| Project/Area Number |
09480156
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Structural biochemistry
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| Research Institution | The Institute of Physical and Chemical Research |
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Principal Investigator |
HIRABAYASHI Yoshio Cellular Glycobiology, National Institute of Physical and Chemical Research, team leader, 糖細胞情報研究チーム, チームリーダー(研究職) (90106435)
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| Co-Investigator(Kenkyū-buntansha) |
IRIE Fumitoshi Cellular Glycobiology, National Institute of Physical and Chemical Research, researcher, 糖細胞情報研究チーム, 研究員 (90291054)
ICHIKAWA Shinichi Cellular Glycobiology, National Institute of Physical and Chemical Research, researcher, 糖細胞情報研究チーム, 研究員 (10223083)
FURUYA Shigeki Cellular Glycobiology, National Institute of Physical and Chemical Research, researcher, 糖細胞情報研究チーム, 研究員 (00222274)
三苫 純也 理化学研究所, 糖細胞情報研究チーム, 研究員 (10281627)
金森 容子 理化学研究所, 糖細胞情報研究チーム, 研究員 (00261173)
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| Project Period (FY) |
1997 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥10,400,000 (Direct Cost: ¥10,400,000)
Fiscal Year 1999: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 1998: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 1997: ¥4,700,000 (Direct Cost: ¥4,700,000)
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| Keywords | Sphingolipid / Ganglioside / Ceramide / Apoptosis / 糖脂質 / プルキンエ細胞 / グルコシルセラミド / アセチル・CoA / シアル酸 |
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| Research Abstract |
Glucosylation of a hydrophobic chain of ceramide by glucosyltransferase (GlcT-1) is a key step to control all GSLs expression and intracellular ceramide concentration. To understand the biological significance of glucosylation under physiological condition, we have taken molecular biological approaches. We have successfully cloned a human cDNA coding for the enzyme by complementation cloning using mouse melanoma mutant, GM-95 deficient in GlcT-1 activity. Homology searches revealed that GlcT-1 is a totally novel protein with type III membrane topology. Genomic analysis of GlcT-1 in several species reveals similar sequences in mouse, rat, Caenorhabditis elegans, Drosophila melanogaster, and cyanobacteria. The phylogenetically conserved nucleotide sequences suggest a biological significance of the protein. To elucidate GSLs function in whole animals, we have tried to generate animals (mouse and Drosophila melanogaster) lacking all GSLs by knockout of the GlcT-1 gene. The knock-out animals have proved that ceramide glucosylation is essential for embryonic development at whole animal level.
In order to understand biological roles of shphingolipids in CNS, we have developed in vitro culture systems of central neurons including Purkinje cells, hippocampal neurons, and motoneurons. During the studies on in vitro functions of shpingolipids, we found that survival and sphingolipid biosynthesis in central neurons were enhanced by media conditioned by astroglial cultures. To our surprise, L-serine and glycine, known as nonessential amino acids, are shown to be cultured astroglia-derived factors. A constant supply of L-serine/glycine from glia cells is essential for the synthesis of serine-derived membrane lipids including ganglioside and, eventually, neuronal survival in vitro. The molecular basis of exogenous L-serine/glycine requirement in neurons has been extensively studied.
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