on the metabolic role of thymidine 2'-hydroxylase (thymidine, 2-oxoglutarate: oxygen oxidoreductase, ec in neurospora crassa. 2002136368
biogenesis of mitochondrial membranes in neurospora crassa. mitochondrial protein synthesis during conidial germination.the conidia of neurospora crassa entered logarithmic growth after a 1-h lag period at 30 degrees c. although [14c]leucine is incorporated quickly early in growth, cellular protein data indicated that no net protein synthesis occurred until after 2 h of growth. neurospora is known to produce ethanol during germination even though respiratory enzymes are present. also, neurospora mitochondria isolated from cells less than 3-h old are uncoupled. since oxygen uptake increased during germination, was ...2002126153
the interactive effect of ultraviolet irradiation and 5-bromouracil at the rib-1 locus in neurospora crassa.5-bromouracil (5-bu) was shown to enhance reverse mutation rates when added to conidia of a rib-1 strain of neurospora crassa previously irradiated with ultraviolet light. a comparison is presented between various incubation intervals in the presence and absence of 5-bu while varying the uv dose. an increase in mutation frequency ranging from 0.028 - 2.05 x 10(2) times greater than the spontaneous frequency, uv frequency alone or 5-bu frequency alone was observed when uv irradiation and 5-bu wer ...2002126795
a reduced pyridine nucleotides-diaphorase activity associated to the assimilatory nitrite reductase complex from neurospora crassa.the neurospora crassa assimilatory nad(p)h-nitrite reductase complex has associated a nad(p)h-diaphorase activity. 1. this nad(p)h-diaphorase activity can use either mammalian cytochrome c, 2,6--dichlorophenol-indophenol, ferricyanide, or menadione as electron acceptor from the reduced pyridine nucleotides, and requires flavin adenine dinucleotide for maximal activity. 2. it is inhibited by p-hydroxymercuribenzoate, 1 mum, and it is unaffected by cyanide, sulfite, or arsenite at concentrations w ...2002136235
mutation induction by difunctional alkylating agents in neurospora crassa.the genetic characterization of ad-3 mutants of neurospora crassa induced by two carcinogenic difunctional akylating agents, 1,2,4,5-diepoxypentane (dep) and 1,2,7,8-diepoxyoctane (deo), has shown that point mutations at the ad-3b locus have similar complementation patterns. in addition to the induction of point mutations, dep induces a low frequency (7.5%) of multilocus deletions, whereas deo induces an extremely high frequency (42.0%). the distribution of the different classes of ad-3 mutants ...2002133852
coordinate activation of a multienzyme complex by the first substrate. evidence for a novel regulatory mechanism in the polyaromatic pathway of neurospora crassa. 2002130831
ultraviolet-inactivation of conidia from heterokaryons of neurospora crassa containing uv-sensitive mutations.the effect of three uv-sensitive mutations of neurospora crassa, upr-i, uvs-4 and uvs-6, on the ultraviolet-inactivation of conidia from two-component heterokaryons was investigated. in two-component heterokaryons with wild-type sensitivity to radiation inactivation, all three conidial fractions exhibited similar ultraviolet-inactivation curves. each uv-sensitive mutation studied uniquely modified the ultraviolet-inactivation curves of conidia from two-component heterokaryons. in heterokaryons h ...2002123634
induction by rna of inositol independence in neurospora crassa.the effect of purified wild-type rna (allo-rna) on genetic reversion of inositol-requiring mutant 89601 of neurospora crassa is described. the mutant (inos minus) strain, on treatment with the wild-type rna preparation, was found to revert to wild type (inos+) in significant numbers. rna from the mutant (iso-rna) and allo-rna digested by rnase were ineffective in causing genetic reversion at the inositol locus. the allo-rna-induced revertants were stable and showed a mendelian transmission of th ...2002123644
the mechanism of arsenate inhibition of the glucose active transport system in neurospora crassa. 2002123729
a kinetic study of thymine 7-hydroxylase from neurospora crassa.the steady-state kinetics of thymine 7-hydroxylase (thymine, 2-oxoglutarate dioxygenase, ec has been investigated. initial velocity plots were all found to be linear and intersecting. variation in concentration of two of the substrates, when the third substrate was at a constant high or low concentration, gave initial velocity plots that conform to an ordered sequential mechanism, where thymine is the second substrate to add. with 5-carboxyuracil, which is the end product in the seque ...2002126696
[possible physiological role of the "high molecular weight polyphosphate-polyphosphate phosphohydrolase" system in neurospora crassa].the biosynthesis of polyphosphatase and the system of active transport of glucose is repressed in the cells of neurospora crassa by glucose at a high concentration. there is a strict correlation between the activity of polyphosphatase and the initial rate of glucose active transport. both systems are repressed during the growth of the mycelium on a glucose medium and are repaired on a medium without glucose. the latter process is inhibited by cycloheximide. under various conditions of cultivatio ...2002125845
adenylate cyclase activity in neurospora crassa. 2003165692
