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排序方式: 共有959条查询结果,搜索用时 15 毫秒
1.
Ana Rodríguez Takehiko Shimada Magdalena Cervera Ana Redondo Berta Alquézar María Jesús Rodrigo Lorenzo Zacarías Lluís Palou María M López Leandro Pe?a 《Plant signaling & behavior》2015,10(6)
Volatile organic compounds (VOCs) are secondary metabolites acting as a language for the communication of plants with the environment. In orange fruits, the monoterpene D-limonene accumulates at very high levels in oil glands from the peel. Drastic down-regulation of D-limonene synthase gene expression in the peel of transgenic oranges harboring a D-limonene synthase transgene in antisense (AS) configuration altered the monoterpene profile in oil glands, mainly resulting in reduced accumulation of D-limonene. This led to fruit resistance against Penicillium digitatum (Pd), Xanthomonas citri subsp. citri (Xcc) and other specialized pathogens. Here, we analyze resistance to pathogens in independent AS and empty vector (EV) lines, which have low, medium or high D-limonene concentrations and show that the level of resistance is inversely related to the accumulation of D-limonene in orange peels, thus explaining the need of high D-limonene accumulation in mature oranges in nature for the efficient attraction of specialized microorganism frugivores. 相似文献
2.
Atsunori Kashiwagi Kazuyuki Sasaki Tamio Noguchi Takehiko Tanaka 《Biochimica et Biophysica Acta (BBA)/General Subjects》1979,582(2):221-233
A factor responsible for stimulating an increase in ornithine decarboxylase activity in the liver of mice was found in tumor cell-free ascites fluid of mice 3 days after inoculation of tumor cells. The factor was purified about 70-fold in 25% yield from tumor cell-free ascites fluid. As little as 1 μg of protein of purified fraction, injected intraperitoneally into normal mice, significantly increased the activity of ornithine decarboxylase in the liver. The most active preparation of the factor formed two major protein bands on analytical polyacrylamide gel electrophoresis and both these bands stained with periodic acid-Schiff's reagent. The factor was a heat-labile, alkaline-stable, acidic protein with a molecular weight of more than 300 000. It was inactivated by treatment with 10 mM dithiothreitol, 5M urea, pronase or mixed glycosidase, but was stable on treatment with DNAase, RNAase or neuraminidase. 相似文献
3.
Takehiko Uchiyama 《Microbiology and immunology》1982,26(3):213-225
The roles of macrophages and T cells in the adjuvant effect of lipopolysaccharide (LPS) were studied. In vitro anti-trinitrophenyl (anti-TNP) antibody responses to TNP-Ficoll and TNP-keyhole limpet hemocyanine (TNP-KLH) in spleen cells of C57BL/6 mice showed the most enhancement, when LPS was added to cultures at 1 μg/ml 48 hr after culture was started. The responses to these antigens were enhanced markedly by LPS in whole and macrophage-depleted spleen cells. The enhancement was greater in the latter group than in the former. The adjuvant effect among whole, T cell-depleted, macrophage-depleted and both macrophage- and T cell-depleted spleen cells was compared. The response to TNP-Ficoll was enhanced markedly by LPS in all groups. The enhancement was greater in the latter two groups than in the first two groups. The response to TNP-KLH was enhanced by LPS strongly in macrophage-depleted spleen cells, moderately in whole and both macrophage- and T cell-depleted spleen cells, and only slightly in T cell-depleted spleen cells. Enhancement was restored to T cell-depleted spleen cells by adding T cells. The response to TNP-KLH of macrophage-depleted spleen cells of LPS-responsive C3H/HeN mice which was enhanced by LPS was suppressed by adding splenic macrophages of C3H/HeN mice, but not of LPS-nonresponsive C3H/HeJ mice. The response to TNP-KLH of macrophage-depleted spleen cells of C3H/HeJ mice was not enhanced by LPS, irrespective of the addition of macrophages of C3H/HeN mice. The results indicate that B cells are activated directly by LPS, and T cells enhance and macrophages suppress the adjuvant effect of LPS. 相似文献
4.
Uchii Kimiko Wakimura Kei Kikko Takeshi Yonekura Ryuji Kawaguchi Riho Komada Honoka Yamanaka Hiroki Kenzaka Takehiko Tani Katsuji 《Limnology》2022,23(1):49-56
Limnology - Gnathopogon caerulescens is an endangered but commercially important fish in Lake Biwa, Japan. The population size of G. caerulescens has drastically reduced in the past decades, and... 相似文献
5.
