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101.
102.
Conserved roles of fibroblast growth factor receptor 2 signaling in the regulation of inner cell mass development in bovine blastocysts
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Misato of Drosophila melanogaster and Saccharomyces cerevisiae DML1 are conserved proteins having a homologous region with a part of the GTPase family that includes eukaryotic tubulin and prokaryotic FtsZ. We characterized human Misato sharing homology with Misato of D. melanogaster and S. cerevisiae DML1. Tissue distribution of Misato exhibited ubiquitous distribution. Subcellular localization of the protein studied using anti-Misato antibody suggested that it is localized to the mitochondria. Further experiments of fractionating mitochondria revealed that Misato was localized to the outer membrane. The transfection of Misato siRNA led to growth deficiencies compared with control siRNA transfected HeLa cells, and the Misato-depleted HeLa cells showed apoptotic nuclear fragmentation resulting in cell death. After silencing of Misato, the filamentous mitochondrial network disappeared and fragmented mitochondria were observed, indicating human Misato has a role in mitochondrial fusion. To examine the effects of overexpression, COS-7 cells were transfected with cDNA encoding EGFP-Misato. Its overexpression resulted in the formation of perinuclear aggregations of mitochondria in these cells. The Misato-overexpressing cells showed low viability and had no nuclei or a small and structurally unusual ones. These results indicated that human Misato has a role(s) in mitochondrial distribution and morphology and that its unregulated expression leads to cell death. 相似文献
105.
The common yellow butterfly Eurema hecabe is widely distributed in East Asia, and is one of the most burdensome species for taxonomists due to the numerous geographic
and seasonal wing colour patterns. Moreover, within this species, individuals with a yellow wing fringe that occur in temperate
regions of Japan (Y type) proved to be biologically different from others that occur widely in subtropical regions of Japan
and all over East Asia (B type). To unveil the genetic variation within and between the two types, a total of 50 butterflies
collected at 18 geographic localities in East Asia were examined for nucleotide sequence variation of three mitochondrial
regions: cytochrome c oxidase subunit I (COI), cytochrome c oxidase subunit III (COIII) and NADH dehydrogenase subunit 5 (ND5). In addition, they were also examined for infection status
with the endosymbiotic bacteria Wolbachia. The three mitochondrial sequences consistently showed that (i) Y type and B type were highly divergent, (ii) nucleotide
variation within B type was very small although sampled from a geographically wide range, and (iii) a weak association existed
between mitochondrial DNA haplotypes and Wolbachia infection status. 相似文献
106.
Furochi H Tamura S Mameoka M Yamada C Ogawa T Hirasaka K Okumura Y Imagawa T Oguri S Ishidoh K Kishi K Higashiyama S Nikawa T 《FEBS letters》2007,581(30):5743-5750
Intact osteoactivin, a novel type I membrane glycoprotein, were shed at a dibasic motif in the juxtamembrane region in C2C12 myoblasts. Extracellular fragments were secreted into the culture media by a putative metalloprotease. Extracellular fragments of osteoactivin, but not control protein, induced matrix metalloprotease-3 (MMP-3) expression in NIH-3T3 fibroblasts. Epidermal growth factor (ERK) kinase inhibitors inhibited the osteoactivin-mediated MMP-3 expression, whereas the extracellular fragment of osteoactivin activated ERK1/2 and p38 in the mitogen-activated protein kinase pathway. Our results suggest that the extracellular fragments of osteoactivin produced by shedding act as a growth factor to induce MMP-3 expression via the ERK pathway in fibroblasts. 相似文献
107.
Adenylate kinase (AK) is localized in sea urchin sperm flagella and embryonic cilia. To investigate sea urchin Strongylocentrotus purpuratus AK (SpAK) enzymatic characteristics, the full-length recombinant protein of 130 kDa (SpAKr) and each of its three catalytic domains were expressed in Escherichia coli. Although the full-length SpAK had high enzymatic activity, each of the three catalytic domains had no activity. The Km for ATP synthesis from ADP was 0.23 mM and the Vmax was 4.51 mumol ATP formed per minute per milligram of protein. The specific AK inhibitor, Ap5A, blocks SpAKr enzymatic activity with an IC50 of 0.53 microM. The pH optimum for SpAKr is 8.1, as compared to 7.7 for the natural SpAK. Calcium inhibits SpAKr activity in a dose-dependent manner. Although SpAKr has three cAMP-dependent protein kinase phosphorylation sites, and can be phosphorylated in vitro, the enzymatic kinetics after phosphorylation are not significantly altered. SpAK and Chlamydomonas flagellar AKs are the only AKs with three catalytic sites. Further study of the SpAKr will aid in understanding the active site of this interesting and important ATP synthase. 相似文献
108.
