| 1.Research Institution | Kyushu Institute of Technology | |
| 2.Research Area | Integrated Fields | |
| 3.Research Field | Information on Life Systems | |
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| 4.Term of Project | FY 1997 ` FY 2001 | |
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| 5.Project Number | 97I00101 | |
| 6.Title of Project | Design and Fabrication of an Interface System for a Life Information Processor and External Environment -Electrophysiological and Biochemical Approach - |
| Name | Institution,Department | Title of Position |
| Takeshi Yamakawa | Kyushu Inst. of Tech., Graduate School of Life Sci. and Sys. Eng. | Professor |
8.Core Members
| Names | Institution,Department | Title of Position |
| Shozo Yasui | Kyushu Inst. of Tech., Graduate School of Life Sci. and Sys. Eng. | Professor |
| Tetsuya Yagi | Osaka Univ., Graduate School of Eng. | Professor |
| Tatsuya Haga | Gakushuin Univ., Institute for Biomolecular Sci. | Professor |
9.Summary of Research Results
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<Electrophysiological Approach>@The adaptation function of the organs of the perception of the bodily
function has been investigated by physiological experiments, and the Vision Chip which is based on the
knowledge from the experiments has been established. Furthermore, the pattern recognition method and the
signal separation method based on the information processing of the bodily function using some artificial
neural networks techniques are established. <Biochemical Approach>@G protein-coupled receptors (GPCRs) are major sensors of cells for extracellular signals and can recognize light, odorants, taste substances, hormones, neurotransmitters and others. We have screened GPCRs from the human genome sequence by taking advantage of the facts that many GPCRs do not have introns and all GPCRs have seven transmembrane segments, and estimated that there are approximately 500 genes for odorant GPCRs and 400-500 genes for other GPCRs in the human genome. GPCRs, after activation by extracellular ligands, activate G protein GDPY trimer at the intracellular face, which involves exchange of GDP-GTP and dissociation of GDPY into GTPY subunits. We have prepared fusion proteins of G protein a subunits with some GPCRs including muscarinic acetylcholine receptors, b adrenergic receptors, and nociceptin receptors, and expressed them in insect cells (Sf9) using baculovirus. Membrane preparations expressing receptor-Ga fusion proteins were shown to recognize ligands for the receptor and to discriminate full-, partial-, inverse-agonists and antagonists by measuring the ligand-induced change in the affinity for GDP. We have prepared fusion proteins with Gi1a or Gsa subunits of novel orphan GPCRs, which we have identified from the human genome sequence, and used them for search of endogenous or surrogate agonists. Receptor-Ga fusion proteins could be used for drug screening and, potentially, as chemical sensors. |
10.Key Words
(1)Electrophysiology@(2)Biochemistry@(3)nrgans of oerception
(4)AdaptationESelf-organization@(5)Analog Sensing Device@(6)G protein-coupled receptors
(7) @(8)