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in vivo chitin-cadmium complexation in cell wall of neurospora crassa.fungal cell wall, mainly composed of chitin, an n-acetylglucosamine polymer, is known to participate in heavy metal detoxification. in the present study, an effort was made to elucidate the sites involved in complexation of cadmium by the chitin material of cell wall of neurospora crassa. based on the results of physical techniques, such as solid-state 13c-nmr, x-ray diffraction, ir and molecular modeling, a structure was proposed for the chitin-cadmium complex. the ring and c-3 hydroxyl oxygens ...200011099854
the external calcium-dependent nadph dehydrogenase from neurospora crassa mitochondria.we have inactivated the nuclear gene coding for a putative nad(p)h dehydrogenase from the inner membrane of neurospora crassa mitochondria by repeat-induced point mutations. the respiratory rates of mitochondria from the resulting mutant (nde-1) were measured, using nadh or nadph as substrates under different assay conditions. the results showed that the mutant lacks an external calcium-dependent nadph dehydrogenase. the observation of nadh and nadph oxidation by intact mitochondria from the nde ...200111073955
gene cloning and molecular characterization of lysine decarboxylase from selenomonas ruminantium delineate its evolutionary relationship to ornithine decarboxylases from eukaryotes.lysine decarboxylase (ldc; ec 4.1.1.18) from selenomonas ruminantium comprises two identical monomeric subunits of 43 kda and has decarboxylating activities toward both l-lysine and l-ornithine with similar k(m) and v(max) values (y. takatsuka, m. onoda, t. sugiyama, k. muramoto, t. tomita, and y. kamio, biosci. biotechnol. biochem. 62:1063-1069, 1999). here, the ldc-encoding gene (ldc) of this bacterium was cloned and characterized. dna sequencing analysis revealed that the amino acid sequence ...200011073919
yeti--a degenerate gypsy-like ltr retrotransposon in the filamentous ascomycete podospora anserina.in the filamentous ascomycete podospora anserina a 6,935-bp retrotransposon, yeti, has been identified and characterized. it is flanked by a 5-bp target site duplication and contains long terminal repeats (ltrs) 354 bp in length. the ltrs show a high degree of identity to the previously reported repetitive element repa, a sequence suggested to represent a solo-ltr element of an unknown transposon. in the investigated podospora strains, the number of complete yeti copies is significantly lower th ...200011057446
functional analysis of the leader peptide of the yeast gene cpa1 and heterologous regulation by other fungal peptides.the 25-amino-acid leader peptide present at the 5' end of yeast cpa1 mrna is responsible for the translational repression of that gene by arginine. we show here that the active domain of the yeast peptide is highly specific and extends over amino acids 6-23. the region between amino acids 6-21 is well conserved between similar peptides present upstream of cpa1-homologous genes in other fungi. the neurospora crassa arg-2 peptide represses the expression of cpa1, whereas the peptide from aspergill ...200011057443
molecular and functional analyses of incompatibility genes at het-6 in a population of neurospora crassa.two closely linked genes, un-24 and het-6, associated with the het-6 heterokaryon incompatibility functional haplotype were examined in 40 neurospora crassa strains from a louisiana sugarcane field. partial diploid analyses were used to determine that half of the strains were functionally oak ridge (or) and half were non-or and indistinguishable from the standard panama (pa) form. pcr-based markers were developed to identify polymorphisms within both un-24 and het-6. two common forms of each gen ...200011035941
a secondary beta deuterium kinetic isotope effect in the chorismate synthase reaction.chorismate synthase (ec 4.6.1.4) is the shikimate pathway enzyme that catalyzes the conversion of 5-enolpyruvylshikimate 3-phosphate (epsp) to chorismate. the enzyme reaction is unusual because it involves a trans-1,4 elimination of the c-3 phosphate and the c-6 pror hydrogen and it has an absolute requirement for reduced flavin. several mechanisms have been proposed to account for the cofactor requirement and stereochemistry of the reaction, including a radical mechanism. this paper describes t ...200011034781
a novel type of fkbp in the secretory pathway of neurospora crassa.fkbps define a subfamily of peptidyl-prolyl cis/trans isomerases (pplases). pplases are known to play roles in cellular protein folding, protein interactions and signal transduction. here we describe ncfkbp22 from neurospora crassa, a novel type of fkbp. ncfkbp22 is synthesized as a precursor protein with a cleavable signal sequence. in addition to a typical fkbp domain in the amino-terminal part mature ncfkbp22 contains a novel second domain which is unique amongst all known fkbps. the amino ac ...200011034311
potassium distribution in the neurospora crassa hypha. 201611029033
antisense expression of the calmodulin gene from colletotrichum trifolii impairs prepenetration development(1).calmodulin is a ubiquitous highly conserved calcium binding protein involved in cell signalling. previous studies in our laboratory suggested a role for calmodulin in prepenetration morphogenesis in colletotrichum trifolii, the causal agent of alfalfa anthracnose. in this report, we describe the cloning, sequencing and partial characterization of the calmodulin gene from c. trifolii. the gene is present as a single copy in the genome of c. trifolii and its predicted amino acid sequence shows con ...200011024266
a single five-step desaturase is involved in the carotenoid biosynthesis pathway to beta-carotene and torulene in neurospora crassa.phytoene desaturase al-1 from neurospora crassa was expressed in escherichia coli and an active enzyme was isolated which catalyzed the stepwise introduction of up to five double bonds into the substrate phytoene. the major reaction products were 3, 4-didehydrolycopene and lycopene. several of the desaturation intermediates, zeta-carotene, neurosporene, and lycopene, were also accepted as a substrate by al-1. in contrast to the structurally related bacterial enzymes, the cofactor involved in the ...200011017770
characterization of the neurospora crassa mus-25 mutant: the gene encodes a protein which is homologous to the saccharomyces cerevisiae rad54 protein.characterization of the neurospora crassa mus-25 mutant suggests that it is defective in recombination repair and belongs to the uvs-6 epistasis group. it shows a high sensitivity to the alkylating agents methyl methanesulfonate (mms) and n-methyl-n'-nitro-n-nitrosoguanidine (mnng), but not to uv radiation. it is barren (i.e. does not produce ascospores) in homozygous crosses. the frequency of mms-induced mutations at the ad-3 loci is approximately three times higher than in the wild type. the r ...200011016845
respiratory chain complex i is essential for sexual development in neurospora and binding of iron sulfur clusters are required for enzyme assembly.we have cloned and disrupted in vivo, by repeat-induced point mutations, the nuclear gene coding for an iron sulfur subunit of complex i from neurospora crassa, homologue of the mammalian tyky protein. analysis of the obtained mutant nuo21.3c revealed that complex i fails to assemble. the peripheral arm of the enzyme is disrupted while its membrane arm accumulates. furthermore, mutated 21.3c-kd proteins, in which selected cysteine residues were substituted with alanines or serines, were expresse ...200011014810
