Hirofumi Aiba - Academia.edu (original) (raw)
Papers by Hirofumi Aiba
The Journal of General and Applied Microbiology
The fission yeast Schizosaccharomyces pombe ecl family genes respond to various starvation signal... more The fission yeast Schizosaccharomyces pombe ecl family genes respond to various starvation signals and induce appropriate intracellular responses, including the extension of chronological lifespan and induction of sexual differentiation. Herein, we propose that the colonization of hemocoel 1 (COH1) protein of Metarhizium robertsii, an insect-pathogenic fungus, is a functional homolog of S. pombe Ecl1 family proteins.
The Journal of General and Applied Microbiology
Fission yeast, Schizosaccharomyces pombe, possesses eight hexose transporters, Ght1~8. In order t... more Fission yeast, Schizosaccharomyces pombe, possesses eight hexose transporters, Ght1~8. In order to clarify the role of each hexose transporter on glucose uptake, a glucose uptake assay system was established and the actual glucose uptake activity of each hexose transporter-deletion mutant was measured. Under normal growth condition containing 2% glucose, ∆ght5 and ∆ght2 mutants showed large and small decrease in glucose uptake activity, respectively. On the other hand, the other deletion mutants did not show any decrease in glucose uptake activity indicating that, in the presence of Ght5 and Ght2, the other hexose transporters do not play a significant role in glucose uptake. To understand the relevance between glucose uptake and lifespan regulation, we measured the chronological lifespan of each hexose transporter deletion mutant, and found that only ∆ght5 mutant showed a significant lifespan extension. Based on these results we showed that Ght5 is mainly involved in the glucose uptake in Schizosaccharomyces pombe, and suggested that the ∆ght5 mutant has prolonged lifespan due to physiological changes similar to calorie restriction.
The rpoS-encoded sS subunit of RNA polymerase regulates the expression of stationary phase and st... more The rpoS-encoded sS subunit of RNA polymerase regulates the expression of stationary phase and stress response genes in Escherichia coli. Recent study of our DNA microarray analysis suggested that the rpoS expression is aŠected by multiple two-component systems. In this study, we identiˆed two-component-system mutants in which the rpoS expression increased. The regulatory manner of the systems on rpoS expression is suggested.
Journal of Biological Chemistry, 1989
FEMS Microbiology Letters, 2016
We identified an essential protein kinase Nnk1 as a determinant of chronological lifespan in fiss... more We identified an essential protein kinase Nnk1 as a determinant of chronological lifespan in fission yeast.
Journal of Bacteriology, 1987
To analyze the function of micF as an antisera RNA in the osmoregulatory expression of the ompF g... more To analyze the function of micF as an antisera RNA in the osmoregulatory expression of the ompF gene in Escherichia coli, we performed two experiments. In the first experiment, two strains were constructed in which the transcription initiation site of the ompF gene and the transcription termination site of the micF gene were separated by 186 and 4,100 base pairs, respectively, on the chromosome. These two strains showed almost the same profile of ompF expression as the wild-type strain in which the two genes are separated by 10(6) base pairs. When a high-copy-number plasmid carrying the micF gene was introduced into these strains, ompF expression was completely repressed, whereas no repression was observed with a low-copy-number plasmid carrying the micF gene. These results indicate that the distance between the two genes on the chromosome is not critical for the function of micF. In the second experiment, expression of the ompF gene was examined by pulse-labeling in both the micF+ ...
Nippon Saikingaku Zasshi, 1996
Cell Cycle, 2014
In eukaryotes, the cyclin-dependent kinase Cdk1p (Cdc2p) plays a central role in entry into and p... more In eukaryotes, the cyclin-dependent kinase Cdk1p (Cdc2p) plays a central role in entry into and progression through nuclear division during mitosis and meiosis. Cdk1p is activated during meiotic nuclear divisions by dephosphorylation of its tyrosine-15 residue. The phosphorylation status of this residue is largely determined by the Wee1p kinase and the Cdc25p phosphatase. In fission yeast, the forkhead-type transcription factor Mei4p is essential for entry into the first meiotic nuclear division. We recently identified cdc25 C as an essential target of Mei4p in the control of entry into meiosis I. Here, we show that wee1 C is another important target of Mei4p in the control of entry into meiosis I. Mei4p bound to the upstream region of wee1 C in vivo and in vitro and inhibited expression of wee1 C , whereas Mei4p positively regulated expression of the adjacent pseudogene. Overexpression of Mei4p inhibited expression of wee1 C and induced that of the pseudogene. Conversely, deletion of Mei4p did not decrease expression of wee1 C but inhibited that of the pseudogene. In addition, deletion of Mei4p-binding regions delayed repression of wee1 C expression as well as induction of expression of the pseudogene. These results suggest that repression of wee1 C expression is primarily owing to Mei4p-mediated transcriptional interference.
