| Project/Area Number |
08670774
|
|---|
| 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 | Tokyo Medical and Dental University, Medical Research Institute |
|---|
Principal Investigator |
FURUKAWA Tetsushi Tokyo Medical and Dental University, MRI,Assistant professor, 難治疾患研究所, 助手 (80251552)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TATSUMI Hitoshi University of Nagoya, Faculty of Medicine, Assistant professor, 医学部, 助手 (20171720)
|
|---|
| Project Period (FY) |
1996 – 1997
|
| Project Status |
Completed (Fiscal Year 1997)
|
| Budget Amount *help |
¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 1997: ¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1996: ¥1,300,000 (Direct Cost: ¥1,300,000)
|
|---|
| Keywords | potassium channel / cytoskeleton / actin / protein-protein interaction / yeast two-hybrid system / patch-clamp / 酵母2バイブリッド / 電気生理学 / 分子生物 / ナノバイオロジー |
|---|
| Research Abstract |
Previously, we had reported that ATP-sensitive potassium channel (K_<ATP> channel)^- required intracellular ATP to maintain its activity and that this effect of ATP is similar to ATP action on polymerization/depolymerization of actin cytoskeleton. Thus, we examined functional modulation of K_<ATP> channel by cytoskeleton.
Actin disruptors diminished K_<ATP> channel activity, while actin stabilizer maintained channel activity. Disruptors or stabilizers of microtubules did not affect K_<ATP> channel activity. Direct application of polymerized form of actin (F-actin) recovered lost channel activity. PIP_2, which binds to all actin binding proteins and inhibits their actin severing activity, act for maintainance of channel activity and recevered prtially lost channel activity. These data indicate that K_<ATP> channel activity was functionally modulated by the status of actin cytoskeleton.
Next, we sought using yeast two hybrid system protein that would interact with nucleotide binding domain (NBD) of sulfonylurea receptor (SUR), a target of intracellular regulation of K_<ATP> channel. An unknown protein was found to interact with NBD1 of cardiac type SUR,(SUR2a), whose transcript are present ubiquitously and most predominantly in the heart. Isolation of full-length of cDNA revealed that there were four isoforms due to alternative splicing. In each isoform, there was a region that had high sequence homology to cytochrome C.Thus, K_<ATP> channel might be regulated by intracellular oxidization reaction.
Currently, we are on the way to examine functional role of interaction of NBD1 in SUR2a and the unknown protein that we found.
|
