2005 Fiscal Year Final Research Report Summary
Actin filament plays an important part as to the acto-myosin motility mechanism.
| Project/Area Number |
16570135
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biophysics
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| Research Institution | Osaka University |
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Principal Investigator |
IWANE Atsuko Osaka University, Graduate School of Frontier Biosciences, Assistant Professor, 生命機能研究科, 助手 (30252638)
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| Project Period (FY) |
2004 – 2005
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| Keywords | Actin / Myosin / Cooperativity / Brawnian motion / Single molecule techniques / Rotation |
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| Research Abstract |
I would like to establish how to actin-myosin interaction mechanism. Many researchers had believed the mechanism of actin-myosin interaction could be explained by "lever arm model". But, we have shown that a truncation mutant of myosin-V and myosin-VI with very short neck domains develop successive steps as large as native myosin-V with long neck domains. I think that I can explain its mechanism by not "lever arm model" but rather "biased brown motion". I assume that the neck region plays an essential role in the biased Brownian motion. On the other hand, EM image showed that myosin VI cooperatively binds to an actin filament at 36nm intervals ("hot spot") in the presence of ATP. I feel even more keenly the importance of actin filament.
In the meantime, Myosin V and VI can cooperatively bind to the special position of an actin filament and move along an actin filament processibly using single molecule imaging. This result conformed the existence of "hot spot". Of particular interest is the actin rotation. Furthermore, we also obtained the result of which 90 degrees rotation of the actin filament was caused during actin-myosin interaction using computer simulation and published the result in BIOPHYSICS, 2005. We reiterated the importance of an actin filament. For direct real-time imaging, I had been going to launch the several recombinant actins using Baculovirus expression system also. I will insert bi-functional fluorescent dye in specific surface positions of an actin filament for observing the actin rotation. Whereas, we had clarified the roles of the myosin neck and reported in (Iwane A.H.et al.,2005,Iwaki M.et al.,2006 and Nishikawa M.et al.,2006). According to the above results, the conformational changes in actin filaments with its rotation should also play an important role in myosin processive moving.
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