hybridization of dna's from neurospora crassa strains may indicate base sequence alterations as a consequence of genetic transformation.deoxyribonucleic acids of neurospora crassa strains involved in genetic transformation experiments were studied by means of dna-dna hybridization. no significant difference was detected in the extent of hybridization reassociating 32p-dna of an inositol-requiring recipient strain with an excess amount of unlabelled homologous dna and that of the transformed, spontaneous revertant and wild-type strains. studies on the thermal stability of hybrids revealed 1.2-1.7% heterology between the recipient ...2003162331
mechanisms controlling the two phosphate uptake systems in neurospora crassa.the development of the high-affinity and low-affinity phosphate uptake systems of neurospora crassa has been followed during germination and early growth. the ratio between the activities of the two systems became constant by the time exponential growth began, although the value of this ratio depended on the external phosphate concentration. the regulatory mechanisms controlling the systems were investigated by following the changes that resulted when exponentially growing germlings adapted to o ...2003156717
mobilization of sequestered metabolities into degradative reactions by nutritional stress in neurospora.the pools of arginine and ornithine rapidly disappear during nitrogen starvation of neurospora crassa. much of this disappearance can be accounted for by degradation catalyzed by preexisting catabolic enzymes. purine degradation is also initiated by nitrogen metabolic stress. mobilization of these compounds into degradative reactions does not appear to be a general response to nutritional stress since neither carbon starvation nor inhibition of protein synthesis elicits this response. it is sugg ...2003156715
isolation and genetic analysis of nuclease halo (nuh) mutants of neurospora crassa.nuclease halo (nuh) mutants of the ascomycete neurospora crassa have been isolated which are characterized reduced release of deoxyribonuclease (dnase) activities from colonies grown on sorbose-containing agar media. to identify nuh mutants, mutagenized isolates were transferred to commercial dnase test agar, or grown on minimal medium and then overlayed with agar that contained heat-denatured dna. dnase activity was visualized by acid precipitation which produced clear rings of digestion (haloe ...2003155773
reversion and interallelic complementation at four urease loci in neurospora crassa.analysis of heat stability of urease in extracts of 24 revertants, six for each of four ure loci, revealed that at least one revertant for each locus had a heat stability about one-third that of wild type. similar results were obtained with urease formed by interallelic complementation at the ure-2 and ure-4 loci, but interallelic complementation at the ure-1 and ure-3 loci produced insufficient urease activity for analysis. the data are interpreted to suggest, as a tentative model, a structural ...2003154055
nitrogen regulation of amino acid catabolism in neurospora crassa.neurospora crassa can utilize numerous compounds including certain amino acids as a sole nitrogen source. mutants of the nit-2 locus, a regulatory gene which is postulated to mediate nitrogen catabolite repression, are deficient in the ability to utilize several amino acids as well as other nitrogen sources used by wild type. various enzymes involved in amino acid catabolism were found to be regulated in distinct ways. arginase, ornithine transaminase, and pyrroline-5-carboxylate dehydrogenase a ...2003150270
purine base transport in nit-2 mutants of neurospora crassa.the nit-2 mutants possess general purine transport activity. reduced hypoxanthine uptake in germinated conidia of these mutants may be a consequence of their defective purine metabolism.2003145435
chloramphenicol-sensitive labelling of protein in microsomes of neurospora crassa. 2003143619
distribution of ions in neurospora crassa determined by quantitative electron microprobe analysis. 2003151300
the molecular basis of an osmotically reparable mutant of neurospora crassa producing unstable glutamate dehydrogenase. 2003140246
sorting of precursor proteins between isolated spinach leaf mitochondria and chloroplasts.the precursors of the f1-atpase beta-subunits from nicotiana plumbaginifolia and neurospora crassa were imported into isolated spinach (spinacia oleracea l.) leaf mitochondria. both f1 beta precursors were imported and processed to mature size products. no import of the mitochondrial precursor proteins into isolated intact spinach chloroplasts was seen. moreover, the precursor of the 33 kda protein of photosynthetic water-splitting enzyme was not imported into the leaf mitochondria. this study p ...20072151717
induction and de novo synthesis of uricase, a nitrogen-regulated enzyme in neurospora crassa.two efficient procedures are presented for the purification of the purine catabolic enzyme uricase from neurospora crassa. a specific antiserum for uricase was prepared and used to examine the regulation of uricase expression. even when wild-type cells are growing under full nitrogen repression conditions, they possess a considerable basal level of uricase. induction results in a severalfold increase in the level of this enzyme and reflects de novo enzyme synthesis. identical forms of uricase we ...20072952636
inducible responses to dna damaging or stress inducing agents in neurospora crassa.two-dimensional polyacrylamide gel electrophoresis has been used to analyze proteins from wild type and mutagen sensitive mutants of neurospora crassa under constitutive conditions and after treatment with mutagens and other stress inducing agents. several proteins have been detected that are either induced or show changes in electrophoretic mobility in response to uv irradiation, 4-nqo, x-ray, paraquat and heat shock. ten proteins were found to respond to more than one of the stress inducing ag ...20082525961
