PMID(sorted descending)
regulation of the expression of three housekeeping genes encoding subunits of the neurospora crassa vacuolar atpase.the vacuolar atpase is a complex enzyme and is encoded by at least nine genes, which appear to be scattered throughout the genome. we have examined the vma-1 vma-2, and vma-3 genes, which encode subunits present in multiple copies within the neurospora crassa vacuolar atpase. we wished to see if the expression of these genes is coordinately regulated and if these genes contain similar promoter elements. a region was sequenced of approximately 1 kb located upstream of the protein coding region fo ...19957500957
purification of a heteromeric ccaat binding protein from neurospora crassa.expression of the neurospora crassa am (nadp-specific glutamate dehydrogenase) gene is controlled by two upstream enhancer-like elements designated ursam alpha and ursam beta. ursam alpha is localized between - 1.3 and - 1.4 kb with respect to the major transcriptional start site. deletion of a 90 bp sequence containing this element resulted in the loss of approximately 50% of normal glutamate dehydrogenase expression. gel mobility shift analysis indicated that a nuclear protein from neurospora ...19957500955
a human homolog of the mitochondrial protein import receptor mom19 can assemble with the yeast mitochondrial receptor complex.import of preproteins into mitochondria requires transport machineries in both mitochondrial membranes that have been characterized in saccharomyces cerevisiae and neurospora crassa. by cdna analysis, we identified a human protein of 16 kda with significant overall homology to the fungal mitochondrial import receptor mom19, including the three typical characteristics: a hydrophobic n-terminal segment, a tetratrico peptide motif in the middle and a negatively charged c-terminus. the human mom19 h ...19957498524
genetic and epigenetic inactivation of repetitive sequences in neurospora crassa: rip, dna methylation, and quelling. 19957493491
physicochemical characterization of the ribosomal rna species of the mollusca. molecular weight, integrity and secondary-structure features of the rna of the large and small ribosomal subunits.1. the rrna species of the cephalopoda octopus vulgaris and loligo vulgaris were found to have unexpectedly high sedimentation coefficients and molecular weights. in 0.1 m-nacl the l-rrna (rna from large ribosomal subunit) has the same s20 value as the l-rrna of the mammals (30.7s), whereas the s-rrna (rna from small ribosomal subunit) sediments at a faster rate (20.1s) than the s-rrna of both the mammals and the fungi (neurospora crassa) (17.5s). the molecular weights of the l-rrna were determi ...19807458915
synthesis of photoreactive tryptophan analogs: enzymatic conversion of azidoindoles to azidotryptophans.four photoreactive azidoindoles, 4, 5, 6, and 7 azidoindole, were synthesized and converted to the corresponding azidotryptophans by a crude enzyme preparation of tryptophan synthetase from neurospora crassa.19817339614
two classes of replicating molecules of adenovirus type 2 dna.replicating dna of human adenovirus type 2, identified as partly single-stranded viral dna in which [3h]thymidine is readily incorporated, was found to be separated into two fractions by chromatography on hydroxyapatite. whereas one of the these fractions was eluted with 180 mm phosphate, the other one was eluted at the same concentration, 240 mm, as fully double-stranded dna. the physical properties of the 180 and 240 mm fractions, in particular their buoyant densities in solutions of cscl and ...19817248295
isolation and genetic analysis of mms-sensitive mus mutants of neurospora.with the aim of obtaining mutants that affect dna repair or recombination, mutants sensitive to methylmethane sulfonate (mms) have been isolated in the ascomycete neurospora crassa. seven of these mutants were backcrossed repeatedly to produce isogenic strains for measurements of relative mutagen sensitivities and for analysis of recombination frequencies. the new mus (mutagen sensitives) were compared to four previously known radiation-sensitive mutants which were shown to be cross-sensitive to ...19807237231
[refractory properties of cardiac tissue at fast sodium current decrease. comparison of atrium and ventricle].investigation of the membrane potential of neurospora crassa mycelial cells was carried out by standard microelectrode technique. the resting potential is equal to--156 +/- 11 mv (negative inside the cell). the light of the spectrum blue-violet zone causes transient hyperpolarization of the cell membrane reaching --38 +/- 5 mv after 25 minutes of illumination.19827138947
genetical and biochemical aspects of quinate breakdown in the filamentous fungus aspergillus the ascomycetous fungus aspergillus nidulans, the expression of two inducible, contiguous or closely linked genes (qutb and qutc) which encode enzymes for quinate breakdown to protocatechuate, appears to be controlled by the product of a tightly linked third genet (quta). the qut gene cluster locates on chromosome viii. the catalytic steps required for this conversion are dehydrogenase, dehydroquinase, and dehydratase, and these activities are induced by the presence of quinate in a similar m ...19827049157
nuclear localization of aspartate transcabamoylase in saccharomyces cerevisiae.the cytochemical technique using the in situ precipitation of orthophosphate ions liberated specifically by the aspartate carbamoyltransferase (atcase) (ec reaction indicated that in saccharomyces cerevisiae this enzyme is confined to the nucleus. this observation is in accordance with the result reported by bernhardt and davis (1972), proc. natl. acad. sci. u. s. a. 69:1868-1872) on neurospora crassa. the nuclear compartmentation was also observed in a mutant strain lacking proteinase ...19827045137
mutagenicity of oil-shale ash.3 oil-shale ash samples were extracted with solvents and analyzed for mutagenicity with a number of tests systems. in salmonella typhimurium, the ash extracts were highly mutagenic with the ames his reversion and the ara-resistant systems. mutation induction by the ash in salmonella was independent of metabolic activation and was of the frameshift type. these ash extracts showed a substantial killing effect, but failed to induced ad-3 reversion in neurospora crassa, gene conversion and mitotic c ...19827035913
