Quantifying mRNA targeting to P-bodies in living human cells reveals their dual role in mRNA decay and storage
Quantifying mRNA targeting to P-bodies in living human cells reveals their dual role in mRNA decay and storage
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DOI：
10.1242/jcs.152975
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发表时间：
2014-10-15
影响因子：
4
通讯作者：
Shav-Tal, Yaron
中科院分区：
文献类型：
--
作者：
Aizer, Adva;Kalo, Alon;Shav-Tal, Yaron
5 '至3 ' mRNA降解机制定位于细胞质加工体（P体），其是在所有真核生物中发现的非膜结构。虽然P体的功能已在酵母中得到深入研究，但对它们在哺乳动物细胞中的作用知之甚少，例如P体酶是否积极参与mRNA降解或P体是否充当mRNA储存库，特别是在细胞应激期间。我们研究了翻译应激过程中哺乳动物mRNA在P-小体中的命运，并表明mRNA在氨基酸饥饿过程中在P-小体中积累。转录本的59和39末端位于P体中，但未检测到poly（A）尾。使用MS 2 mRNA标记系统在活细胞中进行mRNA可视化，我们发现在翻译应激期间在P体中形成了一个固定的mRNA群体，该群体在应激解除后逐渐清除。Dcp 2敲低实验表明，有一个恒定的降解的部分P-体相关的mRNA的人口。这一分析表明，在常规和应力条件下，P-体作为衰变位点和储存区的双重作用。
The 5 '-to-3 ' mRNA degradation machinery localizes to cytoplasmic processing bodies (P-bodies), which are non-membranous structures found in all eukaryotes. Although P-body function has been intensively studied in yeast, less is known about their role in mammalian cells, such as whether P-body enzymes are actively engaged in mRNA degradation or whether P-bodies serve as mRNA storage depots, particularly during cellular stress. We examined the fate of mammalian mRNAs in P-bodies during translational stress, and show that mRNAs accumulate within P-bodies during amino acid starvation. The 59 and 39 ends of the transcripts residing in P-bodies could be identified, but poly(A) tails were not detected. Using the MS2 mRNA-tagging system for mRNA visualization in living cells, we found that a stationary mRNA population formed in P-bodies during translational stress, which cleared gradually after the stress was relieved. Dcp2-knockdown experiments showed that there is constant degradation of part of the P-body-associated mRNA population. This analysis demonstrates the dual role of P-bodies as decay sites and storage areas under regular and stress conditions.