Project/Area Number |
03454522
|
Research Category |
Grant-in-Aid for General Scientific Research (B)
|
Allocation Type | Single-year Grants |
Research Field |
Hematology
|
Research Institution | Tokyo Medical and Dental University |
Principal Investigator |
AOKI Nobuo Tokyo Medical & Dental Univ., Dept.of Medicine, Professor, 医学部第一内科, 教授 (20048937)
|
Co-Investigator(Kenkyū-buntansha) |
MIURA Osamu Tokyo Medical & Dental Univ., Dept.of Medicine, Assistant, 医学部第一内科, 助手 (10209710)
HIROSAWA Shinsaku Tokyo Medical & Dental Univ., Dept.of Medicine, Instructor, 医学部第一内科, 講師 (50143574)
|
Project Period (FY) |
1991 – 1993
|
Project Status |
Completed (Fiscal Year 1993)
|
Budget Amount *help |
¥6,600,000 (Direct Cost: ¥6,600,000)
Fiscal Year 1993: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1992: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1991: ¥3,800,000 (Direct Cost: ¥3,800,000)
|
Keywords | alpha_2-plasmin inhibitor / Congenital Deficiency / Intracellular Transport / Gene Mutation / Impairement of Secretion / 細胞内輸送障害 / 失天性欠損症 / アルフア2プラスミンインヒビタ- / 欠損症 / α_2PIーOkinawa |
Research Abstract |
alpha_2-Plasmin inhibitor (alpha_2PI) deficiency Okinawa results from defective secretion of the inhibitor from the liver and appears to be a direct consequence of the deletion of Glu^<137> in the amino acid sequence of alpha_2PI.To examine the effects of replacing the amino acid occupying position 137 or deleting its neighboring amino acid on alpha_2PI secretion, we used oligonucleotide-directed mutagenesis of alpha_2PI cDNA to change the codon specifying Glu^<137> or delete a codon specifying its neighboring amino acid. The effects were determined by pulsechase experiments and by enzyme-linked immunosorbent assay of media from transiently transfected COS-7 cells. Replacement of Glu^<137> with an amino acid other than Cys had little effect on alpha_2PI secretion. In contrast, deletion of an amino acid in a region spanning a sequence of less than 30 amino acids including positions 127 and 137 severely impaired the secretion. The results suggest that structural integrity of the region, rather than its component amino acids, is important for the intracellular transport and secretion of alpha_2PI.
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