The Effect of Temperature on Microtubule-Based Transport by Cytoplasmic Dynein and Kinesin-1 Motors
The Effect of Temperature on Microtubule-Based Transport by Cytoplasmic Dynein and Kinesin-1 Motors
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DOI：
10.1016/j.bpj.2016.08.006
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发表时间：
2016-09-20
影响因子：
3.4
通讯作者：
Vershinin, Michael
中科院分区：
文献类型：
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作者：
Hong, Weili;Takshak, Anjneya;Vershinin, Michael
细胞质动力蛋白和动蛋白都是基于微管的分子马达，但在结构和进化上是无关的。在标准条件下，两者都以相似的卸载速度朝向微管-(动力蛋白)或正(大多数动蛋白)末端移动。这种相似性很重要，因为它经常被隐含地并入考察细胞内货物流量平衡的模型中，以及单个货物双向运动的模型中。我们检查了这种相似性是否是一个强大的特征，特别是它是否在生物相关的温度范围内持续存在。哺乳动物细胞质动力蛋白的速度，而不是哺乳动物运动蛋白-1的速度，在15摄氏度以下表现出与简单的阿雷尼乌斯行为的断裂，恰好高于哺乳动物快速轴突运输的限制温度。相反，酵母细胞质动力蛋白的速度在较低的温度(类似于8摄氏度)下表现出与阿雷尼乌斯行为的断裂。我们的研究表明，细胞质动力蛋白是一种更具温度可调性的马达，因此是一种潜在的基于微管的运输的温度调节器。我们的理论分析进一步表明，马达速度的变化可以导致单个货物运动的质变，从而导致细胞内净货物通量的变化。我们认为温度有可能被用作细胞内运输的非侵入性探测。
Cytoplasmic dynein and kinesin are both microtubule-based molecular motors but are structurally and evolutionarily unrelated. Under standard conditions, both move with comparable unloaded velocities toward either the microtubule minus (dynein) or plus (most kinesins) end. This similarity is important because it is often implicitly incorporated into models that examine the balance of cargo fluxes in cells and into models of the bidirectional motility of individual cargos. We examined whether this similarity is a robust feature, and specifically whether it persists across the biologically relevant temperature range. The velocity of mammalian cytoplasmic dynein, but not of mammalian kinesin-1, exhibited a break from simple Arrhenius behavior below 15 degrees C just above the restrictive temperature of mammalian fast axonal transport. In contrast, the velocity of yeast cytoplasmic dynein showed a break from Arrhenius behavior at a lower temperature (similar to 8 degrees C). Our studies implicate cytoplasmic dynein as a more thermally tunable motor and therefore a potential thermal regulator of microtubule-based transport. Our theoretical analysis further suggests that motor velocity changes can lead to qualitative changes in individual cargo motion and hence net intracellular cargo fluxes. We propose that temperature can potentially be used as a noninvasive probe of intracellular transport.