REGULATION OF ACTIN MESSENGER-RNA LEVELS AND TRANSLATION RESPONDS TO CHANGES IN CELL CONFIGURATION
REGULATION OF ACTIN MESSENGER-RNA LEVELS AND TRANSLATION RESPONDS TO CHANGES IN CELL CONFIGURATION
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DOI：
10.1128/mcb.3.2.182
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发表时间：
1983-01-01
影响因子：
5.3
通讯作者：
PENMAN, S
中科院分区：
文献类型：
--
作者：
FARMER, SR;WAN, KM;PENMAN, S
利用一个细胞形状和表面接触易于操纵的系统，研究了细胞形态在调节细胞新陈代谢中的作用。依赖锚定的小鼠成纤维细胞悬浮在Metocel中会导致DNA、RNA和蛋白质合成的协调减少。当细胞重新附着到固体表面时，这些过程就会恢复。这一恢复过程有两个或两个以上的组成部分：蛋白质合成的快速恢复只需要表面接触，以及依赖于广泛的细胞扩散的核事件的较慢恢复。3T3细胞在悬浮培养和贴壁培养皿表面后进行检测，以研究特定细胞骨架蛋白基因的细胞形态依赖性表达。与之前研究的3T6细胞相比，这里使用的3T3成纤维细胞系显示了更显著的这些反应。悬浮细胞的总蛋白合成受到强烈抑制，肌动蛋白的合成优先受到抑制，从对照细胞总蛋白合成的12%下降到悬浮细胞的6%。这明显发生在肌动蛋白mRNA的翻译水平上，因为细胞质中肌动蛋白mRNA序列的数量没有变化。体外翻译和与克隆的肌动蛋白c[互补]DNA探针杂交表明，肌动蛋白合成的诱导是由于细胞质中可翻译的mRNA序列增加所致。这些结果暗示了细胞结构、特定细胞骨架蛋白基因的表达和生长控制之间的密切关系。肌动蛋白基因的表达似乎在翻译水平(在悬浮期间)和信使核糖核酸的产生(在恢复期间)都受到调节。
The role of cell configuration in regulating cell metabolism was studied, using a system in which cell shape and surface contact can easily be manipulated. The suspension of anchorage-dependent mouse fibroblasts in Methocel results in a coordinate decrease of DNA, RNA and protein synthesis. These processes are restored upon reattachment of cells to a solid surface. This recovery process has 2 or more components: a rapid recovery of protein synthesis requiring only surface contact and a slower restoration of nuclear events which is dependent upon extensive cell spreading. 3T3 cells were examined while in suspension culture and after attachment to a tissue culture dish surface to study cell configuration-dependent expression of specific cytoskeleton protein genes. The 3T3 line of fibroblasts used here shows these responses much more dramatically compared with 3T6 cells previously studied. Whereas total protein synthesis was strongly inhibited upon suspension, actin synthesis was preferentially inhibited, decreasing from 12% of total protein synthesis in control cells to 6% in suspended cells. This occurred apparently at the level of translation of actin mRNA, since the amount of actin mRNA sequences in the cytoplasm was unchanged. Reattachment initiated the rapid recovery of overall protein synthesis which was accompanied by a dramatic, preferential increase in actin synthesis reaching peak values of 20-25% of total protein synthesis 4-6 h later, but then declining to control values by 24 h. Translation in vitro and hybridization of mRNA to a cloned actin c[complementary]DNA probe revealed that the induction of actin synthesis was due to increased levels of translatable mRNA sequences in the cytoplasm. These results imply a close relationship among cell cytoarchitecture, expression of a specific cytoskeletal protein gene and growth control. The expression of the actin gene appears to be regulated at both the level of translation (during suspension) and mRNA production (during recovery).