ALTERATION IN CROSSBRIDGE KINETICS CAUSED BY MUTATIONS IN ACTIN
ALTERATION IN CROSSBRIDGE KINETICS CAUSED BY MUTATIONS IN ACTIN
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DOI：
10.1038/348440a0
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发表时间：
1990-11-29
期刊：
影响因子：
64.8
通讯作者：
WHITE, DCS
中科院分区：
文献类型：
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作者：
DRUMMOND, DR;PECKHAM, M;WHITE, DCS
肌肉收缩时产生的力是肌球蛋白和肌动蛋白相互作用的结果。这种力产生的动力学在不同肌肉类型之间以及在不同物种的相同肌肉类型内变化1 -2。大多数注意力集中在肌球蛋白亚型在决定这些差异中的作用3 -5。肌动蛋白同工型的作用很少受到关注，主要是因为缺乏合适的细胞类型，其中肌球蛋白同工型保持不变，而肌动蛋白同工型则有所不同。另一种方法是检查肌动蛋白突变的影响，然而，大多数这些导致肌肉结构的严重破坏，机械测量是不可能的6 -10。我们现在已经确定了两个肌动蛋白突变，尽管涉及保守的氨基酸，可以组装成几乎正常的肌原纤维11。肌动蛋白中的这些氨基酸变化显著影响肌纤维产生力的动力学。其中一个突变不在假定的肌球蛋白结合位点，这证明了氨基酸对肌动蛋白功能的长期影响的重要性。
THE generation of force during muscle contraction results from the interaction of myosin and actin. The kinetics of this force generation vary between different muscle types and within the same muscle type in different species1-2. Most attention has focused on the role of myosin isoforms in determining these differences3-5. The role of actin isoforms has received little attention, largely because of the lack of a suitable cell type in which the myosin isoform remains constant yet the actin isoforms vary. An alternative approach would be to examine the effect of actin mutations, however, most of these cause such gross disruption of muscle structure that mechanical measurements are impossible6-10. We have now identified two actin mutations which, despite involving conserved amino acids, can assemble into virtually normal myofibrils11. These amino-acid changes in actin significantly affect the kinetics of force generation by muscle fibres. One of the mutations is not in the putative myosin-binding site, demonstrating the importance of long-range effects of amino acids on actin function.