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991.
992.
Ahmet Can Berkyurek Isao Suetake Kyohei Arita Kohei Takeshita Atsushi Nakagawa Masahiro Shirakawa Shoji Tajima 《The Journal of biological chemistry》2014,289(1):379-386
Dnmt1 is responsible for the maintenance DNA methylation during replication to propagate methylation patterns to the next generation. The replication foci targeting sequence (RFTS), which plugs the catalytic pocket, is necessary for recruitment of Dnmt1 to the replication site. In the present study we found that the DNA methylation activity of Dnmt1 was DNA length-dependent and scarcely methylated 12-bp short hemi-methylated DNA. Contrarily, the RFTS-deleted Dnmt1 and Dnmt1 mutants that destroyed the hydrogen bonds between the RFTS and catalytic domain showed significant DNA methylation activity even toward 12-bp hemi-methylated DNA. The DNA methylation activity of the RFTS-deleted Dnmt1 toward 12-bp hemi-methylated DNA was strongly inhibited on the addition of RFTS, but to a lesser extent by Dnmt1 harboring the mutations that impair the hydrogen bond formation. The SRA domain of Uhrf1, which is a prerequisite factor for maintenance methylation and selectively binds to hemi-methylated DNA, stimulated the DNA methylation activity of Dnmt1. The SRA to Dnmt1 concentration ratio was the determinant for the maximum stimulation. In addition, a mutant SRA, which had lost the DNA binding activity but was able to bind to Dnmt1, stimulated the DNA methylation activity of Dnmt1. The results indicate that the DNA methylation activity of Dnmt1 was stimulated on the direct interaction of the SRA and Dnmt1. The SRA facilitated acceptance of the 12-bp fluorocytosine-containing DNA by the catalytic center. We propose that the SRA removes the RFTS plug from the catalytic pocket to facilitate DNA acceptance by the catalytic center. 相似文献
993.
994.
Plant and Soil - In this study, we examine the rhizosphere processes influencing organic P (Po) utilization in soil with low inorganic P (Pi) availability and how they change with plant... 相似文献
995.
996.
Hiroaki Hobara Koh Inoue Tetsuro Muraoka Kohei Omuro Masanori Sakamoto Kazuyuki Kanosue 《Journal of biomechanics》2010,43(3):506-511
The purpose of the present study was to determine how humans adjust leg stiffness over a range of hopping frequencies. Ten male subjects performed in place hopping on two legs, at three frequencies (1.5, 2.2, and 3.0 Hz). Leg stiffness, joint stiffness and touchdown joint angles were calculated from kinetic and/or kinematics data. Electromyographic activity (EMG) was recorded from six leg muscles. Leg stiffness increased with an increase in hopping frequency. Hip and knee stiffnesses were significantly greater at 3.0 Hz than at 1.5 Hz. There was no significant difference in ankle stiffness among the three hopping frequencies. Although there were significant differences in EMG activity among the three hopping frequencies, the largest was the 1.5 Hz, followed by the 2.2 Hz and then 3.0 Hz. The subjects landed with a straighter leg (both hip and knee were extended more) with increased hopping frequency. These results suggest that over the range of hopping frequencies we evaluated, humans adjust leg stiffness by altering hip and knee stiffness. This is accomplished by extending the touchdown joint angles rather than by altering neural activity. 相似文献
997.
Oba T Uda Y Matsuda K Fukusumi T Ito S Hiratani K Tamiaki H 《Bioorganic & medicinal chemistry letters》2011,21(8):2489-2491
The C3-vinyl group of a chlorophyll derivative, methyl pyropheophorbide-a, was converted into the formyl group by a novel one-pot reaction with thiophenol at room temperature. The mild reaction can provide insight into development of ‘green’ catalysts displacing OsO4 or O3, and into elucidation of unknown biosynthetic processes of chlorophyll-d. 相似文献
998.
Kagatani Kohei Nagao Ryo Shen Jian-Ren Yamano Yumiko Takaichi Shinichi Akimoto Seiji 《Photosynthesis research》2022,154(1):13-19
Photosynthesis Research - Carotenoids (Cars) exhibit two functions in photosynthesis, light-harvesting and photoprotective functions, which are performed through the excited states of Cars.... 相似文献
999.
Yamamoto Kohei Shimamura Masaki Degawa Yousuke Yamada Akiyoshi 《Journal of plant research》2019,132(6):777-788
Journal of Plant Research - In general, Glomeromycotina was thought to be the earliest fungi forming mycorrhiza-like structure (MLS) in land plant evolution. In contrast, because the earliest... 相似文献
1000.
Schizosaccharomyces pombe Δura4 cells lyse when grown on YPD medium. A S. pombe non-essential gene deletion library was screened to determine suppressors of the lysis phenotype. Deletion of the pub1 gene, which encoded E3 ubiquitin ligase, strongly suppressed cell lysis in Δura4 cells. The Δpub1 cells displayed high sensitivity to 5-fluorouracil, a toxic analog of uracil, and this sensitivity was suppressed by deletion of fur4, which encoded a uracil transporter. Fur4 localized primarily to the Golgi apparatus and vacuoles in wild-type cells, but localization was predominantly at the plasma membrane in Δpub1 cells. Fur4 was necessary for the utilization of extracellular uracil, cytosine, or UMP. Uracil uptake activity increased in the Δpub1 strain in a Fur4-dependent manner. In addition, uracil starvation was critical for induction of cell lysis of Δura4 strains and uracil supplementation suppressed lysis. In summary, the increased uracil uptake ability of Δpub1 cells, where Fur4 was predominantly localized to the plasma membrane, resulted in suppression of cell lysis in the Δura4 background. 相似文献