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61.
Ma Dichao Endo Satoshi Betsuyaku Shigeyuki Shimotohno Akie Fukuda Hiroo 《Plant molecular biology》2020,104(6):561-574
Plant Molecular Biology - This study focused on the role of CLE1-CLE7 peptides as environmental mediators and indicated that root-induced CLE2 functions systemically in light-dependent carbohydrate... 相似文献
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63.
Yuzuru Itoh Shun-ichi Sekine Shiro Suetsugu Shigeyuki Yokoyama 《Nucleic acids research》2013,41(13):6729-6738
Selenocysteine (Sec) is translationally incorporated into proteins in response to the UGA codon. The tRNA specific to Sec (tRNASec) is first ligated with serine by seryl-tRNA synthetase (SerRS). In the present study, we determined the 3.1 Å crystal structure of the tRNASec from the bacterium Aquifex aeolicus, in complex with the heterologous SerRS from the archaeon Methanopyrus kandleri. The bacterial tRNASec assumes the L-shaped structure, from which the long extra arm protrudes. Although the D-arm conformation and the extra-arm orientation are similar to those of eukaryal/archaeal tRNASecs, A. aeolicus tRNASec has unique base triples, G14:C21:U8 and C15:G20a:G48, which occupy the positions corresponding to the U8:A14 and R15:Y48 tertiary base pairs of canonical tRNAs. Methanopyrus kandleri SerRS exhibited serine ligation activity toward A. aeolicus tRNASec
in vitro. The SerRS N-terminal domain interacts with the extra-arm stem and the outer corner of tRNASec. Similar interactions exist in the reported tRNASer and SerRS complex structure from the bacterium Thermus thermophilus. Although the catalytic C-terminal domain of M. kandleri SerRS lacks interactions with A. aeolicus tRNASec in the present complex structure, the conformational flexibility of SerRS is likely to allow the CCA terminal region of tRNASec to enter the SerRS catalytic site. 相似文献
64.
Akemi Shodai Toshifumi Morimura Akemi Ido Tsukasa Uchida Takashi Ayaki Rina Takahashi Soichiro Kitazawa Sakura Suzuki Mikako Shirouzu Takanori Kigawa Yutaka Muto Shigeyuki Yokoyama Ryosuke Takahashi Ryo Kitahara Hidefumi Ito Noriko Fujiwara Makoto Urushitani 《The Journal of biological chemistry》2013,288(21):14886-14905
Aggregation of TAR DNA-binding protein of 43 kDa (TDP-43) is a pathological signature of amyotrophic lateral sclerosis (ALS). Although accumulating evidence suggests the involvement of RNA recognition motifs (RRMs) in TDP-43 proteinopathy, it remains unclear how native TDP-43 is converted to pathogenic forms. To elucidate the role of homeostasis of RRM1 structure in ALS pathogenesis, conformations of RRM1 under high pressure were monitored by NMR. We first found that RRM1 was prone to aggregation and had three regions showing stable chemical shifts during misfolding. Moreover, mass spectrometric analysis of aggregated RRM1 revealed that one of the regions was located on protease-resistant β-strands containing two cysteines (Cys-173 and Cys-175), indicating that this region served as a core assembly interface in RRM1 aggregation. Although a fraction of RRM1 aggregates comprised disulfide-bonded oligomers, the substitution of cysteine(s) to serine(s) (C/S) resulted in unexpected acceleration of amyloid fibrils of RRM1 and disulfide-independent aggregate formation of full-length TDP-43. Notably, TDP-43 aggregates with RRM1-C/S required the C terminus, and replicated cytopathologies of ALS, including mislocalization, impaired RNA splicing, ubiquitination, phosphorylation, and motor neuron toxicity. Furthermore, RRM1-C/S accentuated inclusions of familial ALS-linked TDP-43 mutants in the C terminus. The relevance of RRM1-C/S-induced TDP-43 aggregates in ALS pathogenesis was verified by immunolabeling of inclusions of ALS patients and cultured cells overexpressing the RRM1-C/S TDP-43 with antibody targeting misfolding-relevant regions. Our results indicate that cysteines in RRM1 crucially govern the conformation of TDP-43, and aberrant self-assembly of RRM1 at amyloidogenic regions contributes to pathogenic conversion of TDP-43 in ALS. 相似文献
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Xiuling Li Pavel Přibyl Kateřina Bišová Shigeyuki Kawano Vladislav Cepák Vilém Zachleder Mária Čížková Irena Brányiková Milada Vítová 《Biotechnology and bioengineering》2013,110(1):97-107
