The excellent emulsifying capacity of nanocellulose allows for the preparation of porous nanocellulose/polymer composites through the emulsion templating process. However, the effects of the polymer chemical structure and porosity on the material properties have not been extensively explored. Here, we discuss the effects of these two factors on the thermal and mechanical properties of the composites.
View Article and Find Full Text PDF17β-estradiol (E2) regulates various forms of social behavior through the activation of two types of estrogen receptors, ERα and ERβ. The lateral septum (LS) is thought to be one of the potential target sites of E2, but the role played by ERα and ERβ in this brain area remains largely unknown. In the present study, we first analyzed the distribution of ERα and ERβ with double fluorescent immunohistochemistry in a transgenic mouse line in which red fluorescent protein (RFP) signal has been a reliable marker of ERβ expression.
View Article and Find Full Text PDFWe propose a three-step strategy that uses structural and physicochemical properties of chemicals to predict their 72 h algal growth inhibition toxicities against Pseudokirchneriella subcapitata. In Step 1, using a log D-based criterion and structural alerts, we produced an interspecies QSAR between algal and acute daphnid toxicities for initial screening of chemicals. In Step 2, we categorized chemicals according to the Verhaar scheme for aquatic toxicity, and we developed QSARs for toxicities of Class 1 (non-polar narcotic) and Class 2 (polar narcotic) chemicals by means of simple regression with a hydrophobicity descriptor and multiple regression with a hydrophobicity descriptor and a quantum chemical descriptor.
View Article and Find Full Text PDFIn addition to molecular structure profiles, descriptors based on physicochemical properties are useful for explaining the eco-toxicities of chemicals. In a previous study we reported that a criterion based on the difference between the partition coefficient (log POW) and distribution coefficient (log D) values of chemicals enabled us to identify aromatic amines and phenols for which interspecies relationships with strong correlations could be developed for fish-daphnid and algal-daphnid toxicities. The chemicals that met the log D-based criterion were expected to have similar toxicity mechanisms (related to membrane penetration).
View Article and Find Full Text PDFWe propose interspecies quantitative structure-activity-activity relationships (QSAARs), that is, QSARs with descriptors, to estimate species-specific acute aquatic toxicity. Using training datasets consisting of more than 100 aromatic amines and phenols, we found that the descriptors that predicted acute toxicities to fish (Oryzias latipes) and algae were daphnia toxicity, molecular weight (an indicator of molecular size and uptake) and selected indicator variables that discriminated between the absence or presence of various substructures. Molecular weight and the selected indicator variables improved the goodness-of-fit of the fish and algae toxicity prediction models.
View Article and Find Full Text PDFThe circadian system is composed of a number of feedback loops, and multiple feedback loops in the form of oscillators help to maintain stable rhythms. The filamentous fungus Neurospora crassa exhibits a circadian rhythm during asexual spore formation (conidiation banding) and has a major feedback loop that includes the FREQUENCY (FRQ)/WHITE COLLAR (WC) -1 and -2 oscillator (FWO). A mutation in superoxide dismutase (sod)-1, an antioxidant gene, causes a robust and stable circadian rhythm compared with that of wild-type (Wt).
View Article and Find Full Text PDFThe validity of chemical reaction mechanistic domains defined by skin sensitisation in the Quantitative Structure-Activity Relationship (QSAR) ecotoxicity system, KAshinhou Tools for Ecotoxicity (KATE), March 2009 version, has been assessed and an external validation of the current KATE system carried out. In the case of the fish end-point, the group of chemicals with substructures reactive to skin sensitisation always exhibited higher root mean square errors (RMSEs) than chemicals without reactive substructures under identical C- or log P-judgements in KATE. However, in the case of the Daphnia end-point this was not so, and the group of chemicals with reactive substructures did not always have higher RMSEs: the Schiff base mechanism did not function as a high error detector.
