RNP stress-granule formation is inhibited by microtubule disruption
RNP stress-granule formation is inhibited by microtubule disruption
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DOI：
10.1016/s1065-6995(02)00341-4
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发表时间：
2003-01-01
影响因子：
3.9
通讯作者：
Nadezhdina, ES
中科院分区：
文献类型：
--
作者：
Ivanov, PA;Chudinova, EM;Nadezhdina, ES
应激颗粒(SGS)是一种致密的微米级颗粒，聚集在动植物细胞的细胞质中，以应对细胞应激：热休克、药物应用等(nover et al.，1989)。SGS包含翻译启动机制的组件、Poly(A)RNA、一些RNA结合蛋白、40S核糖体亚基和启动因子eIF3、eIF4E和eIF4G(Kedersha等人，2000,2002)。它们被定义为与多聚体处于动态平衡状态的动态非膜细胞室。令人惊讶的是，SG的队形只需要几分钟。目前尚不清楚数百个大分子如何在巨大的细胞体积中如此迅速地找到彼此。我们推测，SG组分可以结合或沿着细胞骨架元件移动，这种结合/移动可以增加分子聚集的几率。本工作研究了SGS与微管、肌动蛋白细丝和中间微丝的相互作用以及SG的形成对微管和肌动蛋白网络完整性的依赖。砷盐处理不影响细胞MTS(图1A，C)或肌动蛋白细丝(数据未显示)。为了研究SGS与细胞骨架的相互作用，我们用2.8 mM的砷酸钠处理培养的哺乳动物细胞CV-1(绿猴肾成纤维细胞)，用戊二醛固定细胞，并用抗体A167(针对eIF3因子p167亚基的抗体，Shanina等人，2001)和商用抗体对细胞骨架结构进行免疫染色。免疫染色的A167细胞显示弥漫的抗原分布，有时细胞质中有非常小的颗粒(图1E)。如果细胞与砷盐孵育，抗原在30分钟内就浓缩在SGS中(图1G)。
Stress-granules (SGs) are dense micrometre sized particles that assemble in the cytoplasm of animal and plant cells in response to cell stress: heat shock, drug application, etc.(Nover et al., 1989). SGs contain components of the translation initiation machinery, poly (A) RNA, some RNA-binding proteins, 40S ribosomal subunit and initiation factors eIF3, eIF4E and eIF4G (Kedersha et al., 2000, 2002). They are defined as dynamic non-membrane cellular compartments existing in dynamic equilibrium with polysomes. Surprisingly, SG formation takes minutes. It is not clear how hundreds of large molecules can find each other so quickly in a large cell volume. We speculated that SG constituents could bind or move along cytoskeletal elements, and this binding/moving could increase the probability of molecules to congregate. Interaction of SGs with microtubules (MTs), actin filaments and intermediate filaments and the dependence of SG formation on the integrity of the MT and actin network were studied in this work.Treatment of cells with sodium arsenate is often used as an approach for SG induction (Kedersha et al., 2000, 2002). Arsenate treatment does not influence cell MTs (Fig. 1A, C) or actin filaments (data not shown). To study the interaction of SGs and cytoskeleton, we treated cultured mammalian cells CV-1 (green monkey kidney fibroblasts) with 2.8 mM sodium arsenate dissolved in growth medium, fixed them with glutaraldehyde, and immunostained with antibody A167 (to p167 subunit of eIF3 factor, described in Shanina et al., 2001) and commercial antibodies to cytoskeletal structures. Immunostained A167 cells demonstrated diffuse antigen distribution or sometimes very small granules in the cytoplasm (Fig. 1E). If cells were incubated with arsenate, the antigen was concentrated in SGs within 30 min (Fig. 1G).