characterization of mrad18sc, a mouse homolog of the yeast postreplication repair gene rad18.the rad18 gene of the yeast saccharomyces cerevisiae encodes a protein with ssdna binding activity that interacts with the ubiquitin-conjugating enzyme rad6 and plays an important role in postreplication repair. we identified and characterized the putative mouse homolog of rad18, designated mrad18sc. the mrad18sc open reading frame encodes a 509-amino-acid polypeptide that is strongly conserved in size and sequence between yeast and mammals, with specific conservation of the ring-zinc-finger and ...200011013078
characterization of two novel redox groups in the respiratory nadh:ubiquinone oxidoreductase (complex i).the proton-pumping nadh:ubiquinone oxidoreductase is the first of the respiratory chain complexes in many bacteria and mitochondria of most eukaryotes. the bacterial complex consists of 14 different subunits. seven peripheral subunits bear all known redox groups of complex i, namely one fmn and five epr-detectable iron-sulfur (fes) clusters. the remaining seven subunits are hydrophobic proteins predicted to fold into 54 alpha-helices across the membrane. little is known about their function, but ...200011004444
regulation of conidiation and adenylyl cyclase levels by the galpha protein gna-3 in neurospora crassa.we have identified a new gene encoding the g protein alpha subunit, gna-3, from the filamentous fungus neurospora crassa. the predicted amino acid sequence of gna-3 is most similar to the galpha proteins mod-d, maga, and cpg-2 from the saprophytic fungus podospora anserina and the pathogenic fungi magnaporthe grisea and cryphonectria parasitica, respectively. deletion of gna-3 leads to shorter aerial hyphae and premature, dense conidiation during growth on solid medium or in standing liquid cult ...200011003665
characterization of an unusual trna-like sequence found inserted in a neurospora retroplasmid.we characterized an unusual trna-like sequence that had been found inserted in suppressive variants of the mitochondrial retroplasmid of neurospora intermedia strain varkud. we previously identified two forms of the trna-like sequence, one of 64 nt (trl-64)and the other of 78 nt (trl-78) containing a 14-nt internal insertion in the anticodon stem at a position expected for a nuclear trna intron. here, we show that trl-78 is encoded in varkud mitochondrial (mt)dna within a 7 kb sequence that is n ...200011001704
asd4, a new gata factor of neurospora crassa, displays sequence-specific dna binding and functions in ascus and ascospore development.a new gene encoding a novel gata factor, asd4, of neurospora crassa was isolated and demonstrated to possess one intron and to specify an open reading frame encoding a protein with 427 amino acid residues. the asd4 protein contains a single gata-type zinc finger and a putative coiled-coil domain. unlike related proteins, dal80 in yeast and nreb in penicillium, asd4 does not appear to be involved in regulation of nitrogen metabolism. an asd-4 null mutant obtained by the rip procedure did not show ...200010998244
comparison of chitin content in the apical and distal parts of fungal hyphae in basidiobolus ranarum, neurospora crassa and coprinus sterquilinus.primary cell wall is synthesized in the growth zone of hyphal apex in fungi and rigidified during maturation along the newly formed hypha. cross-linking of cell-wall components and self-assembly of individual polysaccharide chains into microfibrils are supposed to be involved in the rigidification process. we determined the relative chitin content in the cell wall of hyphal tips and distal walls of three fungal species and demonstrated a general increase in relative chitin content in mature cell ...199910983235
role of mmm1 in maintaining mitochondrial morphology in neurospora crassa.mmm1p is a protein required for maintenance of mitochondrial morphology in budding yeast. it was proposed that it is required to mediate the interaction of the mitochondrial outer membrane with the actin cytoskeleton. we report the cloning and characterization of mmm1 of the filamentous fungus neurospora crassa, an organism that uses microtubules for mitochondrial transport. mutation of the mmm-1 gene leads to a temperature-sensitive slow growth phenotype and female sterility. mutant cells harbo ...200010982393
molecular genetics of heterokaryon incompatibility in filamentous ascomycetes.filamentous fungi spontaneously undergo vegetative cell fusion events within but also between individuals. these cell fusions (anastomoses) lead to cytoplasmic mixing and to the formation of vegetative heterokaryons (i.e., cells containing different nuclear types). the viability of these heterokaryons is genetically controlled by specific loci termed het loci (for heterokaryon incompatibility). heterokaryotic cells formed between individuals of unlike het genotypes undergo a characteristic cell ...200010974123
cellular distribution of cot1 kinase in neurospora crassa.the neurospora crassa cot-1 gene encodes a ser/thr protein kinase, which is involved in hyphal elongation. many vacuoles, abnormally shaped mitochondria, and nuclei, along with differences in the structure of the cell wall and hyphal septa, were observed in hyphae of the cot-1 mutant shortly after a shift to the restrictive temperature. immunolocalization experiments indicated that cot1 was associated with the cytoplasmic membrane; cot1 was also detected in the cytoplasm. the membrane-associated ...200010955908
plasma membrane-adjacent actin filaments, but not microtubules, are essential for both polarization and hyphal tip morphogenesis in saprolegnia ferax and neurospora crassa.the organization and roles of f-actin and microtubules in the maintenance and initiation of hyphal tip growth have been analyzed in saprolegnia ferax and neurospora crassa. in hyphae of both species, the apex is depleted of microtubules relative to subapical regions and near-normal morphogenesis occurs in concentrations of nocodazole or mbc which remove microtubules, slow growth, and disrupt nuclear positioning. in contrast, each species contains characteristic tip-high arrays of plasma membrane ...200010955907
a putative spectrin-containing membrane skeleton in hyphal tips of neurospora crassa.the apical plasma membrane (pm) is important in hyphal tip growth, where it may regulate tip extensibility via its association with an appropriate membrane skeleton (ms). by cell fractionation and immunocytochemistry we show that proteins with characteristics of actin, spectrin, and integrin are associated in a ms-like manner with the pm of neurospora crassa hyphae. the spectrin-like protein in particular is highly concentrated at the pm in the region of maximum apical expansion. this protein sh ...200010955906
the degenerate dna transposon pat and repeat-induced point mutation (rip) in podospora anserina.a degenerate dna transposon, pat, was identified in the genomes of various wild-type strains of the filamentous fungus podospora anserina. in these strains, the number (approximately 20-25 copies per genome) and location of pat sequences appear to be conserved. two copies of pat, one complete and one partial, were cloned and characterized. the sequence of the complete element is 1856 bp long and contains imperfect inverted terminal repeats (itrs) of 53 bp. the target site duplication comprises t ...200010954093
non-coordinate regulation of 5s rrna genes and the gene encoding the 5s rrna-binding ribosomal protein homolog in neurospora crassa.in eukaryotes, the levels of ribosomal proteins are coordinately regulated under varying nutritional conditions and at different developmental stages. little is known about how ribosomal protein levels are coupled to the levels of rrna. the formation of a ribonucleoprotein particle composed of 5s rrna and a ribosomal protein is an early step in ribosome assembly. to investigate how these two ribosomal components are regulated in neurospora crassa, we cloned the gene encoding the 5s rrna-binding ...200010954084
