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51.
Junya Mizumoto Yuka Kikuchi Yo-Hei Nakanishi Naoto Mouri Anrong Cai Tokushiro Ohta Takamitsu Haruyama Yasuyuki Kato-Yamada 《PloS one》2013,8(8)
MgADP inhibition, which is considered as a part of the regulatory system of ATP synthase, is a well-known process common to all F1-ATPases, a soluble component of ATP synthase. The entrapment of inhibitory MgADP at catalytic sites terminates catalysis. Regulation by the ε subunit is a common mechanism among F1-ATPases from bacteria and plants. The relationship between these two forms of regulatory mechanisms is obscure because it is difficult to distinguish which is active at a particular moment. Here, using F1-ATPase from Bacillus subtilis (BF1), which is strongly affected by MgADP inhibition, we can distinguish MgADP inhibition from regulation by the ε subunit. The ε subunit did not inhibit but activated BF1. We conclude that the ε subunit relieves BF1 from MgADP inhibition. 相似文献
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Tatsunori Masatani Naoto Ito Yuki Ito Keisuke Nakagawa Masako Abe Satoko Yamaoka Kota Okadera Makoto Sugiyama 《Microbiology and immunology》2013,57(7):511-517
By using a cultured neuroblastoma cell line, the present authors recently showed that the N protein of virulent rabies virus fixed strain Nishigahara (Ni), but not that of the attenuated derivative Ni‐CE, mediates evasion of induction of type I interferon (IFN). In this study, to determine whether Ni N protein indeed fulfills this function in vivo, the abilities to suppress IFN responses in the mouse brain of Ni‐CE and the virulent chimeric virus CE(NiN), which has the N gene from Ni in the genetic background of Ni‐CE, were compared. It was demonstrated that CE(NiN) propagates and spreads more efficiently than does Ni‐CE in the brain and that IFN response in brains infected with CE(NiN) is weaker than in those infected with Ni‐CE. It was also shown that amino acids at positions 273 and 394 in the N protein, which are known as pathogenic determinants, affect the ability of the viruses to suppress IFN response in the brain. These findings strongly suggest that, in the brain, rabies virus N protein plays important roles in evasion of innate immune responses and thereby in efficient propagation and spread of virus leading to lethal outcomes of infection. 相似文献
55.
Naoto Burioka Miyako Takata Masahiro Endo Masanori Miyata Kenichi Takeda Hiroki Chikumi 《Chronobiology international》2013,30(1):183-189
This study examined whether in vivo exposure to a β2‐adrenoceptor agonist, tulobuterol, induces human Period1 (hPer1) mRNA expression in cells from peripheral whole blood. In one experiment, oral tulobuterol was administered to five healthy volunteers at 22:00 h, while in another, a transdermally tulobuterol patch was applied to the same five subjects at 20:00 h. In each experiment, serum tulobuterol concentrations were measured at four time points, and total RNA was isolated from peripheral blood cells for determinations of hPer1 mRNA expression by real‐time polymerase chain reaction. Both the tulobuterol tablet and the transdermal patch increased hPer1 mRNA expression, suggesting that analyses of human peripheral blood cells could reliably represent peripheral clock gene mRNA expression in vivo. 相似文献
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Lyudmila A. Romanenko Naoto Tanaka Natalia I. Kalinovskaya Valery V. Mikhailov 《World journal of microbiology & biotechnology》2013,29(7):1169-1177
The aim of this study was to survey microorganisms from the deep surface sediment samples collected from the Sea of Japan and to screen them for antimicrobial and antagonistic effects. Phylogenetic analysis revealed most isolates sharing 98–100 % sequence similarity to recognized species, including those recovered previously from marine or saline environments. Alteromonas, Halomonas, Marinobacter, Pseudoalteromonas, Salinicola, within the class Gammaproteobacteria, Sulfitobacter (Alphaproteobacteria), Bacillus, Paenibacillus and Paenisporosarcina (Firmicutes), Nocardiopsis and Streptomyces (Actinobacteria) occurred abundantly in all sediment samples. Antimicrobial screening revealed twenty three strains (13 %) capable to inhibit growth of one to eight test cultures and deep sediment isolates. Based on phylogenetic analysis mostly active strains belonged to the genera Bacillus, Brevibacillus, Nocardiopsis, Paenibacillus and Streptomyces. Antimicrobial substances (1–3) were isolated from strain Paenibacillus sp. Sl 79w showing a high inhibitory activity. On the basis of combined spectral analyses (IR, UV, 1H and 13C NMR) the compounds 1, 2 and 3 with [M + H]+ at 409.1 and 409.2 m/z, and with [M + Na]+ at 822.5 m/z were found to have a carbon skeleton of isocoumarin and peptide antibiotics, respectively. Our findings demonstrated that the deep surface sediments of the Sea of Japan represent an untapped source of diverse microorganisms capable of antimicrobial metabolite production. 相似文献
58.