pyruvate dehydrogenase complex from baker's yeast. 1. purification and some kinetic and regulatory properties.pyruvate dehydrogenase complex, for the first time, was highly purified from commercial baker's yeast (saccharomyces cerevisiae). proteolytic degradation was prevented by the inclusion of the protease inhibitors pepstatin a, leupeptin, and phenylmethanesulfonyl fluoride during the enzyme purification. the yield from 1 kg of pressed yeast was about 15--20 mg enzyme with a specific activity of 17--30 u/mg. most of the kinetic and regulatory properties of the yeast enzyme were found similar to thos ...19817030740
the influence of growth conditions on the synthesis of molybdenum cofactor in proteins mirabilis.cell-free extracts of proteus mirabilis were able to reconstitute nadph-dependent assimilatory nitrate reductase in crude extracts of the neurospora crassa mutant strain nit-1, lacking molybdenum cofactor. molybdenum cofactor was formed in the cytoplasm of the bacterium even in the presence of oxygen during growth though under these conditions no molybdo enzymes are formed. as a consequence no cofactor could be released by acid treatment from membranes of cells growth aerobically. the amount of ...19817030254
enzymatic synthesis and function of folylpolyglutamates.derivatives of folic acid occur in nature predominantly as poly (gamma-glutamyl) derivatives containing 2-8 glutamate residues. the data regarding the function of these derivatives, and their biosynthesis by eucaryotic and procaryotic folylpolyglutamate synthetases, is reviewed. the most universal functions of folylpolyglutamates appear to be (a) as the actual cofactors in vivo for folate dependent enzymes, (b) as inhibitors of folate dependent enzymes for which they are not substrates, and (c) ...19817027025
identification of the molybdenum cofactor in chlorate-resistant mutants of escherichia coli.experiments were performed to determine whether defects in molybdenum cofactor metabolism were responsible for the pleiotropic loss of the molybdoenzymes nitrate reductase and formate dehydrogenase in chl mutants of escherichia coli. in wild-type e. coli, molybdenum cofactor activity was present in both the soluble and membrane-associated fractions when the cells were grown either aerobically or anaerobically, with and without nitrate. molybdenum cofactor in the soluble fraction decreased when t ...19817026535
construction and characterization of salmonella typhimurium strains that accumulate and excrete alpha- and beta-isopropylmalate.two salmonella typhimurium strains, which could be used as sources for the leucine biosynthetic intermediates alpha- and beta-isopropylmalate were constructed by a series of p22-mediated transductions. one strain, jk527 [flr-19 leua2010 delta(leud-ara)798 fol-162], accumulated and excreted alpha-isopropylmalate, whereas the second strain, jk553 (flr-19 leua2010 leub698), accumulated and excreted alpha- and beta-isopropylmalate. the yield of alpha-isopropylmalate isolated from the culture medium ...19806991477
reconstitution of adenylate cyclase in neurospora from two components of the enzyme.the atp-mg2+-dependent, guanine nucleotide-stimulated adenylate cyclase of neurospora crassa was shown to be composed of distinct components which, when mixed, can reconstitute a holoenzyme. after brief heat treatment, the adenylate cyclase activity in crude homogenates of neurospora was found to have reduced activity and greatly reduced sensitivity to stimulation by guanyl-5'-yl-imidodiphosphate (gpp(nh)p). gpp(nh)p sensitivity could be restored by addition of a homogenate from a crisp-1 (cr-1) ...19836830259
active polypeptide fragments common to prokaryotic, eukaryotic, and mitochondrial dna polymerases.with a procedure that allows the renaturation of the dna polymerase catalytic activity in situ after sds-polyacrylamide gel electrophoresis, we have compared the active polypeptides present in extracts from organisms covering a wide evolutionary range from prokaryotes to eukaryotes, namely: escherichia coli, oryza sativa, daucus carota , neurospora crassa, dictyostelium discoideum, saccharomyces cerevisiae, ceratitis capitata, leucophaea maderae , xenopus laevis, rat tissues and human lymphoblas ...19826765191
molybdenum cofactor from the cytoplasmic membrane of proteus mirabilis.molybdenum cofactor was extracted from membranes of proteus mirabilis by three methods: acidification, heat treatment and heat treatment in the presence of sodium-dodecylsulphate (sds). extracts prepared by the latter method contained the highest concentration of molybdenum cofactor. in these extracts molybdenum cofactor was present in a low molecular weight form. it could not penetrate an ym-2 membrane during ultrafiltration suggesting a molecular weight above 1000. during aerobic incubation of ...19826763509
the biosynthesis of brominated pyrrolnitrin derivatives by pseudomonas aureofaciens.the mutant strain acn of pseudomonas aureofaciens atcc 15926 produces several bromo derivatives of pyrrolnitrin. five brominated amino- and three brominated nitrophenyl pyrrole compounds could be isolated, and their structures were established by 1h nmr, uv and mass spectroscopy. the isolated amino compounds showed no biological activity; the nitro derivatives inhibited the growth of neurospora crassa atcc 9276, though not as effective as pyrrolnitrin itself. 2-carboxy-4-(2-amino-3-bromophenyl)p ...19836662814
[purification and isolation of the arom aggregates of schizosaccharomyces pombe].the five enzymes that catalyzing steps two through six in the prechorismate polyaromatic amino acid biosynthetic pathway are physically associated and have been purified up to 400-fold from schizosaccharomyces pombe. the native arom aggregate has a molecular weight of approx. 140,000-145,000 based on gel filtration, glycerol-density-gradient centrifugation, and polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. similarities between the s. pombe arom aggregate and that ...19836624143
molybdopterin in carbon monoxide oxidase from carboxydotrophic bacteria.the carbon monoxide oxidases (coxs) purified from the carboxydotrophic bacteria pseudomonas carboxydohydrogena and pseudomonas carboxydoflava were found to be molybdenum hydroxylases, identical in cofactor composition and spectral properties to the recently characterized enzyme from pseudomonas carboxydovorans (o. meyer, j. biol. chem. 257:1333-1341, 1982). all three enzymes exhibited a cofactor composition of two flavin adenine dinucleotides, two molybdenums, eight irons and eight labile sulfid ...19846582059
