Stabilization of ATF4 protein is required for the regulation of epithelial–mesenchymal transition of the avian neural crest

AbstractEpithelial–mesenchymal transition (EMT) permits neural crest cells to delaminate from the epithelial ectoderm and to migrate extensively in the embryonic environment. In this study, we have identified ATF4, a basic-leucine-zipper transcription factor, as one of the neural crest EMT regulators. Although ATF4 alone was not sufficient to drive the formation of migratory neural crest cells, ATF4 cooperated with Sox9 to induce neural crest EMT by controlling the expression of cell–cell and cell–extracellular matrix adhesion molecules. This was likely, at least in part, by inducing the expression of Foxd3, which encodes another neural crest transcription factor. We also found that the ATF4 protein level was strictly regulated by proteasomal degradation and p300-mediated stabilization, allowing ATF4 protein to accumulate in the nuclei of neural crest cells undergoing EMT. Thus, our results emphasize the importance of the regulation of protein stability in the neural crest EMT

Effect of Furnish on Temperature and Vapor Pressure Behavior in the Center of Mat Panels during Hot Pressing

Particleboard achieves its overall performance characteristics during hot pressing process. As this process is influenced by several factors, particularly temperature and pressure, it is very important to understand the behavior of both. This study investigates the effects of furnish materials on temperature and vapor pressure behavior inside particleboard mat panels during hot pressing. Strand type particles from hinoki and ring-flaker recycled wood particles were used as furnish for laboratory-scale particleboard panels with a target density of 0.76 g/cm³. Mat panels with a moisture content of about 10% were hot pressed at a platen temperature of 180°C and an initial pressure of 3 MPa until the mat center reached the same temperature as the platen. A press monitoring device (PressMAN Lite) was used for detecting the temperature and vapor pressure change in the center of the mat panels. The study showed that the furnish type affected the temperature and vapor behavior inside the mat panels. Particleboard made of hinoki strand resulted in a longer plateau time, a higher plateau temperature and a higher gas pressure generated during hot pressing than those of ring-flaker recycled wood particles. Mixed board resulted in values between those of the two other furnish materials

Mitochondria-specific RNA-modifying Enzymes Responsible for the Biosynthesis of the Wobble Base in Mitochondrial tRNAs

Human mitochondrial (mt) tRNALys has a taurine-containing modified uridine, 5-taurinomethyl-2-thiouridine (τm5s2U), at its anticodon wobble position. We previously found that the mt tRNALys, carrying the A8344G mutation from cells of patients with myoclonus epilepsy associated with ragged-red fibers (MERRF), lacks the τm5s2U modification. Here we describe the identification and characterization of a tRNA-modifying enzyme MTU1 (mitochondrial tRNA-specific 2-thiouridylase 1) that is responsible for the 2-thiolation of the wobble position in human and yeast mt tRNAs. Disruption of the yeast MTU1 gene eliminated the 2-thio modification of mt tRNAs and impaired mitochondrial protein synthesis, which led to reduced respiratory activity. Furthermore, when MTO1 or MSS1, which are responsible for the C5 substituent of the modified uridine, was disrupted along with MTU1, a much more severe reduction in mitochondrial activity was observed. Thus, the C5 and 2-thio modifications act synergistically in promoting efficient cognate codon decoding. Partial inactivation of MTU1 in HeLa cells by small interference RNA also reduced their oxygen consumption and resulted in mitochondria with defective membrane potentials, which are similar phenotypic features observed in MERRF.This work was supported by grants-in-aid for scientific research on priority areas from the Ministry of Education, Science, Sports, and Culture of Japan, and by a grant from the New Energy and Industrial Technology Development Organization (to T. S.)