Osamu Hashimoto Hirofumi Ohtsuki Takehiko Kakizaki Kento Amou Ryo Sato Satoru Doi Sara Kobayashi Ayaka Matsuda Makoto Sugiyama Masayuki Funaba Takashi Matsuishi Fumio Terasawa Junji Shindo Hideki Endo 《PloS one》2015,10(2)
Brown adipose tissue (BAT) plays an important role in thermoregulation in species living in cold environments, given heat can be generated from its chemical energy reserves. Here we investigate the existence of BAT in blubber in four species of delphinoid cetacean, the Pacific white-sided and bottlenose dolphins, Lagenorhynchus obliquidens and Tursiops truncates, and Dall’s and harbour porpoises, Phocoenoides dalli and Phocoena phocoena. Histology revealed adipocytes with small unilocular fat droplets and a large eosinophilic cytoplasm intermingled with connective tissue in the innermost layers of blubber. Chemistry revealed a brown adipocyte-specific mitochondrial protein, uncoupling protein 1 (UCP1), within these same adipocytes, but not those distributed elsewhere throughout the blubber. Western blot analysis of extracts from the inner blubber layer confirmed that the immunohistochemical positive reaction was specific to UCP1 and that this adipose tissue was BAT. To better understand the distribution of BAT throughout the entire cetacean body, cadavers were subjected to computed tomography (CT) scanning. Resulting imagery, coupled with histological corroboration of fine tissue structure, revealed adipocytes intermingled with connective tissue in the lowest layer of blubber were distributed within a thin, highly dense layer that extended the length of the body, with the exception of the rostrum, fin and fluke regions. As such, we describe BAT effectively enveloping the cetacean body. Our results suggest that delphinoid blubber could serve a role additional to those frequently attributed to it: simple insulation blanket, energy storage, hydrodynamic streamlining or contributor to positive buoyancy. We believe delphinoid BAT might also function like an electric blanket, enabling animals to frequent waters cooler than blubber as an insulator alone might otherwise allow an animal to withstand, or allow animals to maintain body temperature in cool waters during sustained periods of physical inactivity. 相似文献
6.
Yuka Kobayashi Norikazu Kiguchi Yohji Fukazawa Fumihiro Saika Takehiko Maeda Shiroh Kishioka 《The Journal of biological chemistry》2015,290(20):12603-12613
Peripheral neuroinflammation caused by activated immune cells can provoke neuropathic pain. Herein, we investigate the actions of macrophages and T cells through glucocorticoid-induced tumor neurosis factor receptor ligand (GITRL) and its receptor (GITR) in neuropathic pain. After partial sciatic nerve ligation (PSL) in enhanced green fluorescent protein (eGFP) chimeric mice generated by the transplantation of eGFP+ bone marrow cells, eGFP+ macrophages, and T cells markedly migrated to the injured site after PSL. Administration of agents to deplete macrophages (liposome-clodronate and Clophosome-ATM) or T cells (anti-CD4 antibody and FTY720) could suppress PSL-induced thermal hyperalgesia and tactile allodynia. The expression levels of co-stimulatory molecules GITRL and GITR were increased on infiltrating macrophages and T cells, respectively. The perineural injection of a GITRL neutralizing antibody that could inhibit the function of the GITRL-GITR pathway attenuated PSL-induced neuropathic pain. Additionally, the induction of inflammatory cytokines and the accumulation of GITR+ T cells in the injured SCN were abrogated after macrophage depletion by Clophosome-ATM. In conclusion, GITRL expressed on macrophages drives cytokine release and T cell activation, resulting in neuropathic pain via GITR-dependent actions. The GITRL-GITR pathway might represent a novel target for the treatment of neuropathic pain. 相似文献
7.