transhyphal electrical currents in fungi.representative mycelial fungi from the phycomycete, ascomycete and basidiomycete groups (achlya bisexualis, neurospora crassa, aspergillus nidulans, schizophyllum commune and coprinus cinereus) all generated steady electrical currents around their hyphal tips; the generation of a transhyphal ion current may therefore be a universal characteristic of hyphal growth. as with all other tip growing organisms, positive current always entered apically and left distally; non-growing hyphae did not drive ...19846520604
metabolic sequestration of putrescine in neurospora crassa. 19826462139
control of the flux in the arginine pathway of neurospora crassa. modulations of enzyme activity and concentration.the influence of particular enzyme activities on the flux of metabolites in a pathway can be estimated by 'modulating' enzymes (i.e. changing turnover or concentration) and measuring the response in various parts of the system. by controlling the nuclear ration of two genetically different nuclear types in heterokaryons, the enzyme concentrations at four different steps in the arginine pathway were decreased over a range. this range was extended by the use of bradytrophs, mutant strains specifyi ...19816462136
[problems concerned with microbial mutagenicity tests].mutagenicity tests using microorganisms are the salmonella-typhimurium test (ames), the test with a polymerase a deficient escherichia coli, the saccharomyces cerevisiae d3 system and the neurospora crassa test. differences in results of ames-test may be due to differences preserving the tester strains, the choice of solvent and the dosage of the test compounds, last not least is the production of s-9. the polymerase a deficient escherichia coli system seems easier to handle than the saccharomyc ...19826461834
induction of acyl coenzyme a synthetase and hydroxyacyl coenzyme a dehydrogenase during fatty acid degradation in neurospora crassa.neurospora crassa is able to use long-chain fatty acids as the sole carbon and energy source. after growth on oleate there was nearly a 10-fold induction of the acyl coenzyme a (coa) synthetase and a fivefold increase in the activity of the 3-hydroxyacyl-coa dehydrogenase. there was a slight induction of the enoyl-coa hydratase and 3-ketoacyl-coa thiolase, but no apparent induction of the flavin-linked acyl-coa dehydrogenase. these noncoordinate changes in the fatty acid degradation enzymes sugg ...19826461637
energy requirement for the mobilization of vacuolar arginine in neurospora crassa.the bulk of the intracellular arginine pool in exponentially growing mycelia of neurospora crassa is sequestered in the vacuoles. vacuolar arginine effluxes from the vacuoles into the cytosol and is catabolized to ornithine and urea upon nitrogen starvation. the energy requirement for mobilization has been studied by treating nitrogen-starved mycelia with inhibitors or respiration or glycolysis or an uncoupler of respiration. mobilization was inhibited by the inhibitors or the uncoupler of respi ...19826461635
energetics of vacuolar compartmentation of arginine in neurospora crassa.the energy requirements for the uptake and retention of arginine by vacuoles of neurospora crassa have been studied. exponentially growing mycelial cultures were treated with inhibitors of respiration or glycolysis or an uncoupler of respiration. catabolism of arginine was monitored as urea production in urease-less strains. the rationale was that the rate and extent of such catabolism was indicative of the cytosolic arginine concentration. no catabolism was observed in cultures treated with an ...19826461634
genes in neurospora that suppress recombination when they are heterozygous.genes that suppress recombination when heterozygous have been found distributed as a polymorphism in wild and laboratory populations of neurospora crassa. three alleles, sse, sss and ssc, are associated, respectively, with th the three wild types emerson, st. lawrence 74a and costa rica a. it is proposed that ss (synaptic sequence) genes modulate recombination by determining the pairing closeness of dna duplexes in the vicinity of the nit-2 locus. when heterozygous, ss suppresses recombination 2 ...19816461572
binding and screening by cations and the effect on exogenous nad(p)h oxidation in neurospora crassa mitochondria.1. the uncoupled oxidation of exogenous nadh by mitochondria from neurospora crassa has a ph optimum at 7.0. in the presence of edta (1 mm) the optimum is at ph 6.5; maximal inhibition (65%) occurs at ph 7.2. this is comparable to the results with higher plant mitochondria. 2. the corresponding ph optima for nadph oxidation are 7.75 (control), 7.0 (+ edta) and 8.0 (effect of edta), respectively. nadph oxidation is completely inhibited by edta at ph 8.0. these ph optima are all about 1 higher tha ...19826461553
estimation of deuteration levels in whole cells and cellular proteins by 1h n.m.r. spectroscopy and neutron scattering.methods using conventional fourier transform 1h n.m.r. spectroscopy at 250 mhz for the determination of the overall deuteration levels of cells cultured in media containing 2h2o or deuterated carbon sources are described. these were developed for escherichia coli as a model, and extended to neurospora crassa hyphae and mouse myeloma cells p815. the results were investigated by 1h n.m.r. and neutron scattering measurements on deuterated proteins that were obtained from e. coli. it is concluded th ...19816461329
circadian rhythms in neurospora crassa: a mutation affecting temperature compensation.the circadian rhythm of conidiation (spore formation) in neurospora crassa is known to be temperature compensated, that is, the period is only slightly affected by the incubation temperature. thus, the q10 (the relative rate enhancement corresponding to a 10 degrees c rise in temperature) of the rhythm of the bd csp strain from 14 to 30 degrees c was 1.1, whereas the q10 of the uncompensated growth rate in the same interval was 2.4. a mutation at the cel locus resulted in loss of the temperature ...19826461008
