Mechanism of catch force: tethering of thick and thin filaments by twitchin.
Mechanism of catch force: tethering of thick and thin filaments by twitchin.
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DOI：
10.1155/2010/725207
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发表时间：
2010
影响因子：
--
通讯作者：
Siegman MJ
中科院分区：
文献类型：
--
作者：
Butler TM;Siegman MJ
捕捉是发生在一些无脊椎动物平滑肌中的机械状态，其特征在于在极慢的松弛期间保持高力和抗拉伸。 在捕捞过程中，细胞内钙离子浓度接近基础浓度，肌球蛋白跨桥循环速度极慢。捕获力通过蛋白激酶A介导的微肌联蛋白tickin（~526 kDa）N-和C-末端附近位点的磷酸化而放松。 在次最大钙浓度下，一些抓力维持车也与循环肌球蛋白过桥一起发生，但不是在肌肉最大激活时。 此外，负责抓地力的链接可以在次最大激活肌肉缩短期间进行调整，并在新的较短长度处保持抓地力。Twitchin结合到粗和细的细丝，并且由Twitchin的N-和C-末端部分显示的细丝结合通过调节捕获的位点的磷酸化而减少。这些数据表明，tickin分子本身就是连接粗细纤维的捕捉力。我们提出了一个模型，其中的tickin系绳可以从薄的细丝（a）的磷酸化tickin和（B）的附着力高肌球蛋白crossbridge的调控。
Catch is a mechanical state occurring in some invertebrate smooth muscles characterized by high force maintenance and resistance to stretch during extremely slow relaxation. During catch, intracellular calcium is near basal concentration and myosin crossbridge cyctng rate is extremely slow. Catch force is relaxed by a protein kinase A-mediated phosphorylation of sites near the N- and C- temini of the minititin twitchin (~526 kDa). Some catch force maintenance car also occur together with cycling myosin crossbridges at submaximal calcium concentrations, but not when the muscle is maximally activated. Additionally, the link responsible for catch can adjust during shortening of submaximally activated muscles and maintain catch force at the new shorter length. Twitchin binds to both thick and thin filaments, and the thin filament binding shown by both the N- and Cterminal portions of twitchin is decreased by phosphorylation of the sites that regulate catch. The data suggest that the twitchin molecule itself is the catch force beanng tether between thick and thin filaments. We present a model for the regulation of catch in which the twitchin tether can be displaced from thin filaments by both (a) the phosphorylation of twitchin and (b) the attachment of high force myosin crossbridges.
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影响因子：
3.4
作者：
Butler, TM;Mooers, SU;Siegman, MJ
通讯作者：
Siegman, MJ
影响因子：
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通讯作者：
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影响因子：
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作者：
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影响因子：
3.4
作者：
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通讯作者：
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