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91.
Sakuraba Y Sezutsu H Takahasi KR Tsuchihashi K Ichikawa R Fujimoto N Kaneko S Nakai Y Uchiyama M Goda N Motoi R Ikeda A Karashima Y Inoue M Kaneda H Masuya H Minowa O Noguchi H Toyoda A Sakaki Y Wakana S Noda T Shiroishi T Gondo Y 《Biochemical and biophysical research communications》2005,336(2):609-616
The large-scale mouse mutagenesis with ENU has provided forward-genetic resources for functional genomics. The frozen sperm archive of ENU-mutagenized generation-1 (G1) mice could also provide a "mutant mouse library" that allows us to conduct reverse genetics in any particular target genes. We have archived frozen sperm as well as genomic DNA from 9224 G1 mice. By genome-wide screening of 63 target loci covering a sum of 197 Mbp of the mouse genome, a total of 148 ENU-induced mutations have been directly identified. The sites of mutations were primarily identified by temperature gradient capillary electrophoresis method followed by direct sequencing. The molecular characterization revealed that all the identified mutations were point mutations and mostly independent events except a few cases of redundant mutations. The base-substitution spectra in this study were different from those of the phenotype-based mutagenesis. The ENU-based gene-driven mutagenesis in the mouse now becomes feasible and practical. 相似文献
92.
93.
Saito S Frank GD Mifune M Ohba M Utsunomiya H Motley ED Inagami T Eguchi S 《The Journal of biological chemistry》2002,277(47):44695-44700
Reactive oxygen species are involved in the mitogenic signal transduction cascades initiated by several growth factors and play a critical role in mediating cardiovascular diseases. Interestingly, H(2)O(2) induces tyrosine phosphorylation and trans-activation of the platelet-derived growth factor receptor and the epidermal growth factor receptor in many cell lines including vascular smooth muscle cells. To investigate the molecular mechanism by which reactive oxygen species contribute to vascular diseases, we have examined a signal transduction cascade involved in H(2)O(2)-induced platelet-derived growth factor receptor activation in vascular smooth muscle cells. We found that H(2)O(2) induced a ligand-independent phosphorylation of the platelet-derived growth factor-beta receptor at Tyr(1021), a phospholipase C-gamma binding site, involving the requirement of protein kinase C-delta and c-Src that is distinct from a ligand-dependent autophosphorylation. Also, H(2)O(2) induced the association of protein kinase C-delta with the platelet-derived growth factor-beta receptor and c-Src in vascular smooth muscle cells. These findings will provide new mechanistic insights by which enhanced reactive oxygen species production in vascular smooth muscle cells induces unique alleys of signal transduction distinct from those induced by endogenous ligands leading to an abnormal vascular remodeling process. 相似文献
94.
Kumon Y Yokoyama R Haque Z Yokochi T Honda D Nakahara T 《Marine biotechnology (New York, N.Y.)》2006,8(2):170-177
We show here that a new labyrinthulid strain, L72, isolated from a fallen leaf in the Seto Inland Sea of Japan, produced only
docohexaenoic acid (DHA) among all the long-chain polyunsaturated fatty acids (LCPUFAs). The main fatty acid composition was
16:0 (28.9%), 18:0 (7.2%), 18:1 (5.7%), 18:2 (10.4%), and DHA (45.9%) without any other LCPUFA. The lipid content of the strain
was 27.4%. The cells had many lipid bodies, which were densely located in all of the cells. On phylogenetic analysis using
the 18S rDNA sequence, the strain was located in the labyrinthulids group, forming a monophyletic group with Labyrinthula sp. (strain s) and Labyrinthuila sp. (strain L59). We further tested the culture optimization of strain L72 to evaluate the ability of the strain to produce
DHA. The optimum salt concentration and the temperature of the strain were 100% of artificial seawater and 20°C. Strain L72
could grow well on soybean oil (SBO) or soybean lecithin (SBL) as the carbon source. When 20 g/l of SBL was added to the medium,
DHA production reached the maximum amount at 0.67 g/l for 14 d. The two important facts, that the strain can use SBL as the
main nutrient and contains only DHA among the LCPUFAs, will be of great advantage for industry. 相似文献
95.