Journal of Biological Chemistry, 2010
Chronological life span is defined by how long a cell can survive in a non-dividing state. In yea... more Chronological life span is defined by how long a cell can survive in a non-dividing state. In yeast, it is measured by viability after entry into stationary phase. To date, some factors affecting chronological life span have been identified; however, the molecular details of how these factors regulate chronological life span have not yet been elucidated clearly. Because life span is a complicated phenomenon and is supposedly regulated by many factors, it is necessary to identify new factors affecting chronological life span to understand life span regulation. To this end, we have screened for long-lived mutants and identified Pma1, an essential P-type proton ATPase, as one of the determinants of chronological life span. We show that partial loss of Pma1 activity not only by mutations but also by treatment with the Pma1 inhibitory chemical vanadate resulted in the longlived phenotype in Schizosaccharomyces pombe. These findings suggest a novel way to manipulate chronological life span by modulating Pma1 as a molecular target.
FEMS Yeast Research, 2008
We have identified a novel gene from Schizosaccharomyces pombe that we have named ecl1 1 (extende... more We have identified a novel gene from Schizosaccharomyces pombe that we have named ecl1 1 (extender of the chronological lifespan). When ecl1 1 is provided on a high-copy number plasmid, it extends the viability of both the Dsty1 MAP kinase mutant and the wild-type cells after entry into the stationary phase. ecl1 1 encodes an 80-amino acid polypeptide that had not been annotated in the current database. The ecl1 1-mRNA increases transiently when the growth phase is changed from the log phase to the stationary phase. The Ecl1 protein is localized in the nucleus. Calorie restriction extends the chronological lifespan of wild-type and Decl1 cells but not ecl1 1-overproducing cells. The Dpka1 mutant shows little, if any, additional extension of viability when Ecl1 is overproduced. The ste11 1 gene that is negatively controlled by Pka1 is up regulated when Ecl1 is overproduced. From these results we propose that the effect of Ecl1 overproduction may be mainly linked to and negatively affects the Pka1-dependent pathway.
FEBS Letters, 1995
The gpd1 + gene of Schizosaccharomyces pombe encodes an isozyme of NADH‐dependent glycerol‐3‐phos... more The gpd1 + gene of Schizosaccharomyces pombe encodes an isozyme of NADH‐dependent glycerol‐3‐phosphate dehydrogenases that is involved in glycerol synthesis, whose expression is induced upon an upshift of the medium osmolarity. We provide evidence that this osmotic induction of gpd1 + in S. pombe is under the control of a MAP‐signaling pathway involving the wis1 + gene‐product, which is a homologue of MAP‐kinase kinases. The results suggested that the gpd1 + gene is a downstream target of the osmosensing signaling that is transmitted through Wis1, thereby defects of either of these genes result in the similar phenotype, namely, osmosensitive for growth, because of the failure in accumulation of the intracellular osmoprotectant, glycerol.
Bioscience, Biotechnology, and Biochemistry, 2012
Ecl1, a product of the YGR146C gene in Saccharomyces cerevisiae, was identified as a factor invol... more Ecl1, a product of the YGR146C gene in Saccharomyces cerevisiae, was identified as a factor involved in chronological lifespan. In this study we found evidence that the function of Ecl1 in the extension of chronological lifespan is dependent on mitochondrial function. The respiratory activity of cells increased when Ecl1 was overexpressed or cells were grown under calorie restriction, but there was no additive effect of calorie restriction and Ecl1 overexpression on increases in respiratory activity or on the extension of chronological lifespan. Based on these results, we propose that overexpression of Ecl1 has same effect as caloric restriction and that its function also depends on mitochondria, just like caloric restriction.
Bioscience, Biotechnology, and Biochemistry, 2009
We found that YGR146C of Saccharomyces cerevisiae encodes a functional homolog of Ecl1 that is in... more We found that YGR146C of Saccharomyces cerevisiae encodes a functional homolog of Ecl1 that is involved in the chronological lifespan of Schizosaccharomyces pombe. When YGR146C is overexpressed, it extends the viability of wild-type S. cerevisiae cells after entry into the stationary phase, as in the case of Ecl1. We propose that Ecl1 family proteins are novel regulatory factors involved in chronological lifespan among yeasts.