View Article and Find Full Text PDFLight signal transduction was studied in extracts of mycelia of the fungus Neurospora crassa, and the third internodes of dark-grown Pisum sativum cv Alaska. Both processes increased the phosphorylation of nucleoside diphosphate kinase (NDPK). NDPK may function as a carrier of reduction equivalents, as it binds NADH, thereby providing electrons to transform singlet oxygen to superoxide by catalases (CAT).
View Article and Find Full Text PDFThis study investigated the reactive oxygen species (ROS) tolerance mechanism of a paraquat-resistant Pisum sativum line (R3-1) compared with the wild type (WT). Physiological and biochemical analyses showed significant differences in the phenotypes, such as delayed leaf and floral development, superior branching, and greater biomass and yields in the R3-1 line, as well as an increased level of antioxidant pigments and a lower rate of cellular lipid peroxidation in the resistant R3-1. Additionally, the phosphorylation of crude proteins showed distinguishable differences in band mobility and intensity between the R3-1 and WT plants.
View Article and Find Full Text PDFA nucleoside diphosphate kinase-1-disrupted (ndk-1(RIP-1)) mutant was observed to be defective in aerial hyphal and conidial development. In this study, two types of hyphae, fine and thick, were observed in wild-type (Wt) strains. However, only fine-type hyphae were observed in the ndk-1(RIP-1) mutants.
View Article and Find Full Text PDFMol Genet Genomics
February 2008
Conidial formation in the filamentous fungus Neurospora crassa is regulated by nutritional conditions, light, and the circadian clock. We found that a sod-1 mutant, with a defective superoxide dismutase catalyzing the conversion of superoxide to hydrogen peroxide, had a slightly shorter period length than the wild type and clear conidial banding similar to a mutant of band (bd). However, unlike the bd mutant, the sod-1 mutant could sustain conidial banding with light pulses on a nutrient-rich medium, which involved an enhancement of the light-induced transcription of frequency (frq).
View Article and Find Full Text PDFRecently we reported that Catalase-1 (CAT-1) played an important role in protecting conidial viability in Neurospora crassa, and interacted with a light signal transducer, nucleoside diphosphate kinase-1 (NDK-1). To disclose the functional interaction between CAT-1 and NDK-1 at the genetic level, we created CAT-1 and NDK-1 double mutants, cat-1;ndk-1-1 and cat-1;ndk-1-2, by crossing single mutants of cat-1 ( RIP ) and ndk-1 ( P72H ) previously isolated in our laboratory. The double mutant strains grew normally, but showed increased CAT-2 activity.
View Article and Find Full Text PDFLight is one of the most important factors inducing morphogenesis in Neurospora crassa. The reception of light triggers the generation of reactive oxygen species (ROS) including hydrogen peroxide (H(2)O(2)). Catalase-1 (Cat-1) is one of three catalases known to detoxify H(2)O(2) into water and oxygen.
View Article and Find Full Text PDFFEMS Microbiol Lett
August 2006
Nucleoside diphosphate kinase (NDK) is a housekeeping enzyme localized in cellular organelles and distributed in various organs in prokaryotes and eukaryotes. In Neurospora crassa, NDK-1 is suggested to control catalases in response to heat, oxidative stress and light. In this study, we identified the presence of NDK-1 during most developmental stages in submerged mycelia, aerial hyphae, asexual conidia and perithecia, and the localization of it in soluble, mitochondrial, nuclear and membrane fractions in the mycelial cell.
View Article and Find Full Text PDFNucleoside diphosphate kinase (NDK) is an ubiquitous enzyme with the function of a signal transducer. In Neurospora crassa, an ndk-1(P72H) mutant carrying the point mutation Pro72His was isolated. We found that ndk-1(P72H) showed hypersensitivity to oxidative and heat stress and a decrease in the levels of catalase (Cat)-1 and -3 induced by oxidative, heat stress and illumination compared with wild type (Wt).
