Author
Kenji Sugimoto
Other affiliations: Kyoto University, National Archives and Records Administration, Nagoya University ...read more
Bio: Kenji Sugimoto is an academic researcher from Nara Institute of Science and Technology. The author has contributed to research in topics: Polynomial matrix & Feed forward. The author has an hindex of 33, co-authored 357 publications receiving 5557 citations. Previous affiliations of Kenji Sugimoto include Kyoto University & National Archives and Records Administration.
Papers published on a yearly basis
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TL;DR: The results indicate that euchromatic H3-K9 methylation regulated by G9a is essential for early embryogenesis and is involved in the transcriptional repression of developmental genes.
Abstract: Covalent modification of histone tails is crucial for transcriptional regulation, mitotic chromosomal condensation, and heterochromatin formation. Histone H3 lysine 9 (H3-K9) methylation catalyzed by the Suv39h family proteins is essential for establishing the architecture of pericentric heterochromatin. We recently identified a mammalian histone methyltransferase (HMTase), G9a, which has strong HMTase activity towards H3-K9 in vitro. To investigate the in vivo functions of G9a, we generated G9a-deficient mice and embryonic stem (ES) cells. We found that H3-K9 methylation was drastically decreased in G9a-deficient embryos, which displayed severe growth retardation and early lethality. G9a-deficient ES cells also exhibited reduced H3-K9 methylation compared to wild-type cells, indicating that G9a is a dominant H3-K9 HMTase in vivo. Importantly, the loss of G9a abolished methylated H3-K9 mostly in euchromatic regions. Finally, G9a exerted a transcriptionally suppressive function that depended on its HMTase activity. Our results indicate that euchromatic H3-K9 methylation regulated by G9a is essential for early embryogenesis and is involved in the transcriptional repression of developmental genes.
1,169 citations
TL;DR: It is shown that a SET domain-containing protein, G9a, is a novel mammalian lysine-preferring HMTase, like Suv39 h1, but with a 10–20-fold higher activity and may contribute to the organization of the higher order chromatin structure of non-centromeric loci.
755 citations
TL;DR: It is suggested that Aurora-C is a novel chromosomal passenger protein that cooperates with Aurora-B to regulate mitotic chromosome dynamics in mammalian cells.
149 citations
TL;DR: Results indicate that alpha-arbutin is an effective and safe ingredient for skin-lightening.
Abstract: We studied the inhibitory effects of 4-hydroxyphenyl α-glucopyranoside (α-arbutin) on melanogenesis in cultured human melanoma cells, HMV-II, and in a three-dimensional cultured human skin model. α-Arbutin showed no inhibitory effect on HMV-II cell growth at a concentration below 1.0 mM. Melanin synthesis in cells treated with α-arbutin at 0.5 mM decreased to 76% of that in non-treated cells. The cellular tyrosinase activity of HMV-II cells also significantly decreased, while the expression of its mRNA was not affected. Melanin synthesis in a human skin model was also evaluated by the macro- and microscopic observation of its pigmentation as well as by quantitative measurements of melanin. Treatment of the human skin model with 250 μg of α-arbutin did not inhibit cell viability, while melanin synthesis was reduced to 40% of that in the control. These results indicate that α-arbutin is an effective and safe ingredient for skin-lightening.
125 citations
TL;DR: Haplophytine was first isolated by Snyder and co-workers in 1952, and identified as the principle bioactive component of the wild flower Haplophyton cimicidum, valued for centuries by the Aztecs and subsequent settlers of Central America for its insecticidal properties.
Abstract: Despite the many impressive accomplishments in the field of total synthesis in recent years, a number of natural products have proven stubbornly resistant to its advances. Among them is haplophytine (1, Scheme 1a), which has only very recently succumbed to synthesis following the elegant work of Fukuyama, Tokuyama and co-workers. Haplophytine was first isolated by Snyder and co-workers in 1952, and identified as the principle bioactive component of the wild flower Haplophyton cimicidum, valued for centuries by the Aztecs and subsequent settlers of Central America for its insecticidal properties. A heterodimeric indole alkaloid, haplophytine features a particularly complex polycyclic array of ten rings, six stereocenters (five of which are quaternary) and a highly congested carbon carbon bond adjoining the two distinct halves of the molecule. The tetracyclic left-hand domain features a unique bridged ketone structure, while the righthand domain consists of the naturally occurring aspidosperma alkaloid, aspidophytine (2, Scheme 1b). A complete appreciation of haplophytine s molecular structure was only reached some 21 years subsequent to its isolation, following extensive chemical degradation, spectroscopic, and X-ray crystallographic studies from the groups of Cava, Yates, and Zacharias, which included identification of the dihydrobromide derivative 3 (Scheme 1a). As depicted, this compound is formed through a unique acid-mediated skeletal rearrangement of the left-hand domain involving the 1,2-shift of an aminal C N bond. Under basic conditions, however, this process can be reversed such as to return haplophytine through a complementary semi-pinacol type mechanism. As
121 citations
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01 Jan 2006
TL;DR: Probability distributions of linear models for regression and classification are given in this article, along with a discussion of combining models and combining models in the context of machine learning and classification.
Abstract: Probability Distributions.- Linear Models for Regression.- Linear Models for Classification.- Neural Networks.- Kernel Methods.- Sparse Kernel Machines.- Graphical Models.- Mixture Models and EM.- Approximate Inference.- Sampling Methods.- Continuous Latent Variables.- Sequential Data.- Combining Models.
10,141 citations
TL;DR: It is proposed that this epigenetic marking system represents a fundamental regulatory mechanism that has an impact on most, if not all, chromatin-templated processes, with far-reaching consequences for cell fate decisions and both normal and pathological development.
Abstract: Chromatin, the physiological template of all eukaryotic genetic information, is subject to a diverse array of posttranslational modifications that largely impinge on histone amino termini, thereby regulating access to the underlying DNA. Distinct histone amino-terminal modifications can generate synergistic or antagonistic interaction affinities for chromatin-associated proteins, which in turn dictate dynamic transitions between transcriptionally active or transcriptionally silent chromatin states. The combinatorial nature of histone amino-terminal modifications thus reveals a “histone code” that considerably extends the information potential of the genetic code. We propose that this epigenetic marking system represents a fundamental regulatory mechanism that has an impact on most, if not all, chromatin-templated processes, with far-reaching consequences for cell fate decisions and both normal and pathological development.
9,309 citations
2,820 citations
2,618 citations
TL;DR: The key electrophysiological features of I(CRAC) and other store-operated Ca(2+) currents and how they are regulated are described, and recent advances that have shed insight into the molecular mechanisms involved in this ubiquitous and vital Ca( 2+) entry pathway are considered.
Abstract: In electrically nonexcitable cells, Ca2+ influx is essential for regulating a host of kinetically distinct processes involving exocytosis, enzyme control, gene regulation, cell growth and prolifera...
2,248 citations