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41.
Kuratani M Kasai T Akasaka R Higashijima K Terada T Kigawa T Shinkai A Bessho Y Yokoyama S 《Proteins》2011,79(7):2065-2075
The hypermodified nucleoside N6‐threonylcarbamoyladenosine resides at position 37 of tRNA molecules bearing U at position 36 and maintains translational fidelity in the three kingdoms of life. The N6‐threonylcarbamoyl moiety is composed of L ‐threonine and bicarbonate, and its synthesis was genetically shown to require YrdC/Sua5. YrdC/Sua5 binds to tRNA and ATP. In this study, we analyzed the L ‐threonine‐binding mode of Sua5 from the archaeon Sulfolobus tokodaii. Isothermal titration calorimetry measurements revealed that S. tokodaii Sua5 binds L ‐threonine more strongly than L ‐serine and glycine. The Kd values of Sua5 for L ‐threonine and L ‐serine are 9.3 μM and 2.6 mM, respectively. We determined the crystal structure of S. tokodaii Sua5, complexed with AMPPNP and L ‐threonine, at 1.8 Å resolution. The L ‐threonine is bound next to AMPPNP in the same pocket of the N‐terminal domain. Thr118 and two water molecules form hydrogen bonds with AMPPNP in a unique manner for adenine‐specific recognition. The carboxyl group and the side‐chain hydroxyl and methyl groups of L ‐threonine are buried deep in the pocket, whereas the amino group faces AMPPNP. The L ‐threonine is located in a suitable position to react together with ATP for the synthesis of N6‐threonylcarbamoyladenosine. Proteins 2011. © 2011 Wiley‐Liss, Inc. 相似文献
42.
Genomic insights into the origin of parasitism in the emerging plant pathogen Bursaphelenchus xylophilus 总被引:8,自引:0,他引:8
43.
Agrobacterium tumefaciens-mediated transformation (ATMT) has been successfully applied to the violet root-rot fungus Helicobasidium mompa, which is the causal agent of violet root-rot disease. The A. tumefaciens strains carried a binary plasmid vector containing the hygromycin B phosphotransferase gene (hph) controlled by the heterologous fungal Agaricus bisporus P-gpd (glyceraldehyde-3-phosphate dehydrogenase) promoter and the trpC terminator. The transformation system was optimized using defined cocultivation conditions. When H. mompa strain V17 was cocultivated with A. tumefaciens strain AGL-1 using 5% agar, we obtained more hygromycin-resistant colonies than with strains EHA105 or MAFF301222 using 2%
agar. In addition, our results suggest that the activated carbon is necessary in ATMT to reduce background growth of H. mompa. The presence of the hph gene in transformants was detected by polymerase chain reaction (PCR), and single-copy integration of the marker gene was
demonstrated by Southern blot analysis. Thus, the ATMT system can be considered a promising tool for insertional mutagenesis
studies of H. mompa. 相似文献
44.
Arisa Miyagawa‐Yamaguchi Takuma Okami Nozomu Kira Haruo Yamaguchi Kouhei Ohnishi Masao Adachi 《Phycological Research》2011,59(2):113-119
A nuclear transformation system for the centric diatom Chaetoceros sp. has been established using two plasmids pTpfcp/nat and pTpNR/green fluorescent protein (GFP) that had been used for Thalassiosira pseudonana transformation. These contain the nourseothricin resistance gene (nat) with the fucoxanthin chlorophyll a/c binding protein (fcp) promoter/terminator from T. pseudonana and the enhanced green fluorescent protein gene (egfp), with the nitrate reductase (NR) promoter/terminator from T. pseudonana, respectively. Transformants were recovered in the presence of the antibiotic nourseothricin. One to four copies of both nat and egfp genes were integrated into genomic DNA of the transformants. Transformation efficiency was 1.5–6.0 transformants per 108 cells. This work is the first report of stable genetic transformation of Chaetoceros, which is important as not only a constituent member of marine ecosystem but also feed for aquaculture. 相似文献
45.
