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61.
Adenine excisional repair function of MYH protein on the adenine:8-hydroxyguanine base pair in double-stranded DNA 总被引:5,自引:2,他引:3
Shinmura K Yamaguchi S Saitoh T Takeuchi-Sasaki M Kim SR Nohmi T Yokota J 《Nucleic acids research》2000,28(24):4912-4918
Adenine paired with 8-hydroxyguanine (oh8G), a major component of oxidative DNA damage, is excised by MYH base excision repair protein in human cells. Since repair activity of MYH protein on an A:G mismatch has also been reported, we compared the repair activity of His6-tagged MYH proteins, expressed in Spodoptera frugiperda Sf21 cells, on A:oh8G and A:G mismatches by DNA cleavage assay and gel mobility shift assay. We also compared the repair ability of type 1 mitochondrial protein with type 2 nuclear protein, as well as of polymorphic type 1-Q324 and 2-Q310 proteins with type 1-H324 and 2-H310 proteins by DNA cleavage assay and complementation assay of an Escherichia coli mutM mutY strain. In a reaction buffer with a low salt (0–50 mM) concentration, adenine DNA glycosylase activity of type 2 protein was detected on both A:oh8G and A:G substrates. However, in a reaction buffer with a 150 mM salt concentration, similar to physiological conditions, the glycosylase activity on A:G, but not on A:oh8G, was extremely reduced and the binding activity of type 2 protein for A:G, but not for A:oh8G, was proportionally reduced. The glycosylase activity on A:oh8G and the ability to suppress spontaneous mutagenesis were greater for type 2 than type 1 enzyme. There was apparently no difference in the repair activities between the two types of polymorphic MYH proteins. These results indicate that human MYH protein specifically catalyzes the glycosylase reaction on A:oh8G under physiological salt concentrations. 相似文献
62.
Sugano K Yoshida S Takaku M Haramura M Saitoh R Nabuchi Y Ushio H 《Bioorganic & medicinal chemistry letters》2000,10(17):1939-1942
The intestinal permeability of benzamidine analogue thrombin inhibitor is correlated with molecular volume, lipophilicity (calculated log P and IAM column capacity factor), hydrogen bond acidity/basicity and dipolarity. 相似文献
63.
A New System for Stringent, High-Titer Vesicular Stomatitis Virus G Protein-Pseudotyped Retrovirus Vector Induction by Introduction of Cre Recombinase into Stable Prepackaging Cell Lines 总被引:3,自引:2,他引:1 下载免费PDF全文
64.
Miura I; Ohtani H; Nakamura M; Ichikawa Y; Saitoh K 《Molecular biology and evolution》1998,15(12):1612-1619
Sex chromosomes of the Japanese frog Rana rugosa are heteromorphic in the
male (XX/XY) or in the female (ZZ/ZW) in two geographic forms, whereas they
are still homomorphic in both sexes in two other forms (Hiroshima and
Isehara types). To make clear the origin and differentiation mechanisms of
the heteromorphic sex chromosomes, we isolated a sex-linked gene, ADP/ATP
translocase, and constructed a phylogenetic tree of the genes derived from
the sex chromosomes. The tree shows that the Hiroshima gene diverges first,
and the rest form two clusters: one includes the Y and Z genes and the
other includes the X, W, and Isehara genes. The Hiroshima gene shares more
sequence similarity with the Y and Z genes than with the X, W, and Isehara
genes. This suggests that the Y and Z sex chromosomes originate from the
Hiroshima type, whereas the X and W chromosomes originate from the
Isehara-type sex chromosome. Thus, we infer that hybridization between two
ancestral forms, with the Hiroshima-type sex chromosome in one and the
Isehara-type sex chromosome in the other, was the primary event causing
differentiation of the heteromorphic sex chromosomes.
相似文献
65.