Bioscience, Biotechnology, and Biochemistry, 2009
An Escherichia coli mutant lacking three major K þ uptake systems, Trk, Kup, and Kdp, did not gro... more An Escherichia coli mutant lacking three major K þ uptake systems, Trk, Kup, and Kdp, did not grow under low K þ and high Na þ concentrations. The introduction of fkuA and of fkuB of a marine bacterium, Vibrio alginolyticus, has been reported to compensate for the growth defect by accelerating the rate of K þ uptake (Nakamura, Katoh, Shimizu, Matsuba, and Unemoto, Biochim. Biophys. Acta, 1277, 201-208 (1996)). We investigated the function of unknown genes of E. coli, yggS and yggT, homologs of fkuA and fkuB respectively. E. coli TK2420 cells, which lack the three K þ uptake systems, did not grow under high Na þ or mannitol concentrations. The growth defect was compensated by the introduction of the yggT gene alone: yggS was not required. Here we found that YggT endowed E. coli cells with a tolerance for osmotic shock, and discuss a possible mechanism.
Bioscience, Biotechnology, and Biochemistry, 1997
The gpdJ gene of Schizosllccharomyces pombe, encoding an isozyme of NADH-dependent giycerol-3-pho... more The gpdJ gene of Schizosllccharomyces pombe, encoding an isozyme of NADH-dependent giycerol-3-phosphate dehydrogenase, is responsible for an osmoinducible glycerol production in response to external high osmotic stimuli, and its expression is osmoregulated at the level of transcription. In this study, the structure of the osmoinducible promoter of gpdl + is described. Not only the core promoter elements including the putative TAT A-box and transcription start site, but also a short upstream activation sequence (UAS) was identified, which are invohed in the osmotic induction of the gpdJ + gene through the Wisl MAP (mitogen activated protein) kinase pathway.
Bioscience, Biotechnology, and Biochemistry, 1993
FEMS Yeast Research, 2021
Sulfur is an essential component of various biologically important molecules, including methionin... more 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. Although fission yeast can use sulfate as a sulfur source, its sulfur metabolism pathway is slightly different from that of budding yeast because it does not have a trans-sulfuration pathway. In recent years, it has been found that sulfur starvation causes various cellular responses in S. pombe, including sporulation, cell cycle arrest at G2, chronological lifespan extension, autophagy induction and reduced translation. This MiniReview identifies two sulfate transporters in S. pombe, Sul1 (en...
The Journal of General and Applied Microbiology
The fission yeast Schizosaccharomyces pombe ecl family genes respond to various starvation signal... more The fission yeast Schizosaccharomyces pombe ecl family genes respond to various starvation signals and induce appropriate intracellular responses, including the extension of chronological lifespan and induction of sexual differentiation. Herein, we propose that the colonization of hemocoel 1 (COH1) protein of Metarhizium robertsii, an insect-pathogenic fungus, is a functional homolog of S. pombe Ecl1 family proteins.
The Journal of General and Applied Microbiology
Fission yeast, Schizosaccharomyces pombe, possesses eight hexose transporters, Ght1~8. In order t... more Fission yeast, Schizosaccharomyces pombe, possesses eight hexose transporters, Ght1~8. In order to clarify the role of each hexose transporter on glucose uptake, a glucose uptake assay system was established and the actual glucose uptake activity of each hexose transporter-deletion mutant was measured. Under normal growth condition containing 2% glucose, ∆ght5 and ∆ght2 mutants showed large and small decrease in glucose uptake activity, respectively. On the other hand, the other deletion mutants did not show any decrease in glucose uptake activity indicating that, in the presence of Ght5 and Ght2, the other hexose transporters do not play a significant role in glucose uptake. To understand the relevance between glucose uptake and lifespan regulation, we measured the chronological lifespan of each hexose transporter deletion mutant, and found that only ∆ght5 mutant showed a significant lifespan extension. Based on these results we showed that Ght5 is mainly involved in the glucose uptake in Schizosaccharomyces pombe, and suggested that the ∆ght5 mutant has prolonged lifespan due to physiological changes similar to calorie restriction.
The rpoS-encoded sS subunit of RNA polymerase regulates the expression of stationary phase and st... more The rpoS-encoded sS subunit of RNA polymerase regulates the expression of stationary phase and stress response genes in Escherichia coli. Recent study of our DNA microarray analysis suggested that the rpoS expression is aŠected by multiple two-component systems. In this study, we identiˆed two-component-system mutants in which the rpoS expression increased. The regulatory manner of the systems on rpoS expression is suggested.
