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the neurospora crassa white collar-1 dependent blue light response requires acetylation of histone h3 lysine 14 by ngf-1.blue light-induced transcription in neurospora crassa is regulated by the white collar-1 (wc-1) photoreceptor. we report that residue k14 of histone h3 associated with the light-inducible albino-3 (al-3) promoter becomes transiently acetylated after photoinduction. this acetylation depends on wc-1. the relevance of this chromatin modification was directly evaluated in vivo by construction of a neurospora strain with a mutated histone h3 gene (hh3(k14q)). this strain phenocopies a wc-1 blind muta ...200616914525
a model for the proteolipid ring and bafilomycin/concanamycin-binding site in the vacuolar atpase of neurospora crassa.the vacuolar atpase has been implicated in a variety of physiological processes in eukaryotic cells. bafilomycin and concanamycin, highly potent and specific inhibitors of the vacuolar atpase, have been widely used to investigate the enzyme. derivatives have been developed as possible therapeutic drugs. we have used random mutagenesis and site-directed mutagenesis to identify 23 residues in the c subunit involved in binding these drugs. we generated a model for the structure of the ring of c sub ...200616912037
epigenetic regulation in drosophila.epigenetic regulation of gene transcription relies on molecular marks like dna methylation or histone modifications. here we review recent advances in our understanding of epigenetic regulation in the fruit fly drosophila melanogaster. in the past, dna methylation research has primarily utilized mammalian model systems. however, several recent landmark discoveries have been made in other organisms. for example, the interaction between dna methylation and histone methylation was first described i ...200616909905
gpr-4 is a predicted g-protein-coupled receptor required for carbon source-dependent asexual growth and development in neurospora crassa.the filamentous fungus neurospora crassa is able to utilize a wide variety of carbon sources. here, we examine the involvement of a predicted g-protein-coupled receptor (gpcr), gpr-4, during growth and development in the presence of different carbon sources in n. crassa. deltagpr-4 mutants have reduced mass accumulation compared to the wild type when cultured on high levels of glycerol, mannitol, or arabinose. the defect is most severe on glycerol and is cell density dependent. the genetic and p ...200616896213
circadian rhythms in neurospora crassa and other filamentous fungi. 200616896204
distinct white collar-1 genes control specific light responses in mucor circinelloides.light regulates many developmental and physiological processes in a large number of organisms. the best-known light response in the fungus mucor circinelloides is the biosynthesis of beta-carotene. here, we show that m. circinelloides sporangiophores also respond to light, exhibiting a positive phototropism. analysis of both responses to different light wavelengths within the visible spectrum demonstrated that phototropism is induced by green and blue light, whereas carotenogenesis is only induc ...200616879651
[a comparative study of the components of the antioxidant defense system during growth of the mycelium of a wild-type neurospora crassa strain and mutants, white collar-1 and white collar-2].a comparative study of the changes in the components of the antioxidant defense system (ads), the activity of superoxide dismutase (sod) and catalase and the level of extractable sh-groups, during the growth of wild-type and mutant (white collar-1 and white colar-2) neurospora crassa strains was performed. oxidative stress developing during spore germination and upon the transition to a stationary growth phase was accompanied in all strains by an increase in the level of extractable sh-groups an ...200616878551
circadian time keeping: the daily ups and downs of genes, cells, and organisms.light-sensitive organisms - from cyanobacteria to humans - contain circadian clocks that produce approximately 24-h cycles in the absence of external time cues. in various systems, clock genes have been identified and their functions examined. negative feedback loops in clock gene expression were initially believed to control circadian rhythms in all organisms. however, recent experiments with cyanobacteria and the filamentous fungus neurospora crassa tend to favour protein phosphorylation cycle ...200616876581
in silico mining in expressed sequences of neurospora crassa for identification and abundance of microsatellites.in the present study, 3217 unigene sequences of neurospora crassa downloaded from the national center for biotechnology information (ncbi) were mined for the identification of microsatellites or simple sequence repeats (ssrs). a total of 287 ssrs detected gives density of 1ssr/14.6 kb of 4187.86 kb sequences mined suggests that only 250 (7.8%) of sequences contained ssrs. depending on the repeat units, the length of ssrs ranged from 14 to 17 bp for mono-, 14 to 48 bp for di-, 18 to 90 bp for tri ...200716875812
generation and analysis of expressed sequence tags from botrytis cinerea.botrytis cinerea is a filamentous plant pathogen of a wide range of plant species, and its infection may cause enormous damage both during plant growth and in the post-harvest phase. we have constructed a cdna library from an isolate of b. cinerea and have sequenced 11,482 expressed sequence tags that were assembled into 1,003 contigs sequences and 3,032 singletons. approximately 81% of the unigenes showed significant similarity to genes coding for proteins with known functions: more than 50% of ...200616874411
