Search

Your search keyword '"Hara, Masatoshi"' showing total 234 results
Start Over Author "Hara, Masatoshi"
234 results on '"Hara, Masatoshi"'

55. Identification of PNG kinase substrates uncovers interactions with the translational repressor TRAL in the oocyte-to-embryo transition

Author

Massachusetts Institute of Technology. Department of Biology, Orr-Weaver, Terry, Hara, Masatoshi, Lourido, Sebastian, Petrova, Boryana, Lou, Hua Jane, Von Stetina, Jessica R, Kashevsky, Helena, Turk, Benjamin E, Massachusetts Institute of Technology. Department of Biology, Orr-Weaver, Terry, Hara, Masatoshi, Lourido, Sebastian, Petrova, Boryana, Lou, Hua Jane, Von Stetina, Jessica R, Kashevsky, Helena, and Turk, Benjamin E

Abstract

The Drosophila Pan Gu (PNG) kinase complex regulates hundreds of maternal mRNAs that become translationally repressed or activated as the oocyte transitions to an embryo. In a previous paper (Hara et al., 2017), we demonstrated PNG activity is under tight developmental control and restricted to this transition. Here, examination of PNG specificity showed it to be a Thrkinase yet lacking a clear phosphorylation site consensus sequence. An unbiased biochemical screen for PNG substrates identified the conserved translational repressor Trailer Hitch (TRAL). Phosphomimetic mutation of the PNG phospho-sites in TRAL reduced its ability to inhibit translation in vitro. In vivo, mutation of tral dominantly suppressed png mutants and restored Cyclin B protein levels. The repressor Pumilio (PUM) has the same relationship with PNG, and we also show that PUM is a PNG substrate. Furthermore, PNG can phosphorylate BICC and ME31B, repressors that bind TRAL in cytoplasmic RNPs. Therefore, PNG likely promotes translation at the oocyte-to-embryo transition by phosphorylating and inactivating translational repressors., National Institutes of Health (U.S.) (Grant GM39341), National Institutes of Health (U.S.) (Grant GM118090)

Published
2018

57. Cyclin B–Cdk1 inhibits protein phosphatase PP2A-B55 via a Greatwall kinase–independent mechanism

Author

OKUMURA, EIICHI, Morita, Atsushi, Wakai, Mizuho, Mochida, Satoru, Hara, Masatoshi, and Kishimoto, Takeo

Subjects
Cyclin D, Cyclin A, Cyclin B, macromolecular substances, environment and public health, Report, Chromosome Segregation, CDC2 Protein Kinase, Animals, Protein Phosphatase 2, Phosphorylation, Research Articles, Cells, Cultured, Cyclin, Cyclin-dependent kinase 1, biology, Cell Biology, Protein phosphatase 2, Phosphoproteins, Molecular biology, Cell biology, Enzyme Activation, enzymes and coenzymes (carbohydrates), Meiosis, Asterina, biology.protein, Cyclin-dependent kinase complex, Rabbits, biological phenomena, cell phenomena, and immunity, Protein Processing, Post-Translational, Cyclin A2
Abstract

The role of Greatwall kinase in autoregulatory activation of cyclin B–Cdk1 at M phase onset can be bypassed by cyclin B–Cdk1–mediated direct phosphorylation of Arpp19, leading to PP2A-B55 inhibition., Entry into M phase is governed by cyclin B–Cdk1, which undergoes both an initial activation and subsequent autoregulatory activation. A key part of the autoregulatory activation is the cyclin B–Cdk1–dependent inhibition of the protein phosphatase 2A (PP2A)–B55, which antagonizes cyclin B–Cdk1. Greatwall kinase (Gwl) is believed to be essential for the autoregulatory activation because Gwl is activated downstream of cyclin B–Cdk1 to phosphorylate and activate α-endosulfine (Ensa)/Arpp19, an inhibitor of PP2A-B55. However, cyclin B–Cdk1 becomes fully activated in some conditions lacking Gwl, yet how this is accomplished remains unclear. We show here that cyclin B–Cdk1 can directly phosphorylate Arpp19 on a different conserved site, resulting in inhibition of PP2A-B55. Importantly, this novel bypass is sufficient for cyclin B–Cdk1 autoregulatory activation. Gwl-dependent phosphorylation of Arpp19 is nonetheless necessary for downstream mitotic progression because chromosomes fail to segregate properly in the absence of Gwl. Such a biphasic regulation of Arpp19 results in different levels of PP2A-B55 inhibition and hence might govern its different cellular roles.

