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101.
Takayuki Sekimoto Tsukasa Oda Kiminori Kurashima Fumio Hanaoka Takayuki Yamashita 《Molecular and cellular biology》2015,35(4):699-715
DNA rereplication is a major form of aberrant replication that causes genomic instabilities, such as gene amplification. However, little is known about which DNA polymerases are involved in the process. Here, we report that low-fidelity Y-family polymerases (Y-Pols), Pol η, Pol ι, Pol κ, and REV1, significantly contribute to DNA synthesis during rereplication, while the replicative polymerases, Pol δ and Pol ε, play an important role in rereplication, as expected. When rereplication was induced by depletion of geminin, these polymerases were recruited to rereplication sites in human cell lines. This finding was supported by RNA interference (RNAi)-mediated knockdown of the polymerases, which suppressed rereplication induced by geminin depletion. Interestingly, epistatic analysis indicated that Y-Pols collaborate in a common pathway, independently of replicative polymerases. We also provide evidence for a catalytic role for Pol η and the involvement of Pol η and Pol κ in cyclin E-induced rereplication. Collectively, our findings indicate that, unlike normal S-phase replication, rereplication induced by geminin depletion and oncogene activation requires significant contributions of both Y-Pols and replicative polymerases. These findings offer important mechanistic insights into cancer genomic instability. 相似文献
102.
Yuji Haraguchi Tatsuya Shimizu Kiminori Mizuuchi Hiroto Kawata Mari Kobayashi Yasushi Hirai Shin-ichi Iwana 《Biochemistry and Biophysics Reports》2015
Cell sheet engineering allows investigators/clinicians to prepare cell-dense three-dimensional (3-D) tissues, and various clinical trials with these fabricated tissues have already been performed for regenerating damaged tissues. Cell sheets are easily manipulated and 3-D tissues can be rapidly fabricated by layering the cell sheets. This study used optical coherence tomography (OCT) to noninvasively analyze the following processes: (1) adhesions between layered cell sheets, and (2) the beating and functional interaction of cardiac cell sheet-tissues for fabricating functional thicker 3-D tissues. The tight adhesions and functional couplings between layered cell sheets could be observed cross-sectionally and in real time. Importantly, the noninvasive and cross-sectional analyses of OCT make possible to fabricate 3-D tissues by confirming the adherence and functional couplings between layered cell sheets. OCT technology would contribute to cell sheet engineering and regenerative medicine. 相似文献
103.
Kiminori Matsubara Yasushi Matsuura Kanji Hori Keisuke Miyazawa 《Journal of applied phycology》2000,12(1):9-14
An anticoagulant isolated from the marine green alga Codium pugniformis was composed mainly of glucose with minor amounts of arabinose and galactose. It was highly sulfated (326 μg mg-1 polysaccharide) and contained protein(52 μg mg-1 polysaccharide) and was thus a proteoglycan. The anticoagulant properties of the purified proteoglycan were compared with
those of heparin by studying the activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time(TT)
using normal human plasma. The proteoglycan showed similar activities to heparin, but was weaker than heparin. On the other
hand, the proteoglycan did not affect PT even at the concentration at which APTT and TT were prolonged. The anticoagulation
mechanism of this proteoglycan was due to the direct inhibition of thrombin and the potentiation of antithrombin III.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
104.
Meng Mi Hongting Jin Baoli Wang Kiminori Yukata Tzong-jen Sheu Qiao Han Ke Peijian Tong Hee-Jeong Im Guozhi Xiao Di Chen 《Gene》2013
The specific role of endogenous Bmp2 gene in chondrocytes and in osteoblasts in fracture healing was investigated by generation and analysis of chondrocyte- and osteoblast-specific Bmp2 conditional knockout (cKO) mice. The unilateral open transverse tibial fractures were created in these Bmp2 cKO mice. Bone fracture callus samples were collected and analyzed by X-ray, micro-CT, histology analyses, biomechanical testing and gene expression assays. The results demonstrated that the lack of Bmp2 expression in chondrocytes leads to a prolonged cartilage callus formation and a delayed osteogenesis initiation and progression into mineralization phase with lower biomechanical properties. In contrast, when the Bmp2 gene was deleted in osteoblasts, the mice showed no significant difference in the fracture healing process compared to control mice. These findings suggest that endogenous BMP2 expression in chondrocytes may play an essential role in cartilage callus maturation at an early stage of fracture healing. Our studies may provide important information for clinical application of BMP2. 相似文献
105.
Takeshi Nishimura Kiminori Toyooka Mayuko Sato Sachiko Matsumoto M. Mercedes Lucas Miroslav Strnad Franti?ek Balu?ka Tomokazu Koshiba 《Plant signaling & behavior》2011,6(12):2013-2022
To investigate the distribution of IAA (indole-3-acetic acid) and the IAA synthetic cells in maize coleoptiles, we established immunohistochemistry of IAA using an anti-IAA-C-monoclonal antibody. We first confirmed the specificity of the antibody by comparing the amounts of endogenous free and conjugated IAA to the IAA signal obtained from the IAA antibody. Depletion of endogenous IAA showed a corresponding decrease in immuno-signal intensity and negligible cross-reactivity against IAA-related compounds, including tryptophan, indole-3-acetamide, and conjugated-IAA was observed. Immunolocalization showed that the IAA signal was intense in the approximately 1 mm region and the outer epidermis at the approximately 0.5 mm region from the top of coleoptiles treated with 1-N-naphthylphthalamic acid. By contrast, the IAA immuno-signal in the outer epidermis almost disappeared after 5-methyl-tryptophan treatment. Immunogold labeling of IAA with an anti-IAA-N-polyclonal antibody in the outer-epidermal cells showed cytoplasmic localization of free-IAA, but none in cell walls or vacuoles. These findings indicated that IAA is synthesized in the 0–2.0 mm region of maize coleoptile tips from Trp, in which the outer-epidermal cells of the 0.5 mm tip are the most active IAA synthetic cells. 相似文献
106.