functional analysis of an endo-1,6-beta-d-glucanase gene (neg-1) from neurospora crassa.the 1,6-beta-d-glucanase gene (neg1) of neurospora crassa was disrupted by repeat-induced point mutations. sequence analysis of the neg1 gene in the r12-1 mutant showed that 9 nucleotides within the coding region of the gene changed from gc to at. the base transition of c to a at position 662 resulted in a codon. no apparent phenotypic changes were observed in the mutant, but congo-red, sds, and cetyltrimethyl ammonium bromide (ctab), which affect fungal cell walls or membranes, markedly inhibit ...200616861813
analysis of strains with mutations in six genes encoding subunits of the v-atpase: eukaryotes differ in the composition of the v0 sector of the enzyme.to address questions about the structure of the vacuolar atpase, we have generated mutant strains of neurospora crassa defective in six subunits, c, h, a, c, c', and c''. except for strains lacking subunit c', the mutant strains were indistinguishable from each other in most phenotypic characteristics. they did not accumulate arginine in the vacuoles, grew poorly at ph 5.8 with altered morphology, and failed to grow at alkaline ph. consistent with findings from saccharomyces cerevisiae, the data ...200616857684
development and application of a suite of polysaccharide-degrading enzymes for analyzing plant cell walls.to facilitate analysis of plant cell wall polysaccharide structure and composition, we cloned 74 genes encoding polysaccharide-degrading enzymes from aspergillus nidulans, aspergillus fumigatus, and neurospora crassa and expressed the genes as secreted proteins with c-terminal myc and 6x his tags. most of the recombinant enzymes were active in enzyme assays, and optima for ph and temperature were established. a subset of the enzymes was used to fragment polysaccharides from the irregular xylem 9 ...200616844780
light-dependent subcellular localization of nucleoside diphosphate kinase-1 in neurospora crassa.nucleoside diphosphate kinase (ndk) is a housekeeping enzyme localized in cellular organelles and distributed in various organs in prokaryotes and eukaryotes. in neurospora crassa, ndk-1 is suggested to control catalases in response to heat, oxidative stress and light. in this study, we identified the presence of ndk-1 during most developmental stages in submerged mycelia, aerial hyphae, asexual conidia and perithecia, and the localization of it in soluble, mitochondrial, nuclear and membrane fr ...200616842360
interactions between iron availability, aluminium toxicity and fungal siderophores.the influence of iron, aluminium and of the combined application of both metals on microbial biomass and production of siderophores by three fungi (aspergillus nidulans, neurospora crassa and hymenoscyphus ericae) were investigated. all three species showed a strong iron regulation and al-sensitivity of siderophore biosynthesis although several differences remained species dependent. inhibitory effects of fe and al on siderophore-production were additive and the higher binding capacity of sidero ...200616841246
comparative est analysis provides insights into the basal aquatic fungus blastocladiella emersonii.blastocladiella emersonii is an aquatic fungus of the chytridiomycete class, which is at the base of the fungal phylogenetic tree. in this sense, some ancestral characteristics of fungi and animals or fungi and plants could have been retained in this aquatic fungus and lost in members of late-diverging fungal species. to identify in b. emersonii sequences associated with these ancestral characteristics two approaches were followed: (1) a large-scale comparative analysis between putative unigene ...200616836762
the ste20/germinal center kinase pod6 interacts with the ndr kinase cot1 and is involved in polar tip extension in neurospora crassa.members of the ste20 and ndr protein kinase families are important for normal cell differentiation and morphogenesis in various organisms. we characterized pod6 (ncu02537.2), a novel member of the gck family of ste20 kinases that is essential for hyphal tip extension and coordinated branch formation in the filamentous fungus neurospora crassa. pod-6 and the ndr kinase mutant cot-1 exhibit indistinguishable growth defects, characterized by cessation of cell elongation, hyperbranching, and altered ...200616822837
consecutive gene deletions in aspergillus nidulans: application of the cre/loxp system.the ability to perform multiple gene deletions is an important tool for conducting functional genomics. we report the development of a sequential gene deletion protocol for the filamentous fungus aspergillus nidulans using the cre/loxp recombinase system of bacteriophage p1. a recyclable genetic marker has been constructed by incorporating loxp direct repeats either side of the neurospora crassa pyr-4 gene (encodes orotidine 5'-monophosphate decarboxylase) which is able to complement the a. nidu ...200616783565
light regulation of asexual development in the rice blast fungus, magnaporthe oryzae.light is a major environmental factor that influences many biological processes. we characterized the roles of light in asexual development (including the formation of aerial hyphae and conidiophore) in magnaporthe oryzae, which is the causal agent of rice blast disease. our data revealed a complex nature of light regulation in the asexual developments of m. oryzae. asexual development of m. oryzae is suppressed by blue light in a light/dark cycling environment and asexual spore release is contr ...200616765070
chromosome pairing and meiotic recombination in neurospora crassa spo11 mutants.some organisms, such as mammals, green plants and fungi, require double-strand breaks in dna (dsbs) for synapsis of homologous chromosomes at pachynema. drosophila melanogaster and caenorhabditis elegans are exceptions, achieving synapsis independently of dsb. spo11 is responsible for generating dsbs and perhaps for the initiation of recombination in all organisms. although it was previously suggested that neurospora may not require dsbs for synapsis, we report here that mutation of neurospora s ...200616758206
