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61.
62.
Kojima K Oshita M Nanjo Y Kasai K Tozawa Y Hayashi H Nishiyama Y 《Molecular microbiology》2007,65(4):936-947
Oxidative stress inhibits the repair of photodamaged photosystem II (PSII). This inhibition is due initially to the suppression, by reactive oxygen species (ROS), of the synthesis de novo of proteins that are required for the repair of PSII, such as the D1 protein, at the level of translational elongation. To investigate in vitro the mechanisms whereby ROS inhibit translational elongation, we developed a translation system in vitro from the cyanobacterium Synechocystis sp. PCC 6803. The synthesis of the D1 protein in vitro was inhibited by exogenous H2O2. However, the addition of reduced forms of elongation factor G (EF-G), which is known to be particularly sensitive to oxidation, was able to reverse the inhibition of translation. By contrast, the oxidized forms of EF-G failed to restore translational activity. Furthermore, the overexpression of EF-G of Synechocystis in another cyanobacterium Synechococcus sp. PCC 7942 increased the tolerance of cells to H2O2 in terms of protein synthesis. These observations suggest that EF-G might be the primary target, within the translational machinery, of inhibition by ROS. 相似文献
63.
Hattori K Uematsu K Tanikake Y Habata T Tanaka Y Yajima H Takakura Y 《Arthritis research & therapy》2007,9(5):R88-9
We investigated the use of a commercial spectrocolorimeter and the application of two color models (L* a* b* colorimetric system and spectral reflectance distribution) to describe and quantify cartilage plugs in a rabbit model of osteochondral autografting. Osteochondral plugs were removed and then replaced in their original positions in Japanese white rabbits. The rabbits were sacrificed at 4 or 12 weeks after the operation and cartilage samples were assessed using a spectrocolorimeter. The samples were retrospectively divided into two groups on the basis of the histological findings (group H: hyaline cartilage, successful; group F: fibrous tissue or fibrocartilage, failure) and investigated for possible significant differences in the spectrocolorimetric analyses between the two groups. Moreover, the relationships between the spectrocolorimetric indices and the Mankin histological score were examined. In the L* a* b* colorimetric system, the L* values were significantly lower in group H than in group F (P = 0.02), whereas the a* values were significantly higher in group H than in group F (P = 0.006). Regarding the spectral reflectance distribution, the spectral reflectance percentage 470 (SRP470) values, as a coincidence index for the spectral reflectance distribution (400 to 470 nm in wavelength) of the cartilage plugs with respect to intact cartilage, were 99.8 +/- 6.7% in group H and 119.8 +/- 10.6% in group F, and the difference between these values was significant (P = 0.005). Furthermore, the a* values were significantly correlated with the histological score (P = 0.004, r = -0.76). The SRP470 values were also significantly correlated with the histological score (P = 0.01, r = 0.67). Our findings demonstrate the ability of spectrocolorimetric measurements to predict the histological findings of cartilage plugs after autologous osteochondral grafting. In particular, the a* values and SRP470 values can be used to judge the surface condition of an osteochondral plug on the basis of objective data. Therefore, spectrocolorimetry may contribute to orthopedics, rheumatology and related research in arthritis, and arthroscopic use of this method may potentially be preferable for in vivo assessment. 相似文献
64.
Takeshi Inagaki Satoshi Iwasaki Yoshihiro Matsumura Takeshi Kawamura Toshiya Tanaka Yohei Abe Ayumu Yamasaki Yuya Tsurutani Ayano Yoshida Yoko Chikaoka Kanako Nakamura Kenta Magoori Ryo Nakaki Timothy F. Osborne Kiyoko Fukami Hiroyuki Aburatani Tatsuhiko Kodama Juro Sakai 《The Journal of biological chemistry》2015,290(7):4163-4177
Polycomb repressive complex 1 (PRC1) plays an essential role in the epigenetic repression of gene expression during development and cellular differentiation via multiple effector mechanisms, including ubiquitination of H2A and chromatin compaction. However, whether it regulates the stepwise progression of adipogenesis is unknown. Here, we show that FBXL10/KDM2B is an anti-adipogenic factor that is up-regulated during the early phase of 3T3-L1 preadipocyte differentiation and in adipose tissue in a diet-induced model of obesity. Interestingly, inhibition of adipogenesis does not require the JmjC demethylase domain of FBXL10, but it does require the F-box and leucine-rich repeat domains, which we show recruit a noncanonical polycomb repressive complex 1 (PRC1) containing RING1B, SKP1, PCGF1, and BCOR. Knockdown of either RING1B or SKP1 prevented FBXL10-mediated repression of 3T3-L1 preadipocyte differentiation indicating that PRC1 formation mediates the inhibitory effect of FBXL10 on adipogenesis. Using ChIP-seq, we show that FBXL10 recruits RING1B to key specific genomic loci surrounding the key cell cycle and the adipogenic genes Cdk1, Uhrf1, Pparg1, and Pparg2 to repress adipogenesis. These results suggest that FBXL10 represses adipogenesis by targeting a noncanonical PRC1 complex to repress key genes (e.g. Pparg) that control conversion of pluripotent cells into the adipogenic lineage. 相似文献
65.