Kenji Seiwa Yoshiko Miwa Shigetoshi Akasaka Hiroshi Kanno Mizuki Tomita Tomoyuki Saitoh Naoto Ueno Megumi Kimura Yoichi Hasegawa Miki Konno Kazuhiko Masaka 《Ecological Research》2013,28(1):29-41
To evaluate the extent to which landslides affect community dynamics and consequent species diversity in a beech-dominated forest, differences in the composition and size structure of tree species were compared between landslide and adjacent stable (control) stands. Demography and changes in size were compared between the two stands over a 5-year period about 60 years after a landslide. In the control stand, replacement occurred even amongst late-successional species, with beech (Fagus crenata)—the most dominant species—increasing in relative abundance. In the landslide stand, very few large individuals of late-successional species occurred, whereas large individuals of early-successional species occurred only in the landslide stand. The traits indicate that the landslide strongly facilitated species diversity, not only by reducing the dominance of late-successional species, but also by promoting recruitment of early-successional species. However, new recruitment of early-successional species was inhibited in the landslide stand, although we observed succeeding regeneration and subsequent population growth of late-successional species there. As a result, the relative dominance of late-successional species increased with succession after the landslide, thus decreasing future species diversity. In beech-dominant forest landscapes in Japan that include communities with different developmental stages, the mosaic of serial stages may facilitate species diversity after a landslide. 相似文献
59.
We review the use of stable carbon isotope ratios (δ13C) and radiocarbon natural abundances (Δ14C) for stream food web studies. The δ13C value of primary producers (e.g., periphytic algae, hereafter periphyton) in streams is controlled by isotopic fractionation during photosynthesis and variable δ13C of dissolved CO2. When periphyton δ13C differs from that of terrestrial primary producers, the relative contribution of autochthony and allochthony to stream food webs can be calculated. Moreover, the variation in periphyton δ13C can reveal how much stream consumers rely on local resources because each stream habitat (e.g., riffle vs. pool, open vs. shaded) usually has a distinctive δ13C. However, periphyton δ13C often overlaps with that of terrestrial organic matter. On the other hand, periphyton Δ14C is less variable than δ13C among habitats, and reflects the Δ14C of dissolved CO2, which could be a mixture of “aged” (Δ14C < 0 ‰) and “modern” (Δ14C > 0 ‰) carbon. This is because the Δ14C is corrected by its δ13C value for the isotopic fractionation during photosynthesis. Recent studies and our data indicate that many stream food webs are supported by “aged” carbon derived from the watershed via autochthonous production. The combined use of δ13C and Δ14C allows robust estimation of the carbon transfer pathway in a stream food web at multiple spatial scales ranging from the stream habitat level (e.g., riffle and pool) to watershed level (autochthony and allochthony). Furthermore, the Δ14C of stream food webs will expand our understanding about the time frame of carbon cycles in the watersheds. 相似文献
60.
Shigehiro Kamoda Naoto Habu Masahiro Samejima Tomotaka Yoshimoto 《Bioscience, biotechnology, and biochemistry》2013,77(10):2757-2761
A novel dioxygenase, lignostilbene-a,β-dioxygenase (LSD), which catalyzes cleavage of the interphenyl double bond of lignin-derived stilbenes, was isolated. Four isozymes of LSD were separated from cell-free extracts of Pseudomonas sp. TMY1009 by ion-exchange chromatography on a DEAE- Toyopearl column. The major isozyme, LSD-I, was purified to electrophoretic homogeneity and characterized.LSD-I cleaved the interphenyl double bond of l,2-bis(4′-hydroxy-3′-methoxyphenyl)ethylene with the optimum pH at 8.5. The Km of LSD-I was 11 μm for the stilbene and 110/iM for oxygen. The molecular weight of LSD-I, which is composed of two identical subunits, was estimated to be 94,000. LSD-I contained 1 g atom of iron per 1 mol of enzyme protein. 相似文献