| Project/Area Number |
10670666
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Circulatory organs internal medicine
|
|---|
| Research Institution | Kochi Medical School |
|---|
Principal Investigator |
MIYAHARA Kaoru Kochi Medical School, Dept. Medical Chemistry, Research Associate, 医学部, 助手 (30229877)
|
|---|
| Project Period (FY) |
1998 – 1999
|
| Project Status |
Completed (Fiscal Year 1999)
|
| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1999: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1998: ¥1,100,000 (Direct Cost: ¥1,100,000)
|
|---|
| Keywords | NO synthase / endothelial cells / promoter activity / transcriptional factors / NO合成酵素 / 一酸化窒素 / プロモーター |
|---|
| Research Abstract |
In endothelial cells, endothelial nitric oxide synthase(eNOS) catalyzes the conversion of L-arginine to L-citrulline and nitric oxide(NO) to play a role in vasodilatation and inhibition of platelet aggregation. To characterize the regulation of the human eNOS gene expression in endothelial cells, we have analyzed the promoter activity of the 5' flanking region of the eNOS gene. We have shown that a Sp1 -binding consensus motif(- 104 to -96) is essential for a core promoter activity of the eNOS gene. In this report, the proximal region from -108 to - 16 was continuously protected in DNase I footprinting analyses. Pyrimidine-rich and purine-rich strings containing three repeats of CCCCTCC and the Sp1-binding motif were included in the protected region. One or two repeats of CCCCTCC were not enough to bind to make any complexes, but all the three repeats should be required for binding to make several DNA-protein complexes on incubation with nuclear extract from the endothelial cells. Transfection expression analyses with substitution mutations showed that the three repeats also have an effective role in transcriptional activity of the eNOS gene.
Furthermore, HIV Tat activates NF-kapperB and this activation can be attenuated by endogenous or exgenous NO. We demonstrate that the Sp1 motifs and the pyrimidine-rich strings in the NOS gene promoter are required for the induction of the NOS gene expression by Tat.
|