a natural case of rip: degeneration of the dna sequence in an ancestral tandem duplication.5s rrna genes of neurospora crassa are generally dispersed in the genome and are unmethylated. the xi-eta region of oak ridge strains represents an informative exception. most of the cytosines in this region, which consists of a diverged tandem duplication of a 0.8-kilobase-pair segment including a 5s rrna gene, appear to be methylated (e. u. selker and j. n. stevens, proc. natl. acad. sci. usa 82:8114-8118, 1985). previous work demonstrated that the xi-eta region functions as a portable signal ...20082531278
unstable mitochondrial dna in natural-death nuclear mutants of neurospora crassa.the natural-death mutant of neurospora crassa has an accelerated senescence phenotype caused by a recessive mutation, nd, in a nuclear gene that is located in linkage group i. an examination of mitochondrial functions, however, revealed that the mutant has phenotypic and molecular defects similar to those commonly associated with maternally transmitted fungal senescence syndromes, including (i) deficiencies in cytochromes aa3 and b; (ii) a deficit in small subunits of mitochondrial ribosomes, an ...20082531276
the actions of neurospora endo-exonuclease on double strand dnas.neurospora crassa endo-exonuclease, an enzyme implicated in recombinational dna repair, was found previously to have a distributive endonuclease activity with a high specificity for single strand dna and a highly processive exonuclease activity. the activities of endo-exonuclease on double strand dna substrates have been further explored. endo-exonuclease was shown to have a low bona fide endonuclease activity with completely relaxed covalently closed circular dna and made site-specific breaks i ...20082546947
involvement of tyrosyl-trna synthetase in splicing of group i introns in neurospora crassa mitochondria: biochemical and immunochemical analyses of splicing activity.we reported previously that mitochondrial tyrosyl-trna synthetase, which is encoded by the nuclear gene cyt-18 in neurospora crassa, functions in splicing several group i introns in n. crassa mitochondria (r. a. akins and a. m. lambowitz, cell 50:331-345, 1987). two mutants in the cyt-18 gene (cyt-18-1 and cyt-18-2) are defective in both mitochondrial protein synthesis and splicing, and an activity that splices the mitochondrial large rrna intron copurifies with a component of mitochondrial tyro ...20082526294
regulation of fructose 2,6-bisphosphate levels in neurospora crassa.both wild type and cr-1 mutant (adenylate cyclase and cyclic amp-deficient) strains of neurospora crassa contain fructose 2,6-bisphosphate at levels of 27 nmol/g dry tissue weight. this level decreases by about 50% in both strains upon depriving the cells of carbon or nitrogen sources for 3 h. an increase in cyclic amp levels produced by addition of lysine to nitrogen-starved cells produced no increase in fructose 2,6-bisphosphate levels. both strains respond to short-term addition of salicylate ...20083040112
gene organization and regulation in the qa (quinic acid) gene cluster of neurospora crassa. 20092931582
the qa repressor gene of neurospora crassa: wild-type and mutant nucleotide sequences.the qa-1s gene, one of two regulatory genes in the qa gene cluster of neurospora crassa, encodes the qa repressor. the qa-1s gene together with the qa-1f gene, which encodes the qa activator protein, control the expression of all seven qa genes, including those encoding the inducible enzymes responsible for the utilization of quinic acid as a carbon source. the nucleotide sequence of the qa-1s gene and its flanking regions has been determined. the deduced coding sequence for the qa-1s protein en ...20103010294
protein chemistry of the neurospora crassa plasma membrane h+-atpase.a highly effective procedure for fragmenting the neurospora crassa plasma membrane h+-atpase and purifying the resulting peptides is described. the enzyme is cleaved with trypsin to form a limit digest containing both hydrophobic and hydrophilic peptides, and the hydrophobic and hydrophilic peptides are then separated by extraction with an aqueous ammonium bicarbonate solution. the hydrophilic peptides are fractionated by sephadex g-25 column chromatography into three pools, and the individual p ...20102903697
purification of vacuolar membranes, mitochondria, and plasma membranes from neurospora crassa and modes of discriminating among the different h+-atpases. 20102906719
circadian rhythms in neurospora crassa: the effects of point mutations on the proteolipid portion of the mitochondrial atp synthetase.five oligomycin-resistant (olir) mutant strains of neurospora crassa were analyzed for their growth rate and for the periodicity of their circadian rhythm. the most resistant strains had periods of 18-19 h while the least resistant strain had a normal period of 21.0 h. there was a rough correlation between the in vivo degree of oligomycin-resistance and the amount of change in the period. several of the olir mutations have been previously described by sebald et al. (1977) in terms of known amino ...20102863735
[vegetable cytology. intracellular localization of transaminase alanine-glyoxylate and malate synthetase in neurospora crassa]. 20114979219