effect of mutations in tom40 on stability of the translocase of the outer mitochondrial membrane (tom) complex, assembly of tom40, and import of mitochondrial preproteins.mitochondrial preproteins synthesized in the cytosol are imported through the mitochondrial outer membrane by the translocase of the outer mitochondrial membrane (tom) complex. tom40 is the major component of the complex and is essential for cell viability. we generated 21 different mutations in conserved regions of the neurospora crassa tom40 protein. the mutant genes were transformed into a tom40 null nucleus maintained in a sheltered heterokaryon, and 17 of the mutant genes gave rise to viabl ...200616757481
identification of a new human mtdna polymorphism (a14290g) in the nadh dehydrogenase subunit 6 gene.leber's hereditary optic neuropathy (lhon) is a maternally inherited form of retinal ganglion cell degeneration leading to optic atrophy in young adults. several mutations in different genes can cause lhon (heterogeneity). the nd6 gene is one of the mitochondrial genes that encodes subunit 6 of complex i of the respiratory chain. this gene is a hot spot gene. fourteen persian lhon patients were analyzed with single-strand conformational polymorphism and dna sequencing techniques. none of these p ...200616751977
a nonself recognition gene complex in neurospora crassa.nonself recognition is exemplified in the fungal kingdom by the regulation of cell fusion events between genetically different individuals (heterokaryosis). the het-6 locus is one of approximately 10 loci that control heterokaryon incompatibility during vegetative growth of n. crassa. previously, it was found that het-6-associated incompatibility in oak ridge (or) strains involves two contiguous genes, het-6 and un-24. the or allele of either gene causes "strong" incompatibility (cell death) whe ...200616751666
studies in carotenogenesis. 30. the problem of lycopersene formation in neurospora crassa. 196316749006
observations on the effects of methionine and homocysteine on growth of a cholineless mutant of neurospora crassa. 196116748933
the oxidation of various synthetic alpha-amino-acids by mammalian d-amino-acid oxidase, l-amino-acid oxidase of cobra venom and the l- and d-amino-acid oxidases of neurospora crassa. 195016748663
two circadian timing circuits in neurospora crassa cells share components and regulate distinct rhythmic processes.in neurospora crassa, frq, wc-1, and wc-2 proteins comprise the core circadian frq-based oscillator that is directly responsive to light and drives daily rhythms in spore development and gene expression. however, physiological and biochemical studies have demonstrated the existence of additional oscillators in the cell that function in the absence of frq (collectively termed frq-less oscillators [flos]). whether or not these represent temperature-compensated, entrainable circadian oscillators is ...200616731655
flexibility of the neck domain enhances kinesin-1 motility under load.kinesin-1 is a dimeric motor protein that moves stepwise along microtubules. a two-stranded alpha-helical coiled-coil formed by the neck domain links the two heads of the molecule, and forces the motor heads to alternate. by exchanging the particularly soft neck region of the conventional kinesin from the fungus neurospora crassa with an artificial, highly stable coiled-coil we investigated how this domain affects motor kinetics and motility. under unloaded standard conditions, both motor constr ...200616714343
characterization of calcineurin-dependent response element binding protein and its involvement in copper-metallothionein gene expression in neurospora.in continuation of our recent observations indicating the presence of a lone calcineurin-dependent response element (cdre) in the -3730bp upstream region of copper-induced metallothionein (cumt) gene of neurospora [k.s. kumar, s. dayananda, c. subramanyam, copper alone, but not oxidative stress, induces copper-metallothionein gene in neurospora crassa, fems microbiol. lett. 242 (2005) 45-50], we isolated and characterized the cdre-binding protein. the cloned upstream region of cumt gene was used ...200616707100
isolation, characterization, and disruption of dnr1, the area/nit-2-like nitrogen regulatory gene of the zoophilic dermatophyte, microsporum canis.a homolog of the major nitrogen regulatory genes area from aspergillus nidulans and nit-2 from neurospora crassa was isolated from the zoophilic dermatophyte, microsporum canis. this gene, dnr1, encodes a polypeptide of 761 amino acid residues containing a single zinc-finger dna-binding domain, which is almost identical in amino acid sequence to the zinc-finger domains of area and nit-2. the functional equivalence of dnr1 to area was demonstrated by complementation of an area loss-of-function mu ...200616702104
cloning and sequencing of the genes for a and b subunits of the v-type na(+)-atpase of a facultatively anaerobic alkaliphile.the structural genes for a and b subunits of the v-type na(+)-atpase from a facultatively anaerobic alkaliphile (amphibacillus sp.), strain m-12, were cloned and sequenced. transformation of escherichia coli with the genes overexpressed two proteins, which crossreacted with an antiserum against a and b subunits of the v-type na(+)-atpase from enterococcus hirae. the deduced amino acid sequence (594 amino acids; mr, 66,144) of a subunit of the m-12 enzyme exhibited 73%, 51%, 49% and 53% identitie ...200516701541
interaction of nucleoside diphosphate kinase and catalases for stress and light responses in neurospora crassa.nucleoside diphosphate kinase (ndk) is an ubiquitous enzyme with the function of a signal transducer. in neurospora crassa, an ndk-1(p72h) mutant carrying the point mutation pro72his was isolated. we found that ndk-1(p72h) showed hypersensitivity to oxidative and heat stress and a decrease in the levels of catalase (cat)-1 and -3 induced by oxidative, heat stress and illumination compared with wild type (wt). we found, by conducting a yeast two-hybrid assay, that cat-1 interacted with ndk-1. ndk ...200616697373
