Sampling the cell with anomalous diffusion - The discovery of slowness
Sampling the cell with anomalous diffusion - The discovery of slowness
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DOI：
10.1529/biophysj.107.117044
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发表时间：
2008-01-01
影响因子：
3.4
通讯作者：
Weiss, Matthias
中科院分区：
文献类型：
--
作者：
Guigas, Gernot;Weiss, Matthias
扩散介导的寻找相互作用伙伴是细胞生物学中普遍存在的过程。例如，转录因子搜索特定的DNA序列，信号蛋白旨在与特定的辅因子相互作用，外周膜蛋白试图停靠在膜结构域。然而，布朗运动受到分子拥挤的影响，分子拥挤会引起蛋白质和较大结构的异常扩散（所谓的亚扩散），从而损害扩散运输和相关的采样过程。与亚扩散阻碍细胞过程的天真期望相反，我们在这里通过计算机模拟表明，亚扩散反而增加了找到附近目标的可能性。因此，与正常扩散相比，蛋白质复合物形成和信号传播等重要事件得到增强。因此，细胞确实受益于它们拥挤的内部状态和相关的异常扩散。
Diffusion-mediated searching for interaction partners is an ubiquitous process in cell biology. Transcription factors, for example, search specific DNA sequences, signaling proteins aim at interacting with specific cofactors, and peripheral membrane proteins try to dock to membrane domains. Brownian motion, however, is affected by molecular crowding that induces anomalous diffusion (so-called subdiffusion) of proteins and larger structures, thereby compromising diffusive transport and the associated sampling processes. Contrary to the naive expectation that subdiffusion obstructs cellular processes, we show here by computer simulations that subdiffusion rather increases the probability of finding a nearby target. Consequently, important events like protein complex formation and signal propagation are enhanced as compared to normal diffusion. Hence, cells indeed benefit from their crowded internal state and the associated anomalous diffusion.