Rotational Movement of the Formin mDia1 Along the Double Helical Strand of an Actin Filament
Rotational Movement of the Formin mDia1 Along the Double Helical Strand of an Actin Filament
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DOI：
10.1126/science.1197692
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发表时间：
2011-01-07
期刊：
影响因子：
56.9
通讯作者：
Watanabe, Naoki
中科院分区：
文献类型：
--
作者：
Mizuno, Hiroaki;Higashida, Chiharu;Watanabe, Naoki
形成蛋白同源蛋白（形成蛋白）延长肌动蛋白丝（F-肌动蛋白）通过不断与细丝尖端，潜在地利用肌动蛋白产生的推力。在这种进行性延伸过程中，预计formin将沿着双螺旋F-肌动蛋白结构的轴旋转（在此称为螺旋旋转），尽管这尚未明确显示。我们通过单分子荧光偏振（FLP）证明了α mDia 1的螺旋旋转。FLP标记的F-肌动蛋白，既延长和解聚从固定的mDia 1，振荡的周期性对应的F-肌动蛋白长螺距螺旋，这是不改变肌动蛋白结合的核苷酸或肌动蛋白结合蛋白profilin。因此，螺旋旋转是formin的内在属性。为了利用不断增长的F-肌动蛋白的推力，formins必须灵活地锚定到细胞结构。
Formin homology proteins (formins) elongate actin filaments (F-actin) by continuously associating with filament tips, potentially harnessing actin-generated pushing forces. During this processive elongation, formins are predicted to rotate along the axis of the double helical F-actin structure (referred to here as helical rotation), although this has not yet been definitively shown. We demonstrated helical rotation of the formin mDia1 by single-molecule fluorescence polarization (FLP). FLP of labeled F-actin, both elongating and depolymerizing from immobilized mDia1, oscillated with a periodicity corresponding to that of the F-actin long-pitch helix, and this was not altered by actin-bound nucleotides or the actin-binding protein profilin. Thus, helical rotation is an intrinsic property of formins. To harness pushing forces from growing F-actin, formins must be anchored flexibly to cell structures.