Published
2014

58. Association of Lower Serum Bilirubin With Loss of Residual Kidney Function in Peritoneal Dialysis Patients.

Author

Tsujikawa, Hiroaki, Tanaka, Shigeru, Hara, Masatoshi, Kawai, Yasuhiro, Matsukuma, Yuta, Torisu, Kumiko, Nakano, Toshiaki, Tsuruya, Kazuhiko, and Kitazono, Takanari

Subjects
PERITONEAL dialysis, BILIRUBIN, HEMODIALYSIS patients, PROPORTIONAL hazards models, CIRRHOSIS of the liver
Abstract

Bilirubin is recognized as an endogenous antioxidant, and low serum bilirubin is reported to be associated with the progression of kidney disease. However, it is unclear whether serum bilirubin levels are associated with the loss of residual kidney function (RKF) in peritoneal dialysis (PD) patients. This study investigated the relationship between serum total bilirubin and loss of RKF. We prospectively followed 94 PD patients who started PD in our hospital between June 2006 and May 2016. Ten patients who had chronic liver disease or cirrhosis were excluded. Patients were divided into three groups based on serum total bilirubin concentration tertiles: tertile 1 (T1) < 0.3, T2 = 0.3, and T3 ≥ 0.4 mg/dL. We estimated the relationship between serum bilirubin and loss of RKF, defined as daily urine volume (<100 mL) within 3 years after starting PD, using a Cox proportional hazards model. During the 3‐year observation period, 22 patients lost RKF. The incidence rate of loss of RKF increased linearly with the decrease in serum total bilirubin levels (P for trend < 0.05). After adjusting for confounding factors, low serum total bilirubin level was shown to be an independent predictor of loss of RKF (hazard ratio [HR] for every 0.1 mg/dL decrease, 1.50; 95% confidence interval [CI], 1.01–2.51; HR [95%CI] for T2 and T1 [vs. T3] 2.03 [0.65–7.88] and 3.70 [1.00–15.9]). This study suggests that low serum total bilirubin levels are associated with the loss of RKF in PD patients. [ABSTRACT FROM AUTHOR]

Published
2020
Full Text
View/download PDF

62. Control of PNG kinase, a key regulator of mRNA translation, is coupled to meiosis completion at egg activation

Author

Massachusetts Institute of Technology. Department of Biology, Whitehead Institute for Biomedical Research, Orr-Weaver, Terry, Hara, Masatoshi, Petrova, Boryana, Massachusetts Institute of Technology. Department of Biology, Whitehead Institute for Biomedical Research, Orr-Weaver, Terry, Hara, Masatoshi, and Petrova, Boryana

Abstract

The oocyte-to-embryo transition involves extensive changes in mRNA translation, regulated in Drosophila by the PNG kinase complex whose activity we show here to be under precise developmental control. Despite presence of the catalytic PNG subunit and the PLU and GNU activating subunits in the mature oocyte, GNU is phosphorylated at Cyclin B/CDK1sites and unable to bind PNG and PLU. In vitro phosphorylation of GNU by CyclinB/CDK1 blocks activation of PNG. Meiotic completion promotes GNU dephosphorylation and PNG kinase activation to regulate translation. The critical regulatory effect of phosphorylation is shown by replacement in the oocyte with a phosphorylation-resistant form of GNU, which promotes PNG-GNU complex formation, elevation of Cyclin B, and meiotic defects consistent with premature PNG activation. After PNG activation GNU is destabilized, thus inactivating PNG. This short-lived burst in kinase activity links development with maternal mRNA translation and ensures irreversibility of the oocyteto- embryo transition., National Institutes of Health (U.S.) (GM39341), National Institutes of Health (U.S.) (GM118098)

Published
2017

65. Production of Multi-Features Driven Nationwide Vegetation Physiognomic Map and Comparison to MODIS Land Cover Type Product

Author

Sharma, Ram C., primary, Hara, Keitarou, additional, Hirayama, Hidetake, additional, Harada, Ippei, additional, Hasegawa, Daisuke, additional, Tomita, Mizuki, additional, Geol Park, Jong, additional, Asanuma, Ichio, additional, M. Short, Kevin, additional, Hara, Masatoshi, additional, Hirabuki, Yoshihiko, additional, Fujihara, Michiro, additional, and Tateishi, Ryutaro, additional

Published
2017
Full Text
View/download PDF

66. Modified Simple Peritoneal Wall Anchor Technique (Pwat) in Peritoneal Dialysis

Author

Oka, Hideaki, primary, Yamada, Shunsuke, additional, Kamimura, Taro, additional, Hara, Masatoshi, additional, Hirashima, Yutaro, additional, Matsueda, Shumei, additional, Shukuri, Tomoya, additional, Aihara, Seishi, additional, Koresawa, Mai, additional, Eriguchi, Masahiro, additional, Harada, Atsumi, additional, Tsuruya, Kazuhiko, additional, and Kitazono, Takanari, additional

