| Project/Area Number |
08672654
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Laboratory medicine
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| Research Institution | Osaka Medical College |
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Principal Investigator |
HATANAKA Michiyo Osaka Medical College, Clinical Pathology, Assistant Professor, 医学部, 助手 (50218484)
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| Co-Investigator(Kenkyū-buntansha) |
SEYA Tsukasa Osaka Medical Center for Cancer and Cardiovascular Diseases., 6部, 部長
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1997: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1996: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | GPI-anchored protein / complement regulatory protein / CD59 / dimer formation / signal transduction / C9 / peptide / intracellular Ca^<2+> concentration / トランスジューサ-分子 / Caveolin / 細胞増殖 / 架橋試薬 |
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| Research Abstract |
Many proteins are attached to the cell membranes via glycosyl phosphatidyl anchor rather than by a transmembrane anchor and have no direct contact with the inside of the cells. Despite this, cross-linking of GPI-anchored proteins with antibodies causes activation of T cells and neutrophils. The activation is likely to be mediated through Src kinases. It has been suggested that interaction of the GPI-anchored molecule with kinases requires a transmembrane-transducing element, the identity of which remained controversial.
In this study, we focused on a GPI-anchored complement regulatory protein, CD59, as a model, to elucidate the GPI-anchored protein mediating signaling. We identified CD59 associating protein by cross-linking of surface proteins with chemical cross-linker followed by Western blotting with anti-CD59 antibody. The Cd59-associating molecules were estimated to be 13-18 kDa in size. Two-dimensional electrophoresis of the cross-linked products revealed no trace of molecules other than CD59. The cross-linked products showed the same N-terminal sequences as CD59 and a strikingly similar amino acid composition to that of CD59. Thus, most likely, the cross-linked products are CD59 dimers. The finding that CD59 localized on outer membranes is all in the form of dimers suggests the importance of dimerization for CD59 functioning.
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