on a medium containing 4% ...200312619694
tok homologue in neurospora crassa: first cloning and functional characterization of an ion channel in a filamentous fungus.in contrast to animal and plant cells, very little is known of ion channel function in fungal physiology. the life cycle of most fungi depends on the "filamentous" polarized growth of hyphal cells; however, no ion channels have been cloned from filamentous fungi and comparatively few preliminary recordings of ion channel activity have been made. in an attempt to gain an insight into the role of ion channels in fungal hyphal physiology, a homolog of the yeast k(+) channel (sctok1) was cloned from ...200312582135
a circadian oscillator in aspergillus spp. regulates daily development and gene expression.we have established the presence of a circadian clock in aspergillus flavus and aspergillus nidulans by morphological and molecular assays, respectively. in a. flavus, the clock regulates an easily assayable rhythm in the development of sclerotia, which are large survival structures produced by many fungi. this developmental rhythm exhibits all of the principal clock properties. the rhythm is maintained in constant environmental conditions with a period of 33 h at 30 degrees c, it can be entrain ...200312684372
role of the two type ii myosins, myo2 and myp2, in cytokinetic actomyosin ring formation and function in fission yeast.the formation and contraction of a cytokinetic actomyosin ring (car) is essential for the execution of cytokinesis in fission yeast. unlike most organisms in which its composition has been investigated, the fission yeast car contains two type ii myosins encoded by the genes myo2(+) and myp2(+). myo2(+) is an essential gene whilst myp2(+) is dispensable under normal growth conditions. myo2 is hence the major contractile protein of the car whilst myp2 plays a more subtle and, as yet, incompletely ...200312589679
promoter analysis of the avirulence gene avr9 of the fungal tomato pathogen cladosporium fulvum in the model filamentous fungus aspergillus nidulans.the promoter of avirulence gene avr9 of the fungal tomato pathogen cladosporium fulvum contains 12 sequences within a region of 0.6 kb that are reminiscent of the binding sequences of the gata-type regulator involved in nitrogen utilisation of the filamentous fungi aspergillus nidulans and neurospora crassa. mutational analysis of this 0.6-kb promoter region, fused to the beta-glucuronidase reporter gene, revealed that two regions, each containing two tagata boxes in inverted orientation and ove ...200312695849
the genome sequence of the filamentous fungus neurospora crassa.neurospora crassa is a central organism in the history of twentieth-century genetics, biochemistry and molecular biology. here, we report a high-quality draft sequence of the n. crassa genome. the approximately 40-megabase genome encodes about 10,000 protein-coding genes--more than twice as many as in the fission yeast schizosaccharomyces pombe and only about 25% fewer than in the fruitfly drosophila melanogaster. analysis of the gene set yields insights into unexpected aspects of neurospora bio ...200312712197
the yeast isn1 (yor155c) gene encodes a new type of imp-specific 5'-nucleotidase.the purine salvage enzyme inosine 5'-monophosphate (imp)-specific 5'-nucleotidase catalyzes degradation of imp to inosine. although this enzymatic activity has been purified and characterized in saccharomyces cerevisiae, the gene encoding imp 5'-nucleotidase had not been identified.200312735798
a complete inventory of fungal kinesins in representative filamentous ascomycetes.complete inventories of kinesins from three pathogenic filamentous ascomycetes, botryotinia fuckeliana, cochliobolus heterostrophus, and gibberella moniliformis, are described. these protein sequences were compared with those of the filamentous saprophyte, neurospora crassa and the two yeasts saccharomyces cerevisiae and schizosaccharomyces pombe. data mining and phylogenetic analysis of the motor domain yielded a constant set of 10 kinesins in the filamentous fungal species, compared with a sma ...200312742059
molecular genetics of fungal siderophore biosynthesis and uptake: the role of siderophores in iron uptake and storage.to acquire iron, all species have to overcome the problems of iron insolubility and toxicity. in response to low iron availability in the environment, most fungi excrete ferric iron-specific chelators--siderophores--to mobilize this metal. siderophore-bound iron is subsequently utilized via the reductive iron assimilatory system or uptake of the siderophore-iron complex. furthermore, most fungi possess intracellular siderophores as iron storage compounds. molecular analysis of siderophore biosyn ...200312759789
the role of adaptor protein ste50-dependent regulation of the mapkkk ste11 in multiple signalling pathways of yeast.in saccharomyces cerevisiae, ste50 functions in cell signalling between the activated g protein and the mitogen-activated protein kinase (mapk) kinase kinase (mapkkk) ste11. scste50 is an essential component of three mapk-mediated signalling pathways, which control the mating response, invasive/filamentous growth and osmotolerance (hog pathway), respectively. scste50 signalling may also contribute to cell wall integrity in vegetative cells. the protein contains a sterile alpha motif (sam) and a ...200312764668
diversification of exogenous genes in vivo in neurospora.we have adapted the meiotic recombination hotspot cog of neurospora crassa for shuffling exogenous dna, providing a means of generating novel genes in situ from sequences introduced into chromosomes. genes to be diversified are inserted between the his-3 locus and cog. diversification crosses are heterozygous both for alleles of the exogenous dna and for auxotrophic alleles of his-3. progeny selected for ability to grow without histidine supplementation are enriched for exchange events within th ...200312756504
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