liposome-mediated genetic transformation of neurospora crassa.transformation of neurospora crassa spheroplasts is reported for three different genes, using uncloned neurospora dna, both naked and encapsulated in synthetic phosphatidylserine liposomes. whereas transformation by naked dna is dnase-sensitive, that by liposomes is not. per unit of transforming dna, liposome transformation is significantly more efficient than that with naked dna, ranging from 19x for the am gene to 41x for pyr-3. levels of activity of pyr-3 and am transformants, and segregation ...19816460917
use of four short-term tests to evaluate the mutagenicity of municipal water.some ways in which four short-term tests may be used to evaluate the mutagenicity of drinking water were explored by testing raw and treated water from lake bloomington, which serves the town of bloomington, illinois (population, 44,000). the water was collected from february 1976 to october 1977 and was concentrated by evaporation or by use of xad-2 resin. the water was tested for the ability to induce reverse mutation in a prokaryote, salmonella typhimurium; forward mutation in a mold, neurosp ...19826460874
solubility of (1 leads to 3)-beta-d/(1 leads to 6)-beta-d-glucan in fungal walls: importance of presumed linkage between glucan and saccharomyces cerevisiae, neurospora crassa, aspergillus nidulans and coprinus cinereus most of the alkali-insoluble (1 leads to 3)-beta-d/(1 leads to 6)-beta-d-glucan of the wall can be extracted with dimethyl sulphoxide. the same fraction, and in saccharomyces cerevisiae a small additional fraction, can be extracted by a destructive procedure involving 40% naoh at 100 degrees c. the small fraction of the glucan which resists this treatment becomes soluble after a subsequent treatment with h ...19816460846
cell-biology of ageing. 1. isolation of gamma-ray induced ageing mutants of neurospora crassa and their preliminary characterizations. 19816460560
inhibition of adenine and hypoxanthine uptake by guanosine in conidia of neurospora crassa.guanosine competitively inhibits the uptake of adenine and hypoxanthine by the general purine-base permease in conidia of neurospora crassa. there is no reciprocal effect of adenine or hypoxanthine on guanosine uptake so it is suggested that guanosine can bind to the general purine-base permease to cause this inhibition but is not transported through this system. it is known that guanosine is transported by two separate nucleoside transport sites. guanosine also noncompetitively inhibits the spe ...20136460550
changes in nucleotide pools during conidial germination in neurospora crassa. 20136460549
mutagenesis at the ad-3a and ad-3b loci in haploid uv-sensitive strains of neurospora crassa. v. comparison of dose--response curves of single- and double-mutant strains with wild-type.the interactions of mutant alleles that individually confer radiation sensitivity in neurospora crassa are being studied with regard to their effects on radiation-induced inactivation and forward-mutation induction at the ad-3 loci. this paper reports attempts to construct 3 double-mutant strains containing the following pair-wise combinations of repair-deficient mutants: upr-1,uvs-2; uvs-2,uvs-6; and uvs-3,uvs-6. the double-mutant strain with the 2 excision-repair-deficient mutants upr-1 and uv ...19816460180
the testing of 4cmb, 4hmb and bc for mutagenicity in a new neurospora crassa heterokaryon.this genetic system permits both point mutations and deletion to be detected in the same experimental material. 4cmb and bc are regarded as being mutagenic in this system. 4hmb induced mutations in only 1 of the 3 treatment protocols used, and its mutagenicity is questionable.20126460177
biochemical analysis of mutants defective in nitrate assimilation in neurospora crassa: evidence for autogenous control by nitrate reductase.a biochemical analysis of mutants altered for nitrate assimilation in neurospora crassa is described. mutant alleles at each of the nine nit (nitrate-nonutilizing) loci were assayed for nitrite reductase activity, for three partial activities of nitrate reductase, and for nitrite reductase activity. in each case, the enzyme deficiency was consistent with data obtained from growth tests and complementation tests in previous studies. the mutant strains at these nit loci were also examined for alte ...19816460156
role of lipids in the neurospora crassa membrane: iv. biochemical and electrophysiological changes caused by growth on phytanic acid.neurospora crassa strain cel, which is deficient in fatty acid synthesis, was grown with phytanic acid supplementation. the temperature dependence of membrane potential is increased by growth on phytanic acid. a temperature change of 40 degrees c produces a change of 184 mv in phytanic acid-grown cells as compared to a 50 mv change for cel grown on palmitic acid or wild-type. membrane resistance (measured as dc input resistance) of phytanic acid-grown cells did not differ from cel grown on palmi ...19826460106
properties of mitochondria as a function of the growth stages of neurospora crassa.the oxidative and phosphorylative properties of mitochondria isolated from neurospora crassa were investigated as a function of growth stage. the rates of oxidation of exogenous nadh and nadph varied independently of each other, thus ruling out the existence of only one unspecific dehydrogenase. two different pathways were involved in the oxidation of nad-linked substrates, as indicated by changes in the rate of oxygen uptake, the sensitivity to rotenone, and the efficiency of phosphorylation. o ...19826460022
aminotransferase study of neurospora crassa ser-3 versus wild type st4a. 19816459952
the cell-free protein synthesis system from the 'slime' mutant of neurospora crassa. preparation and characterisation of importance of 7-methylguanosine for translation of viral and cellular mrnas.a simple procedure for preparation of a cell-free protein synthesis system (23000 x g supernatant) from the protoplast-like 'slime' mutant of neurospora crassa is described. a variety of messenger rnas of viral and cellular origin could be efficiently and faithfully translated in this system into proteins with mr as large as 180000. the importance of the 7-methylguanosine cap for mrna translation in the neurospora system was studied in detail using the cap analogs and chemically decapped messeng ...19816459928