Cloning of an isoform of mouse TGF-β type II receptor gene

AbstractA variant of transforming growth factor-β type II receptor (TGF-βRII) cDNA was isolated from a mouse brain cDNA library. The predicted receptor is identical to previously reported mouse TGF-βRII except that the isoform has an insertion sequence of 25 amino acids in the predicted ligand-binding domain. By the use of reverse transcription-polymerase chain reaction (RT-PCR), transcripts for both isoforms were detected in all tissues and developing embryos examined. The isoform transiently expressed in COS cells showed a similar ligand-binding specificity to authentic TGF-βRII. These results suggest that the mouse TGF-βRII gene generates multiple isoforms, possibly by alternative splicing, as reported for activin type IIB receptor; and an isoform which has the extra sequence in the ligand-binding domain is also involved in the TGF-β signal transduction

Perceptual Continuity and Naturalness of Expressive Strength in Singing Voices Based on Speech Morphing

This paper experimentally shows the importance of perceptual continuity of the expressive strength in vocal timbre for natural change in vocal expression. In order to synthesize various and continuous expressive strengths with vocal timbre, we investigated gradually changing expressions by applying the STRAIGHT speech morphing algorithm to singing voices. Here, a singing voice without expression is used as the base of morphing, and singing voices with three different expressions are used as the target. Through statistical analyses of perceptual evaluations, we confirmed that the proposed morphing algorithm provides perceptual continuity of vocal timbre. Our results showed the following: (i) gradual strengths in absolute evaluations, and (ii) a perceptually linear strength provided by the calculation of corrected intervals of the morph ratio by the inverse (reciprocal) function of an equation that approximates the perceptual strength. Finally, we concluded that applying continuity was highly effective for achieving perceptual naturalness, judging from the results showing that (iii) our gradual transformation method can perform well for perceived naturalness

High pressure conditions promote the proliferation of rat cultured mesangial cells in vitro

AbstractGlomerular capillary pressure is involved in the development of chronic renal failure and has at least two effects on mesangial cells: transmembrane hydrostatic pressure and stretch. To clarify whether pure hydrostatic pressure itself affects the proliferation of cultured rat mesangial cells, we compared the cell number under atmospheric pressure condition with high pressure condition. At 24 and 48h with 0.5% serum, cell number was significantly higher under high pressure condition than under atmospheric pressure condition. At 48h, cell number under high pressure condition was increased in a pressure-dependent manner. Furthermore, flow cytometric assay indicated that pressure-load could promote DNA synthesis rate at S phase and enhance G1/S progression induced by low concentration of serum (0.5%). These results suggest that pure hydrostatic pressure itself can promote the proliferation of cultured rat mesangial cells by advancing cell cycle progression in vitro

Detection of reverse transcriptase activity by enzyme-linked immunosorbent assay in human immunodeficiency virus type 1.

An enzyme-linked immunosorbent assay (ELISA) using biotin-labelled oligo-dT primer and digoxigenin (Dig)-dUTP was designed to measure the reverse transcriptase (RT) activity of human immunodeficiency virus type 1 (HIV-1). The ELISA system involves the selective detection step of a newly synthesized cDNA by two specific bindings, biotin-streptavidin binding and alkaline phosphatase (AP)-conjugated anti-Dig-Dig binding, and the enzymatic amplification step to increase coloring generated by AP. This method was used to measure the activity of RT in the culture supernatants of peripheral leukocytes obtained from four anti-HIV-1-positive persons cocultivated with those from four anti-HIV-1-negative persons. RT activity was detected in all of four anti-HIV-1-positive culture supernatants but not in those cultivated with anti-HIV-1-negative supernatants alone. Thus, our improved ELISA for detection of HIV-1 appears to be sensitive enough and useful for routine laboratory work. This non-radioactive method will also be useful for detecting other retroviruses and for screening of RT inhibitors.</p

日本の高校・大学英語授業における内容重視の言語指導 : CBI 関連タスクにおける生徒のライティングパフォーマンス・タスク認識・コース認識

早大学位記番号:新9319博士(教育学)早稲田大