a potassium-proton symport in neurospora crassa.combined ion flux and electrophysiological measurements have been used to characterized active transport of potassium by cells of neurospora crassa that have been moderately starved of k+ and then maintained in the presence of millimolar free calcium ions. these conditions elicit a high-affinity (k1/2 = 1-10 microm) potassium uptake system that is strongly depolarizing. current-voltage measurements have demonstrated a k+-associated inward current exceeding (at saturation) half the total current ...20113014042
regulation of exocellular proteases in neurospora crassa: role of neurospora proteases in induction.cells of neurospora crassa strain 74a, grown on sucrose for 12 h and transferred to a medium containing protein as sole carbon source, would not produce exocellular protease in significant amounts. when a filtrate from a culture induced to make protease by normal growth on a medium containing protein as principal carbon source was added to an exponential-phase culture in protein medium, exocellular protease was made in amounts similar to those made during normal induction. the material in the cu ...20144270446
regulation of a sulfur-controlled protease in neurospora crassa.wild-type neurospora crassa produces and secretes extracellular protease(s) when grown on a medium containing a protein as its principle sulfur source. readily available sulfur sources, such as sulfate or methionine, repress the synthesis of the proteolytic activity. preliminary characterization of the proteolytic enzyme shows it to have a molecular weight of about 31,000, a ph optimum of 6 to 9 with casein as substrate, and esterolytic activity against acetyl-tyrosine ethyl ester with a ph opti ...20144270448
sexuality in neurospora crassa. i. mutations to male sterility. 20144263083
increased viability of a strain of neurospora crassa after treatment with ultraviolet radiation or other agents.a strain of neurospora crassa with low viability but near normal germination shows a two- to sixfold increase in the number of colonies formed after treatment with ultraviolet radiation, x radiation, nitrous acid, or heat (50 c). effective dosages of these agents produce moderate killing of the wild type.20144266244
thermostimulation of conidiation and succinic oxidative metabolism of neurospora crassa. 20144303684
purification and properties of neurospora crassa laccase.extracellular neurospora laccase (p-diphenol:oxygen oxidoreductase; ec has been purified to apparent homogeneity by classical purification techniques. the enzyme, which consists of mainly one form, has a molecular weight of 64,800 and contains 11% carbohydrate. the ultraviolet, visible, and electron paramagnetic resonance spectra indicate that both type i and type ii copper are present, as described for the polyporus versicolor enzyme. with the exception of phloroglucinol, only para- a ...20144278681
genetic recombination in neurospora crassa affected by changes in the supply of cellular energy. 20144281764
genetic analysis of a suppressor of urease-deficiency in neurospora crassa. 20144281763
an inducible amino acid transport system in neurospora crassa. 20144258482
the effect of phosphate buffer on the differential response of two genes in neurospora crassa to uv. 20144263301
control of non-allelic recombination in neurospora crassa. 20144273091
multigenic control of ribosomal properties associated with cycloheximide sensitivity in neurospora crassa. 20144274736
hyphal wall peptides and colonial morphology in neurospora crassa. 20144279659
studies on the glutamate dehydrogenase from neurospora crassa. 20154403951
regulation of nitrate reductase in neurospora crassa: stability in vivo.nicotinamide adenine dinucleotide phosphate, reduced form (nadph)-nitrate reductase and its related enzyme activities, nadph-cytochrome c reductase and reduced benzyl viologen-nitrate reductase, are all induced following the transfer of ammonia-grown wild-type neurospora mycelia to nitrate medium. after nitrate reductase is induced to the maximal level, the addition of an ammonium salt to, or the removal of nitrate from, the cultures results in a rapid inactivation of nitrate reductase and its t ...20154401813
isolation and characterization of an unsaponifiable lipid from neurospora crassa. 20154364989
comparison of cysteine and tryptophan content of insoluble proteins derived from wild-type and mi-1 strains of neurospora crassa.the possibility of an amino acid substitution (cysteine for tryptophan) in a membrane protein of the [mi-1] strain of neurospora crassa has been investigated in detail by using a double radioactive labeling procedure. auxotrophic strains of neurospora having wild-type [+] or [mi-1] cytoplasm have been grown under conditions which result in the specific labeling of protein tryptophan with (3)h and protein cysteine with (35)s. although the least soluble 1 to 20% of the [mi-1] mitochondrial membran ...20154334762
cold-induced increase of glycerol kinase in neurospora crassa. 20154270897
isolation, mapping, and characterization of trehalaseless mutants of neurospora crassa.mutant strains of neurospora crassa that lack trehalase and are unable to grow on trehalose were isolated, and the gene (tre) was positioned on the right arm of linkage group i. maltase and beta-galactosidase activities are almost identical in tre(-) strains, whereas that of invertase was reduced by more than half and those of acid phosphatase and amylase were somewhat increased. heterocaryons between standard and trehalaseless strains yield less than one-tenth the activity of the former. in add ...20165001211