general control of arginine biosynthetic enzymes in neurospora crassa.the response of six amino acid synthetic enzymes, including four concerned with arginine synthesis, one with histidine synthesis and one with lysine synthesis, to conditions of histidine and arginine limitation and to exogenously provided amino acids is described in neurospora crassa. the activities of all these enzymes increased in response to lowered levels of histidine or arginine, but showed little or no repression in wild-type cultures supplemented with casein hydrolysate. the activity of g ...19816459428
an isolated pseudogene related to the 5s rna genes in neurospora crassa. 19816458767
folylpoly-gamma-glutamate synthesis by bacteria and mammalian cells.the purification and properties of folylpolyglutamate synthetase from corynebacterium sp, and some properties of partially purified enzyme from lactobacillus casei, streptococcus faecalis, neurospora crassa, pig liver, and chinese hamster ovary cells, are described. the corynebacterium enzyme catalyzes a mgatp-dependent addition of glutamate to a variety of reduced pteroate and pteroylmono-, di-, and triglutamate substrates, with the concomitant production of mgadp and phosphate. although glutam ...19816458762
enzymatic alterations secondary to adenyl cyclase deficiency in the cr-1 (crisp) mutant of neurospora crassa: anomalies of the beta-glucosidase system. 19816458343
sex-hormones in neurospora crassa. differences in the biological property of the hormonal extracts of fertile and sterile strains.sexual hormones, isolated from the wild strains and sterile mutants of neurospora crassa, were used for the improvement of fertility of sterile crosses, i. e., st. l. a x7232-a, st. l. a x 9312-a and st. l. a x 8455-a. improvement of fertility was observed in case of the cross st. l. a x 9312-a. of the different extracts, hormonal substances present in the extract of 7232-a (sterile mutant) and also of the wild types (em a, em a, st. l. a, st. l. a) exerted the most prominent effects. for the ex ...19816458180
genetic organization and transcriptional regulation in the qa gene cluster of neurospora crassa.a transcription map of the qa gene cluster of neurospora crassa has been constructed by using cloned dna fragments as hybridization probes. the mrnas encoded in the previously identified qa-2 (3-dehydroquinate hydro-lyase, ec, qa-4 (dehydroshikimate dehydratase), qa-3 (quinate:nad+ 3-oxidoreductase, ec, and qa-1 (regulatory protein) genes have been characterized. in addition, mrnas encoded in two new genes in this cluster (qa-x, qa-y) have been identified. regulation of this ...19816458044
photoreception in neurospora crassa: correlation of reduced light sensitivity with flavin deficiency.the effect of flavin deficiency on blue light responses in neurospora crassa was studied through the use of two riboflavin mutants (rib-1 and rib-2). the photoresponses assayed were the suppression of circadian conidiation, the phase shifting of the circadian conidiation rhythm, and the induction of carotenoid synthesis. flavin deficiency was induced in the rib-1 mutant by restrictive growth temperatures and in the rib-2 mutant by low levels of supplemental riboflavin. at 26 degrees c, a semires ...19816458042
purification and characterization of the plasma membrane atpase of neurospora crassa.the plasma membrane of neurospora crassa contains a proton-translocating atpase, which functions to generate a large membrane potential and thereby to drive a variety of h+-dependent co-transport systems. we have purified this atpase by a three-step procedure in which 1) loosely bound membrane proteins are removed by treatment with 0.1% deoxycholate; 2) the atpase is solubilized with 0.6% deoxycholate in the presence of 45% glycerol; and 3) the solubilized enzyme is purified by centrifugation th ...19816457834
isolation and characterization of plasma membranes from wild type neurospora crassa.a method has been developed to isolate plasma membranes with high atpase activity from wild type neurospora. cells are treated with snail enzyme to weaken their cell walls, disrupted by gentle homogenization in a medium designed to keep mitochondria and other organelles intact, and fractionated by differential centrifugation. after removal of mitochondria, several higher speed particulate fractions (particularly one sedimenting at 40,000 x g) contain an atpase that can be identified as the plasm ...19816457833
the involvement of proteolysis in conformational stability of the carbamoyl-phosphate synthetase/aspartate carbamoyltransferase enzyme of neurospora crassa.the pyrimidine-3 gene of neurospora crassa codes for a bifunctional enzyme catalysing the first two steps of the pyrimidine biosynthetic pathway. difficulties have been experienced in purification due to the lability of the enzyme. the enzyme loses carbamoyl-phosphate synthetase (carbon-dioxide: ammonia ligase (adp-forming, carbamate-phosphorylating), ec activity and undergoes a change in apparent molecular weight from the native 650,000 to 100,000 of the only detectable fragment. atte ...19816457644
the regulation of nitrate assimilation in neurospora crassa: biochemical analysis of the nmr-1 mutants.neurospora crassa nmr-1 mutants, selected on the basis of their sensitivity to chlorate in the presence of glutamine, have elevated levels of the nitrate assimilation enzymes, nadph-nitrate reductase and nad(p)h-nitrite reductase. immunoelectrophoretic determinations show that the higher nitrate reductase activities in nmr-1 mutants are due to greater enzyme concentrations. the half-life of nitrate reductase in these mutants is unaltered. as in wild-type, expression of nitrate assimilation in nm ...19816457234
the regulation of nitrate assimilation in neurospora crassa: the isolation and genetic analysis of nmr-1 mutants.four mutants of neurospora crassa have been isolated which have altered regulation of nitrate reductase. they each carry a mutation which results in derepressed synthesis of nitrate reductase even in the presence of glutamine. they map to a single locus which has been designated nmr-1 and which is located between am and gln on linkage group vr. the mutations appear to affect only nitrate assimilation. the nit-2, nit-3 and nit-4/5 mutations are epistatic to nmr-1 since the double mutants have the ...19816457233
neurospora crassa nad(p)h-nitrite reductase. studies on its composition and structure.neurospora crassa nitrite reductase (mr = 290,000) catalyzes the nad(p)h-dependent 6-electron reduction of nitrite to ammonia via flavin and siroheme prosthetic groups. homogeneous n. crassa nitrite reductase has been prepared employing conventional purification methods followed by affinity chromatography on blue dextran-sepharose 4b. sodium dodecyl sulfate-polyacrylamide gel electrophoresis of homogeneous nitrite reductase reveals a single subunit band of mr = 140,000. isoelectric focusing of d ...19816457037
