THE RATE OF ACTIN-BASED MOTILITY OF INTRACELLULAR LISTERIA-MONOCYTOGENES EQUALS THE RATE OF ACTIN POLYMERIZATION
THE RATE OF ACTIN-BASED MOTILITY OF INTRACELLULAR LISTERIA-MONOCYTOGENES EQUALS THE RATE OF ACTIN POLYMERIZATION
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DOI：
10.1038/357257a0
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发表时间：
1992-05-21
期刊：
影响因子：
64.8
通讯作者：
PORTNOY, DA
中科院分区：
文献类型：
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作者：
THERIOT, JA;MITCHISON, TJ;PORTNOY, DA
革兰氏阳性细菌单核细胞增生李斯特菌是一种兼性细胞内病原体，能够在宿主细胞质中快速移动。本文还讨论了L.单核细胞增多症本身就是一个有趣的问题，其答案可能揭示细胞中基于肌动蛋白的运动的一般过程。移动的细胞内细菌显示由肌动蛋白丝组成的相密集的“彗星尾”，其形成是细菌运动性所必需的2，3。我们已经研究了动态的肌动蛋白丝在彗星尾巴使用的荧光光活化技术，它允许监测标记的肌动蛋白丝的运动和营业额激活后，通过照射紫外线。我们发现，当细菌向前移动时，肌动蛋白丝在细胞质中保持静止，并且彗星尾巴的长度与移动速率成线性比例。我们的研究结果意味着，运动机制涉及连续聚合和释放的肌动蛋白丝在细菌表面和丝的产生速度有关的运动速度。我们认为，肌动蛋白聚合提供了细菌推进的驱动力。
THE Gram-positive bacterium Listeria monocytogenes is a facultative intracellular pathogen capable of rapid movement through the host cell cytoplasm 1. The biophysical basis of the motility of L. monocytogenes is an interesting question in its own right, the answer to which may shed light on the general processes of actin-based motility in cells. Moving intracellular bacteria display phase-dense 'comet tails' made of actin filaments, the formation of which is required for bacterial Motility 2,3. We have investigated the dynamics of the actin filaments in the comet tails using the technique of photoactivation of fluorescence, which allows monitoring of the movement and turnover of labelled actin filaments after activation by illumination with ultraviolet light. We find that the actin filaments remain stationary in the cytoplasm as the bacterium moves forward, and that length of the comet tails is linearly proportional to the rate of movement. Our results imply that the motile mechanism involves continuous polymerization and release of actin filaments at the bacterial surface and that the rate of filament generation is related to the rate of movement. We suggest that actin polymerization provides the driving force for bacterial propulsion.