characterization of hch, the podospora anserina homolog of the het-c heterokaryon incompatibility gene of neurospora crassa.the het-c locus controls heterokaryon formation in neurospora crassa. it is subject to balancing selection operating to maintain polymorphism at that locus in natural populations. we have isolated hch, the het-c homolog from the related species podospora anserina (hch for het-c homolog), in order to determine if this gene also functions as a het gene in that species. the het-c and hch sequences are highly similar but differ in the region defining allele specificity in n. crassa het-c. analysis o ...200010953880
exploitation of a cellulose-binding domain from neurospora crassa.after eight decades as a purely research organism, neurospora crassa is becoming a production system for heterologous peptides. the present work exploits the cbh-1 gene, which encodes a class c cellobiohydrolase (ec 3.2.1.91) and has, at its carboxy-terminus, a domain with homology to other fungal cellulose-binding domains. we describe the construction of two translational fusions of the putative cellulose-binding domain with a reporter gene, which is the catalytic domain of the gla-1 glucoamyla ...200010938423
the lis1-related nudf protein of aspergillus nidulans interacts with the coiled-coil domain of the nude/ro11 protein.the nudf gene of the filamentous fungus aspergillus nidulans acts in the cytoplasmic dynein/dynactin pathway and is required for distribution of nuclei. nudf protein, the product of the nudf gene, displays 42% sequence identity with the human protein lis1 required for neuronal migration. haploinsufficiency of the lis1 gene causes a malformation of the human brain known as lissencephaly. we screened for multicopy suppressors of a mutation in the nudf gene. the product of the nude gene isolated in ...200010931877
function of tyrosyl-trna synthetase in splicing group i introns: an induced-fit model for binding to the p4-p6 domain based on analysis of mutations at the junction of the p4-p6 stacked helices.we used an escherichia coli genetic assay based on the phage t4 td intron to test the ability of the neurospora crassa mitochondrial tyrosyl-trna synthetase (cyt-18 protein) to suppress mutations that cause structural defects around its binding site in the p4-p6 domain of the group i intron catalytic core. we analyzed all possible combinations of nucleotides at either p4 bp-1 or p6 bp-1, which together form the junction of the p4-p6 stacked helices, and looked for synergistic effects in double m ...200010926509
cellular responses and repair of single-strand breaks introduced by uv damage endonuclease in mammalian cells.although single-strand breaks (ssbs) occur frequently, the cellular responses and repair of ssb are not well understood. to address this, we established mammalian cell lines expressing neurospora crassa uv damage endonuclease (uvde), which introduces a ssb with a 3'-oh immediately 5' to uv-induced cyclobutane pyrimidine dimers or 6-4 photoproducts and initiates an alternative excision repair process. xeroderma pigmentosum group a cells expressing uvde show uv resistance of almost the wild-type l ...200010924509
properties of a constitutive alkaline phosphatase from strain 74a of the mold neurospora crassa.a constitutive alkaline phosphatase was purified to apparent homogeneity as determined by polyacrylamide gel electrophoresis from mycelia of the wild strain 74a of the mold neurospora crassa, after growth on acetate and in the presence of saturating amounts of inorganic phosphate (pi) for 72 h at 30 degrees c. the molecular mass was 58 kda and 56 kda as determined by exclusion chromatography and sds-page, respectively. this monomeric enzyme shows an apparent optimum ph ranging from 9.5 to 10.5 a ...200010920432
a group of expressed cdna sequences from the wheat fungal leaf blotch pathogen, mycosphaerella graminicola (septoria tritici).a group of expressed sequence tags (ests) from the wheat fungal pathogen mycosphaerella graminicola utilizing ammonium as a nitrogen source has been analyzed. single pass sequences of complementary dnas from 986 clones were determined. contig analysis and sequence comparisons allowed 704 unique ests (unigenes) to be identified, of which 148 appeared as multiple copies. searches of the nrdb95 protein database at embl using the blast2x algorithm revealed 407 (57.8%) sequences that generated high t ...200010919380
cloning and characterisation of a chitin synthase gene cdna from the cultivated mushroom agaricus bisporus and its expression during morphogenesis.full-length cdna of a chitin synthase gene (chs1) was cloned from agaricus bisporus by screening a cdna library with a pcr amplified fragment of the chitin synthase gene. the chs1 contains an open reading frame of 2727 bp encoding a polypeptide of 909 amino acids and deduced molecular mass 102.3 kda and pi 8.23. the central region of chs1 showed strong homology to other fungal chitin synthase genes with seven conserved domains. it belongs to the chitin synthase class iii, analogous to chsb from ...200010913868
the tryptophan synthase-encoding trpb gene of aspergillus nidulans is regulated by the cross-pathway control system.the tryptophan synthase-encoding gene, trpb, of aspergillus nidulans was cloned and characterized. it was mapped to chromosome i, between the gene meda, which is required for sexual and asexual development, and an orf encoding a protein with significant similarity to subunit b of vacuolar atp synthases. the 5' untranslated region was found to be at least 142 nucleotides (nt) long, the poly(a) addition site was localized at position + 216 relative to the stop codon by sequencing of several indepe ...200010905354
biosynthesis of pyridoxine: origin of the nitrogen atom of pyridoxine in microorganisms.the amide nitrogen atom of glutamine was incorporated into pyridoxine in four eukaryotes, emericella nidulans, mucor racemosus, neurospora crassa and saccharomyces cerevisiae, and two prokaryotes, staphylococcus aureus and bacillus subtilis, but not in the following prokaryotes, pseudomonas putida, enterobacter aerogenes and escherichia coli. on the other hand, the nitrogen atom of glutamate was incorporated into pyridoxine in p. putida, e. aerogenes and e. coli, but not in s. aureus and b. subt ...200010885790
interconnected feedback loops in the neurospora circadian system.in neurospora crassa, white collar 1 (wc-1), a transcriptional activator and positive clock element, is rhythmically expressed from a nonrhythmic steady-state pool of wc-1 transcript, consistent with posttranscriptional regulation of rhythmicity. mutations in frq influence both the level and periodicity of wc-1 expression, and driven frq expression not only depresses its own endogenous levels, but positively regulates wc-1 synthesis with a lag of about 8 hours, a delay similar to that seen in th ...200010884222
a tip-high gradient of a putative plasma membrane snare approximates the exocytotic gradient in hyphal apices of the fungus neurospora crassa.antibodies to the saccharomyces cereviseae plasma membrane t-snare sso2p identify a putative 39-kda homologue in neurospora crassa. the 39-kda protein is enriched in plasma membrane (pm) and occurred with other membranes. it is extractable by detergent, but not chaotropic or alkali agents, suggesting membrane insertion. immunoprecipitation with anti-sso2p coprecipitated a approximately 100-kda, mg(+)-atp-sensitive band with the 39-kda protein, suggesting a ternary snare complex. affinity-purifie ...200010882535