how temperature affects the circadian clock of neurospora crassa.light and temperature are major environmental cues that influence circadian clocks. the molecular effects of these zeitgebers on the circadian clock of neurospora crassa have been studied intensively during the last decade. while signal transduction of light into the circadian clock is quite well characterized, we have only recently begun to understand the molecular mechanisms that underlie temperature sensing. here we summarize briefly the current knowledge about the effects of temperature on t ...200616687282
entrainment of the neurospora circadian clock.neurospora crassa has been systematically investigated for circadian entrainment behavior. many aspects of synchronization can be investigated in this simple, cellular system, ranging from systematic entrainment and drivenness to masking. clock gene expression during entrainment and entrainment without clock genes suggest that the known transcription/translation feedback loop is not alone responsible for entrainment in neurospora.200616687281
the transition metal chelator nicotianamine is synthesized by filamentous fungi.nicotianamine is an important metal ligand in plants. surprisingly, recent genome sequencing revealed that ascomycetes encode proteins with similarity to plant nicotianamine synthases (nas). by expression in a zn2+-hypersensitive fission yeast mutant we show for a protein from neurospora crassa that it indeed possesses nas activity. using electrospray-ionization-quadrupole-time-of-flight mass spectrometry we prove the formation of nicotianamine in n. crassa. transcript level is strongly upregula ...200616684531
crystal structure of 2-nitropropane dioxygenase complexed with fmn and substrate. identification of the catalytic base.nitroalkane compounds are widely used in chemical industry and are also produced by microorganisms and plants. some nitroalkanes have been demonstrated to be carcinogenic, and enzymatic oxidation of nitroalkanes is of considerable interest. 2-nitropropane dioxygenases from neurospora crassa and williopsis mrakii (hansenula mrakii), members of one family of the nitroalkane-oxidizing enzymes, contain fmn and fad, respectively. the enzymatic oxidation of nitroalkanes by 2-nitropropane dioxygenase o ...200616682407
direct measurement of vdac-actin interaction by surface plasmon resonance.vdac--a mitochondrial channel involved in the control of aerobic metabolism and apoptosis--interacts in vitro and in vivo with a wide repertoire of proteins including cytoskeletal elements. a functional interaction between actin and neurospora crassa vdac was reported, excluding other vdac isoforms. from a recent genome-wide screen of the vdac interactome, we found that human actin is a putative ligand of yeast vdac. since such interaction may have broader implications for various mitochondrial ...200616678788
adp-glucose transport by the chloroplast adenylate translocator is linked to starch biosynthesis.in organello starch biosynthesis was studied using intact chloroplasts isolated from spinach leaves (spinacia oleracea). immunoblot analysis using a specific antiserum against the mitochondrial adenylate (adp/atp) translocator of neurospora crassa shows the presence of an adenylate translocator protein in the chloroplast envelope membranes, similar to that existing in mitochondria and amyloplasts from cultured cells of sycamore (acer pseudoplatanus). the double silicone oil layer-filtering centr ...199116668585
purification and characterization of chorismate synthase from euglena gracilis: comparison with chorismate synthases of plant and microbial origin.chorismate synthase was purified 1200-fold from euglena gracilis. the molecular mass of the native enzyme is in the range of 110 to 138 kilodaltons as judged by gel filtration. the molecular mass of the subunit was determined to be 41.7 kilodaltons by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. purified chorismate synthase is associated with an nadph-dependent flavin mononucleotide reductase that provides in vivo the reduced flavin necessary for catalytic activity. in vitro, flavi ...199116668543
calcium activates an electrogenic proton pump in neurospora plasma membrane.calcium ionophoresis into coenocytic cells of neurospora crassa activates the plasma membrane proton pump as measured by current-voltage analysis. this is direct evidence that intracellular calcium regulates the activity of a key transport enzyme found in higher plants and fungi.198916666998
immunochemical analysis shows that an atp/adp-translocator is associated with the inner-envelope membranes of amyloplasts from acer pseudoplatanus l.pure preparations of intact amyloplasts and chloroplasts, free from mitochondrial contamination, were isolated from cultured cells of the white-wild and green-mutant lines of sycamore (acer pseudoplatanus l.), respectively. a specific rabbit antiserum against yeast mitochondrial cytochrome c(1) only cross-reacted with mitochondrial membranes from the white-wild sycamore cells. the outer and inner envelope-membranes of the two plastid-types were isolated and subsequently analyzed by sodium dodecy ...198916666656
characterization of nitrate reductase deficient mutants of chlorella sorokiniana.after x-ray irradiation, 13 mutants of chlorella sorokiniana incapable of using no(3) (-) as n source were isolated using a pinpoint method. using immunoprecipitation and western blot assays, no nitrate reductase was found in five strains while in eight mutants the enzyme was detected. the latter strains contained different patterns of nitrate reductase partial reactions. all isolates were of the nia-type as indicated by the inducibility of purine hydroxylase i and by complementation of nitrate ...198916666622