The usefulness of RT-PCR for the detection of MHV in tissues and feces of experimentally infected animals has been reported, but it was unclear whether the method was also applicable for the detection of MHV during a natural outbreak. Enterotropic infection is considered to be the most common form of natural infection among various forms of MHV infection. In this paper, RT-nested PCR was performed to detect MHV excreted in the feces during an outbreak in an immunocompromised A/WySnJ mouse colony. The expected bands were amplified after nested PCR from 20 fecal samples out of 37. These results showed that RT-nested PCR could be applicable for the diagnosis for MHV natural infection. 相似文献
66.
The parasporal inclusion proteins of the type strain of Bacillus thuringiensis serovar higo (H44), that have moderate mosquitocidal activity, were characterized. The purified parasporal inclusions, spherical in shape, were examined for activity against the two mosquito species, Culex pipiens molestus and Anopheles stephensi and the moth-fly, Telmatoscopus albipunctatus . The LC50 values of the inclusion for the two mosquitoes were 3·41 and 0·15 μg ml−1 , respectively. No mortality was shown for T. albipunctatus larvae by the inclusions at concentrations up to 1 mg ml−1 . Solubilized parasporal inclusions exhibited no haemolytic activity against sheep erythrocytes. Parasporal inclusions consisted of eight proteins with molecular masses of 98, 91, 71, 63, 59, 50, 44 and 27 kDa. Of these, the 50 and 44 kDa proteins were the major components. Analysis with immunoblotting revealed that, among several inclusion proteins of B. thuringiensis serovar israelensis, only two proteins of 130 kDa and 110 kDa reacted weakly with antibodies against higo proteins. N-terminal amino acid sequences of the 98, 91, and 71 kDa proteins showed 85–100% identity to those of the two established Cry protein classes, Cry4A and Cry10A. 相似文献
67.
Yasuyuki Ishibashi Takashi Saitoh Syuiti Abe Michihiro C. Yoshida 《Population Ecology》1998,40(1):51-59
Kinship amongClethrionomys rufocanus was investigated during the winter of 1992/93 in a 3-ha enclosure using both molecular and catch-mark-release techniques.
Forty-six adult voles (22 males and 24 females) having high heterozygosities, which were collected from several natural populations,
were released into the enclosure on 29 September 1992. Most fall-born individuals of both sexes stayed in their natal site
during the non-breeding period (December–March), although reproductively active females dispersed during the fall breeding
season (October–November). These philopatric individuals aggregated and formed an maternal family in the winter. Several females
which failed to reproduce were solitary during this season. Some individuals which were derived from several families also
aggregated into a mixed lineage group. Survival rate of fall-born voles from earlier litters was higher than that from later
ones. Maternal families broke up soon after the onset of spring reproduction. Most females established a territory near the
wintering site and made a kincluster, in which close relatives neighbored each other. Maternal families in winter bring about
female kin-clusters in spring, which may influence reproductive output in the breeding season. 相似文献
68.
Tomohito Sato Manabu Kinoshita Tetsuo Yamamoto Masataka Ito Takafumi Nishida Masaru Takeuchi Daizoh Saitoh Shuhji Seki Yasuo Mukai 《PloS one》2015,10(2)
Ascorbic acid is an effective antioxidant and free radical scavenger. Therefore, it is expected that ascorbic acid should act as a radioprotectant. We investigated the effects of post-radiation treatment with ascorbic acid on mouse survival. Mice received whole body irradiation (WBI) followed by intraperitoneal administration of ascorbic acid. Administration of 3 g/kg of ascorbic acid immediately after exposure significantly increased mouse survival after WBI at 7 to 8 Gy. However, administration of less than 3 g/kg of ascorbic acid was ineffective, and 4 or more g/kg was harmful to the mice. Post-exposure treatment with 3 g/kg of ascorbic acid reduced radiation-induced apoptosis in bone marrow cells and restored hematopoietic function. Treatment with ascorbic acid (3 g/kg) up to 24 h (1, 6, 12, or 24 h) after WBI at 7.5 Gy effectively improved mouse survival; however, treatments beyond 36 h were ineffective. Two treatments with ascorbic acid (1.5 g/kg × 2, immediately and 24 h after radiation, 3 g/kg in total) also improved mouse survival after WBI at 7.5 Gy, accompanied with suppression of radiation-induced free radical metabolites. In conclusion, administration of high-dose ascorbic acid might reduce radiation lethality in mice even after exposure. 相似文献
69.
