排序方式: 共有81条查询结果,搜索用时 656 毫秒
51.
Sydowia japonica, a new name for Leptosphaerulina japonica based on morphological and molecular data
Yuuri Hirooka Hayato Masuya Mitsuteru Akiba Takanori Kubono 《Mycological Progress》2013,12(2):173-183
We examined the taxonomic position of Leptosphaerulina japonica, a parasitic fungus on male strobili of Japanese cedar (Cryptomeria japonica) using morphology and molecular phylogeny. Because neither specimens nor illustrations were designated in the original paper, this name is neotypified with a fresh specimen collected from the type locality, Yamagata, Japan. Leptosphaerulina japonica has asci produced in a broad layer arising from the entire base of the locule, stipitate acervuli, and a hormonema-like synanamorph. These characteristics are not typical of the genus Leptosphaerulina (Didymellaceae, Pleosporales). In a molecular phylogenetic analysis of ITS sequences, L. japonica was placed into the Dothideaceae/Dothioraceae, Dothideales. Although muriform ascospores and an anamorph with long stipitate acervuli have not been reported for species in Sydowia, the other morphology and phylogeny support placement of L. japonica in that genus. Thus, a new combination, Sydowia japonica, is proposed. 相似文献
52.
Matsutani M Hirakawa H Nishikura M Soemphol W Ali IA Yakushi T Matsushita K 《Biochemical and biophysical research communications》2011,(1):120-124
Constitution of oxidative defense systems and, correspondingly, oxidative stress prevention are highly dependent on amino acid supply. In vitro, experiments have demonstrated that amino acid availability participates to the homeostasis of reactive oxygen species. However the molecular mechanisms involved in the maintenance of redox homeostasis responsive to circulating amino acid levels remain unclear. As GCN2 is a protein kinase considered to be an important sensor for amino acids availability and a potential regulator of redox homeostasis, we hypothesized that this kinase can modulate redox homeostasis in vivo, in response to an amino acid-imbalanced diet.We investigated the response of GCN2+/+ and GCN2−/− mice to a long-term (24 weeks) leucine-imbalanced diet (EDΔLeu). In order to evaluate the oxidation level in each group of mice, we determined the degree of protein oxidation in the liver. Interestingly, GCN2−/− mice exhibited an increase in protein carbonylation, a marker of oxidative stress, in response to the EDΔLeu diet. These data correlate with a decrease in hepatic GPX1 expression, a major antioxidant enzyme, and a decrease in total GPX activity in the liver. Our results suggest that GCN2 and its downstream signaling pathway have an important role in the protection against oxidative injuries induced by an amino acid-imbalanced diet, and that it can play a critical role in the prevention of oxidative damage. 相似文献
53.
Large-scale identification and characterization of alternative splicing variants of human gene transcripts using 56,419 completely sequenced and manually annotated full-length cDNAs
下载免费PDF全文
![点击此处可从《Nucleic acids research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
54.
Charalambous M Ferron SR da Rocha ST Murray AJ Rowland T Ito M Schuster-Gossler K Hernandez A Ferguson-Smith AC 《Cell metabolism》2012,15(2):209-221
- Download : Download high-res image (266KB)
- Download : Download full-size image
55.
Madoka Takahashi Wakako Handa Hiromi Umeta Saki Ishikawa Kouwa Yamashita Mitsuteru Numazawa 《The Journal of steroid biochemistry and molecular biology》2009,116(3-5):191-199
To gain the structure–activity relationship of Δ1-androstenediones (Δ1-ADs) as mechanism-based inactivator of aromatase, series of 2-alkyl- and 2-alkoxy-substitiuted Δ1-ADs (6 and 9) as well as 2-bromo-Δ1-AD (14) were synthesized and tested. All of the inhibitors examined blocked aromatase in human placental microsomes in a competitive manner. In a series of 2-alkyl-Δ1-ADs (6), n-hexyl compound 6f was the most powerful inhibitor with an apparent Ki value of 31 nM. The inhibitory activities of 2-alkoxy steroids 9 decreased in relation to length of the alkyl chain up to n-hexyloxy group (Ki: 95 nM for methoxy 9a). All of the alkyl steroids 6 along with the alkoxy steroid 9, except for the ethyl and n-propyl compounds 6b and 6c, caused a time-dependent inactivation of aromatase. The inactivation rates (kinact: 0.020–0.084 min−1) were comparable to that of the parent compound Δ1-AD. The inactivation was prevented by the substrate AD, and no significant effect of l-cysteine on the inactivation was observed in each case. The results indicate that the 2-hexyl compound 6f act as the most powerful mechanism-based inactivator of aromatase among Δ1-AD analogs and may be submitted to the preclinical study in estrogen-dependent breast cancer. 相似文献
56.