factors associated with the instability of nitrate-insensitive proton transport by maize root microsomes.proton transport catalyzed by the nitrate-insensitive, vanadate-sensitive h(+)-atpase in microsomes from maize (zea mays l.) roots washed with 0.25 molar ki decreased as a function of time at 0 to 4 degrees c. the rate of proton transport was approximately one-half of that by freshly isolated microsomes after 6 to 18 hours of cold storage. the decrease in proton transport coincided with losses in membrane phosphatidylcholine and was not associated with a change in vanadate-sensitive atp hydrolys ...198816666192
h-atpase activity from storage tissue of beta vulgaris: iv. n,n'-dicyclohexylcarbodiimide binding and inhibition of the plasma membrane h-atpase.the molecular weight and isoelectric point of the plasma membrane h(+)-atpase from red beet storage tissue were determined using n,n'-dicyclohexylcarbodiimide (dccd) and a h(+)-atpase antibody. when plasma membrane vesicles were incubated with 20 micromolar [(14)c]-dccd at 0 degrees c, a single 97,000 dalton protein was visualized on a fluorograph of a sodium dodecyl sulfate polyacrylamide gel. a close correlation between [(14)c]dccd labeling of the 97,000 dalton protein and the extent of atpase ...198716665290
intracellular and extracellular cyclic nucleotides in wild-type and white collar mutant strains of neurospora crassa: temperature dependent efflux of cyclic amp from mycelia.cyclic amp and cyclic gmp were released into the growth medium of mycelia of neurospora crassa wild-type strains st.l.74a and em5297a and by white collar-1 and white collar-2 mutant strains. after growth for 6 days at 18 degrees c, there were 2.19 (st.l.74a), 5.83 (em5297a), 1.38 (white collar-1), and 1.10 (white collar-2) nanomoles of cyclic amp per gram dry weight of mycelia in the growth medium. these values corresponded to concentrations of cyclic amp of between approximately 10 and 50 nanom ...198716665253
voltage-dependent channels found in the membrane fraction of corn mitochondria.transmembrane channels have been found in the membrane fraction of corn (zea mays w64an) mitochondria that exhibit a remarkable resemblance to the voltage dependent anion-selective channels (vdac) located in the outer membrane of animal (rattus norvegicus), protist (paramecium aurelia), and fungal (neurospora crassa) mitochondria. the channels in corn were demonstrated to be essentially identical to vdac channels in three characteristic properties: (a) single channel conductance magnitude, (b) w ...198516664537
blue light-reducible cytochromes in membrane fractions from neurospora crassa.we have assayed absorbance changes generated by blue light in plasma membranes, endoplasmic reticulum, and mitochondrial membranes from neurospora crassa. light minus dark difference spectra, obtained anaerobically in the presence of ethylenediaminetetraacetate, indicated that b-type cytochromes could be photoreduced in all three membranes. in plasma membranes, a b-type cytochrome with a distinct difference spectrum was photoreducible without addition of exogenous flavin. addition of riboflavin ...198516664261
effects of respiratory inhibitors on respiration, atp contents, and the circadian conidiation rhythm of neurospora crassa.effects of respiratory inhibitors on the circadian clock, respiratory activity, and atp content were examined in neurospora crassa. all inhibitors, potassium cyanide, sodium azide, antimycin a, and carbonyl cyanide m-chlorophenyl hydrazone (cccp), shifted the phase of the conidiation rhythm. all the phase response curves were similar and resembled that for cycloheximide, but were different from the phase response curve for light. phase shifting by azide and cccp was proportional to the lowering ...198416663893
calcium inhibits phase shifting of the circadian conidiation rhythm of neurospora crassa by the calcium ionophore a23187.effects of the calcium ionophore, a23187, and antimycin a on the circadian conidiation rhythm of neurospora crassa were examined. a23187 at a concentration of 1 mum in medium not containing divalent cations delayed the phase by 10 hours at ct 10 and advanced it by 5 hours at ct 14 (ct 12 corresponds to the time that discs are transferred from light to dark). this phase shifting was completely inhibited by addition of 0.1 millimolar cacl(2) but not by mgcl(2) at any concentrations examined.antimy ...198416663409
genetic analysis of phototropism of neurospora crassa perithecial beaks using white collar and albino mutants.positive phototropism of perithecial beaks in the fungus neurospora crassa has been demonstrated. the effect was shown to be mediated by blue light. when mutants (white collar-1 and white collar-2) which are blocked in the light induction of enzymes in the carotenoid biosynthetic pathway were used as the protoperithecial parent in crosses, the resulting perithecial beaks did not show a phototropic response. however, when wild type, albino-1, albino-2, or albino-3 strains were used as the protope ...198316663152
modification of blue light photoresponses by riboflavin analogs in neurospora crassa.the effect of riboflavin analogs on blue light responses in a riboflavin mutant of neurospora crassa was studied. the analogs 1-deazariboflavin and roseoflavin, which have red-shifted absorption, acted as photoreceptors for the photosuppression and phase shifting of circadian conidiation by 540 nm light, but were ineffective as photoreceptors for the induction of carotenoid synthesis. these results provide addtional evidence implicating a flavin photoreceptor for at least two blue light response ...198316663082
intracellular localization of nitrate reductase in neurospora crassa.nitrate reductase was localized in mycelial cells of neurospora crassa by immunohistochemical labeling with ferritin. the enzyme is found in the cell wall-plasmalemma region and in the tonoplast membranes.198216662763
