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81.
Katayama Kazuhiro Hosui Atsushi Sakai Yoshiyuki Itou Minoru Matsuzaki Yasushi Takamori Yoriyuki Hosho Keiko Tsuru Tomomi Takikawa Yasuhiro Michitaka Kojiro Ogawa Eishin Miyoshi Yoko Ito Toshifumi Ida Shinobu Hamada Izumi Miyoshi Katsunori Kodama Hiroko Takehara Tetsuo 《Biological trace element research》2020,195(1):71-81
Biological Trace Element Research - The essential trace element zinc maintains liver functions. Liver diseases can alter overall zinc concentrations, and hypozincemia is associated with various... 相似文献
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We sequenced nucleosomal DNA fragments of the filamentous ascomycetes Aspergillus nidulans and Aspergillus oryzae and then mapped those sequences on their genomes. We compared the GC content and nucleosome density in the exonic and intronic regions in the genes of A. nidulans and A. oryzae. Although the GC content and nucleosome density in the exonic regions tended to be higher than those in the intronic regions, the difference in the distribution of the GC content was more notable than that of the nucleosome density. Next, we compared the GC content and nucleosome density in the exonic regions of 9616 orthologous gene pairs. In both Aspergillus species, the GC content did not correlate with the nucleosome density. In addition, the Spearman's rank correlation coefficient (ρ = 0.51) between the GC content of the exonic regions of the 9616 orthologous gene pairs was higher than that (ρ = 0.31) of the nucleosome densities of A. nidulans and A. oryzae. These results strongly suggest that the GC content in the exons of the orthologous gene pairs has been conserved during evolution but the nucleosome density has varied throughout. 相似文献
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Masato Hayakawa Tatsuya Ohyama Yoko Yamaguchi Shingo Iwabuchi Tomohiko Nakagawa Tamie Nakajima 《Molecular simulation》2013,39(9):644-656
To elucidate the specific interactions between the peroxisome proliferator-activated receptor (PPARα) and ligand GW409544 (GW), we obtained the solvated structures of the PPARα+GW complexes for human, mouse and rat by classical molecular mechanics calculations, and investigated their electronic properties by ab initio fragment molecular orbital calculations. The results indicate that the positively charged amino acids (Lys and Arg) of PPARα make a major contribution to the binding between PPARα and GW. In addition, it was clarified that Ser280 and Tyr314 of human and rat PPARα have a large attractive interaction with GW, while Ser280, Tyr314 and His440 of mouse PPARα have large interaction. These results on the difference in specific interactions between human and mouse/rat PPARα will be useful for predicting the effects of new chemicals on the human body based on the biomedical studies for the experimental animals such as mouse and rat. 相似文献
87.
In polar seas, ice algal communities can acclimate to extremely low light conditions. Reduced acclimation to shade in ice algal communities, as a result of shortened ice seasons at the lower latitude limits of sea ice distribution, has been suggested as advantageous for avoiding strong photoinhibition when cells are released into high light levels at the water’s surface. Thermal dissipation of excess energy by xanthophyll cycle pigments in the de-epoxidated state may occur in ice algal communities released from retreating sea ice. A light exposure experiment was conducted on ice algal communities obtained from sea ice at Saroma-Ko Lagoon in Hokkaido, Japan. Photoprotective responses to direct sunlight were examined through non-photochemical quenching (NPQ) of chlorophyll fluorescence and xanthophyll pigments. De-epoxidation of diadinoxanthin (DD) to diatoxanthin (DT) occurred rapidly, and NPQ showed a dynamic response to high light exposure. The linear relationship between the ratio of DT to chlorophyll a and NPQ followed a steeper slope than previously observed for mesophilic diatoms. The steeper slope could be explained by an apparent increase in DT for the mesophilic diatoms and induction of NPQ in response to low temperatures only in the ice algal communities. Enhanced production of DT in mesophilic diatoms could be the result of de-epoxidation of DD plus de novo synthesis, and the enhancement of NPQ might be caused by low temperature stress in the ice algae. Although the response of NPQ might be related to temperature, NPQ independent of DT synthesis should also be studied. 相似文献
88.
Tomohiko Matsuzawa Hideki Tohda Kaoru Takegawa 《Applied microbiology and biotechnology》2013,97(15):6835-6843
In the fission yeast Schizosaccharomyces pombe, the gld1 + gene encoding glycerol dehydrogenase is repressed by glucose and induced by ethanol and 1-propanol. The promoter region of gld1 + was cloned into a multicopy vector designated as pEG1 for evaluation as an ethanol-inducible expression vector using EGFP as a model heterologous protein. Expression of EGFP was repressed in the presence of high glucose and induced in the presence of ethanol, low-glucose, and 1-propanol in the absence of glucose. Addition of ethanol to cells harboring pEG1–EGFP was found to be the most effective means for inducing EGFP production. Protein yields were found to increase in proportion to ethanol concentration. As a further test of effectiveness, secreted recombinant human growth hormone was produced using the pEG1 expression vector in medium containing glycerol and ethanol. The pEG1 gene expression system is an effective tool for the production of heterologous proteins under glucose-limiting conditions, including medium containing glycerol as a carbon source. 相似文献
89.
Blanca R. Jarilla Shinji Tokuhiro Mitsuru Nagataki Kouji Uda Tomohiko Suzuki Luz P. Acosta Takeshi Agatsuma 《Experimental parasitology》2013
The two-domain taurocyamine kinase (TK) from Paragonimus westermani was suggested to have a unique substrate binding mechanism. We performed site-directed mutagenesis on each domain of this TK and compared the kinetic parameters KmTc and Vmax with that of the wild-type to determine putative amino acids involved in substrate recognition and binding. Replacement of Y84 on domain 1 and Y87 on domain 2 with R resulted in the loss of activity for the substrate taurocyamine. Y84E mutant has a dramatic decrease in affinity and activity for taurocyamine while Y87E has completely lost catalytic activity. Substituting H and I on the said positions also resulted in significant changes in activity. Mutation of the residues A59 on the GS region of domain 1 also caused significant decrease in affinity and activity while mutation on the equivalent position on domain 2 resulted in complete loss of activity. 相似文献
90.
Tomohiko Maehama Masayoshi Fukasawa Tomoko Date Takaji Wakita Kentaro Hanada 《Biochemical and biophysical research communications》2013
Phosphoinositides function as fundamental signaling molecules and play roles in diverse cellular processes. Certain types of viruses may employ host cell phosphoinositide signaling systems to facilitate their replication cycles. Here we demonstrate that the β isoform of class II PI3K (PI3K-C2β) plays an indispensable role in hepatitis C virus (HCV) propagation in human hepatocellular carcinoma cells. Knockdown of PI3K-C2β abrogated HCV propagation in the cell. Using an HCV replicon system, we found that knockdown of PI3K-C2β substantially repressed the full-genome replication, while showing relatively small reductions in sub-genome replication, in which structural proteins including core protein were deleted. We also found that HCV core protein showed the binding activity towards D4-phosphorylated phosphoinositides and overlapped localization with phosphatidylinositol 3,4-bisphosphate in the cell. These results suggest that the phosphoinositide generated by PI3K-C2β plays an indispensable role in the HCV replication cycle through the binding to HCV core protein. 相似文献