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101.
Kazumasa Matsuki M.D. Hiroo Maeda Takeo Juji Hidetoshi Inoko Asako Ando Kimiyoshi Tsuji Yutaka Honda 《Immunogenetics》1988,27(2):87-90
Taq I-generated HLA-DQrestriction fragment length polymorphism was examined in Japanese patients with narcolepsy. All patients were DR2 positive and shared a 6.0 kb fragment, although this fragment was found only in 54 % of the healthy DR2-positive Japanese. This finding added the DQ
gene to the list of candidates for the possible narcolepsy-susceptibility gene. In contrast, there was no complete association between narcolepsy and DXrestriction fragment length polymorphism. These findings suggest that a narcolepsy-susceptibility gene is located closer to the DQ locus than to the DX locus. 相似文献
102.
S Saeki F Masugi T Ogihara A Otsuka Y Kumahara K Watanabe K Tamura A Akashi A Kumagai 《Life sciences》1985,37(4):325-329
The direct cardiac action of 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine (PAF) was studied in isolated perfused guinea-pig heart preparations. PAF produced a fall in left ventricular pressure, decreases in the rate of rise of the left ventricular pressure (dp/dt) and coronary flow, but had no effect on heart rate. These results indicate that PAF is a cardiodepressant with inotropic selectivity and this effect on heart is blocked by CV-3988, a specific PAF antagonist. 相似文献
103.
Teppei Ikeya David Ban Donghan Lee Yutaka Ito Koichi Kato Christian Griesinger 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(2):287-306
Background
To understand the mechanisms related to the ‘dynamical ordering’ of macromolecules and biological systems, it is crucial to monitor, in detail, molecular interactions and their dynamics across multiple timescales. Solution nuclear magnetic resonance (NMR) spectroscopy is an ideal tool that can investigate biophysical events at the atomic level, in near-physiological buffer solutions, or even inside cells.Scope of review
In the past several decades, progress in solution NMR has significantly contributed to the elucidation of three-dimensional structures, the understanding of conformational motions, and the underlying thermodynamic and kinetic properties of biomacromolecules. This review discusses recent methodological development of NMR, their applications and some of the remaining challenges.Major conclusions
Although a major drawback of NMR is its difficulty in studying the dynamical ordering of larger biomolecular systems, current technologies have achieved considerable success in the structural analysis of substantially large proteins and biomolecular complexes over 1 MDa and have characterised a wide range of timescales across which biomolecular motion exists. While NMR is well suited to obtain local structure information in detail, it contributes valuable and unique information within hybrid approaches that combine complementary methodologies, including solution scattering and microscopic techniques.General significance
For living systems, the dynamic assembly and disassembly of macromolecular complexes is of utmost importance for cellular homeostasis and, if dysregulated, implied in human disease. It is thus instructive for the advancement of the study of the dynamical ordering to discuss the potential possibilities of solution NMR spectroscopy and its applications. This article is part of a Special Issue entitled “Biophysical Exploration of Dynamical Ordering of Biomolecular Systems” edited by Dr. Koichi Kato. 相似文献104.
Using food network unfolding to evaluate food–web complexity in terms of biodiversity: theory and applications 下载免费PDF全文
Yoshikazu Kato Michio Kondoh Naoto F. Ishikawa Hiroyuki Togashi Yukihiro Kohmatsu Mayumi Yoshimura Chikage Yoshimizu Takashi F. Haraguchi Yutaka Osada Nobuhito Ohte Naoko Tokuchi Noboru Okuda Takeshi Miki Ichiro Tayasu 《Ecology letters》2018,21(7):1065-1074
Food–web complexity often hinders disentangling functionally relevant aspects of food–web structure and its relationships to biodiversity. Here, we present a theoretical framework to evaluate food–web complexity in terms of biodiversity. Food network unfolding is a theoretical method to transform a complex food web into a linear food chain based on ecosystem processes. Based on this method, we can define three biodiversity indices, horizontal diversity (DH), vertical diversity (DV) and range diversity (DR), which are associated with the species diversity within each trophic level, diversity of trophic levels, and diversity in resource use, respectively. These indices are related to Shannon's diversity index (H′), where H′ = DH + DV ? DR. Application of the framework to three riverine macroinvertebrate communities revealed that D indices, calculated from biomass and stable isotope features, captured well the anthropogenic, seasonal, or other within‐site changes in food–web structures that could not be captured with H′ alone. 相似文献
105.