Tsubaki T Arita N Kawakami T Shiratsuchi T Yamamoto H Takubo N Yamada K Nakata S Yamamoto S Nose M 《Arthritis research & therapy》2005,7(4):R825-R836
The disease category of early rheumatoid arthritis (RA) has been limited with respect to clinical criteria. Pathological manifestations
of synovitis in patients whose disease is clinically classified as early RA seem to be heterogeneous, with regular variations.
To clarify the relation between the molecular and histopathological features of the synovitis, we analyzed gene-expression
profiles in the synovial lining tissues to correlate them with histopathological features. Synovial tissues were obtained
from knee joints of 12 patients with early RA by targeted biopsy under arthroscopy. Surgical specimens of long-standing RA
(from four patients) were examined as positive controls. Each histopathological parameter characteristic of rheumatoid synovitis
in synovial tissues was scored under light microscopy. Total RNAs from synovial lining tissues were obtained from the specimens
selected by laser capture microdissection and the mRNAs were amplified by bacteriophage T7 RNA polymerase. Their cDNAs were
analyzed in a cDNA microarray with 23,040 cDNAs, and the levels of gene expression in multilayered lining tissues, compared
with those of normal-like lining tissues in specimens from the same person, were determined to estimate gene-expression profiles
characteristic of the synovial proliferative lesions in each case. Based on cluster analysis of all cases, gene-expression
profiles in the lesions in early RA fell into two groups. The groups had different expression levels of genes critical for
proliferative inflammation, including those encoding cytokines, adhesion molecules, and extracellular matrices. One group
resembled synovitis in long-standing RA and had high scores for some histopathological features – involving accumulations
of lymphocytes and plasma cells – but not for other features. Possible differences in the histopathogenesis and prognosis
of synovitis between the two groups are discussed in relation to the candidate genes and histopathology. 相似文献
46.
Sato Y Yokoyama A Shibata K Akimoto Y Ogino S Nodasaka Y Kohgo T Tamura K Akasaka T Uo M Motomiya K Jeyadevan B Ishiguro M Hatakeyama R Watari F Tohji K 《Molecular bioSystems》2005,1(2):176-182
Carbon nanotubes (CNTs) are single- or multi-cylindrical graphene structures that possess diameters of a few nanometers, while the length can be up to a few micrometers. These could have unusual toxicological properties, in that they share intermediate morphological characteristics of both fibers and nanoparticles. To date, no detailed study has been carried out to determine the effect of length on CNT cytotoxicity. In this paper, we investigated the activation of the human acute monocytic leukemia cell line THP-1 in vitro and the response in subcutaneous tissue in vivo to CNTs of different lengths. We used 220 nm and 825 nm-long CNT samples for testing, referred to as "220-CNTs" and "825-CNTs", respectively. 220-CNTs and 825-CNTs induced human monocytes in vitro, although the activity was significantly lower than that of microbial lipopeptide and lipopolysaccharide, and no activity appeared following variation in the length of CNTs. On the other hand, the degree of inflammatory response in subcutaneous tissue in rats around the 220-CNTs was slight in comparison with that around the 825-CNTs. These results indicated that the degree of inflammation around 825-CNTs was stronger than that around 220-CNTs since macrophages could envelop 220-CNTs more readily than 825-CNTs. However, no severe inflammatory response such as necrosis, degeneration or neutrophil infiltration in vivo was observed around both CNTs examined throughout the experimental period. 相似文献
47.
