| Project/Area Number |
13440248
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
動物生理・代謝
|
|---|
| Research Institution | CHIBA UNIVERSITY |
|---|
Principal Investigator |
KIMURA Sumiko CHIBA UNIVERSITY, DEPARTMENT OF BIOLOGY, FACULTY OF SCIENCE, ASSOCIATE PROFESSOR, 理学部, 助教授 (50093232)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MARUYAMA Koscak NATIONAL CENTER FOR UNIVERSITY ENTRANCE EXAMINATIONS, PRESIDENT, センター長 (60012267)
|
|---|
| Project Period (FY) |
2001 – 2004
|
| Project Status |
Completed (Fiscal Year 2004)
|
| Budget Amount *help |
¥15,000,000 (Direct Cost: ¥15,000,000)
Fiscal Year 2004: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2003: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2002: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2001: ¥10,300,000 (Direct Cost: ¥10,300,000)
|
|---|
| Keywords | I-Connectin / Giant sarcomere / Elastic protein / PEVK / obliquely striated muscle / Titin / striated muscle / invertebrate / 1分子計測 / ザリガニ |
|---|
| Research Abstract |
The giant filamentous protein, connectin (3000-3700 kDa) contributes to organize a contractile sarcomere by extending from the Z line over the thick filament up to the M line at the center of the sarcomere in vertebrate striated muscle. A molecule of connectin is very flexible and approximately 1 μm long in resting sarcomeres, and can be passively stretched resulting in tension generation.
In crayfish claw closer muscle, the giant sarcomeres are 8.3 μm long at rest, 3.5 times longer than vertebrate striated muscle sarcomeres and they are extensible up to 13 μm upon stretch. In order to clarify what kind of primary structure makes such a remarkable extension possible, we sequenced the cDNA encoding the Invertebrate-connectin (I-connectin) in crayfish claw closer muscle. The entire sequence of crayfish I-connectin was predicted from cDNA sequences of 53,424 bp (17,352 residues ; 1960 kDa). Crayfish I-connectin contains a novel SEK repeats, and also two PEVK domains and one kettin region. Kettin is a small isoform of I-connectin. Immunoblot tests using antibody to the SEK repeats, revealed the presence of I-connectin also in long sarcomeres of insect leg muscle and barnacle ventral muscle. The force measurements of the single recombinant SEK polypeptide were performed by intemolecular force microscopy(IFM), a refined AFM system. The force versus extension curves were well fit to the wormlike chain(WLC) model and the obtained persistence length of 0.37 nm indicates that the SEK region is a random coil for full length. Immunofluorescence microscopy demonstrated that the two repeats, the long spacer and the two PEVK domains contribute to sarcomere extension. These regions may allow a span of a 3.5 μm distance as a new class of composite spring.
|
