Functional analysis of substrate-aggregation inhibition and unfoldase activities in the 20S proteasome
| Project/Area Number |
13680717
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Functional biochemistry
|
|---|
| Research Institution | Kurume University |
|---|
Principal Investigator |
INOUE Masahiro Kurume Univ. Sch. Med., Dept. Parasitol., Assistant Professor, 医学部, 講師 (00232562)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
HARA Tatsuru Kurume Univ. Sch. Med., Dept. Parasitol., Associate, 医学部, 助手 (30238159)
YANO Mihiro Tokushima Univ, Institute for Enzyme Research, Associate Professor, 分子酵素化学研究センター, 助教授 (40304555)
KIDO Hiroshi Tokushima Univ, Institute for Enzyme Research, Professor, 分子酵素化学研究センター, 教授 (50144978)
|
|---|
| Project Period (FY) |
2001 – 2002
|
| Project Status |
Completed (Fiscal Year 2002)
|
| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2002: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2001: ¥2,200,000 (Direct Cost: ¥2,200,000)
|
|---|
| Keywords | molecular chaperone / proteasome / 19S Cap / unfolding / heat-inducible aggregation / ATP / ADP / ATP-ADP exchange reaction / 19SCap / アンフオールディング / Hsp70 / リフォールディング / 活性中心 |
|---|
| Research Abstract |
The 20S proteasome, a complex of multifunctional proteases acts as a molecular chaperone. ATP-ADP exchange reactions require upon the binding of molecular chaperone to its substrate. We have found C6 and C8 subunits in 20S proteasome are indispensable for ATP-ADP exchange reaction. Although the chaperone activities against heat-inducible aggregation of proteins were observed in a dose dependent manner, neither unfoldase activities not folding activities against denatured aggregated proteins were not detected. On the contrary the 26S of which the 19S Cap regulatory subunits attached on the both sides of the 20S proteasome, had aggregation inhibitory and unfoldase activities. We have also found the 19S Cap solely has the both activities. Proteolytic activities of the 26S are dependent on ATP because ATP is required to transport the substrates to inside the cylinder. Nevertheless, we found the inhibitory effects on the heat-inducible aggregation of the proteins and unfoldase activities of the 20S and the 26S were independent on ADP and ATP. In addition, we found substrates seem to be bound to outside the ring or cylinder to get a structural change by the effect of protease K which digests the denatured proteins. In general, the proteasome function as a chaperone is thought to be ATP-independent inhibition of aggregation plus unfoldase, and ATP-dependent substrates-transport to inside the cylinder.
|
Report
(3 results)
Research Products
(10 results)