senescent: a new neurospora crassa nuclear gene mutant derived from nature exhibits mitochondrial abnormalities and a "death" phenotype.fungi are capable of potentially unlimited growth. we resolved nuclear types from multinuclear mycelium of a phenotypically normal wild isolate of the fungus neurospora intermedia by plating its uninucleate microconidia and obtained a strain which, unlike the "parent" strain, exhibited clonal senescence in subcultures. the mutant gene, senescent, was introgressed into n. crassa and mapped four map units to the right of the his-1 locus on linkage group vr. senescent is the first nuclear gene muta ...200010882533
vegetative incompatibility in the het-6 region of neurospora crassa is mediated by two linked genes.non-self-recognition during asexual growth of neurospora crassa involves restriction of heterokaryon formation via genetic differences at 11 het loci, including mating type. the het-6 locus maps to a 250-kbp region of lgiil. we used restriction fragment length polymorphisms in progeny with crossovers in the het-6 region and a dna transformation assay to identify two genes in a 25-kbp region that have vegetative incompatibility activity. the predicted product of one of these genes, which we desig ...200010880472
dynein and dynactin deficiencies affect the formation and function of the spitzenkörper and distort hyphal morphogenesis of neurospora crassa.the impact of mutations affecting microtubule-associated motor proteins on the morphology and cytology of hyphae of neurospora crassa was studied. two ropy mutants, ro-1 and ro-3, deficient in dynein and dynactin, respectively, were examined by video-enhanced phase-contrast microscopy and image analysis. in contrast to the regular, hyphoid morphology of wild-type hyphae, the hyphae of the ropy mutants exhibited a great variety of distorted, non-hyphoid morphologies. the ropy hyphae were slow-gro ...200010878138
short tpa-rich segments of the zeta-eta region induce dna methylation in neurospora crassa.the mechanisms that establish dna methylation in eukaryotes are poorly understood. in principle, methylation in a particular chromosomal region may reflect the presence of a "signal" that recruits methylation, the absence of a signal that prevents methylation, or both. experiments were carried out to address these possibilities for the 1.6 kb zeta-eta (zeta-eta) region, a relict of repeat-induced point mutation (rip) in the fungus neurospora crassa. the zeta-eta region directs its own de novo me ...200010873464
nucleotide sequence and intron structure of the apocytochrome b gene of neurospora crassa mitochondria.the sequence of the apocytochrome b (cob) gene of neurospora crassa has been determined. the structural gene is interrupted by two intervening sequences of approximately 1260 bp each. the polypeptide encoded by the exons shows extensive homology with the cob proteins of aspergillus nidulans and saccharomyces cerevisiae (79% and 60%, respectively). the two introns are, however, located at sites different from those of introns in the cob genes of a. nidulans and s. cerevisiae (which contain highly ...198310872314
blue-light regulation of phytoene dehydrogenase (carb) gene expression in mucor circinelloides.the carb gene, encoding the phytoene dehydrogenase of mucor circinelloides, was isolated by heterologous hybridisation with a probe derived from the corresponding gene of phycomyces blakesleeanus. the cdna and genomic copies complemented phytoene dehydrogenase defects in escherichia coli and in carb mutants of m. circinelloides, respectively. fluence-response curves for transcript accumulation were constructed after different blue-light pulses. the level of carb mrna accumulation reached values ...200010872226
histidine kinase, two-component signal transduction proteins of candida albicans and the pathogenesis of candidosis.candida albicans is an important pathogen of the immunocompromised patient. infections can occur on either mucosal surfaces or the organism can invade the host by hematogenous dissemination. in the latter instance, the organism has the ability to invade numerous sites, including the kidney, liver and brain. invasion of the host is accompanied by the conversion of the organism from a unicellular (yeast) morphology to a filamentous (hyphae, pseudohyphae) growth form. the morphogenetic change which ...199910865904
two approaches to isolate cytoplasmic dynein atpase from neurospora crassa.cytoplasmic dynein is a force-producing enzyme that, in association with dynactin, conducts minus-end directed transport of various organelles along microtubules. biochemical analyses of cytoplasmic dynein and dynactin have been conducted primarily in vertebrate systems, whereas genetic analyses have been explored mainly in yeast and the filamentous fungi. to provide a complementary biochemical approach for the study of fungal dynein, we isolated/partially purified cytoplasmic dynein atpase from ...200010863006
import of a cytosolic protein into lysosomes by chaperone-mediated autophagy depends on its folding state.we have analyzed the folding state of cytosolic proteins imported in vitro into lysosomes, using an approach originally developed by eilers and schatz, (eilers, m., and schatz, g. (1986) nature 322, 228-232) to investigate protein import into mitochondria. the susceptibility toward proteases of mouse dihydrofolate reductase (dhfr), synthesized in a coupled transcription-translation system with rabbit reticulocytes, decreased in the presence of its substrate analogue, methotrexate. this analogue ...200010862611
the cyanide-resistant alternative oxidases from the fungi pichia stipitis and neurospora crassa are monomeric and lack regulatory features of the plant enzyme.both plant and fungal mitochondria have cyanide-resistant alternative oxidases that use reductant from the mitochondrial ubiquinone pool to reduce oxygen to water in a reaction that conserves no energy for atp synthesis. the dimeric plant alternative oxidase is relatively inactive when its subunits are linked by a disulfide bond. when this bond is reduced, the enzyme can then be stimulated by its activators, alpha-keto acids. a cys in the n-terminal section of the protein is responsible for both ...200010860541
sn-1,2-diacylglycerol levels in the fungus neurospora crassa display circadian rhythmicity.the fungus neurospora crassa is a model organism for investigating the biochemical mechanism of circadian (daily) rhythmicity. when a choline-requiring strain (chol-1) is depleted of choline, the period of the conidiation rhythm lengthens. we have found that the levels of sn-1,2-diacylglycerol (dag) increase in proportion to the increase in period. other clock mutations that change the period do not affect the levels of dag. membrane-permeant dags and inhibitors of dag kinase were found to furth ...200010859307
differential complementation of a neurospora crassa galpha(i) mutation using mammalian galpha protein genes.heterotrimeric (alphabetagamma) g proteins interact with sensory receptors to transduce signals to downstream effectors in eukaryotes. we previously reported that gna-1 from neurospora crassa is a microbial member of the galphai family found in higher organisms. deletion of gna-1 leads to female sterility, slower growth rates on normal and hyperosmotic solid medium, and increased resistance to heat and oxidative stress. in this study we compare mammalian genes for proteins of the galphai sub-fam ...200010852494