ultrastructural cytochemistry of perinucleolar dense spots in heat-treated macroconidia of neurospora crassa.upon heat treatment at 46 degrees c of neurospora macroconidia, numerous dense sports appear around the nucleolus but disappear completely 5 h after shift-down to normal temperature. cytochemical reactions and high-resolution autoradiography after pulse-labeling with tritiated uridine indicate that these dense sports contain rna (perhaps pre-rrna), rnp and other proteins, but no dna.19816456905
studies on myo-inositol-1-phosphate from lilium longiflorum pollen, neurospora crassa and bovine testis. further evidence that a classical aldolase step is not utilized. 19816456770
the effect of polyethylene glycol on the dna uptake in neurospora crassa. 19816456636
independent localization and regulation of carbamyl phosphate synthetase a polypeptides of neurospora crassa.carbamyl phosphate synthetase a is a two-polypeptide, mitochondrial enzyme of arginine synthesis in neurospora. the large subunit is encoded in the arg-3 locus and can catalyze formation of carbamyl-p with ammonia as the n donor. the small subunit is encoded in the unlinked arg-2 locus and imparts to the holoenzyme the ability to use glutamine, the biological substrate, as the n donor. by using nonsense mutations of arg-3, it was shown that the small subunit of the enzyme enters the mitochrondri ...19816456400
timing of nuclear division cycle in neurospora crassa.the timing of the nuclear division cycle in neurospora crassa was studied by inhibiting dna synthesis with hydroxyurea added to exponentially growing cultures at concentrations that do not inhibit cytoplasmic growth. after the addition of hydroxyurea only the nuclei that have passed the s-phase divide, and therefore by counting the increase in the average number of nuclei per hypha, the stage in the cycle in which completion of s phase occurred was determined in different nutritional conditions ...19816456271
characterization of 2-aminoisobutyric acid transport in neurospora crassa: a general amino acid permease-specific substrate.we report the characterization of an amino acid 2-aminoisobutyric acid was transported solely by the general amino acid permease and not by the neutral amino acid permease. furthermore, this substrate was not metabolized after transport. the potential for a system-specific nonmetabolizable substrate as a tool in the analysis of amino acid transport and its regulation is discussed.19816456264
the isolation of mms- and histidine-sensitive mutants in neurospora crassa.a simple method of replica plating has been used to isolate mutants of neurospora crassa that have increased sensitivity to methyl methanesulfonate (mms) and/or to histidine. twelve mutants with increased sensitivity to mms and one mutant with increased sensitivity to histidine showed mendelian segregation of the mutant phenotypes. three mutants were mapped to loci not previously associated with mms sensitivity. two other were allelic to the uv- and mms-sensitive mutant, mei-3. survival curves i ...19816456170
effect of regulatory mutations of sulphur metabolism on the levels of cysteine- and homocysteine-synthesizing enzymes in neurospora crassa.1. regulation of four enzymes involved in cysteine and homocysteine synthesis, i.e. cysteine synthase (ec, homocysteine synthase (ec, cystathionine beta-synthase (ec 2.1.22) and gamma-cystathionase (ec was studied in the wild type and sulphur regulatory mutants of neurospora crassa. 2. homocysteine synthase and cystathionine beta-synthase were found to be regulatory enzymes but only the former is under control of the cys-3 - scon system regulating several enzymes of ...19806455895
the frq locus in neurospora crassa: a key element in circadian clock organization.four new circadian clock mutants of neurospora crassa have been isolated that alter the period length of the circadian conidiation rhythm. three of these are at the frq locus on linkage group viir, where four other clock mutants are located. in contrast to wild type, which has a period length of 21.6 hr, frq-6 has a period length of 19 hr, while frq-7 and frq-8 have period lengths of 29 hr and represent the largest effects of any single gene mutants on circadian periodicity. thus, seven mutants ...19806455327
meiosis in neurospora crassa. ii. genetic and cytological characterization of three meiotic mutants.three recessive meiotic mutants, asc(dl95), asc(dl243) and asc(dl879), were detected by the abortion of many of their ascospores and were analyzed using both cytological and genetic methods. even though asc(dl95), asc (dl243) and the previously studied meiotic mutant, mei-1 (smith 1975; lu and galeazzi (1978), complement one another in crosses, they apparently do not recombine (delange and griffiths (1980). thus, they may represent alleles of the same gene or comprise a gene cluster. ascospore a ...19806455325
meiosis in neurospora crassa. i. the isolation of recessive mutants defective in the production of viable ascospores.a scheme has been devised for efficient isolation of recessive meiotic mutants of neurospora crassa. these mutants were detected by their reduced fertility or by the abortion of ascospores. their isolation involved the selection and screening of the strains arising from ascospores disomic (n + 1) for linkage group i (lg i), which bears the mating-type locus. these strains are self-fertile heterokaryons that contain two types of haploid nuclei of opposite mating types (a + a). selfings of these s ...19806455324
genetic screening of compounds used in drug abuse treatment. iii. laam.several compounds used clinically in drug abuse therapy were evaluated for genetic activity in a series of in vivo and in vitro assays. this third report in the series describes the results for one of these compounds, laam (l-alpha-acetyl methadol). previous reports described results from a three phase testing program for naltrexone and methadone. laam is related chemically to the narcotic analgesic oxymorphine, and is related chemically to a narcotic antagonist, naloxone. laam exhibited genetic ...19816455284