In order to determine whether or not a 19-hydroxymethyl group of 19-hydroxyandrosta-1,4-diene-3,17-dione (2, 19-hydroxy ADD), an intermediate of aromatase-catalyzed estrone formation from ADD, a suicide substrate of aromatase, is eliminated as formaldehyde, we examine chemical nature of removal of the 19-hydroxymethyl group. 19-Acetate 3 and 19-tert-butyldimethylsiloxy compound 4 are known to convert rapidly to estrone with treatment of NaOH or n-Bu4NF. Since compound 2 was unstable and unobtainable under these conditions, compounds 3 and 4 as equivalents to compound 2 were used in this study. The acetate 3 with 5 mol/l HCl in acetone and 10% KOH in MeOH along with the silyl ether 4 with 5 mol/l HCl in acetone and 1 mol/l n-Bu4NF in THF gave formaldehyde and estrone in which a ratio of the aldehyde to estrone was near 1. This result indicates that the 19-hydroxymethyl groups of compound 3 and 4 are eliminated as formaldehyde along with estrone derived from the steroid skeleton under the acid or base treatment. The findings suggest that a single hydroxylation at the 19 carbon of ADD (1) would be, chemically, all that was required for estrone formation. 相似文献
57.
4-(p-Sulphamoylphenyl)androstenedione (3) and 6α-p-sulphamoylphenyl analogues 12-14 were synthesised and tested as aromatase inhibitors as well as oestrone sulphatase inhibitors in human placental microsomes. All of the p-sulphamoylphenyl compounds synthesised were powerful inhibitors of aromatase with apparent Ki values ranging between 30 and 97 nM. In addition, the aromatase inhibitory activities of 6α-p-hydroxyphenyl compounds 9-11, which may be produced from their respective sulphamoylphenyl compounds by action of oestrone sulphatase, were also high in a range of 23 and 75 nM of the Ki values. On the other hand, all of the sulphamoylphenyl compounds were poor inhibitors of oestrone sulphatase with more than about 200 μM of IC25 values. Although the present findings of the oestrone sulphatase inhibition are disappointing, such attempts may be valuable to develop a new class of drugs having a dual function, aromatase inhibitor and oestrone sulphatase inhibitor, for the treatment of oestrogen-dependent breast cancer. 相似文献
58.
As the first report of monographic studies of the genus Phyllosticta in Japan, four new species, Phyllosticta disanthi on Disanthus cercidifolius, P. hoveniicola on Hovenia dulcis, P. ligustricola on Ligustrum obtusifolium, and Phyllosticta alliacea on Allium fistulosum, are described and illustrated. A new teleomorphic state of P. alliorum, Guignardia alliacea, is confirmed. 相似文献
59.
Genome Structure of the Legume, Lotus japonicus 总被引:1,自引:0,他引:1
Shusei Sato Yasukazu Nakamura Takakazu Kaneko Erika Asamizu Tomohiko Kato Mitsuteru Nakao Shigemi Sasamoto Akiko Watanabe Akiko Ono Kumiko Kawashima Tsunakazu Fujishiro Midori Katoh Mitsuyo Kohara Yoshie Kishida Chiharu Minami Shinobu Nakayama Naomi Nakazaki Yoshimi Shimizu Sayaka Shinpo Chika Takahashi Tsuyuko Wada Manabu Yamada Nobuko Ohmido Makoto Hayashi Kiichi Fukui Tomoya Baba Tomoko Nakamichi Hirotada Mori Satoshi Tabata 《DNA research》2008,15(4):227-239
The legume Lotus japonicus has been widely used as a model system to investigate the genetic background of legume-specific phenomena such as symbiotic nitrogen fixation. Here, we report structural features of the L. japonicus genome. The 315.1-Mb sequences determined in this and previous studies correspond to 67% of the genome (472 Mb), and are likely to cover 91.3% of the gene space. Linkage mapping anchored 130-Mb sequences onto the six linkage groups. A total of 10 951 complete and 19 848 partial structures of protein-encoding genes were assigned to the genome. Comparative analysis of these genes revealed the expansion of several functional domains and gene families that are characteristic of L. japonicus. Synteny analysis detected traces of whole-genome duplication and the presence of synteny blocks with other plant genomes to various degrees. This study provides the first opportunity to look into the complex and unique genetic system of legumes.Key words: Lotus japonicus, genome structure, Fabaceae, comparative analysis 相似文献
60.
The mechanistic aspects of the alkali-catalyzed rearrangement of 16alpha-hydroxy-17-keto steroid 1 to 17beta-hydroxy-16-keto steroid 2 are elucidated by use of (18)O- and deuterium-labeling experiments. The (18)O-labeling experiments refute the gem-hydration-quasi-diaxial dehydration mechanism for the rearrangement previously proposed and support the conventional enolization mechanism. Moreover, equilibrium by gem-hydration-dehydration occurs at the C-17 carbonyl more efficiently than at the C-16 carbonyl. Enolization rate of a carbonyl group at C-16 of 17beta-ketol 2 toward the C-17 position (k(16,17)) was about 8-10 times higher than those of 16alpha-ketol 1 toward the C-16 position (k(17,16)) and ketol 2 toward the C-15 position (k(16,15)). The marked deuterium-isotope effect on each enolization was observed with k(H)/k(D) ranging between 5.4 and 8.8. The present findings reveal that the initial hydration-dehydration equilibration at the C-17 carbonyl of ketol 1 followed by enolization of the carbonyl gives the ene-diol intermediate that isomerizes quantitatively to the 16-keto isomer of which the 16-carbonyl moiety enolizes preferentially toward the C-17 position rather than the C-15 position, yielding the ene-diol. Computational calculations of ground state energies of ketols 1-M and 2-M, trans-cyclohexane/cyclopentane structures, and their activation energies in the rearrangement support the dynamic aspects of the rearrangement as well as the kinetics data of the enolization. 相似文献