tagging of genes involved in multidrug resistance in aspergillus nidulans.we have used a plasmid containing the neurospora crassa pyr4 gene to transform an aspergillus nidulans pyrg89 mutant strain in the presence of bam-hi, and isolated multidrug-sensitive mutants among the transformants. using this approach, we hoped to identify genes whose products are important for drug resistance by analyzing gene disruptions that alter the drug sensitivity of the cell. about 1300 transformants isolated following transformation were screened for sensitivity to drugs or various st ...200010852493
cloning and expression of the s-adenosylmethionine decarboxylase gene of neurospora crassa and processing of its product.s-adenosylmethionine decarboxylase (adometdc) catalyzes the formation of decarboxylated adometdc, a precursor of the polyamines spermidine and spermine. the enzyme is derived from a proenzyme by autocatalytic cleavage. we report the cloning and regulation of the gene for adometdc in neurospora crassa, spe-2, and the effect of putrescine on enzyme maturation and activity. the gene was cloned from a genomic library by complementation of a spe-2 mutant. like other adometdcs, that of neurospora is d ...200010852489
an rna-dependent rna polymerase gene in arabidopsis is required for posttranscriptional gene silencing mediated by a transgene but not by a virus.posttranscriptional gene silencing is a defense mechanism in plants that is similar to quelling in fungi and rna interference in animals. here, we describe four genetic loci that are required for posttranscriptional gene silencing in arabidopsis. one of these, sde1, is a plant homolog of qde-1 in neurospora crassa that encodes an rna-dependent rna polymerase. the sde1 mutation was specific for posttranscriptional gene silencing induced by transgenes rather than by viruses. we propose that the ro ...200010850496
confocal microscopy of fm4-64 as a tool for analysing endocytosis and vesicle trafficking in living fungal hyphae.confocal microscopy of amphiphilic styryl dyes has been used to investigate endocytosis and vesicle trafficking in living fungal hyphae. hyphae were treated with fm4-64, fm1-43 or tma-dph, three of the most commonly used membrane-selective dyes reported as markers of endocytosis. all three dyes were rapidly internalized within hyphae. fm4-64 was found best for imaging the dynamic changes in size, morphology and position of the apical vesicle cluster within growing hyphal tips because of its stai ...200010849201
senescence associated with the over-replication of a mitochondrial retroplasmid in neurospora crassa.mitochondrial dna rearrangements and deletions are a prevailing feature of filamentous fungal cultures that undergo senescence. in neurospora spp., strains containing the mauriceville and varkud mitochondrial retroplasmids routinely senesce at elevated temperatures, a process that is initiated by the integration of variant forms of the plasmids into the mitochondrial genome. here, we describe a strain that is phenotypically distinguishable from previously characterized senescent strains and show ...200010821177
immunolocalization of ca ii and h+ v-atpase in epithelial cells of the mouse and rat epididymis.acidification of the epididymal lumen has been suggested to play an important role in sperm functions; however, the cell types, pumps, and mechanisms involved have not been fully addressed. in this study, carbonic anhydrase ii (ca ii) and a 67-kd subunit of neurospora crassa vacuolar proton adenosinetriphosphatase (h+ v-atpase) pump were immunolocalized using light microscopy and electron microscopy (em) in the epididymis of rats and mice. in both animals, narrow cells, identified in the initial ...200010819445
evolutionarily conserved features of the arginine attenuator peptide provide the necessary requirements for its function in translational regulation.neurospora crassa arg-2 mrna contains an evolutionarily conserved upstream open reading frame (uorf) encoding the arg attenuator peptide (aap) that confers negative translational regulation in response to arg. we examined the regulatory role of the aap and the rna encoding it using an n. crassa cell-free translation system. aaps encoded by uorfs in four fungal mrnas each conferred negative regulation in response to arg by causing ribosome stalling at the uorf termination codon. deleting the aap ...200010818103
presence of a pertussis toxin-sensitive g protein alpha subunit in sporothrix schenckii.as an initial step in the study of the role of g proteins in signal transduction in sporothrix schenckii, we identified a galphai subunit using different experimental approaches. western blots of fungal membrane preparations using anti-galphacommon and anti-galphai1-galphai2 antibodies identified a band of approximately 41 kda. pertussis toxin-catalyzed adenosine diphosphate (adp)-ribosylation of these membrane fractions confirmed the presence of a protein substrate of 41 kda. a 357 bp polymeras ...200010817227
methylation of the foreign transposon restless in vegetative mycelia of neurospora crassa.methylation of foreign and/or repeated sequences in the filamentous fungus neurospora crassa is believed to be directed against invading transposable elements. to test this hypothesis, the fate of a transposon in n. crassa was investigated. vectors were constructed which carried the transposon restless, an active class-ii element isolated from the fungus tolypocladium inflatum. these vectors were introduced into n. crassa strains by protoplast transformation. two strategies were employed: (1) ec ...200010794177
isolation of repeated and self-complementary sequences from e. coli dna.we have used the single-strand specific nuclease from neurospora crassa and chromatography on methylated albumin-kieselguhr to purify and characterize repeated and self-complementary sequences from escherichia coli dna. approximately 0.5% of the genome renatures spontaneously at zero time and another 2% renatures somewhat more rapidly than the total dna. the early renaturing dna has a base composition and a tm similar to the total dna and contains on the average 100 base pairs; the self-compleme ...197410793709
a nuclease from neurospora crassa specific for d(a-t) rich regions in double stranded dna.a nuclease from n. crassa has been prepared to the hydroxylapatite stage of purification described by rabin and fraser (1). it degrades single stranded dna in an essentially exonucleolytic process. it does not give any appreciable acid soluble material with double stranded dna as substrate. this shows its high degree of specificity towards single stranded dna. an extra activity which makes double strand breaks in the at rich regions of dna is described. a limited number of breaks are observed wi ...197410793677
the bacillus subtilis cysp gene encodes a novel sulphate permease related to the inorganic phosphate transporter (pit) family.sulphate permeases in the plasma membrane are responsible for uptake of environmental sulphate used in the sulphate assimilation pathway in bacteria and plants. here it is reported that the orf designated cysp, located on the bacillus subtilis chromosome between cysh and five putative genes involved in sulphate assimilation, encodes a sulphate permease. cysp is able to complement escherichia coli cysteine auxotrophs with mutations affecting either the membrane or periplasmic components of the su ...200010784039