genetic screening of compounds used in drug abuse treatment. ii. methadone.several compounds used clinically in drug abuse therapy were evaluated for genetic activity in a series of in vivo and in vitro assays. the second report in this series describes the results for one of these compounds, methadone. a previous report described the results for naltrexone. methadone is a synthetic narcotic analgesic used as a substitute for heroin in drug detoxification programs. methadone demonstrated weak activity in the e. coli dna repair system and in the neurospora crassa and th ...19816455283
inactivation of normal and mutant neurospora crassa conidia by visible light and near-uv: role of 1o2, carotenoid composition and sensitizer location. 19816454899
mutagenicity of cigarette smoke condensate in neurospora crassa.the mutagenicity of cigarette smoke condensate (csc) was investigated in neurospora crassa in the presence and absence of s9 mix prepared from aroclor-1254-induced rat liver. csc from the university of kentucky reference cigarette 1r1 was assayed in a forward-mutation test at the adenine-3 (ad-3) region in resting conidia of 2-component heterokaryons. in the absence of s9 mix, csc exhibited direct-acting mutagenicity. csc was also mutagenic in the presence of s9 mix, but higher doses were requir ...19816454843
mutagenicity of fractions of cigarette smoke condensate in neurospora crassa and salmonella typhimurium.the mutagenicities of selected fractions of cigarette smoke condensate (csc) were studied in neurospora crassa for the presence of direct-acting mutagens. cscs from the university of kentucky reference cigarette 1r1 were assayed in a forward-mutation test at the adenine-3 (ad-3) region in resting conidia of a 2-component heterokaryon. direct-acting mutagenic activity was found in an enriched polycyclic aromatic hydrocarbons (epah) fraction and in a basic fraction (swain 5). no direct-acting muta ...19816454842
mutagenesis at the ad-3a and ad-3b loci haploid uv-sensitive strains of neurospora crassa. iii. comparison of dose-response curves for inactivation and mutation induced by gamma-rays.gamma-ray-induced inactivation and induction of mutations at the ad-3a and ad-3b loci of neurospora crassa have been compared among 6 different uv-sensitive strains and a standard wild-type strain. the 6 strains show varying degrees of sensitivity to gamma-ray-induced inactivation, with the relative sensitivity at 37% survival being uvs-6 greater than upr-1 greater than uvs-2 greater than uvs-3 greater than wild-type greater than uvs-5 greater than uvs-4. studies on the induction of ad-3 mutants ...19816454839
cycloheximide-induced phase shifting of circadian clock of neurospora.cycloheximide (chx), an inhibitor of cytosolic (80s) protein synthesis in eucaryotes, causes phase shifts of the circadian clock of neurospora crassa when administered as 4-h pulses to cultures in liquid medium. differential effects of the pulses at different phases of the circadian cycle were observed and plotted as a phase-response curve (prc). nearly all phase shifts observed were phase advances, with maximum sensitivity in the middle of the subjective day. inhibition of protein synthesis by ...19816454353
mitochondrial ribosome assembly in neurospora crassa. purification of the mitochondrially synthesized ribosomal protein, neurospora, one mitochondrial ribosomal protein (s-5, mr = 52,000) is synthesized intramitochondrially and is presumably encoded by mitochondrial dna. we have developed a rapid method for the purification of s-5 which takes advantage of its high affinity for carboxymethyl-sepharose in the presence of 6 m urea. using this method, s-5, at purity greater than 95%, can be prepared by column chromatography in a single batch elution step. the amino acid composition of s-5 was determined. judged by ...19816453873
uracil's uncoupling of the decarboxylation of alpha-ketoglutarate in the thymine 7-hydroxylase reaction of neurospora crassa.highly purified preparations of thymine 7-hydroxylase from neurospora crassa catalyzed the decarboxylation of alpha-ketoglutarate but yielded no hydroxylated product when uracil was substituted for thymine in the standard incubation mixture. although the uracil-dependent decarboxylation was much slower than the coupled reaction, both reactions were similar with respect to the requirement for molecular oxygen, the stoichiometric formation of succinate, and the stimulations effected by fe2+, ascor ...19816453866
incorporation of photolabile azido fatty acid probes in neurospora crassa and saccharomyces cerevisiae. 19816453723
subunit structure of anthranilate synthase from neurospora crassa: preparation and characterization of a protease-free form. 19816453559
15n nmr studies of nitrogen metabolism in intact mycelia of neurospora crassa.suspensions of intact mycelia of neurospora crassa grown in medium containing 15nh4cl have been found to give well-resolved 15n nuclear magnetic resonance spectra for metabolites that play crucial roles in intermediary nitrogen metabolism. these include the amide nitrogen of glutamine, the alpha-amino nitrogens of glutamate and other amino acids, the guanidino nitrogens of arginine, the ureido nitrogen of citrulline, the side-chain nitrogens of ornithine or lysine, or both, and uridine diphospha ...19816453347
nucleotide sequence of 5s ribosomal rna from aspergillus nidulans and neurospora crassa.the nucleotide sequences of 5s rrna molecules isolated from the cytosol and the mitochondria of the ascomycetes a. nidulans and n. crassa were determined by partial chemical cleavage of 3'-terminally labelled rna. the sequence identity of the cytosolic and mitochondrial rna preparations confirms the absence of mitochondrion-specific 5s rrna in these fungi. the sequences of the two organisms differ in 35 positions, and each sequence differs from yeast 5s rrna in 44 positions. both molecules conta ...19816453331
the nucleotide sequence at the 3'-end of neurospora crassa 25s-rrna and the location of a 5.8s-rrna binding site.the sequence of 110 nucleotides adjacent to the 3'-end of neurospora crassa 25s-rrna has been derived by chemical sequencing methods. sequences present between 40 and 85 nucleotides of the 3'-end were found to complement sequences at the 3'- and 5'-ends of 5.8s-rrna. interaction was shown to occur between 5.8s-rrna and a specific 3'-terminal fragment of 85 nucleotides derived from 25s-rrna. we have also demonstrated that the nucleotide sequence at the 3'-end of n. crassa 5.8s-rrna (-ucauuoh) is ...19816453330
