Motor number controls cargo switching at actin-microtubule intersections in vitro.
Motor number controls cargo switching at actin-microtubule intersections in vitro.
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DOI：
10.1016/j.cub.2010.03.024
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发表时间：
2010-04-27
期刊：
影响因子：
--
通讯作者：
Goldman YE
中科院分区：
文献类型：
--
作者：
Schroeder HW 3rd;Mitchell C;Shuman H;Holzbaur EL;Goldman YE
细胞活动，如内吞和分泌，需要货物在微管(MT)和肌动蛋白细丝(AF)网络之间主动切换。细胞研究表明，转换可能涉及MT和AF基础运动功能的拉锯战或协调调节。为了验证马达数量可以用来指导拔河比赛结果的假设，我们在MT-AF交叉口重新构建了一个最小系统中的货物切换，将纯化的肌球蛋白V和动力蛋白-动力蛋白马达绑定到珠子上。含有两个马达的珠子经常在交叉口停下来，绕着垂直于两个细丝的轴旋转，这表明相互竞争的马达对他们的货物施加了扭矩。力量测量表明，运动力与参与的肌球蛋白V和动力蛋白-动力蛋白马达的数量成比例。珠子是留在MT或AF上，还是切换到备用轨道上，取决于哪组电机共同产生更大的力。无论珠子靠近MT或AF上的交叉口，通过和切换的概率都是相似的。力比接近1的珠子在MT上离开、在AF上离开或在交叉口保持熄火的概率大致相等。一个简单的统计模型定量地描述了切换概率与电机数量之间的关系。货物切换可以通过1-4个肌球蛋白V和1-4个动力蛋白-动力蛋白结合的马达通过一个简单的力中介机制进行调整。
Cellular activities such as endocytosis and secretion require that cargos actively switch between the microtubule (MT) and actin filament (AF) networks. Cellular studies suggest that switching may involve a tug-of-war or coordinate regulation of MT- and AF-based motor function. To test the hypothesis that motor number can be used to direct the outcome of a tug-of-war process, we reconstituted cargo switching at MT-AF intersections in a minimal system with purified myosin V and dynein-dynactin motors bound to beads. Beads containing both motors often paused at the intersections and rotated about an axis perpendicular to both filaments, suggesting that competing motors apply a torque on their cargo. Force measurements showed that motor forces scale with the number of engaged myosin V and dynein-dynactin motors. Whether beads remained on a MT or AF or switched to the alternate track was determined by which set of motors collectively produced greater force. Passing and switching probabilities were similar whether the bead approached an intersection on either a MT or AF. Beads with a force ratio near unity had approximately equal probabilities of exiting on the MT, exiting on the AF, or remaining stalled at the intersection. A simple statistical model quantitatively describes the relationship between switching probability and motor number. Cargo switching can be tuned via combinations of 1-4 myosin V and 1-4 dynein-dynactin engaged motors through a simple force-mediated mechanism.
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DOI：
10.1083/jcb.200810147
发表时间：
2009-08-24
期刊：
The Journal of cell biology
影响因子：
--
作者：
Jung G;Titus MA;Hammer JA 3rd
通讯作者：
Hammer JA 3rd
DOI：
10.1073/pnas.0436709100
发表时间：
2003-03-04
影响因子：
11.1
作者：
Block, SM;Asbury, CL;Lang, MJ
通讯作者：
Lang, MJ
DOI：
10.1073/pnas.0510191103
发表时间：
2006-06-06
影响因子：
11.1
作者：
Gebhardt, J. Christof M.;Clemen, Anabel E. -M.;Rief, Matthias
通讯作者：
Rief, Matthias
影响因子：
9.2
作者：
Mallik, R;Petrov, D;Gross, SP
通讯作者：
Gross, SP
影响因子：
3.3
作者：
Al-Haddad, AH;Shonn, MA;Kuznetsov, SA
通讯作者：
Kuznetsov, SA