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Microscopic heat pulses induce activation of thin filaments in striated muscle
https://repo.qst.go.jp/records/79074
https://repo.qst.go.jp/records/7907440eab654-67e6-4d0a-a5f8-9680b6d25b83
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2020-02-27 | |||||
| タイトル | ||||||
| タイトル | Microscopic heat pulses induce activation of thin filaments in striated muscle | |||||
| タイトル | ||||||
| タイトル | 局所熱パルス刺激は横紋筋の細いフィラメントを活性化させる | |||||
| 言語 | en | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Ishii, Shuya
× Ishii, Shuya× Oyama, Kotaro× Fuyu, Kobirumaki-Shimozawa× Shin'ichi, Ishiwata× Fukuda, Norio× Ishii, Shuya× Oyama, Kotaro |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | During excitation-contraction coupling of the muscle, sarcomeres are activated via thin filament structural changes, i.e., from the “off” state to the “on” state, in response to a rise in the intracellular Ca2+concentration. We systematically investigated the effects of rapid heating by infra-red (IR) laser irradiation on the sliding of thin filaments reconstituted with human α-tropomyosin (Tm), bovine ventricular troponin (Tn), or rabbit fast skeletal Tm-Tn complex in the in vitro motility assay. Temperature was varied from room temperature (R.T.; ~24˚C) to ~45˚C within 2-10 s. With increasing temperature, the sliding velocity of F-actin and thin filaments reconstituted with cardiac Tm-Tn was accelerated in the presence of ATP and Ca2+, with a temperature coefficient (Q10) of ~2 (R.T. ~41˚C). In the absence of Ca2+ and in the presence of ATP at R.T., thin filaments reconstituted with cardiac regulatory proteins did not move; however, IR laser irradiation elicited movements of reconstituted thin filaments with a Q10 of 5.5. Likewise, IR laser irradiation elicited movements of thin filaments reconstituted with fast skeletal Tm-Tn with a Q10 of 11.0, showing higher sensitivity to temperature. The heating-induced acceleration was observed in the presence of Ca2+ for cardiac and fast skeletal thin filaments, with temperature dependency >2-fold less in both cases. These findings suggest that, 1) the “on-off” equilibrium of the cardiac thin filament state is partially shifted toward the “on” state in diastole at the body temperature, enabling rapid and efficient myocardial dynamics in systole, and 2) the higher temperature dependency for fast skeletal thin filaments is optimized for the muscle’s physiological properties in vivo. | |||||
| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | 第97回日本生理学会大会 | |||||
| 発表年月日 | ||||||
| 日付 | 2020-03-19 | |||||
| 日付タイプ | Issued | |||||