View Article and Find Full Text PDFWe previously demonstrated that the NDK-1 (Nucleoside Diphosphate Kinase-1) point mutant, ndk-1(P72H), displays a defective phenotype in light-induced perithecial polarity in Neurospora crassa. To investigate the biological function of NDK-1 in detail, we isolated two ndk-1 mutants, ndk-1(RIP-1) and ndk-1(RIP-2), using the RIPing (repeat induced point mutation) method. Notably, we detected no accumulation of ndk-1(RIP-1) mRNA and truncated NDK-1(RIP-2) protein.
View Article and Find Full Text PDFPreviously, we found that intracellular reactive oxygen species (ROS) affect photomorphogenesis in Neurospora crassa. In this study, we investigated the physiological roles of ROS in the response to light and found that the exposure of mycelia to air was important for the light-induced carotenogenesis. Mycelia treated with a high concentration of O(2) gas and H(2)O(2) to release ROS showed an enhancement of light-induced carotenoid accumulation and the expression of gene related to light-inducible carotenogenesis.
View Article and Find Full Text PDFTo better understand genetic regulation of differential growth of plant organs, a dominant and semidwarf mutant, constitutive differential growth 1-Dominant (cdg1-D), was isolated utilizing the technique of activation tagging. cdg1-D showed pleiotropic phenotype including dwarfism, exaggerated leaf epinasty, and twisted or spiral growth in hypocotyl, inflorescence stem, and petiole. Hypocotyls of cdg1-D were longer than those of wild type under light conditions.
View Article and Find Full Text PDFNucleoside diphosphate kinases (NDPKs) are key metabolic enzymes that catalyze the synthesis of non-adenosine nucleoside triphosphates (NTP) by transfer of the terminal phosphate between NDP and NTP. Recently we isolated three NDPK cDNAs from Chinese cabbage cDNA library. BcNDK1 has 636 bp and encodes a putative 17.
View Article and Find Full Text PDFIn Neurospora crassa, several biological phenomena such as the synthesis of carotenoids in the mycelia and polarity of perithecia are regulated by light. We found that a sod-1 mutant, with a defective Cu,Zn-type superoxide dismutase (SOD), showed accelerated light-dependent induction of carotenoid accumulation in the mycelia compared with the wild type. The initial rate of light-induced carotenoid accumulation in the sod-1 mutant was faster than that in the vvd mutant known to accumulate high concentrations.
View Article and Find Full Text PDFPlant Cell Physiol
October 2003
Plants sense various environmental stimuli and have specific signaling pathways to respond to these cues. We focused on light responsive components and found that NDKs were phosphorylated specifically after red light irradiation in Pisum sativum [Tanaka et al. (1998) J.
View Article and Find Full Text PDFJ Bioenerg Biomembr
February 2003
The putative functions of NDP (nucleoside diaphosphate) kinases from various organisms focusing to fungi and plants are described. The biochemical reactions catalyzed by NDP kinase are as follows. (i) Phosphotransferring activity from mainly ATP to cognate NDPs generating nucleoside triphosphates (NTPs).
View Article and Find Full Text PDFNihon Kokyuki Gakkai Zasshi
August 2001
A 66-year-old man was admitted to our hospital because of induction therapy of interferon for chronic hepatitis due to hepatitis C virus. On routine investigation, a mass-like lesion was detected at the level of the hilum of the left lung on the chest plain radiograph. On the thoracic CT, the heterogeneous tumor, including calcification, was 6 cm in diameter in the posterior mediastinal area, and the rib and vertebra had been damaged by it.
View Article and Find Full Text PDFIn Neurospora crassa, the phosphorylation of nucleoside diphosphate kinase (NDK)-1 is rapidly enhanced after blue light irradiation. We have investigated the function of NDK-1 in the blue light signal transduction pathway. A mutant called psp (phosphorylation of small protein) shows undetectable phosphorylation of NDK-1 and is defective in light-responsive regulation of perithecial polarity.
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