| Project/Area Number |
04670135
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
General medical chemistry
|
|---|
| Research Institution | Yamagata University |
|---|
Principal Investigator |
ISHIKAWA Kazunobu (1993) Yamagata Uni.Sch.of Med, Assistant, 医学部, 助手 (80222959)
斧 秀勇 (1992) 山形大学, 医学部, 助教授 (40160915)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
ONO Hideyu Yamagaa Uni.Sch.of Med., Associate Professor, 医学部, 助教授 (40160915)
YOSHIDA Tadashi Yamagata Uni.Sch.of Med., Associate Professor, 医学部, 教授 (10004673)
石川 和信 山形大学, 医学部, 助手 (80222959)
|
|---|
| Project Period (FY) |
1992 – 1993
|
| Project Status |
Completed (Fiscal Year 1993)
|
| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1993: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1992: ¥1,200,000 (Direct Cost: ¥1,200,000)
|
|---|
| Keywords | mitochondria / protein transport / transport machinery / re-translocation / bypass-import / porin / ミトコンドリア蛋白質前駆体 / コンタクトサイト / 膜透過装置 / 膜間腔蛋白質 |
|---|
| Research Abstract |
Although no binding of porin-precursor to trypsin-pretreated rat liver mitochondria was detectable, its integration into these mitochondria was observed to some extent, possibly by the bypass-import system first demonstrated in fungus mitochondria. A topographical study of this bypass-import system demonstrated that import of porin occurs at contact sites between the outer and inner membrane. Furthermore, antibodies to 29 KDa outer membrane protein, a component of the import machinery in contact sites for precursors of ornithine aminotransferase and sulfite oxidase, inhibited the integration of porin, suggesting that the 29 KDa protein is involved in the imports of most mitochondrial precursor proteins.
When inverted vesicles prepared from the inner membrane of rat liver mitochondria were incubated with prepro-rat serum albumin, considerable amounts of prepro-albumin and pro-albumin were recovered with the inverted vesicles re-isolated by centrifugation. Pro-albumin was resistant to trypsin, but prepro-albumin was completely digested by trypsin, indicating that prepro-albumin was transported into the vesicles and concomitantly converted to pro-albumin. This transport process required ATP, but not a membrane potential. These results suggest that some export machinery for a protein having an amino acid sequence in its N-terminal portion similar to the signal sequence of secretory protein exists in the inner mitochondrial membrane.
|