Published
2017
Full Text
View/download PDF

68. Greatwall kinase and cyclin B-Cdk1 are both critical constituents of M-phase-promoting factor

Author

Hara, Masatoshi, Abe, Yusuke, Tanaka, Toshiaki, Yamamoto, Takayoshi, OKUMURA, EIICHI, and Kishimoto, Takeo

Subjects
Cyclin D, Cyclin A, Maturation-Promoting Factor, Cyclin B, General Physics and Astronomy, Protein Serine-Threonine Kinases, Xenopus Proteins, General Biochemistry, Genetics and Molecular Biology, Article, Xenopus laevis, CDC2 Protein Kinase, Animals, Cells, Cultured, Multidisciplinary, biology, Cell Cycle, Cyclin-dependent kinase 3, General Chemistry, M-Phase Promoting Factor, Cell biology, Asterina, biology.protein, Cyclin-dependent kinase complex, Oocytes, Female, biological phenomena, cell phenomena, and immunity, Cyclin A2, Cell Division
Abstract

Maturation/M-phase-promoting factor is the universal inducer of M-phase in eukaryotic cells. It is currently accepted that M-phase-promoting factor is identical to the kinase cyclin B–Cdk1. Here we show that cyclin B–Cdk1 and M-phase-promoting factor are not in fact synonymous. Instead, M-phase-promoting factor contains at least two essential components: cyclin B–Cdk1 and another kinase, Greatwall kinase. In the absence of Greatwall kinase, the M-phase-promoting factor is undetectable in oocyte cytoplasm even though cyclin B–Cdk1 is fully active, whereas M-phase-promoting factor activity is restored when Greatwall kinase is added back. Although the excess amount of cyclin B–Cdk1 alone, but not Greatwall kinase alone, can induce nuclear envelope breakdown, spindle assembly is abortive. Addition of Greatwall kinase greatly reduces the amount of cyclin B–Cdk1 required for nuclear envelope breakdown, resulting in formation of the spindle with aligned chromosomes. M-phase-promoting factor is thus a system consisting of one kinase (cyclin B–Cdk1) that directs mitotic entry and a second kinase (Greatwall kinase) that suppresses the protein phosphatase 2A-B55 which opposes cyclin B–Cdk1., Cyclin B–Cdk1 is thought to be synonymous with the promoting factor that drives entry into M-phase of the cell cycle. Here, Greatwall kinase is shown to be required for the breakdown of the nuclear envelope and the assembly of the spindle on entry into M-phase, suggesting that it too is a part of the M-phase-promoting factor.

Published
2012

74. Chicks' maze learning reinforced by visual pitfall extending downward

Author

Hayashibe, Keikichi, Hara, Masatoshi, and Tsuji, Keiichiro

Subjects
Perception in animals -- Research, Depth perception -- Research, Learning in animals -- Testing, Chicks -- Behavior, Health, Psychology and mental health
Abstract

The present study examined whether visually evoked fear of depth could reinforce a particular response of animals, i.e., to special maze learning. The maze was composed of four units of Y-shaped alley. In this maze, the visual pitfalls were set behind corners of the alley in place of a physical barrier. The experiments showed that eight of 13 male chicks could achieve the initial learning and that three successful ones could also achieve reversal learning. The results suggest that the visually evoked fear of depth provided by motion parallax can act as a reinforcer.

Published
1989

84. Habitat divergence in sympatric Fagaceae tree species of a tropical montane forest in northern Thailand

Author

Noguchi, Hideyuki, primary, Itoh, Akira, additional, Mizuno, Takashi, additional, Sri-ngernyuang, Kriangsak, additional, Kanzaki, Mamoru, additional, Teejuntuk, Sakhan, additional, Sungpalee, Witchaphart, additional, Hara, Masatoshi, additional, Ohkubo, Tatsuhiro, additional, Sahunalu, Pongsak, additional, Dhanmmanonda, Pricha, additional, and Yamakura, Takuo, additional

Published
2007
Full Text
View/download PDF

86. Effects of management practices for abandoned fields of shifting cultivation on their vegetation component and tree establishment in two hill tribes in Doi Inthanon National Park of Thailand

Author

Nishio, Takayoshi, primary, Kanzaki, Mamoru, additional, Hara, Masatoshi, additional, Ohkubo, Tatsuhiro, additional, Hayami, Yoko, additional, Matsue, Keigo, additional, Sahunalu, Pongsak, additional, Preechapanya, Pornchai, additional, Sri-ngernyuang, Kriangsak, additional, and Teejuntuk, Sakhan, additional