Journal of Biological Chemistry, 1989
FEMS Microbiology Letters, 2016
We identified an essential protein kinase Nnk1 as a determinant of chronological lifespan in fiss... more We identified an essential protein kinase Nnk1 as a determinant of chronological lifespan in fission yeast.
Journal of Bacteriology, 1987
To analyze the function of micF as an antisera RNA in the osmoregulatory expression of the ompF g... more To analyze the function of micF as an antisera RNA in the osmoregulatory expression of the ompF gene in Escherichia coli, we performed two experiments. In the first experiment, two strains were constructed in which the transcription initiation site of the ompF gene and the transcription termination site of the micF gene were separated by 186 and 4,100 base pairs, respectively, on the chromosome. These two strains showed almost the same profile of ompF expression as the wild-type strain in which the two genes are separated by 10(6) base pairs. When a high-copy-number plasmid carrying the micF gene was introduced into these strains, ompF expression was completely repressed, whereas no repression was observed with a low-copy-number plasmid carrying the micF gene. These results indicate that the distance between the two genes on the chromosome is not critical for the function of micF. In the second experiment, expression of the ompF gene was examined by pulse-labeling in both the micF+ ...
Nippon Saikingaku Zasshi, 1996
Cell Cycle, 2014
In eukaryotes, the cyclin-dependent kinase Cdk1p (Cdc2p) plays a central role in entry into and p... more In eukaryotes, the cyclin-dependent kinase Cdk1p (Cdc2p) plays a central role in entry into and progression through nuclear division during mitosis and meiosis. Cdk1p is activated during meiotic nuclear divisions by dephosphorylation of its tyrosine-15 residue. The phosphorylation status of this residue is largely determined by the Wee1p kinase and the Cdc25p phosphatase. In fission yeast, the forkhead-type transcription factor Mei4p is essential for entry into the first meiotic nuclear division. We recently identified cdc25 C as an essential target of Mei4p in the control of entry into meiosis I. Here, we show that wee1 C is another important target of Mei4p in the control of entry into meiosis I. Mei4p bound to the upstream region of wee1 C in vivo and in vitro and inhibited expression of wee1 C , whereas Mei4p positively regulated expression of the adjacent pseudogene. Overexpression of Mei4p inhibited expression of wee1 C and induced that of the pseudogene. Conversely, deletion of Mei4p did not decrease expression of wee1 C but inhibited that of the pseudogene. In addition, deletion of Mei4p-binding regions delayed repression of wee1 C expression as well as induction of expression of the pseudogene. These results suggest that repression of wee1 C expression is primarily owing to Mei4p-mediated transcriptional interference.
Journal of Biological Chemistry, 2010
Chronological life span is defined by how long a cell can survive in a non-dividing state. In yea... more Chronological life span is defined by how long a cell can survive in a non-dividing state. In yeast, it is measured by viability after entry into stationary phase. To date, some factors affecting chronological life span have been identified; however, the molecular details of how these factors regulate chronological life span have not yet been elucidated clearly. Because life span is a complicated phenomenon and is supposedly regulated by many factors, it is necessary to identify new factors affecting chronological life span to understand life span regulation. To this end, we have screened for long-lived mutants and identified Pma1, an essential P-type proton ATPase, as one of the determinants of chronological life span. We show that partial loss of Pma1 activity not only by mutations but also by treatment with the Pma1 inhibitory chemical vanadate resulted in the longlived phenotype in Schizosaccharomyces pombe. These findings suggest a novel way to manipulate chronological life span by modulating Pma1 as a molecular target.
FEMS Yeast Research, 2008
We have identified a novel gene from Schizosaccharomyces pombe that we have named ecl1 1 (extende... more We have identified a novel gene from Schizosaccharomyces pombe that we have named ecl1 1 (extender of the chronological lifespan). When ecl1 1 is provided on a high-copy number plasmid, it extends the viability of both the Dsty1 MAP kinase mutant and the wild-type cells after entry into the stationary phase. ecl1 1 encodes an 80-amino acid polypeptide that had not been annotated in the current database. The ecl1 1-mRNA increases transiently when the growth phase is changed from the log phase to the stationary phase. The Ecl1 protein is localized in the nucleus. Calorie restriction extends the chronological lifespan of wild-type and Decl1 cells but not ecl1 1-overproducing cells. The Dpka1 mutant shows little, if any, additional extension of viability when Ecl1 is overproduced. The ste11 1 gene that is negatively controlled by Pka1 is up regulated when Ecl1 is overproduced. From these results we propose that the effect of Ecl1 overproduction may be mainly linked to and negatively affects the Pka1-dependent pathway.