The Extracellular A-loop of Dual Oxidases Affects the Specificity of Reactive Oxygen Species Release
Takehiko Ueyama Megumi Sakuma Yuzuru Ninoyu Takeshi Hamada Corinne Dupuy Miklós Geiszt Thomas L. Leto Naoaki Saito 《The Journal of biological chemistry》2015,290(10):6495-6506
NADPH oxidase (Nox) family proteins produce superoxide (O2⨪) directly by transferring an electron to molecular oxygen. Dual oxidases (Duoxes) also produce an O2⨪ intermediate, although the final species secreted by mature Duoxes is H2O2, suggesting that intramolecular O2⨪ dismutation or other mechanisms contribute to H2O2 release. We explored the structural determinants affecting reactive oxygen species formation by Duox enzymes. Duox2 showed O2⨪ leakage when mismatched with Duox activator 1 (DuoxA1). Duox2 released O2⨪ even in correctly matched combinations, including Duox2 + DuoxA2 and Duox2 + N-terminally tagged DuoxA2 regardless of the type or number of tags. Conversely, Duox1 did not release O2⨪ in any combination. Chimeric Duox2 possessing the A-loop of Duox1 showed no O2⨪ leakage; chimeric Duox1 possessing the A-loop of Duox2 released O2⨪. Moreover, Duox2 proteins possessing the A-loops of Nox1 or Nox5 co-expressed with DuoxA2 showed enhanced O2⨪ release, and Duox1 proteins possessing the A-loops of Nox1 or Nox5 co-expressed with DuoxA1 acquired O2⨪ leakage. Although we identified Duox1 A-loop residues (His1071, His1072, and Gly1074) important for reducing O2⨪ release, mutations of these residues to those of Duox2 failed to convert Duox1 to an O2⨪-releasing enzyme. Using immunoprecipitation and endoglycosidase H sensitivity assays, we found that the A-loop of Duoxes binds to DuoxA N termini, creating more stable, mature Duox-DuoxA complexes. In conclusion, the A-loops of both Duoxes support H2O2 production through interaction with corresponding activators, but complex formation between the Duox1 A-loop and DuoxA1 results in tighter control of H2O2 release by the enzyme complex. 相似文献
8.
The effect of endotoxin or lipopolysaccharide (LPS) on tolerance induction in bone marrow-derived lymphoid cells (B cells) was investigated. Dinitrophenylated amino acid copolymer-l-(glutamic acid, lysine) (DNP-GL) acts as a potent tolerogen on normal and DNP-primed B cells. LPS significantly enhanced the anti-sheep red blood cell plaque-forming cell (anti-SRBC PFC) response that occurred after the immunization with a low dose of SRBC. LPS did not induce the primary anti-DNP PFC response after the injection of DNP-GL, nor did it prevent the tolerance induction in normal and DNP-primed B cells that occurred after the administration of DNP-GL. 相似文献
9.
Junko Morimoto Kento Hirabayashi Emu Mizumoto Takehiko Katsuno Yukihiro Morimoto 《Landscape and Ecological Engineering》2011,7(2):185-193
To develop an appropriate method of conservation for native Rhododendron sections Brachycalyx and Tsutsusi, the symbol of Satoyama, field experiments were performed in the dry granite region of Japan. When carpet-type landscape
of native rhododendrons was desired, all plants were cut at 20 cm above the ground level of all trees and shrubs, and herbs
and ferns were weeded (once and three times, respectively). When shrubby-type landscape of native rhododendrons was desired,
all plants, excluding native rhododendrons, were cut at 20 cm above the ground level of all trees and shrubs, herbs and ferns
were weeded, and litter was swept. After 3 years of monitoring of the percentage and depth of crowns with flower buds, the
following major results were obtained: Cutting all plants excluding native rhododendrons was effective to maintain the depth
of crowns with flower buds. However, weeding and sweeping of litter on the ground caused desiccation of surface soil, which
induced a transitory decrease in the percentage of crowns with flower buds. One weeding was effective in maintaining the depth
of crowns with flower buds; however, the second and third weedings had no distinct effect. In dry granite regions, considerable
attention to desiccation of surface soil is critical, as opposed to limiting attention to maintenance of sunlight as is common
practice. 相似文献
10.
Anna Valenti Giuseppe Perugino Takehiko Nohmi Mos Rossi Maria Ciaramella 《Nucleic acids research》2009,37(13):4287-4295
Reverse gyrase is a unique DNA topoisomerase endowed with ATP-dependent positive supercoiling activity. It is typical of microorganisms living at high temperature and might play a role in maintenance of genome stability and repair. We have identified the translesion DNA polymerase SsoPolY/Dpo4 as one partner of reverse gyrase in the hyperthermophilic archaeon Sulfolobus solfataricus. We show here that in cell extracts, PolY and reverse gyrase co-immunoprecipitate with each other and with the single strand binding protein, SSB. The interaction is confirmed in vitro by far-western and Surface Plasmon Resonance. In functional assays, reverse gyrase inhibits PolY, but not the S. solfataricus B-family DNA polymerase PolB1. Mutational analysis shows that inhibition of PolY activity depends on both ATPase and topoisomerase activities of reverse gyrase, suggesting that the intact positive supercoiling activity is required for PolY inhibition. In vivo, reverse gyrase and PolY are degraded after induction of DNA damage. Inhibition by reverse gyrase and degradation might act as a double mechanism to control PolY and prevent its potentially mutagenic activity when undesired. Inhibition of a translesion polymerase by topoisomerase-induced modification of DNA structure may represent a previously unconsidered mechanism of regulation of these two-faced enzymes. 相似文献