end-product regulation of the tryptophan-nicotinic acid pathway in neurospora crassa.the regulation of the tryptophan-nicotinic acid pathway in neurospora crassa was examined with mutants (nic-2, nic-3) which require nicotinamide for growth. the accumulation of n-acetylkynurenin and 3-hydroxyanthranilic acid by these mutants served to estimate the level of function of the early reactions in the pathway. in still cultures, maximal accumulation occurred with media containing growth-limiting amounts of nicotinamide; the accumulation of intermediates was almost negligible with nicot ...20144107105
formation of assimilatory nitrate reductase by in vitro inter-cistronic complementation in neurospora vitro complementation of the soluble assimilatory nicotinamide adenine dinucleotide phosphate, reduced form (nadph)-nitrate reductase was attained by mixing cell-free preparations of certain neurospora nitrate reductase mutants: induced nit-1 (uniquely possessing inducible nadph-cytochrome c reductase) with (a) uninduced or induced nit-2 or nit-3, or (b) uninduced wild type. the complementing activity of induced nit-1 is soluble while that of nit-2, nit-3, and wild type is particulate but not ...20154391854
a regulatory system controlling the production of cytochrome aa3 in neurospora crassa.the mitochondria of the cyt-2-1, cya-3-16, cya-4-23 and 299-1 nuclear mutants and the [mi-3] and [exn-5] cytoplasmic mutants of neurospora crassa are deficient in cytochrome aa3, while the cyb-1-1 and cyb-2-1 mutants have mitochondrial b-cytochrome deficiencies. however, the mitochondria from cyb-1-1 cyt-2-1, cyb-1-1 [mi-3] and cyb-2-1 [mi-3] double mutants contain 30% to 50% of the amount of cytochrome aa3 that is present in mitochondria from wild-type; i.e. cyb-1-1 and cyb-2-2 act as suppresso ...1979216899
influence of the carbon source on glycerol kinase activity in neurospora crassa.the level of glycerol kinase activity in neurospora crassa was shown to change in response to resuspension of sucrose-grown mycelia in fresh medium containing a new carbon source: the magnitude of the change depended on the new carbon source provided. certain carbon sources, such as glucose and fructose, inhibited the small increase that occurred in the absence of any carbon source. others, and in particular deoxyribose, galactose, glycerol and ribose, greatly enhanced this increase. the activit ...1987174743
amino acids and peptides. xxiv. synthesis of neurospora crassa metallothionein and related cysteine-containing peptides and examination of their heavy metal-binding properties.a pentacosapeptide corresponding to the entire amino acid sequence of neurospora crassa metallothionein and several related cysteine-containing peptides were synthesized by the conventional solution method and their heavy metal-binding properties were examined. the cu2+- or cu+-binding properties of the various peptides were similar to each other, whereas the cd2+-binding properties of these peptides were fairly structure-dependent.20072532570
nucleotide sequence of pho-4+, encoding a phosphate-repressible phosphate permease of neurospora crassa.the nucleotide (nt) sequence of the neurospora crassa pho-4+ gene, which encodes a phosphate-repressible phosphate permease, has been determined. the gene specifies a protein of 590 amino acids (aa) and contains two introns. two rna transcripts of 3.3 and 2.4 kb have been identified, and transcription start points (tsp) and termination sites and/or processing sites have been located. the 3.3-kb message is initiated about 890 nt upstream from the tsp for the 2.4-kb transcript. a hydropathy profil ...20082531109
interaction of galactosaminoglycan with neurospora conidia.the inactivation of neurospora crassa conidia by galactosaminoglycan isolated from cultures of this organism was followed by measuring colony-forming ability and ability to take up radiolabeled metabolites. when kinetic data on the loss of transport function and on killing were analyzed by use of target theory, it appeared that few "hits" are required for inactivation. however, studies with radio-labeled galactosaminoglycan mucopolysaccharides showed that cells receiving a single lethal hit have ...20144281775
induction of beta-glucosidases in neurospora crassa.the induction of beta-glucosidases (ec was studied in neurospora crassa. cellobiase was induced by cellobiose, but other inducers had little effect on this enzyme. cellobiase activity was very low in all stages of the vegetative life cycle in the absence of di-beta-glucoside inducer. aryl-beta-glucosidase was semiconstitutive at late stages of culture growth prior to conidiation. at early stages, aryl-beta-glucosidase was induced by cellobiose, laminaribiose, and gentiobiose, and weakl ...20154270443
[repression of urease biosynthesis in neurospora crassa by ammonium ions].the regulation of the synthesis of the enzyme urease (urea amido hydrolase e.c. in neurospora crassa was investigated. the biosynthesis of urease is repressed by ammonium ions. under ammonium excess conditions the specific activity of urease decreases from 0.980 to 0.180 mumoles nh3/min/mg protein. by addition of cycloheximide it was shown that ammonia influences the synthesis of this enzyme. enzyme induction by the substrate could be excluded. even under the conditions of highest repr ...2002127430
evidence for distinct kynureninase and hydroxykynureninase activities in neurospora crassa.previous studies have indicated that a single enzyme, "kynureninase," catalyzes the reactions of l-kynurenine to anthranilate and l-3-hydroxykynurenine to 3-hydroxyanthranilate in neurospora crassa and in other organisms. the present report describes separate enzymes which catalyze these reactions in n. crassa. the first, a kynureninase, preferentially catalyzes kynurenine to anthranilate and is induced over 400-fold by tryptophan or a catabolite of tryptophan. the second, a hydroxykynureninase, ...20154331500
