ソウセツ バセドウビョウ ノ セイイン ト TSH ジュヨウタイ コウタイ

journal articl

Observation of B0→D*-(5π)+, B+→D*-(4π)++ and B+→D̅*0 (5π)+

journal articl

改正中華人民共和国消費者権利利益保護法

departmental bulletin pape

経済協力開発機構 (OECD) における水資源管理対策 (二)

departmental bulletin pape

APPLICATION OF PSP IN LOW PRESSURE REGIME

The PSP technique has the capability to be applied to high Knudsen number flows, such as low density gas flows, micro-flows, and so on. In this study, fundamental properties of PSPs such as sensitivity to pressure are examined especially in the range of pressure below 150 Pa (about 1 Torr), to select the most suitable PSP for the low pressure range. One of the PSP is Bath-Ru adsorbed directly on anodized aluminum, and the other PSPs are composed of porphyrin complexes bound by glassy polymer poly(TMSP). As an application of PSP to low density gas flows, we measure a pressure distribution on a surface of an aluminum plate interacting with a low density supersonic free jet. The clear two-dimensional pressure distribution was obtained by using PtTFPP/poly(TMSP), showing the feasibility of quantitative pressure measurement using the PSP.journal articl

Histone H3 Lysine 56 Acetylation Enhances AP Endonuclease 1‑Mediated Repair of AP Sites in Nucleosome Core Particles

Deciphering factors modulating DNA repair in chromatin is of great interest because nucleosomal positioning influences mutation rates. H3K56 acetylation (Ac) is implicated in chromatin landscape regulation, impacting genomic stability, yet the effect of H3K56Ac on DNA base excision repair (BER) remains unclear. We determined whether H3K56Ac plays a role in regulating AP site incision by AP endonuclease 1 (APE1), an early step in BER. Our in vitro studies of acetylated, well-positioned nucleosome core particles (H3K56Ac-601-NCPs) demonstrate APE1 strand incision is enhanced compared with that of unacetylated WT-601-NCPs. The high-mobility group box 1 protein enhances APE1 activity in WT-601-NCPs, but this effect is not observed in H3K56Ac-601-NCPs. Therefore, our results suggest APE1 activity on NCPs can be modulated by H3K56Ac

Expression of human <i>POLβ</i> into <i>S. cerevisiae rad27</i> mutants.

<p>(A) Immunoblot illustrating human Pol β expression in <i>S. cerevisiae</i>. Total extract protein was isolated (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0047945#s2" target="_blank">Materials and Methods</a>) from the indicated five strains. The indicated extracts (50 µl each) from <i>wild-type</i> (lane 1), <i>rad27</i>Δ (lane 2), <i>rad27::POLβ</i> (lane 3), <i>rad27::polβ-D256A</i> (lane 4), or <i>rad27::polβ-3K</i> (lane 5), respectively, were separated by SDS-PAGE, transferred to a nitrocellulose membrane, and probed either with an antibody against pol β (upper panel) or with an antibody against GAPDH (bottom panel). Bands corresponding to Pol β (39 kDa) were observed. GAPDH was used as a loading control. (B and C) 5′-dRP lyase assays. Schematic representations of the dRP lyase substrates (3′- or 5′-end ³²P-labeled) and the expected ³²P-labeled products formed as a result of lyase activity of the extract are illustrated. (B) DNA substrate (100 nM) was incubated with extracts from <i>wild-type</i> (lane 1), <i>rad27</i>Δ (lane 2), <i>rad27::POLβ</i> (lane 3), <i>rad27::polβ-D256A</i> (lane 4), and <i>rad27::polβ-3K</i> (lane 5), with <i>purified</i> Pol β (lane 6), or with DNA alone (lane 7). After a 15-min incubation at 35°C, the DNA products were stabilized by NaBH₄ and analyzed as described under Material and Methods. The positions of the substrate and product are indicated. (C) 5′-end ³²P-labeled DNA substrate (100 nM) was incubated either with DNA alone (lanes 1–2) or with extracts from <i>wild-type</i> (lanes 3–4), <i>rad27</i>Δ (lanes 5–6), <i>rad27::POLβ</i> (lanes 7–8), <i>rad27::polβ-D256A</i> (lanes 9–10), and <i>rad27::polβ-3K</i> (lane11–12), respectively. After 5 and 10 min incubations at 35°C, the DNA products were stabilized and processed as in (B). The position of the product is indicated.</p