phase shifting of the circadian clock by diethylstilbestrol and related compounds in neurospora crassa.phase shifts of the circadian conidiation rhythm in neurospora crassa were induced by 3-hour treatments of mycelia in liquid medium with diethylstilbestrol (des), dienestrol (die), hexestrol (hex), diethylstilbestroldipropionate (desp), and dienestroldiacetate (diea). over a 24-hour period beginning 24 hours after the transition from light to constant dark, maximum phase shifts occurred about 36 hours. des was the most effective of the drugs tested, giving 10-hour phase advances at 20 micromolar ...198216662655
intracellular localization of nitrate reductase in neurospora crassa.nitrate reductase was localized in mycelial cells of neurospora crassa by immunohistochemical labeling with ferritin. the enzyme is found in the cell wall-plasmalemma region and in the tonoplast membranes.198216662592
nuclear buoyant density determination and the purification and characterization of wild-type neurospora nuclei using percoll density gradients.a procedure has been developed using percoll density gradients for the isolation and purification of nuclei from germinated conidia of wild-type neurospora crassa st. lawrence strain 74a. crude nuclei were purified isopycnically in gradients of percoll, which is silica coated with polyvinylpyrrolidone. a dna:rna:protein ratio of 1:3.5:6.5 was found in purified nuclei. cytoplasmic contamination was found to be negligible in the nuclear preparations, as determined by electron microscopy and by fol ...198216662561
effects of membrane atpase inhibitors on light-induced phase shifting of the circadian clock in neurospora crassa.effects of several membrane atpase inhibitors on light-induced phase shifting of the circadian conidiation rhythm in neurospora crassa were examined using mycelial discs in liquid culture. suppression of phase shifting by the inhibitors was strongly dependent on the ph of the liquid medium in which the discs were cultured during the time from light-dark transition (beginning of free-run) to light irradiation. when discs were cultured in ph 6.7 medium, azide, the inhibitors of plasma membrane atp ...198216662260
temperature compensation of circadian period length in clock mutants of neurospora crassa.temperature compensation of circadian period length in 12 clock mutants of neurospora crassa has been examined at temperatures between 16 and 34 degrees c. in the wild-type strain, below 30 degrees c (the "breakpoint" temperature), the clock is well-compensated (q(10) = 1), while above 30 degrees c, the clock is less well-compensated (q(10) = 1.3). for mutants at the frq locus, mutations that shorten the circadian period length (frq-1, frq-2, frq-4, and frq-6) do not alter this temperature compe ...198116662086
immunological approach to structural comparisons of assimilatory nitrate reductases.homogeneous squash cotyledon reduced nicotinamide-adenine dinucleotide (nadh):nitrate reductase (nr) was isolated using blue-sepharose and polyacrylamide gel electrophoresis. gel slices containing nr were pulverized and injected into a previously unimmunized rabbit. this process was repeated weekly and antiserum to nr was obtained after four weeks. analysis of the antiserum by ouchterlony double diffusion using a blue-sepharose preparation of nr resulted in a single precipitin band while immunoe ...198116662083
photoregulation of the carotenoid biosynthetic pathway in albino and white collar mutants of neurospora crassa.the conversion of isopentenyl pyrophosphate to phytoene in neurospora crassa requires both a soluble and a particulate fraction. soluble and particulate enzyme fractions obtained from light-treated and dark-grown wild type, albino-1, albino-2, albino-3, and white collar-1 strains were mixed in various combinations, and the activity for conversion of [1-(14)c]isopentenyl pyrophosphate to phytoene was assayed. from such experiments it can be concluded that: (a) albino-3 is defective in the soluble ...198116661992
assay and characteristics of circadian rhythmicity in liquid cultures of neurospora crassa.previous work on circadian rhythms of neurospora crassa has been done almost exclusively with cultures expressing rhythmic conidiation and growing on solid agar medium. such conditions severely restrict the kinds of biochemical experiments that can be carried out. we have now developed systems which allow indirect assay of circadian rhythmicity in liquid culture. neurospora was grown in glucose and acetate liquid media under conditions which result in a range of growth rates and morphologies. li ...198116661683
effects of temperature perturbations on circadian conidiation in neurospora.studies on the circadian rhythm of conidiation in the bd strain of neurospora crassa shear and dodge have shown that temperature step-up and step-down perturbations produce phase advances and delays, respectively. pulse-up and pulse-down treatments lead to both phase advances and delays. the resulting phase shifts can be very large, and few to no transients are observed.small amplitude temperature cycles are capable of entraining the circadian rhythm, and holding bd at low temperatures appears t ...197916661081
spatial distribution of circadian clock phase in aging cultures of neurospora crassa.neurospora crassa has been utilized extensively in the study of circadian clocks. previously, the clock in this organism has been monitored by observing the morphological and biochemical changes occurring at the growing front of cultures grown on solid medium. a method has been developed for assaying the clock in regions of the culture behind the growing front, where no apparent morphological changes occur during the circadian cycle. using this assay with petri dish cultures that were 2 to 7 day ...197916660855
