| Project/Area Number |
01480297
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Hematology
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| Research Institution | Tokyo Medical and Dental University |
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Principal Investigator |
AOKI Nobuo Tokyo Medical and Dental University, Department of Medicine, Professor, 医学部, 教授 (20048937)
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| Co-Investigator(Kenkyū-buntansha) |
MIURA Osamu Tokyo Medical and Dental University, Department of Medicine, Assistant, 医学部, 助手 (10209710)
KATO Atsushi Tokyo Medical and Dental University, Department of Medicine, Assistant, 医学部, 助手 (50183265)
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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 |
¥4,200,000 (Direct Cost: ¥4,200,000)
Fiscal Year 1990: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1989: ¥2,700,000 (Direct Cost: ¥2,700,000)
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| Keywords | Alpha 2 plasmin inhibitor / Fibrinolysis / Hereditary deficiency / Intracellular transport / Frameshift / アミノ酸欠失 / アルファ2プラスミンインヒビタ- / α_2PIーNara / 遺伝子変異 / 先天性欠損症 / α_2PI-Okinawa / α_2PI-Nara / フレ-ムシフト変異 |
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| Research Abstract |
We analyzed the alpha_2PI genes from the two Japanese families with congenital alpha_2PI deficiency, and found that both families have a change of nucleotide sequence in an exon coding for plasma alpha_2PI. One family, alpha_2PI-Nara, has a single nucleotide insertion in oxon X, and the other, alpha_2PI-Okinawa, has a trinucleotide deletion in exon VII. In the case of alpha_2PI-Nara, a single nucleotide insertion in a region coding for the carboxyl-terminal portion caused a frameshift mutation and resulted in the production of a variant protein with alteration and elongation of the carboxyl terminal part of the molecule. In the case of alpha_2PI-Okinawa, a trinucleotide deletion in exon VII that gives rise to the deletion of Glu 137 was identified by nucleotide sequence analysis of the cloned mutant gene. Using the DNA samples amplified with the polymerase chain reaction, hybridization analysis by oligonucleotide probes confirmed the presence of these mutations in all the affected family members. An eukaryotic expression plasmid for alpha_2PI containing either of these mutations was constructed and transfected into COS-7 cells for transient exression analysis. The results indicated that the mutant alpha_2PIs synthesized are mostly retained within the cells, and only a small portion of it is secreted into the medium. A change of the secondary and tertiary structure in case of alpha_2PI-Nara or a change of the hydropathicity of a particular region in case of alpha_2PI-Okinawa may have affected the intracellular transport and secretion of alpha_2PI, causing congenital deficiency of alpha_2PI.
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