FEBS Letters, 1995
The gpd1 + gene of Schizosaccharomyces pombe encodes an isozyme of NADH‐dependent glycerol‐3‐phos... more The gpd1 + gene of Schizosaccharomyces pombe encodes an isozyme of NADH‐dependent glycerol‐3‐phosphate dehydrogenases that is involved in glycerol synthesis, whose expression is induced upon an upshift of the medium osmolarity. We provide evidence that this osmotic induction of gpd1 + in S. pombe is under the control of a MAP‐signaling pathway involving the wis1 + gene‐product, which is a homologue of MAP‐kinase kinases. The results suggested that the gpd1 + gene is a downstream target of the osmosensing signaling that is transmitted through Wis1, thereby defects of either of these genes result in the similar phenotype, namely, osmosensitive for growth, because of the failure in accumulation of the intracellular osmoprotectant, glycerol.
Bioscience, Biotechnology, and Biochemistry, 2012
Ecl1, a product of the YGR146C gene in Saccharomyces cerevisiae, was identified as a factor invol... more Ecl1, a product of the YGR146C gene in Saccharomyces cerevisiae, was identified as a factor involved in chronological lifespan. In this study we found evidence that the function of Ecl1 in the extension of chronological lifespan is dependent on mitochondrial function. The respiratory activity of cells increased when Ecl1 was overexpressed or cells were grown under calorie restriction, but there was no additive effect of calorie restriction and Ecl1 overexpression on increases in respiratory activity or on the extension of chronological lifespan. Based on these results, we propose that overexpression of Ecl1 has same effect as caloric restriction and that its function also depends on mitochondria, just like caloric restriction.
Bioscience, Biotechnology, and Biochemistry, 2009
We found that YGR146C of Saccharomyces cerevisiae encodes a functional homolog of Ecl1 that is in... more We found that YGR146C of Saccharomyces cerevisiae encodes a functional homolog of Ecl1 that is involved in the chronological lifespan of Schizosaccharomyces pombe. When YGR146C is overexpressed, it extends the viability of wild-type S. cerevisiae cells after entry into the stationary phase, as in the case of Ecl1. We propose that Ecl1 family proteins are novel regulatory factors involved in chronological lifespan among yeasts.
Bioscience, Biotechnology, and Biochemistry, 2009
An Escherichia coli mutant lacking three major K þ uptake systems, Trk, Kup, and Kdp, did not gro... more An Escherichia coli mutant lacking three major K þ uptake systems, Trk, Kup, and Kdp, did not grow under low K þ and high Na þ concentrations. The introduction of fkuA and of fkuB of a marine bacterium, Vibrio alginolyticus, has been reported to compensate for the growth defect by accelerating the rate of K þ uptake (Nakamura, Katoh, Shimizu, Matsuba, and Unemoto, Biochim. Biophys. Acta, 1277, 201-208 (1996)). We investigated the function of unknown genes of E. coli, yggS and yggT, homologs of fkuA and fkuB respectively. E. coli TK2420 cells, which lack the three K þ uptake systems, did not grow under high Na þ or mannitol concentrations. The growth defect was compensated by the introduction of the yggT gene alone: yggS was not required. Here we found that YggT endowed E. coli cells with a tolerance for osmotic shock, and discuss a possible mechanism.
Bioscience, Biotechnology, and Biochemistry, 1997
The gpdJ gene of Schizosllccharomyces pombe, encoding an isozyme of NADH-dependent giycerol-3-pho... more The gpdJ gene of Schizosllccharomyces pombe, encoding an isozyme of NADH-dependent giycerol-3-phosphate dehydrogenase, is responsible for an osmoinducible glycerol production in response to external high osmotic stimuli, and its expression is osmoregulated at the level of transcription. In this study, the structure of the osmoinducible promoter of gpdl + is described. Not only the core promoter elements including the putative TAT A-box and transcription start site, but also a short upstream activation sequence (UAS) was identified, which are invohed in the osmotic induction of the gpdJ + gene through the Wisl MAP (mitogen activated protein) kinase pathway.
Bioscience, Biotechnology, and Biochemistry, 1993
FEMS Yeast Research, 2021
Sulfur is an essential component of various biologically important molecules, including methionin... more 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. Although fission yeast can use sulfate as a sulfur source, its sulfur metabolism pathway is slightly different from that of budding yeast because it does not have a trans-sulfuration pathway. In recent years, it has been found that sulfur starvation causes various cellular responses in S. pombe, including sporulation, cell cycle arrest at G2, chronological lifespan extension, autophagy induction and reduced translation. This MiniReview identifies two sulfate transporters in S. pombe, Sul1 (en...