growth patterns of adenine-3b; supersuppressor strains of neurospora crassa.the interaction between several suppressible ad-3b alleles and several supersuppressor genes had been examined both quantitatively and qualitatively in a tetrad analysis. quantitatively, there is a good deal of variation in mean growth rates of cultures showing supersuppression: part of this variation can be attributed to variation in the suppressibility of ad-3b alleles, part to variation of suppression efficiency of ssu alleles, and part to the action of modifying genes. qualitatively, ad-3b; ...2002126794
identification of the ubiquinone-binding site of nadh:ubiquinone oxidoreductase (complex i) from neurospora order to localize the ubiquinone-binding site of complex i (nadh:ubiquinone oxidoreductase), a novel photoreactive ubiquinone analogue (q0c7arn3) has been synthesized. it is shown that the direct chemical precursor of this analogue (q0c7arno2) and the analogue itself are accepted as substrates in an enzyme assay utilizing ubiquinone-depleted mitochondrial membranes of neurospora crassa. the activity of the enzyme applying these derivatives is inhibited by 50% at a concentration of 9 and 20 mi ...19751445878
induction of neurospora crassa laccase with protein synthesis inhibitors.rapidly growing neurospora crassa does not produce laccase (p-diphenol:oxygen oxidoreductase; ec low concentrations of cycloheximide induce the production of this enzyme, most of which is secreted into the media. in general, limited inhibition of protein synthesis seems to derepress laccase synthesis since actinomycin d and, to a limited extent, puromycin also induce laccase production. similarities in the conditions of laccase and tyrosinase induction, plus investigations with two ty ...20144278535
cyanide-resistant respiration in neurospora crassa.cell respiration in wild type and poky was studied as part of a long-term investigation of cyanide-resistant respiration in neurospora. respiration in wild type proceeds via a cytochrome chain which is similar to that of higher organisms; it is sensitive to antimycin a or cyanide. poky, on the other hand, respires by means of two alternative oxidase systems. one of these is analogous to the wild-type cytochrome chain in that it can be inhibited by antimycin a or cyanide; this system accounts for ...20144333318
multiple intracellular peptidases in neurospora crassa.neurospora crassa possesses multiple intracellular peptidases which display overlapping substrate specificities. they were readily detected by an in situ staining procedure for peptidases separated in polyacrylamide gels, within which the auxilliary enzyme, l-amino acid oxidase, was immobilized. eleven different intracellular peptidases were identified by electrophoretic separation and verified by their individual patterns of substrate specificities. most peptide substrates tested were hydrolyze ...200086534
genetic control of phosphate-metabolizing enzymes in neurospora crassa: relationships among regulatory neurospora crassa, the phosphate-metabolizing enzymes are made during phosphate starvation, but not under phosphate sufficiency. the synthesis of these enzymes is controlled by three regulatory genes: pcon-nuc-2, preg and nuc-1, pcon-nuc-2 and preg are closely linked. a model of the hierarchical relationships among these regulatory genes is presented. studies of double mutants and revertants confirm several predictions of the model. it has been found that nuc-2 (null) and pcon-c (constitutive ...2002123873
9(10)-alkoxystearic acids lengthen the circadian period of a fatty acid auxotroph of neurospora crassa.9- and 10-alkoxystearic acids with alkoxy groups of varying size were synthesized by solvomercuration of methyl oleate. these "knobbed" fatty acids were used to supplement a neurospora strain carrying the cel mutation, which confers a partial fatty acid deficiency. supplemental unsaturated or short-chain fatty acids are known to lengthen dramatically the circadian period of spore formation (conidiation) in cel strains. a similar dramatic lengthening was obtained with the alkoxy supplements. the ...20102955422
nuclear mutants of neurospora crassa temperature-sensitive for the synthesis of cytochrome aa3. i. isolation and preliminary characterization.three nuclear mutants of neurospora crassa, temperature-sensitive for the synthesis of cytochrome aa3 have been isolated. when grown at 41 degrees c the mutants have large amounts of kcn-insensitive respiration, reduced amounts of cytochrome aa3 and cytochrome c oxidase activity, and grow more slowly than wild-type cultures grown at the same temperature. when the mutants are grown at 23 degrees c, they are virtually indistinguishable from wild-type strains. the mutants were selected on the basis ...1979216900
control of neurospora crassa morphology by cyclic adenosine 3', 5'-monophosphate and dibutyryl cyclic adenosine 3', 5'-monophosphate.the role of cyclic adenosine 3', 5'-monophosphate (cyclic amp) in the control of the neurospora asexual life cycle was studied. endogenous cyclic amp levels were 10 to 20 times higher in strains having the wild-type cr-1 allele than in those carrying the mutated allele. in a wild-type strain these levels remained constant throughtout the entire growth period in shaken liquid cultures, except during a short period at the beginning of the stationary growth phase. in this period a marked increase i ...1995177398