a new self-assembled peroxisomal vesicle required for efficient resealing of the plasma membrane.the woronin body is a membrane-bound organelle that has been observed in over 50 species of filamentous fungi. however, neither the composition nor the precise function of the woronin body has yet been determined. here we purify the woronin body from neurospora crassa and isolate hex1, a new protein containing a consensus sequence known as peroxisome-targeting signal-1 (pts1). we show that hex1 is localized to the matrix of the woronin body by immunoelectron microscopy, and that a green fluoresc ...200010783241
large-scale comparison of fungal sequence information: mechanisms of innovation in neurospora crassa and gene loss in saccharomyces cerevisiae.we report a large-scale comparison of sequence data from the filamentous fungus neurospora crassa with the complete genome sequence of saccharomyces cerevisiae. n. crassa is considerably more morphologically and developmentally complex than s. cerevisiae. we found that n. crassa has a much higher proportion of "orphan" genes than s. cerevisiae, suggesting that its morphological complexity reflects the acquisition or maintenance of novel genes, consistent with its larger genome. our results also ...200010779483
understanding circadian rhythmicity in neurospora crassa: from behavior to genes and back again.circadian clocks have been described in organisms ranging in complexity from unicells to mammals, in which they function to control daily rhythms in cellular activities and behavior. the significance of a detailed understanding of the clock can be appreciated by its ubiquity and its established involvement in human physiology, including endocrine function, sleep/wake cycles, psychiatric illness, and drug tolerances and effectiveness. because the clock in all organisms is assembled within the cel ...200010779395
tagging of a nitrogen pathway-specific regulator gene in tolypocladium inflatum by the transposon restless.restless is an endogenous hat transposon found in the cyclosporin-producing fungus tolypocladium inflatum. this element is present in about 15 copies in a particular strain (atcc34921) which was used for successful gene tagging. we have isolated a t. inflatum mutant with a defect in nitrogen metabolism. this mutant carries a copy of the restless element in a gene encoding a c6 zinc-finger protein. the deduced amino acid sequence of the gene product shows a significant similarity to the nit4 prot ...200010778749
comparative analysis of the mating-type loci from neurospora crassa and sordaria macrospora: identification of novel transcribed orfs.the mating-type locus controls mating and sexual development in filamentous ascomycetes. in the heterothallic ascomycete neurospora crassa, the genes that confer mating behavior comprise dissimilar dna sequences (idiomorphs) in the mat a and mat a mating partners. in the homothallic fungus sordaria macrospora, sequences corresponding to both idiomorphs are located contiguously in the mating-type locus, which contains one chimeric gene, smt a-3, that includes sequences which are similar to sequen ...200010778748
molecular analysis of the aureobasidium pullulans ura3 gene encoding orotidine-5'-phosphate decarboxylase and isolation of mutants defective in this gene.orotidine-5'-phosphate decarboxylase (omp decarboxylase) catalyses the final step in the pyrimidine biosynthesis, the conversion of orotidine-5'-phosphate (omp) to uridine-5'-phosphate. the ura3 gene of aureobasidium pullulans. encoding omp decarboxylase, was isolated from an aureobasidium genomic library constructed in the plasmid pblueskriptsk-. the ura3 gene of a. pullulans has an open reading frame of 271 amino acid residues. analysis of the sequence revealed the presence of two introns. in ...200010772469
interaction of the neurospora crassa heat shock factor with the heat shock element during heat shock and different developmental stages.the interaction of the heat shock factor (hsf) with the heat shock element (hse) was determined by a non-radioactive electrophoretic mobility shift assay, in order to analyze hsf regulation in neurospora crassa. hsf binds to hse under normal, non-stress conditions and is thus constitutively trimerized. upon heat shock, the hsf-hse complex shows a retarded mobility. this was also observed in saccharomyces cerevisiae, where this mobility shift was shown to be due to hsf phosphorylation [sorger and ...200010754257
protein transport into mitochondria.mitochondria are made up of two membrane systems that subdivide this organelle into two aqueous subcompartments: the matrix, which is enclosed by the inner membrane, and the intermembrane space, which is located between the inner and the outer membrane. protein import into mitochondria is a complex reaction, as every protein has to be routed to its specific destination within the organelle. in the past few years, studies with mitochondria of neurospora crassa and saccharomyces cerevisiae have le ...200010744987
characterization and expression of a neurospora crassa ribosomal protein gene, crp-7.we have isolated and characterized a neurospora crassa cytoplasmic ribosomal protein gene, named crp-7, which is found upstream of the photolyase gene. the deduced amino-acid sequence of this gene is highly homologous to the ys25 ribosomal protein of saccharomyces cerevisiae. the crp-7 orf consists of two exons which are separated by a short intron. the deduced polypeptide contains 87 amino acid residues and has a calculated molecular weight of 9.7 kda. rflp mapping showed that the crp-7 gene is ...200010743568
a rapid technique for screening of lovastatin-producing strains of aspergillus terreus by agar plug and neurospora crassa bioassay.the success of strain improvement programme depends on the number of isolates that can be screened after mutagenic treatment. a technique to rapidly screen large number of high-yielding isolates was developed. the 'agar plug' method that utilizes the anti-fungal property of lovastatin to produce a zone of inhibition against neurospora crassa was not only economical but also less labour-intensive. we were able to isolate a high-yielding strain, the productivity of which increased by 138% as compa ...200010739348
construction and expression of functional multi-domain polypeptides in escherichia coli: expression of the neurospora crassa metallothionein gene.a system for the construction of polymeric peptides in escherichia coli was utilized to prepare a library of plasmids coding for tandem repeats of the neurospora crassa metallothionein gene. selected oligomeric metallothionein clones were expressed and targeted to the periplasm as a fusion with the maltose-binding protein. bacterial cells harbouring the expressed oligopeptides were characterized for their ability to bind 109cd2+. the metal-binding ability was enhanced for all the oligomeric cons ...200010736021
polyamine regulation of ornithine decarboxylase synthesis in neurospora crassa.ornithine decarboxylase (odc) of the fungus neurospora crassa, encoded by the spe-1 gene, catalyzes an initial and rate-limiting step in polyamine biosynthesis and is highly regulated by polyamines. in n. crassa, polyamines repress the synthesis and increase the degradation of odc protein. changes in the rate of odc synthesis correlate with similar changes in the abundance of spe-1 mrna. we identify two sequence elements, one in each of the 5' and 3' regions of the spe-1 gene of n. crassa, requi ...200010733579
cyclophilin-promoted folding of mouse dihydrofolate reductase does not include the slow conversion of the late-folding intermediate to the active enzyme.cyclophilins accelerate slow protein folding reactions in vitro by catalyzing the cis/trans isomerization of peptidyl-prolyl bonds. cyclophilins were reported to be involved in a variety of cellular functions, including the promotion of protein folding by use of the substrate mouse dihydrofolate reductase (dhfr). the interaction of cyclophilin with dhfr has only been studied under limited conditions so far, not taking into account that native dhfr exists in equilibrium with a non-native late-fol ...200010731431