A Chloroplastic UDP-Glucose Pyrophosphorylase from Arabidopsis Is the Committed Enzyme for the First Step of Sulfolipid Biosynthesis 总被引:1,自引:0,他引:1
107.
Shun Tsuboi Takashi Amemiya Koji Seto Kiminori Itoh Narasimmalu Rajendran 《World journal of microbiology & biotechnology》2013,29(5):759-774
Based on quantification and qualification of bacterial 16S rDNA, we verified the bacterial ecological characteristics of surface sediments of Lakes Shinji and Nakaumi, which are representative of coastal lagoons in Japan. Quantification and qualification of the 16S rDNA sequences was carried out using real time polymerase chain reaction and polymerase chain reaction denaturing gradient gel electrophoresis and non-metric multidimensional scaling, respectively. The results revealed that the copy number per gram of sediment ranged from 8.33 × 108 (Lake Nakaumi) to 1.69 × 1011 (Honjo area), suggesting that bacterial carbon contributed only 0.05–9.64 % of the total carbon content in the samples. Compared with other aquatic environments, these results indicate that sedimentary bacteria are not likely to be important transporters of nutrients to higher trophic levels, or to act as carbon sinks in the lagoons. The bacterial compositions of Lake Shinji and Lake Nakaumi and the Honjo area were primarily influenced by sediment grain sizes and salinity, respectively. Statistical comparisons of the environmental properties suggested that the areas that were oxygen-abundant (Lake Shinji) and at a higher temperature (Honjo area) presented efficient organic matter degradation. The 16S rDNA copy number per gram of carbon and nitrogen showed the same tendency. Consequently, the primary roles of bacteria were degradation and preservation of organic materials, and this was affected by oxygen and temperature. These roles were supported by the bacterial diversity rather than the differences in the community compositions of the sedimentary bacteria in these coastal lagoons. 相似文献
108.
Background
Fluorescence correlation spectroscopy (FCS) provides information about translational diffusion of fluorescent molecules in tiny detection volumes at the single-molecule level. In normal states, cartilage tissue lacks vascularity, so chondrocyte metabolism depends on diffusion for molecular exchanges. The abundant extracellular matrix (ECM) of cartilage is maintained by a limited number of chondrocytes. ECM plays an important role in the regulation of chondrocyte functions. In this study, FCS was used to measure diffusion behaviors of albumin, the major protein of the intra-articular space, using normal and degenerated cartilage. Preliminary investigation of fluorescence dyes including Alexa 488, Rhodamine 6G and Rhodamine 123 was conducted to evaluate their properties in cartilage. 相似文献109.
Yoshimoto Saitoh Kosuke Izumitsu Atsushi Morita Kiminori Shimizu Chihiro Tanaka 《Mycoscience》2010,51(5):327-336
A metallo-oxidase gene from a phytopathogenic filamentous fungus, Cochliobolus heterostrophus was cloned. Structural prediction of ChMco1 indicated that this protein lacks a transmembrane helix and is soluble, whereas other known fungal metallo-oxidases including
Saccharomyces cerevisiae FET3 are localized to the cell membrane. The results of searches in fungal genomic databases and phylogenetic analysis of
fungal metallo-oxidases revealed that ChMco1 and its allies are distinct homologues of Fet3 and unique to filamentous ascomycetous species including C. heterostrophus. We performed a functional analysis of ChMCO1 by generating null mutants for the ChMco1 gene. The ChMco1 null (∆ChMco1) mutants clearly had reduced melanization, although they showed normal growth and conidiation. Results also show that ∆ChMco1 mutants lost laccase activity. These results suggest that ChMCO1 is a novel class of metallo-oxidase that is necessary for
laccase activity and melanization. 相似文献
110.
Tomoko Kayashima Masaharu Mori Ryo Mizutani Kazuyuki Nishio Kouji Kuramochi Kazunori Tsubaki Hiromi Yoshida Yoshiyuki Mizushina Kiminori Matsubara 《Bioorganic & medicinal chemistry》2010,18(17):6305-6309
Ten vitamin K3 derivatives were synthesized and screened for anti-angiogenic activity. Results indicated that amine derivatives (1a–d) exerted a stronger inhibition effect on angiogenesis compared to alkyl derivatives (2a–d). In addition to being the most potent inhibitor, 1b also suppressed human umbilical vein endothelial cell tube formation and proliferation. These results suggest that vitamin K3 amine derivatives with shorter alkyl chains, such as 1b, could be useful for developing anti-angiogenic agents. 相似文献