glycerol non-utilizing mutants in neurospora crassa. isolation by net replication. 1998124714
primary structure, in vitro expression and import into mitochondria of a 29/21-kda subunit of complex i from neurospora crassa.a full-length cdna clone coding for a cytoplasmically-synthesized subunit of complex i from neurospora crassa (apparent molecular mass of 29 kda) was isolated. dna sequencing revealed an open reading frame coding for a protein containing 201 amino acids. a molecular mass of 21323 da was calculated. the precursor polypeptide was efficiently expressed in vitro and imported into isolated mitochondria. it is synthesized without a cleavable signal sequence and needs a membrane potential in order to b ...19612137337
characterization of the aspartate carbamoyltransferase fragment generated by protease action on the pyrimidine-3 gene product of neurospora crassa.the molecular weight of the fragment of aspartate carbamoyltransferase (carbamoylphosphate: l-aspartate carbamoyltransferase, ec of neurospora crassa following proteolysis was found to be 1.0-10(5) (aspartate carbamoyltransferase-l). it differs from the native form of the enzyme (aspartate carbamoyltransferase-n, 6.5-10(5)) in several respects. it has a lower v, has a much greater affinity (approx. 3-fold) for l-aspartate, and is strongly activated by glycine. both forms of aspartate ca ...199821697
conidiation of neurospora crassa induced by treatment with natrium fluoride in submerged culture.a transient treatment of pregerminated conidia of neurospora crassa with naf induced young, submerged cultures to prematurely differentiate conidia. the inductive treatment decreased the rate of respiration (with lower rq), reduced the relative concentration of nucleoside triphosphates, and inhibited leucine incorporation into protein and adenosine incorporation into rna.2001125568
[a simple method for extraction of l-saccharopine from neurospora crassa]. 2002134378
regulation of glutamine synthesis by glycine and serine in neurospora crassa.the biosynthetic activities of the polypeptide subunits alpha and beta of glutamine synthetase (gs) were inhibited in vitro by glycine and serine. these amino acids inhibited the growth of a mutant strain with partial gs activity when grown on glutamate as the nitrogen source and also blocked the synthesis of the glutamine in vivo, thus demonstrating the inhibitory effect on gs activity in vivo. glycine and serine lowered the intracellular glutamine pool and regulated gs beta synthesis. a prefer ...20092867084
organization of the functional domains of anthranilate synthase from neurospora crassa. limited proteolysis studies.treatment of the multifunctional alpha 2 beta 2 anthranilate synthase complex of neurospora crassa with elastase produced two fragments of the complex, one possessing anthranilate synthase activity and the other having both indole-3-glycerol phosphate (ingp) synthase and n-(5'-phosphoribosyl)anthranilate (pra) isomerase activities. sequencing the nh2 terminus of the ingp synthase-pra isomerase fragment revealed that cleavage was between positions 237 and 238 of the beta-subunit within a segment ...20102946679
cold-induced increase of glycerol kinase activity in neurospora crassa: rapid inactivation of the enzyme in vivo.the glycerol kinase activity induced by incubation of neurospora crassa at low temperatures was rapidly lost when cultures were returned to 26 c. after a short lag, the activity disappeared irreversibly with a half-life of approximately 15 min. the loss of activity was not due to a change in the level of an inhibitor or activator. glycerol reduced the activity loss but did not completely prevent it, which was an effect that was dependent on protein synthesis. the cold-induced activity was also a ...20144281774
behavior of cycloaldolase from neurospora crassa towards substrate analogs and aldolase inhibitors. 20154346519
occurrence in wild strains of neurospora crassa of genes controlling genetic recombination.each of the main laboratory wild stocks of n. crassa carries one of two alleles at the rec-1 and rec-2 loci and one of three at the rec-3 locus. the constitutions of the stocks are given in fig. 1. some of those conserved are evidently not the originals. the third rec-3 gene (rec-3l), found in lindegren a, controls recombination at the am-1 locus to a level between that of rec-3+ and rec-3, the relative levels being 1 : 8 : 25. at the his-2 locus rec-3l is indistinguishable from rec-3+ in its le ...2002126680
dna-mediated genetic changes in neurospora crassa.evidence for genetic transformation in neurospora crassa is based on the observations that allo-dna has a specific effect in producing transformants which is abolished by dnaase treatment and that iso-dna is not effective in transformation. here, unambiguous evidence for genetic transformation is provided by transfer of a temperature-sensitive inositol requirement from a donor to a recipient strain. data provided also suggest the role of growth conditions and the involvement of a nuclease gene i ...1990159941
adenosine 3',5'-cyclic monophosphate and morphology in neurospora crassa: drug-induced alterations.grown in liquid culture in the presence of a variety of structurally unrelated drugs, mycelia of wild-type neurospora assume a colonial or semicolonial growth habit similar to that of known morphological mutants. drugs that produce these morphological changes include atropine, theophylline, histamine, and several of the quinoline-containing antimalarials. each of these drugs decrease the endogenous adenosine 3',5'-cyclic monophosphate (camp) concentration of mycelia as a result of their effect o ...2003165170