molecular cloning and functional analysis of apoxin i, a snake venom-derived apoptosis-inducing factor with l-amino acid oxidase activity.we previously purified apoxin i, an apoptosis-inducing factor with l-amino acid oxidase (lao) activity, from western diamondback rattlesnake venom. to determine the primary structure of apoxin i, we cloned its cdna. the amino acid sequence showed that apoxin i has an fad binding domain and shares homology with l-amino acid oxidase (lao) from neurospora crassa, human monoamine oxidase b, and mouse interleukin 4-induced f1g1 protein. the full-length apoxin i has an n-terminal signal sequence that ...200010727211
isolation of trypanosoma brucei cyc2 and cyc3 cyclin genes by rescue of a yeast g(1) cyclin mutant. functional characterization of cyc2.two trypanosoma brucei cyclin genes, cyc2 and cyc3, have been isolated by rescue of the saccharomyces cerevisiae mutant dl1, which is deficient in cln g(1) cyclin function. cyc2 encodes a 24-kda protein that has sequence identity to the neurospora crassa preg1 and the s. cerevisiae pho80 cyclin. cyc3 has the most sequence identity to mitotic b-type cyclins from a variety of organisms. both cyc2 and cyc3 are single-copy genes and expressed in all life cycle stages of the parasite. to determine if ...200010722661
molecular cloning of the calcium and sodium atpases in neurospora crassa.using pcr, reverse transcription-pcr (rt-pcr) and colony hybridization in a genomic library, we isolated six genes which encode type ii p-type atpases in neurospora crassa. the six full-length cdnas were cloned in a yeast expression vector and transformed into saccharomyces cerevisiae null ca2+- or na+-atpase mutants. three cdnas suppressed the defect of the ca2+ mutant and two of these protected from mn2+ toxicity. one cdna suppressed the defect of the na+ mutant and two cdnas were not function ...200010712689
characterization of an unusual trna-like sequence found inserted in a neurospora retroplasmid.we characterized an unusual trna-like sequence that had been found inserted in suppressive variants of the mitochondrial retroplasmid of neurospora intermedia strain varkud. we previously identified two forms of the trna-like sequence, one of 64 nt (trl-64) and the other of 78 nt (trl-78) containing a 14-nt internal insertion in the anticodon stem at a position expected for a nuclear trna intron. here, we show that trl-78 is encoded in varkud mitochondrial (mt)dna within a 7 kb sequence that is ...200010710417
ego-1 is related to rna-directed rna polymerase and functions in germ-line development and rna interference in c. elegans.cell-fate determination requires that cells choose between alternative developmental pathways. for example, germ cells in the nematode worm caenorhabditis elegans choose between mitotic and meiotic division, and between oogenesis and spermatogenesis. germ-line mitosis depends on a somatic signal that is mediated by a notch-type signaling pathway. the ego-1 gene was originally identified on the basis of genetic interactions with the receptor in this pathway and was also shown to be required for o ...200010704412
nadh dehydrogenase in neurospora crassa contains myristic acid covalently linked to the nd5 subunit peptide.the mitochondrial, proton-pumping nadh:ubiquinone oxidoreductase consists of at least 35 subunits whose synthesis is divided between the cytosol and mitochondria; this complex i catalyzes the first steps of mitochondrial electron transfer and proton translocation. radiolabel from [(3)h]myristic acid was incorporated by neurospora crassa into the mitochondrial-encoded, approximately 70 kda nd5 subunit of nadh dehydrogenase, as shown by immunoprecipitation. this myristate apparently was linked to ...200010699461
a non-stop antisense reading frame in the grp78 gene of neurospora crassa is homologous to the achlya klebsiana nad-gdh gene but is not being transcribed.a long non-stop reading frame exists on the antisense strand of the grp78 gene (cdna and genomic dna) of neurospora crassa. computer analysis revealed a strong similarity of the putative antisense protein to the 10th exon of the nad-dependent glutamate dehydrogenase gene (nad-gdh) of achlya klebsiana, which is itself located on the complementary strand of a transcribed hsc70 gene homologue. in neurospora, no grp78 antisense mrna was detected by northern blot and reverse transcription-coupled pol ...200010675602
cryo-electron tomography of neurospora mitochondria.cryo-electron tomography was used to study the structural organization of whole frozen-hydrated mitochondria from neurospora crassa. unlike mitochondria from many other species and tissues, in this case the cristae form a three-dimensional network of interconnected lamellae. basically, the three-dimensional structure of ice-embedded mitochondria from this species is consistent with previous descriptions of mitochondria prepared by chemical fixation and resin embedding. nonetheless, ice-embedded ...200010675296
kalilo plasmids are a family of four distinct members with individual global distributions across species.kalilo is a linear 9-kb plasmid, isolated originally from hawaiian strains of the heterothallic fungus neurospora intermedia. its properties include terminal inverted repeats, two orfs coding for a presumptive dna and an rna polymerase, and the ability to cause senescence in its original host and in the closely related species neurospora crassa. we have examined natural isolates alleged to contain plasmids homologous to kalilo. most of these isolates do in fact contain plasmids with so close an ...200010672443
the frost gene of neurospora crassa is a homolog of yeast cdc1 and affects hyphal branching via manganese homeostasis.the neurospora crassa mutant frost has a hyperbranching phenotype that can be corrected by adding ca(2+), suggesting that characterization of this gene might clarify the mechanism of ca(2+)-dependent tip growth. the wild-type allele was cloned by sib selection using protoplasts from arthroconidia. rflp analysis revealed that the cloned dna fragment mapped to the fr locus. the nucleotide sequence of genomic and cdna was determined. the deduced amino acid sequence showed homology to the saccharomy ...199910669587
comparative analysis of ca2+ and h+ flux magnitude and location along growing hyphae of saprolegnia ferax and neurospora crassa.calcium and proton ion fluxes were mapped at the growing apices of two hyphal organisms, the oomycete saprolegnia ferax and the ascomycete neurospora crassa and pseudohyphal saccharomyces cerevisiae using self-referencing ion-selective probes. s. ferax exhibited well-defined transport zones absent in n. crassa. ca2+ fluxes were located within 8 microm of the growing hyphal tip; the net ca2+ flux was either inward (75% of all experiments) or outward. the inward component of the net flux was inhib ...199910669108
an osmotic-remedial, temperature-sensitive mutation in the allosteric activity site of ribonucleotide reductase in neurospora crassa.an osmotic-remedial, temperature-sensitive conditional mutant (un-24) was generated by repeat induced point mutation (rip) from a cross between a wild-type n. crassa strain and a strain carrying a approximately 250-kb duplication of the left arm of linkage group ii (lgii). the mutation was mapped to the duplicated segment, within 2.6 map units of the heterokaryon incompatibility locus het-6. dna transformation identified a 3.75-kb fragment that complemented the temperature-sensitive phenotype. a ...200010660063
