FORCE GENERATION OF ORGANELLE TRANSPORT MEASURED INVIVO BY AN INFRARED-LASER TRAP
FORCE GENERATION OF ORGANELLE TRANSPORT MEASURED INVIVO BY AN INFRARED-LASER TRAP
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DOI：
10.1038/348346a0
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发表时间：
1990-11-22
期刊：
影响因子：
64.8
通讯作者：
SCHLIWA, M
中科院分区：
文献类型：
--
作者：
ASHKIN, A;SCHUTZE, K;SCHLIWA, M
细胞器沿微管的运输被认为是由细胞器相关的产力分子介导的。两类基于微管的细胞器马达已被确定：kinesin2 - 7和细胞质dynein8-12。为了将力产生的机械化学基础与细胞器的体内行为联系起来，重要的是量化推动细胞器沿着微管运动所需的力，并确定单个马达分子产生的力。在体外选定的条件下（例如，参见文献13和14）可以测量力的产生，但使用完整或重新激活的细胞要困难得多。在这里，我们结合了一个用于研究细胞器运输的有用模型系统，即巨型变形虫（amoebaReticulomyxa15），以及一种基于梯度力光学陷阱（也称为“光学镊子”）的非侵入性操作和对亚细胞成分施加力的新技术。我们证明了使用主动移位细胞器的控制操作来测量直接力的可行性。我们已经确定了沿着微管驱动单个细胞器的力，使我们能够估计单个电机产生的力为2.6 × 10-7达因。
ORGANELLE transport along microtubules is believed to be mediated by organelle-associated force-generating molecules1. Two classes of microtubule-based organelle motors have been identified: kinesin2–7and cytoplasmic dynein8–12. To correlate the mechanochemical basis of force generation with thein vivobehaviour of organelles, it is important to quantify the force needed to propel an organelle along microtubules and to determine the force generated by a single motor molecule. Measurements of force generation are possible under selected conditionsin vitro(for example, see refs 13 and 14), but are much more difficult using intact or reactivated cells. Here we combine a useful model system for the study of organelle transport, the giant amoebaReticulomyxa15, with a novel technique for the non-invasive manipulation of and force application to subcellular components, which is based on a gradient-force optical trap, also referred to as 'optical tweezers'16–19. We demonstrate the feasibility of using controlled manipulation of actively translocating organelles to measure direct force. We have determined the force driving a single organelle along microtubules, allowing us to estimate the force generated by a single motor to be 2.6 × 10-7dynes.