Takumi Chinen Kaho Yamazaki Kaho Hashimoto Ken Fujii Koki Watanabe Yutaka Takeda Shohei Yamamoto Yuka Nozaki Yuki Tsuchiya Daisuke Takao Daiju Kitagawa 《The Journal of cell biology》2021,220(2)
The pericentriolar material (PCM) that accumulates around the centriole expands during mitosis and nucleates microtubules. Here, we show the cooperative roles of the centriole and PCM scaffold proteins, pericentrin and CDK5RAP2, in the recruitment of CEP192 to spindle poles during mitosis. Systematic depletion of PCM proteins revealed that CEP192, but not pericentrin and/or CDK5RAP2, was crucial for bipolar spindle assembly in HeLa, RPE1, and A549 cells with centrioles. Upon double depletion of pericentrin and CDK5RAP2, CEP192 that remained at centriole walls was sufficient for bipolar spindle formation. In contrast, through centriole removal, we found that pericentrin and CDK5RAP2 recruited CEP192 at the acentriolar spindle pole and facilitated bipolar spindle formation in mitotic cells with one centrosome. Furthermore, the perturbation of PLK1, a critical kinase for PCM assembly, efficiently suppressed bipolar spindle formation in mitotic cells with one centrosome. Overall, these data suggest that the centriole and PCM scaffold proteins cooperatively recruit CEP192 to spindle poles and facilitate bipolar spindle formation. 相似文献
106.
Kimura KR Nakata M Sumitomo T Kreikemeyer B Podbielski A Terao Y Kawabata S 《Journal of bacteriology》2012,194(4):804-812
The group A streptococcus (GAS) Streptococcus pyogenes is known to cause self-limiting purulent infections in humans. The role of GAS pili in host cell adhesion and biofilm formation is likely fundamental in early colonization. Pilus genes are found in the FCT (fibronectin-binding protein, collagen-binding protein, and trypsin-resistant antigen) genomic region, which has been classified into nine subtypes based on the diversity of gene content and nucleotide sequence. Several epidemiological studies have indicated that FCT type 1 strains, including serotype M6, produce large amounts of monospecies biofilm in vitro. We examined the direct involvement of pili in biofilm formation by serotype M6 clinical isolates. In the majority of tested strains, deletion of the tee6 gene encoding pilus shaft protein T6 compromised the ability to form biofilm on an abiotic surface. Deletion of the fctX and srtB genes, which encode pilus ancillary protein and class C pilus-associated sortase, respectively, also decreased biofilm formation by a representative strain. Unexpectedly, these mutant strains showed increased bacterial aggregation compared with that of the wild-type strain. When the entire FCT type 1 pilus region was ectopically expressed in serotype M1 strain SF370, biofilm formation was promoted and autoaggregation was inhibited. These findings indicate that assembled FCT type 1 pili contribute to biofilm formation and also function as attenuators of bacterial aggregation. Taken together, our results show the potential role of FCT type 1 pili in the pathogenesis of GAS infections. 相似文献
107.
We show that fruit bodies of Flammulina velutipes can be induced in complete darkness after a sharp temperature reduction (23° to 16°C). However, the fruit bodies that form in complete darkness have a long stipe with an undeveloped pileus on the top (pinhead fruit bodies) and are thinner and whiter than the normal fruit bodies which are formed in the light. This finding suggests that F. velutipes fruit bodies cannot mature in complete darkness. However, when we irradiated the fruit bodies that had formed in complete darkness, a pileus developed immediately, and 4 days later the separation between the stipe and the pileus could be observed. Immediately after light exposure, the stipe also thickened and became increasingly pigmented. The stipe elongation was inhibited until 8 days after light exposure, although stipe elongation progressed very quickly thereafter. Basidospores were also visible in the gills 8 days after light exposure. We consider that the basidiospore development is involved in this rapid stipe elongation, which aids the effective dispersal of basidiospores. 相似文献
108.