the subunit structure of the nicotinamide-adenine dinucleotide phosphate-dependent glutamate dehydrogenase of neurospora crassa. 20154403952
ligand-induced changes in the accessibility of sulphydryl groups of neurospora crassa pyruvate kinase. 2003154420
lipid and cell wall changes in an inositol-requiring mutant of neurospora inositol deficiency in the inositol-requiring (inl) mutant of neurospora crassa led to changes in the composition of the inositol-containing lipids and the cell wall. on deficient levels of inositol, phosphatidyl inositol decreased by 23-fold, di(inositolphosphoryl) ceramide decreased by 4-fold, and monoinositolphosphoryl ceramide increased slightly. the inositol deficiency also led to an aberrant hyphal morphology and changes in both the amount of cell wall and the amino sugar content of the ...1982220215
effect of carbon source on enzymes involved in glycerol metabolism in neurospora crassa.specific activities of eight enzymes involved in glycerol metabolism were determined in crude extracts of three strains of neurospora crassa after growth on six different carbon sources. one of the strains was wild type, which grew poorly on glycerol as sole carbon source; the other two were mutant strains which were efficient glycerol utilizers. a possible basis for this greater efficiency of glycerol utilization was catabolite repression of glyceraldehyde kinase by glycerol in wild type, and t ...1987211971
a nuclear mutant of neurospora crassa lacking subunit 1 of cytochrome c oxidase. 1989210181
electron transport in the cni-1 mutant of neurospora crassa.1. mitochondria from the nuclear mutant cni-1 have no optically detectable cytochrome aa3 in early log phase growth. these mitochondria have a high level of respiration that is not inhibited by cyanide but is inhibited by salicylhydroxamic acid. they also show a substantial amount of cyanide-sensitive respiration. 2. as cultures of mutant cni-1 age, flux through the hydroxamate-sensitive pathway decreases markedly while flux through the cytochrome chain remains constant. 3. growth studies with m ...1992206437
ageing of neurospora crassa. vi. cytochemical and cytological correlates of senescence in three model systems. 1993204837
ageing of neurospora crassa. v. lipid peroxidation and decay of respiratory enzymes in an inositol auxotroph. 1993204836
dna sequence duplications trigger gene inactivation in neurospora crassa.transforming sequences are faithfully replicated in vegetative cells of neurospora but are typically subject at high frequency to sequence alterations and methylation in the period between fertilization and nuclear fusion. previous work showed a correlation between the occurrence of these radical changes, referred to by the acronym rip, and the presence of sequence duplications resulting from the introduced dna. various possible causes for the rip process were investigated. introduction of a sin ...20092842795
phase resetting of the neurospora crassa circadian oscillator: effects of inositol depletion on sensitivity to light.the input pathway between the blue-light photoreceptor and the circadian oscillator of neurospora crassa has not yet been identified. to test the hypothesis that an inositol phospholipid signaling system might be involved in blue-light signal transduction, phase resetting by light was assayed in the inositol-requiring inl strain under conditions of inositol depletion. phase-resetting curves and dose-response curves indicated that cultures maintained on low inositol (25 microm) were several order ...20061421476
carbon-13 nuclear-magnetic-resonance spectroscopy of whole cells and of cytochrome c from neurospora crass grown with (s-me-13c)methionine.neurospora crassa cytochrome c biosynthetically labelled with [s-me-13c]methionine was prepared and analysed by 13c nuclear-magnetic-resonance spectroscopy. the methyl group of methionine is extensively incorporated into an n-trimethyl-lysine-72 residue arise from s-adenosylmethionine transmethylation, and that the methyl carbons of methionine residues are sufficiently close to the haem centre to experience chemical shifts from the ring currents of the tetrapyrrole pi electrons and broadening du ...1997179524
restricted distribution of the tad transposon in strains of neurospora.a simple colony blot procedure was used to screen 336 neurospora strains for the presence of the transposable element tad. these strains included the standard laboratory wild types, all of the available neurospora isolates collected from the ivory coast, and all wild-collected neurospora crassa isolates available from the fungal genetics stock center. tad was found only in the strain of origin from adiopodumé, ivory coast, where it is present in multiple copies. three other strains of african or ...20082546685
effect of ethylene glycol on transcription of neurospora crassa conidial genome.ethylene glycol (eg) was found not to alter dna sequences in neurospora crassa conidia, though it is believed to be mutagenic in nature. molecular hybridization revealed 20% increase in whole rna transcripts in eg-treated conidia, which indicates that while untreated conidia increase rna synthesis by 2.35fold, treated conidia are inhibited and undergo only a 1.2fold increase. thus there is an inhibition in potential rna synthesis, though some rna synthesis goes on in presence of ethylene glycol.2003149018
Displaying items 2001 - 2100 of 5889