Published
2006
Full Text
View/download PDF

90. Tropics

Author

KANZAKI, Mamoru, primary, SRI-NGERNYUANG, Kriangsak, additional, FUJII, Noritsugu, additional, MIZUNO, Takashi, additional, NOGUCHI, Hideyuki, additional, YAMAKURA, Takuo, additional, HARA, Masatoshi, additional, OHKUBO, Tatsuhiro, additional, SAHUNALU, Pongsak, additional, DHANMANOND, Pricha, additional, BUNYAVEJCHEWIN, Sarayudh, additional, and MATHAVARARUG, Anusit, additional

Published
2000
Full Text
View/download PDF

95. Japanese Monkeys' Cardiac Responses to Visual Depth

Author

Hayashibe, Keikichi, Hara, Masatoshi, Tsuji, Keiichiro, and Matsuzawa, Tetsuro

Abstract

The present study examined the heart-rate changes which occurred in the visual-depth situation of Japanese monkeys (Macaca fuscata) Four animals were tested over the first four weeks of age in the visual pitfall designed as a modification of the visual cliff. The infant monkeys showed heart-rate reduction in the depth condition. This reduction was observed from the first week and became remarkable at the third week. There were no differences in heart-rate change between monocular and binocular vision. These findings suggest that the Japanese monkey can discriminate visual depth shortly after birth and that the heart-rate reduction depends upon the fear of visual depth, not upon the novelty of the situation.

Published
1988
Full Text
View/download PDF

99. Centromere/kinetochore is assembled through CENP-C oligomerization

Author

Hara, Masatoshi, Ariyoshi, Mariko, Sano, Tomoki, Nozawa, Ryu-Suke, Shinkai, Soya, Onami, Shuichi, Jansen, Isabelle, Hirota, Toru, Fukagawa, Tatsuo, Hara, Masatoshi, Ariyoshi, Mariko, Sano, Tomoki, Nozawa, Ryu-Suke, Shinkai, Soya, Onami, Shuichi, Jansen, Isabelle, Hirota, Toru, and Fukagawa, Tatsuo

Abstract

Hara M., Ariyoshi M., Sano T., et al. Centromere/kinetochore is assembled through CENP-C oligomerization. Molecular Cell 83, 2188 (2023); https://doi.org/10.1016/j.molcel.2023.05.023., Kinetochore is an essential protein complex required for accurate chromosome segregation. The constitutive centromere-associated network (CCAN), a subcomplex of the kinetochore, associates with centromeric chromatin and provides a platform for the kinetochore assembly. The CCAN protein CENP-C is thought to be a central hub for the centromere/kinetochore organization. However, the role of CENP-C in CCAN assembly needs to be elucidated. Here, we demonstrate that both the CCAN-binding domain and the C-terminal region that includes the Cupin domain of CENP-C are necessary and sufficient for chicken CENP-C function. Structural and biochemical analyses reveal self-oligomerization of the Cupin domains of chicken and human CENP-C. We find that the CENP-C Cupin domain oligomerization is vital for CENP-C function, centromeric localization of CCAN, and centromeric chromatin organization. These results suggest that CENP-C facilitates the centromere/kinetochore assembly through its oligomerization.

100. Centromere/kinetochore is assembled through CENP-C oligomerization

Author

Hara, Masatoshi, Ariyoshi, Mariko, Sano, Tomoki, Nozawa, Ryu-Suke, Shinkai, Soya, Onami, Shuichi, Jansen, Isabelle, Hirota, Toru, Fukagawa, Tatsuo, Hara, Masatoshi, Ariyoshi, Mariko, Sano, Tomoki, Nozawa, Ryu-Suke, Shinkai, Soya, Onami, Shuichi, Jansen, Isabelle, Hirota, Toru, and Fukagawa, Tatsuo

Abstract

Hara M., Ariyoshi M., Sano T., et al. Centromere/kinetochore is assembled through CENP-C oligomerization. Molecular Cell 83, 2188 (2023); https://doi.org/10.1016/j.molcel.2023.05.023., Kinetochore is an essential protein complex required for accurate chromosome segregation. The constitutive centromere-associated network (CCAN), a subcomplex of the kinetochore, associates with centromeric chromatin and provides a platform for the kinetochore assembly. The CCAN protein CENP-C is thought to be a central hub for the centromere/kinetochore organization. However, the role of CENP-C in CCAN assembly needs to be elucidated. Here, we demonstrate that both the CCAN-binding domain and the C-terminal region that includes the Cupin domain of CENP-C are necessary and sufficient for chicken CENP-C function. Structural and biochemical analyses reveal self-oligomerization of the Cupin domains of chicken and human CENP-C. We find that the CENP-C Cupin domain oligomerization is vital for CENP-C function, centromeric localization of CCAN, and centromeric chromatin organization. These results suggest that CENP-C facilitates the centromere/kinetochore assembly through its oligomerization.

Catalog

Books, media, physical & digital resources
See catalog results