Taiji Kawakatsu Graziana Taramino Jun-Ichi Itoh Justin Allen Yutaka Sato Soon-Kwan Hong Ryan Yule Nobuhiro Nagasawa Mikiko Kojima Makoto Kusaba Hitoshi Sakakibara Hajime Sakai Yasuo Nagato 《The Plant journal : for cell and molecular biology》2009,58(6):1028-1040
Most aerial parts of the plant body are products of the continuous activity of the shoot apical meristem (SAM). Leaves are the major component of the aerial plant body, and their temporal and spatial distribution mainly determines shoot architecture. Here we report the identification of the rice gene PLASTOCHRON3 ( PLA3 )/ GOLIATH ( GO ) that regulates various developmental processes including the rate of leaf initiation (the plastochron). PLA3 / GO encodes a glutamate carboxypeptidase, which is thought to catabolize small acidic peptides and produce small signaling molecules. pla3 exhibits similar phenotypes to pla1 and pla2 – a shortened plastochron, precocious leaf maturation and rachis branch-to-shoot conversion in the reproductive phase. However, in contrast to pla1 and pla2 , pla3 showed pleiotropic phenotypes including enlarged embryo, seed vivipary, defects in SAM maintenance and aberrant leaf morphology. Consistent with these pleiotropic phenotypes, PLA3 is expressed in the whole plant body, and is involved in plant hormone homeostasis. Double mutant analysis revealed that PLA1 , PLA2 and PLA3 are regulated independently but function redundantly. Our results suggest that PLA3 modulates various signaling pathways associated with a number of developmental processes. 相似文献
109.
4.5S RNAh is a rodent-specific small noncoding RNA that exhibits extensive homology to the B1 short interspersed element. Although 4.5S RNAh is known to associate with cellular poly(A)-terminated RNAs and retroviral genomic RNAs, its function remains unclear. In this study, we analyzed 4.5S RNAh-binding proteins in mouse nuclear extracts using gel mobility shift and RNA-protein UV cross-linking assays. We found that at least nine distinct polypeptides (p170, p110, p93, p70, p48, p40, p34, p20, and p16.5) specifically interacted with 4.5S RNAhin vitro. Using anti-La antibody, p48 was identified as mouse La protein. To identify the other 4.5S RNAh-binding proteins, we performed expression cloning from a mouse cDNA library and obtained cDNA clones derived from nucleolin mRNA. We identified p110 as nucleolin using nucleolin-specific antibodies. UV cross-linking analysis using various deletion mutants of nucleolin indicated that the third of four tandem RNA recognition motifs is a major determinant for 4.5S RNAh recognition. Immunoprecipitation of nucleolin from the subcellular fractions of mouse cell extracts revealed that a portion of the endogenous 4.5S RNAh was associated with nucleolin and that this complex was located in both the nucleoplasm and nucleolus. 相似文献
110.
Effect of ascorbic acid (AsA) on the proliferation and invasion of rat ascites hepatoma AH109A cells was investigated by measuring
[3H]thymidine incorporation into acid-insoluble fraction of the cells and by co-culturing the hepatoma cells with rat mesentery-derived
mesothelial cells, respectively. AsA suppressed the invasion of AH109A cells in a dose-dependent manner at concentrations
of 62.5–500 μM, while it inhibited the proliferation of the cells at higher concentrations of 250 and 500 μM. Hepatoma cells
previously cultured with hypoxanthine (HX) and xanthine oxidase (XO) or with hydrogen peroxide showed increased invasive activities.
AsA suppressed the reactive oxygen species-potentiated invasive capacity by simultaneously treating AH109A cells with AsA,
HX and XO or with AsA and hydrogen peroxide. Furthermore, AsA reduced the intracellular peroxide levels in AH109A cells. These
results suggest that the antioxidative property of AsA may be involved in its anti-invasive action on hepatoma cells. 相似文献