Atsushi Miyazaki Magne O. Sydnes Minoru Isobe Hiroshi Ohinata Motoi Miyazu Akira Takai 《Bioorganic & medicinal chemistry》2009,17(23):7978-7986
Protein phosphatase 1γ, a serine/threonine phosphatase, is a metalloprotein that coordinates two Mn2+ in the active site when expressed in Escherichia coli in a buffer containing MnCl2. Herein, we report on the oxidatively induced copper for manganese exchange in protein phosphatase 1γ, thus enabling firm confirmation of the four histidine (His) amino acid residues (His66, His125, His173, and His248) involved in metal coordination. By exchanging manganese with copper the oxidation yields for the peptides increased dramatically, thus simplifying detection of the oxidized peptides and analysis of the oxidation sites within the oxidized peptides. We also found that when copper was added during the oxidation process a new metal coordination center was formed at cysteine 39, 105, 140, and 155. 相似文献
96.
Damee Choi Yuka Egashira Jun’ya Takakura Midori Motoi Takayuki Nishimura Shigeki Watanuki 《Journal of physiological anthropology》2015,34(1)
Background
Some studies have reported gender differences in N170, a face-selective event-related potential (ERP) component. This study investigated gender differences in N170 elicited under oddball paradigm in order to clarify the effect of task demand on gender differences in early facial processing.Findings
Twelve males and 10 females discriminated targets (emotional faces) from non-targets (emotionally neutral faces) under an oddball paradigm, pressing a button as quickly as possible in response to the target. Clear N170 was elicited in response to target and non-target stimuli in both males and females. However, females showed more negative amplitude of N170 in response to target compared with non-target, while males did not show different N170 responses between target and non-target.Conclusions
The present results suggest that females have a characteristic of allocating attention at an early stage when responding to faces actively (target) compared to viewing faces passively (non-target). This supports previous findings suggesting that task demand is an important factor in gender differences in N170. 相似文献97.
Yusuke Kawazoe Mutsumi Miyauchi Atsuhiro Nagasaki Hisako Furusho Syunryo Yanagisawa Chea Chanbora Toshihiro Inubushi Hideyuki Hyogo Takashi Nakamoto Keiko Suzuki Sawako Moriwaki Susumu Tazuma Shumpei Niida Takashi Takata 《PloS one》2015,10(9)
Background
Cholestatic liver diseases exhibit higher levels of serum γ-glutamyl transpeptidase (GGT) and incidence of secondary osteoporosis. GGT has been identified as a novel bone-resorbing factor that stimulates osteoclast formation. The aim of this study was to elucidate the interaction of elevated GGT levels and cholestatic liver disease-induced bone loss.Methods
Wistar rats were divided into three groups: sham-operated control (SO) rats, bile duct ligation (BDL) rats, and anti-GGT antibody-treated BDL rats (AGT). Serum GGT level was measured. Bone mineral density (BMD) was analyzed by dual-energy X-ray absorptiometry. Bone morphometric parameters and microarchitectural properties were determined by micro-computed tomography and histomorphometry of the distal metaphysis of femurs. Alterations of bone metabolism-related factors were evaluated by cytokine array. Effects of GGT on osteoblasts or stromal cells were evaluated by RT-PCR, enzyme activity, and mineralization ability.Results
Serum levels of GGT were significantly elevated in the BDL-group. In the BDL group, BMD, bone mass percentage, and osteoblast number were significantly decreased, whereas osteoclast number was significantly increased. These alterations were markedly attenuated in the AGT group. The mRNA levels of vascular endothelial growth factor-A, LPS-induced CXC chemokine, monocyte chemoattractant protein-1, tumor necrosis factor-α interleukin-1β and receptor activator of nuclear factor-kappa B ligand were upregulated, and those of interferon-γ and osteoprotegerin were downregulated in the GGT-treated stromal cells. Furthermore, GGT inhibited mineral nodule formation and expression of alkaline phosphatase and bone sialo-protein in osteoblastic cells.Conclusion
Our results indicate that elevated GGT level is involved in hepatic osteodystrophy through secretion of bone resorbing factor from GGT-stimulated osteoblasts/bone marrow stromal cells. In addition, GGT also possesses suppressive effects on bone formation. Managing elevated GGT levels by anti-GGT antibody may become a novel therapeutic agent for hepatic osteodystrophy in chronic liver diseases. 相似文献98.