blue light-induced absorbance changes in membrane fractions from corn and neurospora.blue light-induced absorbance changes were measured from differentially centrifuged membrane fractions from dark-grown coleoptiles of zea mays l., and mycelia from an albino mutant of neurospora crassa. actinic irradiation caused changes in absorbance consistent with a flavinmediated reduction of a b-type cytochrome. both corn and neurospora showed similar light-minus-dark difference spectra, dose response curves, and kinetics of dark recovery after irradiation. the photoreducible cytochrome sys ...197716659974
effects of chloramphenicol on the circadian rhythm of neurospora crassa.chloramphenicol, an inhibitor of mitochondrial protein synthesis, shortened the period length of the circadian rhythm in the timex strain of neurospora crassa by 2 hours. both the l(+) threo and d(-) threo optical isomers had the same effect on the period of the rhythm, whereas only the d(-) threo isomer significantly inhibited mitochondrial protein synthesis. tetracycline, another inhibitor of mitochondrial protein synthesis, did not change the period of the circadian rhythm. the effect of chlo ...197616659724
action spectrum between 260 and 800 nanometers for the photoinduction of carotenoid biosynthesis in neurospora crassa.an action spectrum for light-induced carotenoid biosynthesis in neurospora crassa was determined in 4 to 20 nm steps from 260 to 800 nm. four-day, dark-grown mycelial pads of n. crassa were exposed to varying amounts of monochromatic radiant energy and time. after a 48-hour incubation period at 6 c, carotenoid content was assayed spectrophotometrically in vivo. the action spectrum has maxima at 450 and 481 nm in the visible range and at 280 and 370 nm in the ultraviolet. a pigment synthesized by ...197616659499
photoreceptor pigment for blue light in neurospora crassa.irradiating the mycelium of neurospora crassa with moderate intensities of blue light causes a reversible photoreduction of a b-type cytochrome. the action spectrum for the photoreduction of cytochrome b is very similar to the absorption spectrum of flavin pigments. prolonged irradiation of the mycelium with strong blue light irreversibly bleaches flavin-like pigments and as these pigments are bleached the photoresponse of cytochrome b is lost. we conclude from these and other data that a flavin ...197516659094
the effect of temperature on photo-induced carotenoid biosynthesis in neurospora crassa.the temperature dependence of carotenoid synthesis in neurospora crassa was investigated. the primary light reaction is independent of temperature, but the amount of carotenoid pigment which subsequently accumulates in the dark is strongly dependent on the temperature during the dark incubation. carotenoid synthesis shows a sensitivity to both high and low temperatures, and of the temperatures tested, 6 c is optimal. exposure to temperatures above 6 c for various times immediately following irra ...197416658849
a direct comparison between circadian and noncircadian rhythms in neurospora crassa.a method has been devised for observing both circadian and noncircadian rhythms in a single wild type strain of neurospora crassa. this method allows a direct comparison of the properties of the two types of rhythm. the circadian rhythm of conidiation always entrains to a light-dark cycle, damps out in constant light, and has a temperature-compensated period length. the noncircadian rhythm of hyphal branching, expressed by the same strain under different environmental conditions, does not entrai ...197416658817
a failure to detect an influence of magnetic fields on the growth rate and circadian rhythm of neurospora crassa.low strength magnetic fields, 6.36 and 32.25 gauss, were found to have no effect, with one questionable exception, on the circadian rhythm and growth rate of neurospora crassa. this was true whether the fields were continuous, pulsed 20 minutes daily, or on a 12: 12, on-off cycle.197416658667
effects of medium composition and carbon dioxide on circadian conidiation in neurospora.efforts to significantly perturb the timing mechanism, and thus the period, of the rhythm responsible for circadian conidiation in bd, a strain of neurospora crassa, by altering the medium composition have been unsuccessful. various salt solutions, sugars, and amino acids do, however, have pronounced effects on growth and conidiation, and thus on the expression and persistence of rhythmicity.aeration stimulates conidiation in growth-tube cultures, thereby allowing experiments which demonstrate t ...197216658116
the effects of light on a circadian rhythm of conidiation in neurospora.the expression of a circadian rhythm of conidiation by timex, a strain of neurospora crassa, is inhibited by growth in continuous white light. the action spectrum for this effect has a strong peak (with minor subpeaks) in the blue region of the visible spectrum, and a broad shoulder in the near ultraviolet. this action spectrum suggests that a carotenoid or flavin compound may be the photoreceptor, but does not allow one to determine conclusively whether the receptor is indeed a carotenoid, flav ...196716656687
nonessentiality of boron in fungi and the nature of its toxicity.an investigation was undertaken to determine whether any of the following fungi had a requirement for boron (b): saccharomyces cerevisiae, aspergillus niger, neurospora crassa, and penicillium chrysogenum. boron was unessential, and hence a study was made of the concentrations of b that reduced the growth of s. cerevisiae and p. chrysogenum and the mode of action of the b toxicity. fifty and 4000 mg b/liter, respectively, significantly (5% level) reduced the growth of the latter 2 species.in bot ...196616656256
some physiological characteristics of ascospore activation in neurospora crassa. 195416654690
