Multiple tail domain interactions stabilize nonmuscle myosin II bipolar filaments
Multiple tail domain interactions stabilize nonmuscle myosin II bipolar filaments
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DOI：
10.1073/pnas.1007025107
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发表时间：
2010-12-07
影响因子：
11.1
通讯作者：
Prehoda, Kenneth E.
中科院分区：
文献类型：
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作者：
Ricketson, Derek;Johnston, Christopher A.;Prehoda, Kenneth E.
肌球蛋白II的收缩力传导源于其组装成双极丝。肌球蛋白II重链的卷曲螺旋尾结构域介导丝的组装，尽管其机制尚不清楚。尾结构域包含交替的静电重复序列，但通常仅尾的一小部分区域（称为“组装结构域”）是组装所必需的。通过计算分析、诱变和电子显微镜技术，我们发现组装结构域并非如先前认为的那样通过自身相互作用发挥作用。相反，组装结构域作为一个独特的、带正电荷的相互作用表面，能够稳定地与上游尾结构域中多个互补的、带负电荷的表面接触。组装结构域与每个互补相互作用表面的相对亲和力决定了在肌球蛋白II丝中观察到的特征性分子交错。这些结果共同解释了电荷重复序列和组装结构域在稳定肌球蛋白双极丝中的关系。
Contractile force transduction by myosin II derives from its assembly into bipolar filaments. The coiled-coil tail domain of the myosin II heavy chain mediates filament assembly, although the mechanism is poorly understood. Tail domains contain an alternating electrostatic repeat, yet only a small region of the tail (termed the "assembly domain") is typically required for assembly. Using computational analysis, mutagenesis, and electron microscopy we discovered that the assembly domain does not function through self-interaction as previously thought. Rather, the assembly domain acts as a unique, positively charged interaction surface that can stably contact multiple complementary, negatively charged surfaces in the upstream tail domain. The relative affinities of the assembly domain to each complementary interaction surface sets the characteristic molecular staggers observed in myosin II filaments. Together these results explain the relationship between the charge repeat and assembly domain in stabilizing myosin bipolar filaments.