Hokuto Ohtsuka 교수

In fission yeast, we identified two genes, named ecl2+ and ecl3+, that are paralogous to ecl1+, which extends the chronological lifespan. Both ecl2+ and ecl3+ extend the chronological lifespan when overexpressed as ecl1+. ecl2+ and ecl3+ encode 84- and 89-amino acid polypeptides respectively that are not annotated in the current database. The Ecl2 protein is localized mainly in the nucleus, as Ecl1. These results suggest that ecl1+, ecl2+, and ecl3+ have overlapping functions in the regulation o

So far, more than 70 genes involved in the chronological lifespan (CLS) of Schizosaccharomyces pombe (fission yeast) have been reported. In this mini-review, we arrange and summarize these genes based on the reported genetic interactions between them and the physical interactions between their products. We describe the signal transduction pathways that affect CLS in S. pombe: target of rapamycin complex 1, cAMP-dependent protein kinase, Sty1, and Pmk1 pathways have important functions in the reg

The fission yeast Schizosaccharomyces pombe employs two main strategies to adapt to the environment and survive when starved for nutrients. The strategies employ sporulation via sexual differentiation and extension of the chronological lifespan. When a cell is exposed to nutrient starvation in the presence of a cell of the opposite sex, the cells undergo fusion through conjugation and sporulation through meiosis. S. pombe spores are highly resistant to diverse stresses and may survive for a very

Ecl1 family genes are conserved among yeast, in which their overexpression extends chronological lifespan. Ecl1 family genes were first identified in the fission yeast Schizosaccharomyces pombe; at the time, they were considered noncoding RNA owing to their short coding sequence of fewer than 300 base pairs. Schizosaccharomyces pombe carries three Ecl1 family genes, ecl1+, ecl2+ and ecl3+, whereas Saccharomyces cerevisiae has one, ECL1. Their overexpression extends chronological lifespan, increa

Nutritional restrictions such as calorie restrictions are known to increase the lifespan of various organisms. Here, we found that a restriction of sulfur extended the chronological lifespan (CLS) of the fission yeast Schizosaccharomyces pombe. The restriction decreased cellular size, RNA content, and ribosomal proteins and increased sporulation rate. These responses depended on Ecl1 family genes, the overexpression of which results in the extension of CLS. We also showed that the Zip1 transcrip

A Langmuir probe is used to study the plasma behaviour in the scrape-off layer of JFT-2a, (a Tokamak with an axisymmetric divertor). The measurements reveal particle fluxes to the divertor and the wall as well as cross-field profiles of density and potential in the scrape-off layer. On the basis of these measurements, the cross-field diffusion coefficient in the scrape-off layer and the divertor efficiency are estimated. The existence of the magnetic limiter is also verified by the method.

ecl1+, ecl2+ and ecl3+ genes encode highly homologous small proteins, and their over-expressions confer both H2O2 stress resistance and chronological lifespan extension on Schizosaccharomyces pombe. However, the mechanisms of how these Ecl1 family proteins function have not been elucidated. In this study, we conducted microarray analysis and identified that the expression of genes involved in sexual development and stress responses was affected by the over-expression of Ecl1 family proteins. In

There are several examples in the nature wherein the mechanism of longevity control of unicellular organisms is evolutionarily conserved with that of higher multicellular organisms. The present microreview focuses on aging and longevity studies, particularly on chronological lifespan (CLS) concerning the unicellular eukaryotic fission yeast Schizosaccharomyces pombe. In S. pombe, >30 compounds, 8 types of nutrient restriction, and >80 genes that extend CLS have been reported. Several CLS control

Nutrients including glucose, nitrogen, sulfur, zinc, and iron are involved in the regulation of chronological lifespan (CLS) of yeast, which serves as a model of the lifespan of differentiated cells of higher organisms. Herein, we show that magnesium (Mg²⁺ ) depletion extends CLS of the fission yeast Schizosaccharomyces pombe through a mechanism involving the Ecl1 gene family. We discovered that ecl1⁺ expression, which extends CLS, responds to Mg²⁺ depletion. The

Sulfur is an essential component of various biologically important molecules, including methionine, cysteine and glutathione, and it is also involved in coping with oxidative and heavy metal stress. Studies using model organisms, including budding yeast (Saccharomyces cerevisiae) and fission yeast (Schizosaccharomyces pombe), have contributed not only to understanding various cellular processes but also to understanding the utilization and response mechanisms of each nutrient, including sulfur.

Leucine (Leu) is a branched-chain, essential amino acid in animals, including humans. Fungi, including the fission yeast Schizosaccharomyces pombe, can biosynthesize Leu, but deletion of any of the genes in this biosynthesis leads to Leu auxotrophy. In this yeast, although a mutation in the Leu biosynthetic pathway, leu1-32, is clearly inconvenient for this species, it has increased its usefulness as a model organism in laboratories worldwide. Leu auxotrophy produces intracellular responses and