Single mRNA molecules demonstrate probabilistic movement in living mammalian cells
Single mRNA molecules demonstrate probabilistic movement in living mammalian cells
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DOI：
10.1016/s0960-9822(02)01436-7
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发表时间：
2003-01-21
期刊：
影响因子：
9.2
通讯作者：
Bertrand, E
中科院分区：
文献类型：
--
作者：
Fusco, D;Accornero, N;Bertrand, E
细胞质mRNA的运动最终决定了蛋白质合成的空间分布。尽管一些mRNA在细胞质区域被分隔，但大多数mRNA，如持家基因mRNA或多聚腺苷酸化的mRNA群体，被认为是分布在整个细胞质中的[1 - 4]。所有mRNA可能移动的一般机制以及这与定位如何相关尚不清楚。在此，我们报道了一种在活的哺乳动物细胞中观察单个mRNA分子的方法，并且我们发现，不管任何特定的细胞质分布如何，单个mRNA分子在微管上表现出快速且定向的运动。重要的是，β - 肌动蛋白mRNA的邮政编码序列增加了这些运动的频率和长度，为定位的和非定位的mRNA提供了一个共同的机制基础。用药物破坏细胞骨架表明，微管和微丝参与了我们所观察到的mRNA运动类型，这些类型包括完全静止、受限扩散和非受限扩散。单个mRNA分子在这些运动之间频繁转换，这表明mRNA经历着锚定、扩散和主动运输的连续循环。
Cytoplasmic mRNA movements ultimately determine the spatial distribution of protein synthesis. Although some mRNAs are compartmentalized in cytoplasmic regions, most mRNAs, such as housekeeping mRNAs or the poly-adenylated mRNA population, are believed to be distributed throughout the cytoplasm [1-4]. The general mechanism by which all mRNAs may move, and how this may be related to localization, is unknown. Here, we report a method to visualize single mRNA molecules in living mammalian cells, and we report that, regardless of any specific cytoplasmic distribution, individual mRNA molecules exhibit rapid and directional movements on microtubules. Importantly, the beta-actin mRNA zipcode increased both the frequency and length of these movements, providing a common mechanistic basis for both localized and nonlocalized mRNAs. Disruption of the cytoskeleton with drugs showed that microtubules and microfilaments are involved in the types of mRNA movements we have observed, which included complete immobility and corralled and nonrestricted diffusion. Individual mRNA molecules switched frequently among these movements, suggesting that mRNAs undergo continuous cycles of anchoring, diffusion, and active transport.