negative cooperativity in the interaction of fructose 1,6-diphosphate with pyruvate kinase of neurospora crassa. 19816453017
studies on phospholipase activities in neurospora crassa conidia. 19816452858
inheritance of dna-induced inositol independence of inositolless neurospora crassa.neurospora crassa (n. crassa) inositolless (inl) strain gives inositol-independent colonies (inl+) if treated with dna from wild type n. crassa. there is an increased number of unusual non-mendelian tetrads (24%) among the progeny. in sexual crosses of these strains with inl alleles ascospores of complete ordered tetrads were isolated. clones of these aberrant tetrads were examined for the inheritance of the inl+ and inl markers respectively. several inl+ clones of single ascospores of these tet ...19806452779
control of growth and of the nuclear division cycle in neurospora crassa. 19816452573
genetic analysis of adenine-3 mutants induced by hycanthone, lucanthone and their indazole analogs in neurospora mutants induced by hycanthone, lucanthone and their indazole analogs, ia-3, ia-4 and ia-5 were studied to characterize the genetic alterations produced by these agents in neurospora crassa. the results of genetic analysis indicate that, in marked contrast to past experiments with chemical mutagens on heterokaryon 12, all of these antischistosomal agents induce a very high frequency of multilocus deletions.19806452485
alternate mechanism for amino acid entry into neurospora crassa: extracellular deamination and subsequent keto acid transport.the growth of the pm nbg mutant strain of neurospora crassa was inhibited by the amino acid analog para-fluorophenylalanine despite the fact that none of the three constitutive amino acid permeases is functional in this strain. this observation led to the detection of both a deaminase which was released into the growth medium in response to para-fluorophenylalanine and a keto acid transport system which allowed entry of the resulting keto acid into the cell. the transported keto acid was recover ...19816452443
some studies on histidine transport in neurospora crassa. 19806452407
conformationally important histidine residue in glutamate dehydrogenase from neurospora crassa. 19806452288
in vitro complementation of assimilatory nad(p)h-nitrate reductase from mutants of chlamydomonas vitro complementation of the soluble assimilatory nad(p)h-nitrate reductase (nad(p)h:nitrate oxidoreductase, ec was attained by mixing cell-free preparations of chlamydomonas reinhardii mutant 104, uniquely possessing nitrate-inducible nad(p)h-cytochrome c reductase, and mutant 305 which possesses solely the nitrate-inducible fmnh2- and reduced benzyl viologen-nitrate reductase activities. full activity and integrity of nad(p)h-cytochrome c reductase from mutant 104 and reduced benzy ...19816452169
electrophoretic analysis of the plasma membrane proteins of a mutant of neurospora crassa which lacks a cell wall.the plasma membrane proteins of a mutant of neurospora crassa (fgsc no. 326) which lacks a cell wall were analyzed by two-dimensional polyacrylamide gel electrophoresis. approximately 180 different proteins were detected in purified plasma membrane preparations. nonpermeating labeling experiments indicated that approximately 40% of these proteins were exposed on the extra-cytoplasmic surface of the plasma membranes of these cells. the studies demonstrate the complexity of the protein composition ...19816452167
reduction of ribosome activity and synthesis of stable rna in neurospora crassa.the addition of cycloheximide (0.02 micrograms/ml) to exponentially growing cultures of neurospora crassa causes a reduction in growth rate and a decrease in the rate of protein accumulation, due to a partial inhibition of protein synthesis, while rna accumulation is unaffected for about 1 h. thus, an increased rna:protein ratio is established in the presence of the inhibitor. rna that accumulates during treatment with cycloheximide has the same characteristics as that of the control cultures an ...19806452164
mutation-induction in repair-deficient strains of neurospora.various mutants sensitive to uv-induced inactivation have been used to study the process of spontaneous and induced mutation in the ad-3 region of neurospora crassa. studies on haploid strains have shown that the process of mutation-induction in the ad-3 region is under genetic control. studies on two-component heterokaryons have shown that this control effects both point mutations and multilocus deletions. comparisons made between an excision-repair deficient two-component heterokaryon (59) hav ...19806452121
mutagen-sensitive mutants in neurospora.initial work on the fungus neurospora crassa has shown that a least two dna-repair systems exist in this eukaryote: excision repair and a mutation-prone repair. the evidence suggests that there is also a third repair system. recently, new mutagen-sensitive strains have been isolated in several laboratories, but they are not yet fully characterized. a hunt for cytoplasmically inherited uv sensitivity has failed to turn up any such mutants among 25 new uv-sensitive isolates.19806452119
mutagen sensitivities and mutator effects of mms-sensitive mutants in neurospora.7 mus (mutagen-sensitive) mutants of neurospora crassa, which are more sensitive to the toxic effects of mms (methyl methanesulfonate) than wild-type, were investigated for cross-sensitivities to other mutagens and inhibitors. these mutants have recently been mapped in 5 new genes, mus-7 to mus-11, and mutant alleles from each gene were checked for their effects on mutation frequencies. it was found that mutants in 3 of these 5 genes showed radiation-induced mutation frequencies similar to wild- ...19816451802
kinetic properties of fatty acid synthetase of neurospora crassa.the kinetic properties of fatty acid synthetase, extracted from the mycelia of neurospora crassa, were studied to determine the role of the multi-enzyme complex in the regulation of long chain saturated fatty acid synthesis. acetyl-coa, a substrate, affects the fatty acid synthetase with increasing concentration in a normal michaelis-menton kinetic mode. malony-coa, another substrate, activates the synthetase in a homotropic manner up to 35 microm with a hill coefficient of 2.8. above that conce ...19806451784
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