transcriptional and post-transcriptional regulation of the circadian clock of cyanobacteria and neurospora.circadian clocks are self-sustained oscillators modulating rhythmic transcription of large numbers of genes. clock-controlled gene expression manifests in circadian rhythmicity of many physiological and behavioral functions. in eukaryotes, expression of core clock components is organized in a network of interconnected positive and negative feedback loops. this network is thought to constitute the pacemaker that generates circadian rhythmicity. the network of interconnected loops is embedded in a ...200616651653
biochemical properties of a thermostable phytase from neurospora crassa.a gene (ncphy) encoding a putative phytase in neurospora crassa was cloned and expressed in pichia pastoris, and the biochemical properties of the recombinant protein were examined in relation to the phytic acid hydrolysis in animal feed. the recombinant phytase (rncphy) hydrolyzed phytic acid with a specific activity of 125 u mg-1, km of 228 micromol l-1, vmax of 0.31 nmol (phosphate) s-1 mg-1, a temperature optimum of 60 degrees c and a ph optimum of 5.5 and a second ph optimum of 3.5. the enz ...200616630256
nucleotide excision repair and photoreactivation in the entomopathogenic fungi beauveria bassiana, beauveria brongniartii, beauveria nivea, metarhizium anisopliae, paecilomyces farinosus and verticillium lecanii.to compare the dna repair capabilities of the entomopathogenic fungus (epf) bassiana to the epf beauveria brongniartii, beauveria nivea, metarhizium anisopliae, paecilomyces farinosus, verticillium lecanii, and the fungi aspergillus niger and neurospora crassa.200616629997
microtubule dynamics and organization during hyphal growth and branching in neurospora crassa.by confocal microscopy, we analyzed microtubule (mt) behavior during hyphal growth and branching in a neurospora crassa strain whose mts had been tagged with gfp. images were assembled spatially and temporally to better understand the 3-d organization of the microtubular cytoskeleton and a clearer view of its dynamics. cytoplasmic mts were mainly arranged longitudinally along the hyphal tube. straight segments were rare; most mts showed a distinct helical curvature with a long pitch and a tenden ...200616621627
[the changes of rare codon and mrna structure accelerate expression of qa-3 in escherichia coli].the key and crucial step of metabolic engineering during quinic acid biosynthesize using shikimic acid pathway is high expression of quinate 5-dehydrogenase. the gene qa-3 which code quinate 5-dehydrogenase from neurospora crassa doesn't express in escherichia coli. by contrast with codon usage in escherichia coli, there are 27 rare codons in qa-3, including eight agg/aga (arg) and nine ggg (gly). two agg are joined together (called box r) and some ggg codons are relative concentrate (called box ...200616607943
efficient cloning of genes of neurospora crassa.we have constructed a genomic library of neurospora crassa dna in a cosmid vector that contains the dominant selectable marker for benomyl resistance. the library is arranged to permit the rapid cloning of neurospora genes by either sib-selection or colony-hybridization protocols. detailed procedures for the uses of the library are described. by use of these procedures, a modest number of unrelated genes have been isolated. the cloning of trp-3, the structural gene for the multifunctional enzyme ...198616593723
germination and growth of neurospora at low water activities.when the water activity (a(w)) of the medium is lowered by the addition of nacl or nonelectrolytes, an inhibition of germination, growth rate, and total growth is observed in neurospora crassa. inhibition of conidial germination is separable from the other effects and is caused, in large measure, by the loss from conidia in media of low water activity of a substance that is essential for their germination. the substance is detectable in the medium and is also extractable from cultures. it is dia ...197116591899
an enzymatic difference among pyr-3 mutants of neurospora crassa. 196016590656
comparative complementation and genetic maps of the pan-2 locus in neurospora crassa. 196016590655
the relationship of sodium, potassium, and deoxycorticosterone in neurospora crassa. 195916590577
studies on normal and genetically altered tryptophan synthetase from neurospora crassa. 195916590520
enzyme complementation in vitro between adenylosuccinaseless mutants of neurospora crassa. 195916590454
genetic alteration of pyrroline-5-carboxylate reductase in neurospora crassa. 195916590370
on a mechanism of suppressor gene regulation of tryptophan synthetase activity in neurospora crassa. 195916590369
complementation at the ad-4 locus in neurospora crassa. 195816590338
dissociation of rubidium uptake by neurospora crassa into entry and binding phases. 195816590325
the biosynthesis of isoleucine and valine in neurospora crassa. 195816590304
production, reproduction, and reversion of protoplast-like structures in the osmotic strain of neurospora crassa. 195816590257
evidence from tetrad analysis for both normal and aberrant recombination between allelic mutants in neurospora crassa. 195816590210
synergism of two cytoplasmically inherited mutants in neurospora crassa. 195616589942
heterocaryosis and protoplasmic incompatibility in neurospora crassa. 195616589916
the q locus of neurospora crassa. 195616589847
on the glutamate-proline-ornithine interrelation in neurospora crassa. 195416589539
a partial map of linkage group d in neurospora crassa. 195416589501
mendelian and non-mendelian factors affecting the cytochrome system in neurospora crassa. 195316589312
pseudo-wild types in neurospora crassa. 195216589148
the accumulation of alpha-phenylglycine by mutants of neurospora crassa stimulated by phenylalanine and tyrosine. 195216589129
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