The alga Parachlorella kessleri, strain CCALA 255, grown under optimal conditions, is characterized by storage of energy in the form of starch rather than lipids. If grown in the complete medium, the cultures grew rapidly, producing large amounts of biomass in a relatively short time. The cells, however, contained negligible lipid reserves (1–10% of DW). Treatments inducing hyperproduction of storage lipids in P. kessleri biomass were described. The cultures were grown in the absence or fivefold decreased concentration of either nitrogen or phosphorus or sulfur. Limitation by all elements using fivefold or 10‐fold diluted mineral medium was also tested. Limitation with any macroelement (nitrogen, sulfur, or phosphorus) led to an increase in the amount of lipids; nitrogen limitation was the most effective. Diluted nutrient media (5‐ or 10‐fold) were identified as the best method to stimulate lipid overproduction (60% of DW). The strategy for lipid overproduction consists of the fast growth of P. kessleri culture grown in the complete medium to produce sufficient biomass (DW more than 10 g/L) followed by the dilution of nutrient medium to stop growth and cell division by limitation of all elements, leading to induction of lipid production and accumulation up to 60% DW. Cultivation conditions necessary for maximizing lipid content in P. kessleri biomass generated in a scale‐up solar open thin‐layer photobioreactor were described. Biotechnol. Bioeng. 2013; 110: 97–107. © 2012 Wiley Periodicals, Inc. 相似文献
67.
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
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69.
Shigeyuki Takenishi Yoshio Tsujisaka 《Bioscience, biotechnology, and biochemistry》2013,77(12):2315-2323
The modes of action of three xylanases (I, II and III) produced by Aspergillus niger van Tieghem on several substrates were investigated. Xylanase I possesed the strongest activity against xylooligosaccharides among the three enzymes and converted them into xylose and xylobiose. Xylanase II and III catalyzed a glycosylating reaction and produced higher polymerized xylooligosaccharides from xylotetraose or xylopentaose. Among three enzymes, xylanase II could split α1,3-arabinofuranosidic bond of arabinose-xylose mixed oligosaccharides.In the case of hydrolysis by three xylanases on xylan and arabinoxylan, the maximum hydrolysis degree and the reaction products were compared with each other. From the results, some speculation were made concerning the modes of action of the enzymes. 相似文献
70.
Kou Kayamori Ken-ichi Katsube Kei Sakamoto Yoshio Ohyama Hideaki Hirai Akane Yukimori Yae Ohata Takumi Akashi Masao Saitoh Kiyoshi Harada Hiroyuki Harada Akira Yamaguchi 《PloS one》2016,11(4)
Recent studies have shown that Notch signaling is involved in many types of cancers, including oral squamous cell carcinomas (OSCCs). However, the role of Notch signaling in the tumor microenvironment is not yet fully understood. In this study, we investigated the roles of NOTCH3 signaling in cancer associated fibroblasts (CAFs) in OSCCs. Immunohistochemical study of 93 human tongue OSCC cases indicated that about one third of OSCCs showed NOTCH3 expression in CAFs, and that this expression significantly correlated with tumor-size. In vitro study showed that OSCC cell lines, especially HO1-N-1 cells stimulated NOTCH3 expression in normal human dermal fibroblasts (NHDFs) through direct cell-to-cell contact. Immunohistochemical and morphometric analysis using human OSCC samples demonstrated that NOTCH3 expression in CAFs significantly correlated with micro-vessel density in cancer stroma. In vitro angiogenesis assays involving co-culture of NHDFs with HO1-N-1 and human umbilical endothelial cells (HUVECs), and NOTCH3 knockdown in NHDFs using siRNA, demonstrated that HO1-N-1 cells significantly promoted tube formation dependent on NOTCH3-expression in NHDFs. Moreover, NOTCH3 expression in CAFs was related to poor prognosis of the OSCC patients. This work provides a new insight into the role of Notch signaling in CAFs associated with tumor angiogenesis and the possibility of NOTCH3-targeted molecular therapy in OSCCs. 相似文献