Interactions and regulation of molecular motors in Xenopus melanophores.
Interactions and regulation of molecular motors in Xenopus melanophores.
复制标题
异爪蟾黑色素团中分子电动机的相互作用和调节。
DOI：
10.1083/jcb.200105055
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发表时间：
2002-03-04
影响因子：
7.8
通讯作者：
Gelfand, Vladimir I
中科院分区：
文献类型：
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作者：
Gross, Steven P;Tuma, M Carolina;Deacon, Sean W;Serpinskaya, Anna S;Reilein, Amy R;Gelfand, Vladimir I
许多细胞成分的运输使用肌动蛋白和微管为基础的运输系统的组合。然而，这两个系统如何协同工作，使运输得到良好的监管，目前还不清楚。我们在非洲爪蟾黑色素细胞模型系统中研究了这个问题，其中三个马达，驱动蛋白II，细胞质动力蛋白和肌球蛋白V，驱动称为黑素体的色素细胞器的聚集或分散。在分散过程中，肌球蛋白V作为一个“分子棘轮”，通过选择性终止动力蛋白驱动的负末端运行来增加向外运输。我们发现，有一个持续的拔河之间的肌动蛋白和微管运输系统，但微管电机驱动蛋白II和动力蛋白可能是协调。最后，我们发现从分散到聚集的过渡增加了动力蛋白介导的运动，减少了肌球蛋白V介导的运动，并且不改变驱动蛋白II依赖的运动。肌球蛋白V的下调通过削弱其与沿沿着运动的有效竞争的能力而促进聚集。
Many cellular components are transported using a combination of the actin- and microtubule-based transport systems. However, how these two systems work together to allow well-regulated transport is not clearly understood. We investigate this question in the Xenopus melanophore model system, where three motors, kinesin II, cytoplasmic dynein, and myosin V, drive aggregation or dispersion of pigment organelles called melanosomes. During dispersion, myosin V functions as a “molecular ratchet” to increase outward transport by selectively terminating dynein-driven minus end runs. We show that there is a continual tug-of-war between the actin and microtubule transport systems, but the microtubule motors kinesin II and dynein are likely coordinated. Finally, we find that the transition from dispersion to aggregation increases dynein-mediated motion, decreases myosin V–mediated motion, and does not change kinesin II–dependent motion. Down-regulation of myosin V contributes to aggregation by impairing its ability to effectively compete with movement along microtubules.