The loop2 insertion of type IX myosin acts as an electrostatic actin tether that permits processive movement.
The loop2 insertion of type IX myosin acts as an electrostatic actin tether that permits processive movement.
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DOI：
10.1371/journal.pone.0084874
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发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Bähler M
中科院分区：
文献类型：
--
作者：
Elfrink K;Liao W;Pieper U;Oeding SJ;Bähler M
虽然IX类肌球蛋白是单头肌球蛋白，但它们表现出沿肌动蛋白细丝的行进运动的特征。沿着肌动蛋白细丝连续移动的双头肌球蛋白通过手到手机制中两个头的连续结合来实现这一点。显然，这种机制不能在单头肌球蛋白上运行。然而，已经有人提出，在loop2的肌球蛋白头部结构域中，一个长的IX类特异性插入起到了F-肌动蛋白锚链的作用，允许单头前进运动。在这里，我们通过分析秀丽线虫(Myo IX)中九类肌球蛋白(Myo IX)的缺失结构的运动来直接测试这一提议。大的基本loop2插入的缺失导致了进行性行为的丧失，而N端头部延伸的缺失，即第IX类肌球蛋白的第二个独特结构域，不影响Myo IX的运动性。随着盐浓度的增加，Myo IX的过程行为也被取消。这些观察直接证明，位于loop2的插入物在Myo IX沿着肌动蛋白轨迹移动的过程中起到了静电肌动蛋白系绳的作用。
Although class IX myosins are single-headed, they demonstrate characteristics of processive movement along actin filaments. Double-headed myosins that move processively along actin filaments achieve this by successive binding of the two heads in a hand-over-hand mechanism. This mechanism, obviously, cannot operate in single-headed myosins. However, it has been proposed that a long class IX specific insertion in the myosin head domain at loop2 acts as an F-actin tether, allowing for single-headed processive movement. Here, we tested this proposal directly by analysing the movement of deletion constructs of the class IX myosin from Caenorhabditis elegans (Myo IX). Deletion of the large basic loop2 insertion led to a loss of processive behaviour, while deletion of the N-terminal head extension, a second unique domain of class IX myosins, did not influence the motility of Myo IX. The processive behaviour of Myo IX is also abolished with increasing salt concentrations. These observations directly demonstrate that the insertion located in loop2 acts as an electrostatic actin tether during movement of Myo IX along the actin track.
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DOI：
10.1083/jcb.140.6.1395
发表时间：
1998-03-23
期刊：
The Journal of cell biology
影响因子：
--
作者：
Hancock WO;Howard J
通讯作者：
Howard J
影响因子：
4.8
作者：
De la Cruz, EM;Ostap, EM;Sweeney, HL
通讯作者：
Sweeney, HL
影响因子：
4.8
作者：
Henn, A;De La Cruz, EM
通讯作者：
De La Cruz, EM
影响因子：
7.5
作者：
Baker, JP;Titus, MA
通讯作者：
Titus, MA
影响因子：
2.9
作者：
Furch, M;Geeves, MA;Manstein, DJ
通讯作者：
Manstein, DJ