Coupling of two non-processive myosin 5c dimers enables processive stepping along actin filaments.
Coupling of two non-processive myosin 5c dimers enables processive stepping along actin filaments.
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DOI：
10.1038/srep04907
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发表时间：
2014-05-09
影响因子：
4.6
通讯作者：
Sakamoto T
中科院分区：
文献类型：
--
作者：
Gunther LK;Furuta K;Bao J;Urbanowski MK;Kojima H;White HD;Sakamoto T
肌球蛋白5c（Myosin 5c，Myo 5c）是一种低占空比的非进行性运动，不能沿沿着肌动蛋白丝连续运动，但被认为参与了脊椎动物细胞分泌囊泡的运输。在这里，我们测量了Myo 5c二聚体的ATP酶动力学，并测试了两个Myo 5c分子的偶联能够进行性运动的可能性。稳态ATP酶活性和ADP解离动力学表明，Myo 5c-HMM（双头重肌球蛋白5c）的二聚体对肌动蛋白丝的Km比Myo 5c-S1（单头肌球蛋白5c亚片段-1）低6倍，表明Myo 5c-HMM的两个头增加了F-肌动蛋白结合亲和力。纳米精度的跟踪分析表明，两个Myo 5c-HMM二聚体通过DNA支架相互连接，并沿着沿着肌动蛋白丝移动。此外，DNA支架上Myo 5c分子之间的距离是进行性运动的重要因素。两个二聚体复合物中的单个Myo 5c分子以30-36 nm的步长随机移动。 这些结果表明，DNA支架上的Myo 5c分子的两个二聚体增加了与F-肌动蛋白重新结合的可能性，并使沿着肌动蛋白丝的进行步骤成为可能，这可用于细胞中的集体货物运输。
Myosin 5c (Myo5c) is a low duty ratio, non-processive motor unable to move continuously along actin filaments though it is believed to participate in secretory vesicle trafficking in vertebrate cells. Here, we measured the ATPase kinetics of Myo5c dimers and tested the possibility that the coupling of two Myo5c molecules enables processive movement. Steady-state ATPase activity and ADP dissociation kinetics demonstrated that a dimer of Myo5c-HMM (double-headed heavy meromyosin 5c) has a 6-fold lower Km for actin filaments than Myo5c-S1 (single-headed myosin 5c subfragment-1), indicating that the two heads of Myo5c-HMM increase F-actin-binding affinity. Nanometer-precision tracking analyses showed that two Myo5c-HMM dimers linked with each other via a DNA scaffold and moved processively along actin filaments. Moreover, the distance between the Myo5c molecules on the DNA scaffold is an important factor for the processive movement. Individual Myo5c molecules in two-dimer complexes move stochastically in 30–36 nm steps. These results demonstrate that two dimers of Myo5c molecules on a DNA scaffold increased the probability of rebinding to F-actin and enabled processive steps along actin filaments, which could be used for collective cargo transport in cells.
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影响因子：
3.7
作者：
Bao J;Huck D;Gunther LK;Sellers JR;Sakamoto T
通讯作者：
Sakamoto T
DOI：
10.1073/pnas.96.24.13726
发表时间：
1999-11-23
影响因子：
11.1
作者：
De La Cruz, EM;Wells, AL;Sweeney, HL
通讯作者：
Sweeney, HL
影响因子：
3.4
作者：
De la Cruz, EM;Sweeney, HL;Ostap, EM
通讯作者：
Ostap, EM
影响因子：
64.5
作者：
CHENEY, RE;OSHEA, MK;MOOSEKER, MS
通讯作者：
MOOSEKER, MS
影响因子：
3.3
作者：
Berg, JS;Powell, BC;Cheney, RE
通讯作者：
Cheney, RE