Mito T Shinmyo Y Kurita K Nakamura T Ohuchi H Noji S 《Development (Cambridge, England)》2011,138(17):3823-3833
Delta/Notch signaling controls a wide spectrum of developmental processes, including body and leg segmentation in arthropods. The various functions of Delta/Notch signaling vary among species. For instance, in Cupiennius spiders, Delta/Notch signaling is essential for body and leg segmentation, whereas in Drosophila fruit flies it is involved in leg segmentation but not body segmentation. Therefore, to gain further insight into the functional evolution of Delta/Notch signaling in arthropod body and leg segmentation, we analyzed the function of the Delta (Gb'Delta) and Notch (Gb'Notch) genes in the hemimetabolous, intermediate-germ cricket Gryllus bimaculatus. We found that Gb'Delta and Gb'Notch were expressed in developing legs, and that RNAi silencing of Gb'Notch resulted in a marked reduction in leg length with a loss of joints. Our results suggest that the role of Notch signaling in leg segmentation is conserved in hemimetabolous insects. Furthermore, we found that Gb'Delta was expressed transiently in the posterior growth zone of the germband and in segmental stripes earlier than the appearance of wingless segmental stripes, whereas Gb'Notch was uniformly expressed in early germbands. RNAi knockdown of Gb'Delta or Gb'Notch expression resulted in malformation in body segments and a loss of posterior segments, the latter probably due to a defect in posterior growth. Therefore, in the cricket, Delta/Notch signaling might be required for proper morphogenesis of body segments and posterior elongation, but not for specification of segment boundaries. 相似文献
66.
Miyanoiri Y Takeda M Jee J Ono AM Okuma K Terauchi T Kainosho M 《Journal of biomolecular NMR》2011,51(4):425-435
Tryptophan (Trp) residues are frequently found in the hydrophobic cores of proteins, and therefore, their side-chain conformations,
especially the precise locations of the bulky indole rings, are critical for determining structures by NMR. However, when
analyzing [U–13C,15N]-proteins, the observation and assignment of the ring signals are often hampered by excessive overlaps and tight spin couplings.
These difficulties have been greatly alleviated by using stereo-array isotope labeled (SAIL) proteins, which are composed
of isotope-labeled amino acids optimized for unambiguous side-chain NMR assignment, exclusively through the 13C–13C and 13C–1H spin coupling networks (Kainosho et al. in Nature 440:52–57, 2006). In this paper, we propose an alternative type of SAIL-Trp with the [ζ2,ζ3-2H2; δ1,ε3,η2-13C3; ε1-15N]-indole ring ([12Cγ, 12Cε2] SAIL-Trp), which provides a more robust way to correlate the 1Hβ, 1Hα, and 1HN to the 1Hδ1 and 1Hε3 through the intra-residue NOEs. The assignment of the 1Hδ1/13Cδ1 and 1Hε3/13Cε3 signals can thus be transferred to the 1Hε1/15Nε1 and 1Hη2/13Cη2 signals, as with the previous type of SAIL-Trp, which has an extra 13C at the Cγ of the ring. By taking advantage of the stereospecific deuteration of one of the prochiral β-methylene protons, which was
1Hβ2 in this experiment, one can determine the side-chain conformation of the Trp residue including the χ2 angle, which is especially important for Trp residues, as they can adopt three preferred conformations. We demonstrated the
usefulness of [12Cγ,12Cε2] SAIL-Trp for the 12 kDa DNA binding domain of mouse c-Myb protein (Myb-R2R3), which contains six Trp residues. 相似文献
67.
The mesoderm-derived segmental somite differentiates into dermomyotome and sclerotome, the latter of which undergoes vertebrogenesis
to spinal cartilage and ultimately to vertebral bones. However, analysis and manipulation of the developing mammalian vertebrae
in the same embryo has been infeasible because of their placental-dependent embryogenesis. Here, we report a novel culture
system of the mouse embryonic tailbud, by which the developmental processes of mammalian vertebral cartilage are traceable
and manipulatable in the same sample. The anaplastic segmental somites/sclerotomes in the tailbud of 13 gestational day (g.d.)
embryo that are structurally continuous to the vertebral column underwent progressive vertebrogenesis when (1) the ectoderm-derived
nascent epidermis was microsurgically removed prior to cultivation, and (2) the sample was incubated at the air-medium interface.
After cultivation for 5 days, the size and shape of the instructed vertebral cartilage showed features comparable to well-differentiated
body vertebra along with the expression of the cartilage marker collagen type II, suggesting that aggressive differentiation
of the sclerotomal cell lineage was achieved. In the presence of recombinant bone morphogenic protein (BMP) and Noggin, or
adenoviral particles for extracellular epimorphin, dramatic alteration of the vertebral morphology ensued in the explants.
Thus, this model system provides an approach to study the detailed molecular mechanisms of mammalian vertebrogenesis and enables
pretreatment strategies of precartilagious fragments for improving the efficacy of subsequent transplantation. 相似文献
68.
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70.
Miyagi Y Higashiyama M Gochi A Akaike M Ishikawa T Miura T Saruki N Bando E Kimura H Imamura F Moriyama M Ikeda I Chiba A Oshita F Imaizumi A Yamamoto H Miyano H Horimoto K Tochikubo O Mitsushima T Yamakado M Okamoto N 《PloS one》2011,6(9):e24143