Evidence for Abasic Site Sugar Phosphate-Mediated Cytotoxicity in Alkylating Agent Treated <em>Saccharomyces cerevisiae</em>

<div><p>To better understand alkylating agent-induced cytotoxicity and the base lesion DNA repair process in <em>Saccharomyces cerevisiae</em>, we replaced the <em>RAD27^FEN1</em> open reading frame (ORF) with the ORF of the bifunctional human repair enzyme DNA polymerase (Pol) β. The aim was to probe the effect of removal of the incised abasic site 5′-sugar phosphate group (i.e., 5′-deoxyribose phosphate or 5′-dRP) in protection against methyl methanesulfonate (MMS)-induced cytotoxicity. In <em>S. cerevisiae</em>, Rad27^Fen1 was suggested to protect against MMS-induced cytotoxicity by excising multinucleotide flaps generated during repair. However, we proposed that the repair intermediate with a blocked 5′-end, i.e., 5′-dRP group, is the actual cytotoxic lesion. In providing a 5′-dRP group removal function mediated by dRP lyase activity of Pol β, the effects of the 5′-dRP group were separated from those of the multinucleotide flap itself. Human Pol β was expressed in <em>S. cerevisiae</em>, and this partially rescued the MMS hypersensitivity observed with <em>rad27^fen1</em>-null cells. To explore this rescue effect, altered forms of Pol β with site-directed eliminations of either the 5′-dRP lyase or polymerase activity were expressed in <em>rad27^fen1</em>-null cells. The 5′-dRP lyase, but not the polymerase activity, conferred the resistance to MMS. These results suggest that after MMS exposure, the 5′-dRP group in the repair intermediate is cytotoxic and that Rad27^Fen1 protection against MMS in wild-type cells is due to elimination of the 5′-dRP group.</p> </div

Mammalian Base Excision Repair: Functional Partnership between PARP-1 and APE1 in AP-Site Repair

<div><p>The apurinic/apyrimidinic- (AP-) site in genomic DNA arises through spontaneous base loss and base removal by DNA glycosylases and is considered an abundant DNA lesion in mammalian cells. The base excision repair (BER) pathway repairs the AP-site lesion by excising and replacing the site with a normal nucleotide via template directed gap-filling DNA synthesis. The BER pathway is mediated by a specialized group of proteins, some of which can be found in multiprotein complexes in cultured mouse fibroblasts. Using a DNA polymerase (pol) β immunoaffinity-capture technique to isolate such a complex, we identified five tightly associated and abundant BER factors in the complex: PARP-1, XRCC1, DNA ligase III, PNKP, and Tdp1. AP endonuclease 1 (APE1), however, was not present. Nevertheless, the complex was capable of BER activity, since repair was initiated by PARP-1’s AP lyase strand incision activity. Addition of purified APE1 increased the BER activity of the pol β complex. Surprisingly, the pol β complex stimulated the strand incision activity of APE1. Our results suggested that PARP-1 was responsible for this effect, whereas other proteins in the complex had no effect on APE1 strand incision activity. Studies of purified PARP-1 and APE1 revealed that PARP-1 was able to stimulate APE1 strand incision activity. These results illustrate roles of PARP-1 in BER including a functional partnership with APE1.</p></div

Effect of PARP-1 on APE1-dependent BER.

<p>(A) A schematic representation of the DNA substrate containing the AP-site and the reaction scheme is shown. The BER reaction conditions and product analysis are described under Materials and Methods. (B) The BER reaction mixtures containing purified proteins XRCC1, PNKP, DNA ligase I and APE1 were supplemented either with PARP-1 (lanes 1–3) or dilution buffer (lanes 4–6). Repair was initiated by transferring the reaction mixtures to 37°C. Aliquots were withdrawn at 5, 10 and 20 min. The reaction products were analyzed as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0124269#pone.0124269.g001" target="_blank">Fig 1</a>. The positions of the BER intermediate (unligated) and ligated BER products are indicated. (C) Quantification of the BER products was performed using ImageQuant software and data plotted as a function of incubation time (min). The plot demonstrates that BER product formation was linear during the 20 min incubation and that PARP-1 stimulated BER at least 2-fold as compared to the reaction without additional PARP-1.</p