Stephen W. Attwood Motomu Ibaraki Yasuhide Saitoh Naoko Nihei Daniel A. Janies 《PLoS neglected tropical diseases》2015,9(7)
Background
Schistosoma japonicum causes major public health problems in China and the Philippines; this parasite, which is transmitted by freshwater snails of the species Oncomelania hupensis, causes the disease intestinal schistosomiasis in humans and cattle. Researchers working on Schistosoma in Africa have described the relationship between the parasites and their snail intermediate hosts as coevolved or even as an evolutionary arms race. In the present study this hypothesis of coevolution is evaluated for S. japonicum and O. hupensis. The origins and radiation of the snails and the parasite across China, and the taxonomic validity of the sub-species of O. hupensis, are also assessed.Methodology/Principal Findings
The findings provide no evidence for coevolution between S. japonicum and O. hupensis, and the phylogeographical analysis suggests a heterochronous radiation of the parasites and snails in response to different palaeogeographical and climatic triggers. The results are consistent with a hypothesis of East to West colonisation of China by Oncomelania with a re-invasion of Japan by O. hupensis from China. The Taiwan population of S. japonicum appears to be recently established in comparison with mainland Chinese populations.Conclusions/Significance
The snail and parasite populations of the western mountain region of China (Yunnan and Sichuan) appear to have been isolated from Southeast Asian populations since the Pleistocene; this has implications for road and rail links being constructed in the region, which will breach biogeographical barriers between China and Southeast Asia. The results also have implications for the spread of S. japonicum. In the absence of coevolution, the parasite may more readily colonise new snail populations to which it is not locally adapted, or even new intermediate host species; this can facilitate its dispersal into new areas. Additional work is required to assess further the risk of spread of S. japonicum. 相似文献70.
Naotaka Sekiyama Kyohei Arita Yoshihiro Ikeda Kohtaro Hashiguchi Mariko Ariyoshi Hidehito Tochio Hisato Saitoh Masahiro Shirakawa 《Proteins》2010,78(6):1491-1502
Post‐translational modification by small ubiquitin‐like modifier (SUMO) provides an important regulatory mechanism in diverse cellular processes. Modification of SUMO has been shown to target proteins involved in systems ranging from DNA repair pathways to the ubiquitin‐proteasome degradation system by the action of SUMO‐targeted ubiquitin ligases (STUbLs). STUbLs recognize target proteins modified with a poly‐SUMO chain through their SUMO‐interacting motifs (SIMs). STUbLs are also associated with RENi family proteins, which commonly have two SUMO‐like domains (SLD1 and SLD2) at their C terminus. We have determined the crystal structures of SLD2 of mouse RENi protein, Nip45, in a free form and in complex with a mouse E2 sumoylation enzyme, Ubc9. While Nip45 SLD2 shares a β‐grasp fold with SUMO, the SIM interaction surface conserved in SUMO paralogues does not exist in SLD2. Biochemical data indicates that neither tandem SLDs or SLD2 of Nip45 bind to either tandem SIMs from either mouse STUbL, RNF4 or to those from SUMO‐binding proteins, whose interactions with SUMO have been well characterized. On the other hand, Nip45 SLD2 binds to Ubc9 in an almost identical manner to that of SUMO and thereby inhibits elongation of poly‐SUMO chains. This finding highlights a possible role of the RENi proteins in the modulation of Ubc9‐mediated poly‐SUMO formation. Proteins 2010. © 2009 Wiley‐Liss, Inc. 相似文献