| Project/Area Number |
01570191
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Experimental pathology
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| Research Institution | Kyoto University |
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Principal Investigator |
NAMBA Yuziro Institute for Virus Research, Kyoto Univ. Department of Cell Biology, Associate Prof., ウイルス研究所, 助教授 (50027322)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1990: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1989: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Protein Phosphorylation / 1-Plastin / Actin binding protein / IL 2 / IL-2 / 増殖シグナル |
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| Research Abstract |
We have characterized a 65-kilodalton protein (p65) as an interleukin 2-stimulated phosphoprotein in human T cells and showed that three endopeptide produced by digestion with lysylendopeptidase of the purified p65 had aminoacid sequences identical with those present in 1-plastin. We have determined the complete primary structure of p65 based on the cDNA isolated from a human T lymphocyte (KUT-2) cDNA library. Analysis of p65 sequences and the amino acid composition of cleaved p65 N-terminal peptide indicated that the deduced p65 amino acid sequence exactly coincides with that of 1-plastin over the C-terminal 580 residues and has a 57-residue extention at the N-terminus to 1-plastin. Computer-assisted structural analysis revealed that p65 is a multidomain molecule involving at least three intriguing functional domains : two putative calcium-binding regions ; and two tandem repeats of putative actin- binding domains in its middle and C-terminal parts, each containing approximately 240 amino acid residues. These results suggest that p65 belong to actin-binding proteins.
The serine residue of p65 which is phosphorylated by IL 2 stimulation exists in the first EF-hand Ca-binding site, suggesting that the phosphorylation of this serine residue might change the calcium dependency of p65.
The mutant gene was constructed in which this serine residue being exchanged to glycine residue. This mutant gene was inserted into the vector which contain metallothionein promotor and transfected to UW-4 cells. By the expression of this mutant protein with zinc sulfate, the I1 2-induced proliferation was severely inhibited suggesting that the phosphorylation of this protein participate in the transduction of IL 2 growth signal.
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