specific binding sites for an antifungal plant defensin from dahlia (dahlia merckii) on fungal cells are required for antifungal activity.dm-amp1, an antifungal plant defensin from seeds of dahlia (dahlia merckii), was radioactively labeled with t-butoxycarbonyl-[35s]-l-methionine n-hydroxy-succinimi-dylester. this procedure yielded a 35s-labeled peptide with unaltered antifungal activity. [35s]dm-amp1 was used to assess binding on living cells of the filamentous fungus neurospora crassa and the unicellular fungus saccharomyces cerevisiae. binding of [35s]dm-amp1 to fungal cells was saturable and could be competed for by preincuba ...200010656585
suppressed recombination and a pairing anomaly on the mating-type chromosome of neurospora tetrasperma.neurospora crassa and related heterothallic ascomycetes produce eight homokaryotic self-sterile ascospores per ascus. in contrast, asci of n. tetrasperma contain four self-fertile ascospores each with nuclei of both mating types (mata and mata). the self-fertile ascospores of n. tetrasperma result from first-division segregation of mating type and nuclear spindle overlap at the second meiotic division and at a subsequent mitotic division. recently, merino et al. presented population-genetic evid ...200010655216
purification and characterization of flavokinase from neurospora crassa.the atp-dependent phosphorylation of riboflavin to fmn by flavokinase is the key step in flavin biosynthesis. flavokinase has been purified from a fungal source for the first time. the enzyme purified from a cell wall lacking mutant of neurospora crassa, slime, is a monomer of m(r) 35.5 kda with maximal activity at alkaline ph and high temperature (55 degrees c). the k(m) for both substrates is the lowest reported for flavokinase from any source so far (120 nm for riboflavin and 210 nm for mgatp ...199910650711
the goodwin oscillator: on the importance of degradation reactions in the circadian clock.this article focuses on the goodwin oscillator and related minimal models, which describe negative feedback schemes that are of relevance for the circadian rhythms in neurospora, drosophila, and probably also in mammals. the temperature behavior of clock mutants in neurospora crassa and drosophila melanogaster are well described by the goodwin model, at least on a semi-quantitative level. a similar semi-quantitative description has been found for neurospora crassa phase response curves with resp ...199910643743
a fission yeast kinesin affects golgi membrane recycling.we report here an in vivo study of kinesin heavy chain (khc) functions in yeast. we have identified in schizosaccharomyces pombe a kinesin motor gene, klp3(+), which has the highest homology to the neurospora crassa khc. using indirect immunofluorescence, ha epitope-tagged klp3 protein is cytoplasmic and appears as one to a few distinct patches that are coincident with microtubules. the klp3 null allele is viable. in klp3 deleted cells, er, golgi and mitochondrial distribution appear normal. mit ...200010641037
in vitro antifungal evaluation and studies on the mode of action of xanthoxyline derivatives.this study describes the fungistatic effect of xanthoxyline (cas 90-24-4) and its derivatives against a panel of yeasts, filamentous fungi and dermatophytes, by using the agar dilution method. results indicated that simple structural modifications led to more potent derivatives, especially in relation with dermatophytes. the most active compound tested (10), which is a benzenesulphonyl derivative, was 12-fold more potent than xanthoxyline itself against trichophyton rubrum. the evaluation of the ...199910635452
localization and light-dependent phosphorylation of white collar 1 and 2, the two central components of blue light signaling in neurospora crassa.in neurospora crassa only two white collar (wc) mutants, wc-1 and wc-2, have been described that seem to be insensitive to light. the pleiotropic phenotypes of these mutants suggest that they represent two central components of blue light signal transduction. the wc proteins have several characteristics of transcription factors consistent with an involvement in transcriptional control of light-regulated genes. here, we present a biochemical analysis of wc1 and wc2 polypeptides in n. crassa. usin ...200010632711
cloning and characterization of a gene (arpa) from aspergillus oryzae encoding an actin-related protein required for normal nuclear distribution and morphology of conidiophores.we have isolated the arpa gene from aspergillus oryzae as a homologue of the neurospora crassa ro-4 gene. in n. crassa, mutations in the ro-4 gene, which encodes a major component of the dynactin complex arp1, causes curling of hyphae and abnormalities in nuclear distribution. the arpa gene contains two introns and encodes a polypeptide of 381 amino acids, with a 78% sequence identity to the n. crassa arp1. overexpression of the arpa gene causes a defect in nuclear migration into elongating hyph ...199910628858
use of atp6 in fungal phylogenetics: an example from the boletales.complete nucleotide sequences have been determined for atp6 from suillus luteus and cox3 from suillus sinuspaulianus (boletales, hymenomycetes, basidiomycota), which code for atpase subunit 6 and cytochrome oxidase subunit 3, respectively. these sequences were used to design pcr primers for the amplification of partial atp6 and cox3 sequences from other members of the boletales and outgroup taxa. in atp6 and cox3 from russula rosacea, one of the outgroup taxa, we observed a number of in-frame tg ...199910620406
circadian rhythms in neurospora crassa: lipid deficiencies restore robust rhythmicity to null frequency and white-collar mutants.the conidiation rhythm in the fungus neurospora crassa is a model system for investigating the genetics of circadian clocks. null mutants at the frq (frequency) locus (frq(9) and frq(10)) make no functional frq gene products and are arrhythmic under standard conditions. the white-collar strains (wc-1 and wc-2) are insensitive to most effects of light, and are also arrhythmic. all three genes are proposed to be central components of the circadian oscillator. we have been investigating two mutants ...200010618405
structural and functional definition of the human chitinase chitin-binding domain.mammalian chitinase, a chitinolytic enzyme expressed by macrophages, has been detected in atherosclerotic plaques and is elevated in blood and tissues of guinea pigs infected with aspergillus. its normal physiological function is unknown. to understand how the enzyme interacts with its substrate, we have characterized the chitin-binding domain. the c-terminal 49 amino acids make up the minimal sequence required for chitin binding activity. the absence of this domain does not affect the ability o ...200010617646
disruption of vma-1, the gene encoding the catalytic subunit of the vacuolar h(+)-atpase, causes severe morphological changes in neurospora crassa.by using the process of repeat-induced point mutation (selker, e. u., and garrett, p. w. (1988) proc. natl. acad. sci. u. s. a. 85, 6870-6874), we inactivated vma-1, the gene encoding subunit a of the v-atpase of neurospora crassa. two vma-1 mutant strains were characterized. one was mutated at multiple sites, did not make a protein product, and produced spores that only rarely germinated. the other had four point mutations, made a protein product, and produced viable spores. neither strain had ...200010617601
induced revertants of biochemical mutants of neurospora crassa: personal recollections. 199910610431
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