HEAT-SHOCK BUT NOT OTHER STRESS INDUCERS LEADS TO THE DISRUPTION OF A SUBSET OF SNRNPS AND INHIBITION OF INVITRO SPLICING IN HELA-CELLS
HEAT-SHOCK BUT NOT OTHER STRESS INDUCERS LEADS TO THE DISRUPTION OF A SUBSET OF SNRNPS AND INHIBITION OF INVITRO SPLICING IN HELA-CELLS
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DOI：
10.1002/j.1460-2075.1988.tb03227.x
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发表时间：
1988-11-01
期刊：
影响因子：
11.4
通讯作者：
BOND, U
中科院分区：
文献类型：
--
作者：
BOND, U
研究了暴露于各种应激反应诱导剂的HeLa细胞中前体mRNA的剪接。在体内，热休克蛋白27基因的含内含子的转录本在热或亚砷酸钠应激的细胞中积累。然而，体外分析揭示了应力对剪接的不同影响：暴露于严重热休克的细胞的核提取物不能剪接外源提供的底物，而剪接在用亚砷酸钠、氨基酸类似物刀豆氨酸或乙醇处理的提取物中不受干扰。在严重热冲击之前用温和热冲击预处理电池保护拼接装置并允许拼接不受阻碍地进行。从热休克细胞提取物中的剪接缺陷的分析表明，剪接的抑制不能占的主要RNA和蛋白质成分的变化的小核核糖核蛋白颗粒（snRNP）或在以前描述的热不稳定的因素，是必不可少的体外剪接。分馏的一个小的核核糖核蛋白颗粒热休克提取物通过天然聚丙烯酰胺凝胶电泳揭示了戏剧性的变化，在某些颗粒，最明显的是在U4/U 5/U6 snRNP复合物和U2 snRNP。这些颗粒的改变伴随着标记的前mRNA转录物组装成不同于正常提取物中形成的异常剪接复合物。
Splicing of pre-mRNA in HeLa cells exposed to various stress response inducers has been investigated. In vivo, intron-containing transcripts of the hsp27 gene accumulate in cells stressed by heat or sodium arsenite. In vitro analysis, however, reveals a differential effect of stress on splicing: nuclear extracts from cells exposed to a severe heat shock are incapable of splicing an exogenously supplied substrate while splicing is not perturbed in extracts treated with sodium arsenite, the amino acid analog canavinine or ethanol. Pretreatment of cells with a mild heat shock prior to a severe heat shock protects the splicing apparatus and allows splicing to proceed unimpeded. Analyses of the splicing defect in extracts from heat-shocked cells show that the inhibition of splicing cannot be accounted for by changes in the major RNA and protein components of small nuclear ribonucleoprotein particles (snRNPs) or in a previously described heat-labile factor that is essential for in vitro splicing. Fractionation of a small nuclear ribonucleoprotein particles from heat-shock extracts by native polyacrylamide gel electrophoresis reveals dramatic changes in certain particles, most noticeably in a U4/U5/U6 snRNP complex and the U2 snRNP. Alterations in these particles are accompanied by the assembly of labeled pre-mRNA transcript into aberrant splicing complexes that differ from those formed in normal extracts.