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961.
Prophage lambda at unusual chromosomal locations. II. Mutations induced by bacteriophage lambda in Escherichia coli K12 总被引:34,自引:0,他引:34
An Escherichia coli strain deleted for the primary λ attachment site was lysogenized with λ at secondary sites. Some lysogens became mutants because of prophage insertion in the affected gene. Mutagenesis by phage λ is not random with respect to the gene affected: most mutants were pro, although certain other genes could be mutated at lower frequencies. In the case of several independent ilv and gal mutants, the sites of prophage insertion were in the same segment of the ilv region and galT gene respectively. The galT location may also be a preferred site for the insertion of DNAs other than prophage λ. Insertion of prophage λ within an operon can reduce the expression of operator-distal genes. A trpC λ insertion mutant expresses the operator-distal trpB function constitutively at a low level. This expression probably derives from a promoter located in the left arm of the prophage. 相似文献
962.
Shigeki Suzuki Hiroaki Hoshino Kazuma Yoshida Jun Nakanishi Shizu Tsuchiya-Hirata Seiji Kobuke Naoto Haruyama Fusanori Nishimura Hideki Shiba 《Biochemical and biophysical research communications》2018,495(3):2303-2309
Chromatin-enriched noncoding RNAs (ncRNAs) have emerged as key molecules in epigenetic processes by interacting with chromatin-associated proteins. Recently, protein-coding mRNA genes have been reported to be chromatin-tethered, similar with ncRNA. However, very little is known about whether chromatin-enriched mRNA is involved in the chromatin modification process. Here, we comprehensively examined chromatin-enriched RNA in squamous cell carcinoma (SQCC) cells by RNA subcellular localization analysis, which was a combination of RNA fractionation and RNA-seq. We identified 11 mRNAs as highly chromatin-enriched RNAs. Among these, we focused on the dentin matrix protein-1 (DMP-1) gene because its expression in SQCC cells has not been reported. Furthermore, we clarified that DMP-1 mRNA was retained in chromatin in its unspliced form in SQCC in vitro and in vivo. As the inhibition of the unspliced DMP-1 mRNA (unspDMP-1) expression resulted in decreased cellular proliferation in SQCC cells, we performed ChIP-qPCR to identify cell cycle-related genes whose expression was epigenetically modified by unspDMP-1, and found that the CDKN1B promoter became active in SQCC cells by inhibiting unspDMP-1 expression. This result was further validated by the increased CDKN1B gene expression in the cells treated with siRNA for unspDMP-1 and by restoration of the decreased cellular proliferation rate by simultaneously inhibiting CDKN1B expression in SQCC cells. Further, to examine whether unspDMP-1 was able to associate with the CDKN1B promoter region, SQCC cells stably expressing PP7-mCherry fusion protein were transiently transfected with the unspDMP-1 fused to 24 repeats of the PP7 RNA stem loop (unspDMP-1-24xPP7) and we found that unspDMP-1-24xPP7 was efficiently precipitated with the antibody against mCherry and was significantly enriched in the CDKN1B promoter region. Thus, unspDMP-1 is a novel chromatin-enriched RNA that epigenetically regulates cellular proliferation of SQCC. 相似文献
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Hearing vulnerability after noise exposure in a mouse model of reactive oxygen species overproduction
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Shigefumi Morioka Hirofumi Sakaguchi Taro Yamaguchi Yuzuru Ninoyu Hiroaki Mohri Takashi Nakamura Yasuo Hisa Kiyokazu Ogita Naoaki Saito Takehiko Ueyama 《Journal of neurochemistry》2018,146(4):459-473
966.
Megumi Narukawa‐Nara Ayako Nakamura Ko Kikuzato Yusuke Kakei Akiko Sato Yuka Mitani Yumiko Yamasaki‐Kokudo Takahiro Ishii Ken‐ichiro Hayashi Tadao Asami Takehiko Ogura Shigeo Yoshida Shozo Fujioka Takashi Kamakura Tsutomu Kawatsu Masanori Tachikawa Kazuo Soeno Yukihisa Shimada 《The Plant journal : for cell and molecular biology》2016,87(3):245-257
We previously reported l ‐α‐aminooxy‐phenylpropionic acid (AOPP) to be an inhibitor of auxin biosynthesis, but its precise molecular target was not identified. In this study we found that AOPP targets TRYPTOPHAN AMINOTRANSFERASE of ARABIDOPSIS 1 (TAA1). We then synthesized 14 novel compounds derived from AOPP to study the structure–activity relationships of TAA1 inhibitors in vitro. The aminooxy and carboxy groups of the compounds were essential for inhibition of TAA1 in vitro. Docking simulation analysis revealed that the inhibitory activity of the compounds was correlated with their binding energy with TAA1. These active compounds reduced the endogenous indole‐3‐acetic acid (IAA) content upon application to Arabidopsis seedlings. Among the compounds, we selected 2‐(aminooxy)‐3‐(naphthalen‐2‐yl)propanoic acid (KOK1169/AONP) and analyzed its activities in vitro and in vivo. Arabidopsis seedlings treated with KOK1169 showed typical auxin‐deficient phenotypes, which were reversed by exogenous IAA. In vitro and in vivo experiments indicated that KOK1169 is more specific for TAA1 than other enzymes, such as phenylalanine ammonia‐lyase. We further tested 41 novel compounds with aminooxy and carboxy groups to which we added protection groups to increase their calculated hydrophobicity. Most of these compounds decreased the endogenous auxin level to a greater degree than the original compounds, and resulted in a maximum reduction of about 90% in the endogenous IAA level in Arabidopsis seedlings. We conclude that the newly developed compounds constitute a class of inhibitors of TAA1. We designated them ‘pyruvamine’. 相似文献
967.
Hiroaki Yasumoto Hideya Katoh Mao Kinoshita Masaru Shimizu Saeko Hamaoka Koichi Akiyama Yoshifumi Naito Teiji Sawa 《Microbiology and immunology》2016,60(2):114-120
Of the various virulence mechanisms of the opportunistic pathogen Pseudomonas aeruginosa, the type III secretion system (TTSS) has been characterized as a major factor associated with acute lung injury, bacteremia and mortality. In addition, PcrV, a component protein of the TTSS, has been characterized as a protective antigen against infection with P. aeruginosa. This study comprised an epidemiological analysis of serum anti‐PcrV titers in a cohort of Japanese adults. From April 2012 to March 2013, serum anti‐PcrV titers of 198 volunteer participants undergoing anesthesia for scheduled surgeries were measured. The median, minimum and maximum serum anti‐PcrV titers among the 198 participants were 4.09 nM, 1.01 nM and 113.81 nM, respectively. The maximum peaks in the histogram were within the anti‐PcrV 2.00–4.99 nM titer range; values for 115 participants (58.1%) were within this range. Anti‐PcrV titers were more than approximately three‐fold greater (>12 nM) than the median value in 21 participants (10.6%). Ten‐year interval age increases, history of treatment for traffic trauma, and a history of past surgery each showed statistically significant associations with higher anti‐PcrV titers (i.e., >10 nM) than did the other factors assessed by binomial analysis. This study revealed a considerable variation in anti‐PcrV titers in adult subjects without any obvious histories of infection with P. aeruginosa. 相似文献
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