Kazuhito Arai Toshihiro Ishimitsu Shinya Fushinobu Hiroyuki Uchikoba Hiroshi Matsuzawa Hayao Taguchi 《Proteins》2010,78(3):681-694
Lactobacillus casei L ‐lactate dehydrogenase (LCLDH) is activated through the homotropic and heterotropic activation effects of pyruvate and fructose 1,6‐bisphosphate (FBP), respectively, and exhibits unusually high pH‐dependence in the allosteric effects of these ligands. The active (R) and inactive (T) state structures of unliganded LCLDH were determined at 2.5 and 2.6 Å resolution, respectively. In the catalytic site, the structural rearrangements are concerned mostly in switching of the orientation of Arg171 through the flexible intersubunit contact at the Q‐axis subunit interface. The distorted orientation of Arg171 in the T state is stabilized by a unique intra‐helix salt bridge between Arg171 and Glu178, which is in striking contrast to the multiple intersubunit salt bridges in Lactobacillus pentosus nonallosteric L ‐lactate dehydrogenase. In the backbone structure, major structural rearrangements of LCLDH are focused in two mobile regions of the catalytic domain. The two regions form an intersubunit linkage through contact at the P‐axis subunit interface involving Arg185, replacement of which with Gln severely decreases the homotropic and hetertropic activation effects on the enzyme. These two regions form another intersubunit linkage in the Q‐axis related dimer through the rigid NAD‐binding domain, and thus constitute a pivotal frame of the intersubunit linkage for the allosteric motion, which is coupled with the concerted structural change of the four subunits in a tetramer, and of the binding sites for pyruvate and FBP. The unique intersubunit salt bridges, which are observed only in the R state structure, are likely involved in the pH‐dependent allosteric equilibrium. Proteins 2010. © 2009 Wiley‐Liss, Inc. 相似文献
99.
Toshihiro Umebayashi Yasuhiro Utsumi Shinya Koga Susumu Inoue Junji Matsumura Kazuyuki Oda Seizo Fujikawa Keita Arakawa Kyoichi Otsuki 《Trees - Structure and Function》2010,24(3):571-583
A dye injection method was used to elucidate the xylem water-conducting pathways of 34 broadleaved evergreen trees growing
in southern Japan: two semi-ring-porous, 26 diffuse-porous, five radial-porous and one non-vessel species. The large earlywood
vessels in semi-ring-porous species have a water transport function in only the outermost annual ring, as in deciduous ring-porous
species. On the other hand, the small vessels in semi-ring-porous species maintain the water transport function in many outer
annual rings. For the other xylem-type species, the many vessels in many outer annual rings have a water transport function.
In diffuse-porous species, we categorized the water-conducting pattern within the annual rings into two types: d1 type, where
water travels through vessels in the whole region; and d2 type, where water travels mainly through the earlywood vessels.
The pattern in radial-porous species is similar to that in the d1 type; the pattern in non-vessels species is similar to that
in the d2 type. The vessel diameter in radial-porous species is similar to that of the earlywood vessels of semi-ring-porous
species. These results suggest that the conduit diameter size is only one of many factors determining the water-conducting
pathways of broadleaved evergreen species. 相似文献
100.
Toshihiro Nakano Eiichi Mizohata Akiho Yokota 《Biochemical and biophysical research communications》2010,392(2):212-216
Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) and RuBisCO-like protein (RLP) catalyze similar enolase-type reactions. Both enzymes have a conserved non-catalytic Lys122 or Arg122 on the β-strand E lying in the interface between the N- and C-terminal domains. We used site-directed mutagenesis to analyze the function of Lys122 in the form II Rhodospirillum rubrum RuBisCO (RrRuBisCO) and Bacillus subtilis RLP (BsRLP). The K122R mutant of RrRuBisCO had a 40% decrease in kcat for carboxylase activity, a 2-fold increase in Km for CO2, and a 1.9-fold increase in Km for ribulose-1,5-bisphosphate. K122M and K122E mutants of RrRuBisCO were almost inactive. None of the substitutions affected the thermal stability of RrRuBisCO. The K122R mutant of BsRLP had a 32% decrease in kcat and lower thermal stability than the wild-type enzyme. The K122M and K122E mutants of BsRLP failed to form a catalytic dimer. Our results suggest that the lysine residue is essential for function in both enzymes, although in each case, its role is likely distinct. 相似文献