2002 Fiscal Year Final Research Report Summary
Analysis of transport mechanism and regulation through the recycling of transport factors.
| Project/Area Number |
13480240
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Cell biology
|
|---|
| Research Institution | RIKEN (2002)
National Institute of Genetics (2001) |
|---|
Principal Investigator |
IMAMOTO Naoko RIKEN, Cellular Dynamics Laboratory, Chief Scientist, 細胞核機能研究室, 主任研究員 (20202145)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KOSE Shingo RIKEN, Cellular Dynamics Laboratory, Research Scientist, 細胞核機能研究室, 研究員 (90333278)
|
|---|
| Project Period (FY) |
2001 – 2002
|
| Keywords | nuclear transport / importin β / CAS / small GTPase Ran / importin α / nuclear pore complex / 70kDa heat-shock cognate protein (hsc70) / β-catenin |
|---|
| Research Abstract |
1.We have initially examined nuclear import and export of importin β in living cells, and found that its nuclear export depends on the presence of energy sources, whereas its import occurs in an energy-independent manner. Analysis in digitonin-permeabilized cell-free system and through the fractionation studies of cytosol, we found that nuclear export of importin β is stimulated not only by small GTPase Ran but also by 70kDa heat-shock cognate protein (hsc70). Point mutated hsc70 lacking ATPase did not stimulate nuclear export of importin β. Our results indicate that additional factor is involved in recycling of importin β and the stimulation is dependent on ATPase activity. 2.β-catenin is an example of a typical molecule that can be bi-directionally translocated through nuclear pore complexes (NPC) on its own in a facilitated manner. We examined the nuclear import and export of β-catenin, and showed that region of β-catenin required for import and export substantially overlapped. However, different nucleocytoplasmic shuttling molecules such as importin β and GAS, differentially blocked nuclear import and export of β-catenin. The different effect was also observed under the condition that induces recycling of transport factor. These data indicates that β-catenin shows an overlapping sequence requirement for its import and export, but that bi-directional movement through the NPC proceeds through distinct molecular interactions. 3.We found that importin α/β mediated nuclear import pathway is down-regulated in response to heat-shock, which was caused by nuclear retention and recycling inhibition of importin α. Such regulation of transport suggests a new regulatory mechanism for the adaptation of cells to environmental changes, such as heat-shock.
|
Research Products
(20 results)
-
-
-
-
-
-
-
-
-
-
-
-
[Publications] Soo Jae Lee, Toshihiro Sekimoto, Wiki Yamashita, Emi Nagoshi, Atsushi Nakagawa, Naoko Imamoto, Masato Yoshimura, Hiroaki Sakai, Khoon Teen Chong, Tomitake Tsukihara, Yoshiro Yoneda.: "The structure of importin β bound to SREBP-2 : Nuclear import of a transcription factor."Science. 302. 1571-1575 (2003)
Description
「研究成果報告書概要(欧文)」より
-
[Publications] Chang-Jie Jiang, Kazuhiro Shoji, Rikyu Matsuki, Akihiki Baba, Noritoshi Inagaki, Hiroshi Ban, Toshisuke Iwasaki, Naoko Imamoto, Yoshihiro Yoneda, Xing-Wang Deng, Naoki Yamamoto.: "Molecular cloning of a novel importin α homologue from Rice, by which constitutive photomorphogenic 1 (COP1) nuclear localization signal (NLS)-protein is preferentially nuclear imported."J.Biol.Chem.. 276. 9322-9329 (2001)
Description
「研究成果報告書概要(欧文)」より
-
-
-
-
-
-
-