Irikura D Inui T Beuckmann CT Aritake K Schreiber G Miyano M Inoue T Urade Y 《Journal of biochemistry》2007,141(2):173-180
Here we report the enzymatic and ligand-binding properties of a major secretory protein in the choroid plexus of cane toad, Bufo marinus, whose protein is homologous with lipocalin-type prostaglandin (PG) D synthase (L-PGDS) and is recombinantly expressed in Xenopus A6 cells and Escherichia coli. The toad protein bound all-trans retinal, bile pigment, and thyroid hormones with high affinities (K(d)=0.17 to 2.00 microM). The toad protein also catalysed the L-PGDS activity, which was accelerated in the presence of GSH or DTT, similar to the mammalian enzyme. The K(m) value for PGH(2) (17 microM) of the toad protein was almost the same as that of rat L-PGDS (14 microM), whereas the turnover number (6 min(-1)) was approximately 28 fold lower than that of rat L-PGDS. Site-directed mutagenesis based on a modeled structure of the toad protein revealed that Cys(59) and Thr(61) residues were crucial for the PGDS activity. The quadruple Gly(39)Ser/Ala(75)Ser/Ser(140)Thr/Phe(142)Tyr mutant of the toad protein, resembling mouse L-PGDS, showed a 1.6 fold increase in the turnover number and a shift in the optimum pH for the PGDS activity from 9.0 to 8.5. Our results suggest that the toad protein is a prototype of L-PGDS with a highly functional ligand-binding pocket and yet with a primitive catalytic pocket. 相似文献
109.
Kouichi Kawamura Masashi Kubota Miki Furukawa Yasushi Harada 《Conservation Genetics》2007,8(5):1163-1176
The amago salmon, Oncorhynchus masou ishikawae, is an endemic subspecies of O. masou in Japan. Owing to the extensive stocking of hatchery fish throughout Japan, indigenous populations of O. m. ishikawae are now on the verge of extinction. We examined the genetic effects of stocking hatchery fish on wild populations in the
River Koza, Japan, using microsatellite and mitochondrial DNA (mtDNA) markers. For mtDNA, haplotype mt1, which is common in
wild populations, was present exclusively in isolated wild populations assumed to be unaffected by previous stocking, while
it was never observed in hatchery fish. Genetic diversity was much higher in wild populations in the stocked area, which shared
many mtDNA haplotypes with hatchery fish, than in isolated wild populations with haplotype mt1. Pairwise F
ST estimates based on microsatellites showed significant differentiation among the isolated populations with many microsatellite
loci monomorphic. Significant deviation from Hardy–Weinberg equilibrium was observed in wild populations in the area subject
to stocking, where a Bayesian-based assignment test showed a high level of introgression with hatchery fish. These results
suggest that wild populations with haplotype mt1, which became isolated through anthropogenic environmental change in the
1950–1960s, represent indigenous populations of O. m. ishikawae in the River Koza. They have low genetic diversity, most likely caused by genetic bottlenecks following damming and environmental
deterioration, while stocking of hatchery fish over the past 30 years apparently had a large impact on the genetic structure
of wild populations in the main channel of the River Koza. 相似文献
110.
Hiroko Kawakami Chihiro Suzuki Haruka Yamaguchi Kojiro Hara Masashi Komine Yoshikazu Yamamoto 《Bioscience, biotechnology, and biochemistry》2019,83(6):996-999
Endolichenic fungi, nonobligate microfungi that live in lichen, are promising as new bioresources of pharmacological compounds. We found that norlichexanthone isolated from the endolichenic fungus in Pertusaria laeviganda exhibited high antioxidant activity. Norlichexanthone produced by endolichenic fungus had the antioxidant activity with same level of ascorbic acid. This is the first report of high antioxidant activity of norlichexanthone.
Abbreviations: AAPH: 2,2?-azobis (2-methylpropionamidine) dihydrochloride; DPPH: 2,2-diphenyl-1-picrylhydrazyl; FL: fluorescein sodium salt; HPLC-PDA: high-performance liquid chromatography with photodiode array; LC-ESI-MS: liquid chromatography with electrospray ionization mass spectrometry; ORAC: oxygen radical absorbance capacity; PB: phosphate buffer; ROS: reactive oxygen species; TLC: thin-layer chromatography 相似文献