Developmental capacity of vitrified immature porcine oocytes following ICSI: effects of cytochalasin B and cryoprotectants 总被引:18,自引:0,他引:18
In the present study, effects of concentration and pretreatment time of cytochalasin B (CB), and of two types of cryoprotectant solutions on the nuclear maturation of vitrified-warmed porcine oocytes were examined. Also, the developmental capacity of vitrified immature porcine oocytes following intracytoplasmic sperm injection (ICSI) was investigated. The nuclear maturation rate (46.8%) of the vitrified-warmed oocytes treated with 7.5 microg/mL CB for 30 min was significantly higher (P < 0.05) than those (13.9-39.2%) of the vitrified-warmed oocytes treated with 0, 2.5, or 5.0 microg/mL CB for 10 or 30 min. Additionally, the nuclear maturation rate of oocytes treated with CB and vitrified in ethylene glycol (EG) (37.1%) was significantly higher (P < 0.05) than that of EG + dimethyl sulfoxide (Me(2)SO) (23.9%). However, no significant differences were observed in the cleavage and blastocyst development rates among the control (45.2 and 20.0%, respectively), the EG group (37.8 and 13.5%, respectively) and the EG + Me(2)SO group (39.3 and 14.3%, respectively). These results demonstrated that: (1) pretreatment with 7.5 microg/mL CB was beneficial for the vitrification of immature porcine oocytes; (2) the combination of EG and Me(2)SO as a cryoprotectant was not advantageous for in vitro maturation (IVM) of vitrified immature porcine oocytes; and (3) vitrified-warmed porcine oocytes matured after IVM, developed to the blastocyst stage without distinct differences compared to fresh oocytes following ICSI. 相似文献
48.
49.
Takuma Kobayashi Kunio Yasuda Masasuke Araki 《Development, growth & differentiation》2010,52(4):351-363
Dorsal and ventral specification in the early optic vesicle plays a crucial role in vertebrate ocular morphogenesis, and proper dorsal‐ventral polarity in the optic vesicle ensures that distinct structures develop in separate domains within the eye primordium. The polarity is determined progressively during development by coordinated regulation of extraocular dorsal and ventral factors. In the present study, we cultured discrete portions of embryonic chick brains by preparing anterior cephalon, anterior dorsal cephalon and anterior ventral cephalon, and clearly demonstrate that bone morphogenetic protein 4 (BMP4) and Sonic hedgehog (Shh) constitute a dorsal‐ventral signaling system together with fibroblast growth factor 8 (FGF8). BMP4 and Shh upregulate Tbx5 and Pax2, as reported previously, and at the same time Shh downregulates Tbx5, while BMP4 affects Pax2 expression to downregulate similarly. Shh induces Fgf8 expression in the ventral optic vesicle. This, in turn, determines the distinct boundary of the retinal pigmented epithelium and the neural retina by suppressing Mitf expression. The lens develops only when signals from both the dorsal and ventral regions come across together. Inverted deposition of Shh and BMP4 signals in organ‐cultured optic vesicle completely re‐organized ocular structures to be inverted. Based on these observations we propose a novel model in which the two signals govern the whole of ocular development when they encounter each other in the ocular morphogenic domain. 相似文献
50.
Oishi Y Arakawa T Tanimura A Itakura M Takahashi M Tajima Y Mizoguchi I Takuma T 《Histochemistry and cell biology》2006,125(3):273-281
We evaluated the role of VAMP-2/synaptobrevin, VAMP-7/TI-VAMP, and VAMP-8/endobrevin in exocytic pathways of HSY cells, a
human parotid epithelial cell line, by coexpressing these VAMP proteins tagged with green fluorescent protein (GFP) and human
growth hormone (hGH) as a secretory cargo. Exocytosis of hGH was constitutive and the fluorescent signal of hGH–GFP was observed
in the Golgi area and small vesicles quickly moving throughout the cytoplasm. The cytoplasmic vesicles containing hGH overlapped
well with VAMP-7-GFP, but did so scarcely with VAMP-2-GFP or VAMP-8-GFP. However, when the vesicle transport from the trans-Golgi network to the plasma membrane was arrested by incubation at 20°C for 2 h and then released by warming up to 37°C;
VAMP-2-GFP and hGH were clearly colocalized together in small cytoplasmic vesicles. Neither VAMP-7-GFP nor hGH–GFP was colocalized
with LAMP-1, a marker for lysosomes and late endosomes. These results suggest that (1) VAMP-2 can be one of the v-SNAREs for
constitutive exocytosis; (2) VAMP-7 is involved in the constitutive exocytosis as a slow, minor v-SNARE, but not in the lysosomal
transport; and (3) VAMP-8 is unlikely to be a v-SNARE for constitutive exocytosis in HSY cells. 相似文献