Shotaro Ayukawa

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Phenotypic diversification of cells is crucial for developmental and regenerative processes in multicellular organisms. The diversification concept is described as the motion of marbles rolling down Waddington's landscape, in which the number of stable states changes as development proceeds. In contrast to this simple concept, the complexity of natural(More)
Creating artificial biological systems is an important research endeavor. Each success contributes to synthetic biology and adds to our understanding of the functioning of the biomachinery of life. In the construction of large, complex systems, a modular approach simplifies the design process: a multilayered system can be prepared by integrating simple(More)
A method of determining histidine decarboxylase activity was established. In this method, 14C-histamine was separated from 14C-histidine by Amberlite CG-resin column in the ammonium form. Lecanoric acid was obtained by screening histidinedecarboxylase inhibitors produced by microorganisms. It is the first isolation of this compound from fungi. The(More)
Aquayamycin was found to be a strong inhibitor of tyrosine hydroxylase. It inhibits tyrosine hydroxylase by 50 % at 3.7x10~7M. The inhibition is non-competitive with tyrosine. The inhibition by 4x10~7 M aquayamycin increases when the concentration of 2-amino-4-hydroxy-6,7-dimethyltetrahydropteridine is increased from 2x10~4M to 1x10~3M. The inhibition of(More)
BACKGROUND Appropriate regulation of respective gene expressions is a bottleneck for the realization of artificial biological systems inside living cells. The modification of several promoter sequences is required to achieve appropriate regulation of the systems. However, a time-consuming process is required for the insertion of an operator, a binding site(More)
Ghrothiomycin inhibits reactions of tyrosine hydroxylase1} and dopamine /?-hydroxylase2>3). It also exhibits weak antibacterial activities. It is obtained as blackish purple crystals containing sulfur and named chrothiomycin. In this paper, characters of chrothiomycin-producing Streptomyces are described together with the chemical and physical properties of(More)
Phenotypic diversification of cells in development and regeneration is conceptually modeled by the motion of marbles rolling down valleys on the Waddington landscape, the main feature of which is bifurcations of the valleys. We have experimentally shown that this feature is sufficient to achieve phenotypic diversification by the construction of a synthetic(More)