REGULATION OF RIBOSOMAL-PROTEIN MESSENGER-RNA CONTENT AND TRANSLATION IN GROWTH-STIMULATED MOUSE FIBROBLASTS
REGULATION OF RIBOSOMAL-PROTEIN MESSENGER-RNA CONTENT AND TRANSLATION IN GROWTH-STIMULATED MOUSE FIBROBLASTS
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DOI：
10.1128/mcb.2.6.685
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发表时间：
1982-01-01
影响因子：
5.3
通讯作者：
JOHNSON, LF
中科院分区：
文献类型：
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作者：
GEYER, PK;MEYUHAS, O;JOHNSON, LF
当静息（G 0）小鼠3 T6成纤维细胞被血清刺激以重新进入细胞周期时，rRNA和核糖体蛋白质的合成速率增加，导致核糖体含量从约开始增加。刺激后6 h。在静息、指数生长和血清刺激的3 T6细胞中监测核糖体蛋白mRNA（rp mRNA）的含量、代谢和翻译。将7 rp mRNA的克隆c[互补DNA]DNA用于DNA过量滤膜杂交研究，以测定rp mRNA。在所有生长条件下，约85%的rp mRNA被聚腺苷酸化。rp mRNA相对于总聚腺苷酸化mRNA的标记率在刺激后变化很小。rp mRNA的半衰期为0.05。在静息细胞中11小时，在指数生长的细胞中，该值与静息和生长细胞中总mRNA的半衰期相似（约8h）。9 h）。rp mRNA相对于总mRNA的含量在静息和生长的3 T6细胞中大致相同。rp的总量直到. apprx才开始增加。刺激后6 h。由于RP mRNA含量的增加似乎并不负责核糖体蛋白合成的增加，RP mRNA的翻译效率在不同条件下测定。在指数生长的细胞中，约85%的脉冲标记rp mRNA与多聚核糖体相关。在静息细胞中，只有大约一半与多聚核糖体相关，并且30%在单体组分中发现。血清刺激后3 h内，分布转移到生长细胞中。当细胞标记10.5h时获得类似的结果。无论标记时间如何，在所有生长状态下，约70%的总多聚腺苷酸化mRNA在多聚体组分中，表明mRNA分布的变化具有种属特异性。生长刺激后rp mRNA的含量和代谢无明显变化。核糖体蛋白质合成的速率似乎是控制在休息-生长过渡期间的RP mRNA的翻译效率的改变，可能在蛋白质合成起始的水平。
When resting (G0) mouse 3T6 fibroblasts are serum-stimulated to reenter the cell cycle, the rates of synthesis of rRNA and ribosomal proteins increase, resulting in an increase in ribosome content beginning .apprx. 6 h after stimulation. The content, metabolism and translation of ribosomal protein mRNA (rp mRNA) was monitored in resting, exponentially growing, and serum-stimulated 3T6 cells. Cloned c[complementary DNA]DNA for 7 rp mRNA were used in DNA-excess filter hybridization studies to assay rp mRNA. About 85% of rp mRNA is polyadenylated under all growth conditions. The rate of labeling of rp mRNA relative to total polyadenylated mRNA changed very little after stimulation. The half-life of rp mRNA was .apprx. 11 h in resting cells and .apprx. 8 h in exponentially growing cells, values which are similar to the half-lives of total mRNA in resting and growing cells (.apprx. 9 h). The content of rp mRNA relative to total mRNA was about the same in resting and growing 3T6 cells. The total amount of rp did not begin to increase until .apprx. 6 h after stimulation. Since an increase in rp mRNA content did not seem to be responsible for the increase in ribosomal protein synthesis, the efficiency of translation of rp mRNA was determined under different conditions. About 85% of pulse-labeled rp mRNA was associated with polysomes in exponentially growing cells. In resting cells only about half was associated with polysomes, and .apprx. 30% was found in the monosomal fraction. The distribution shifted to that found in growing cells within 3 h after serum stimulation. Similar results were obtained when cells were labeled for 10.5 h. About 70% of total polyadenylated mRNA was in the polysome fraction in all growth states regardless of labeling time, indicating that the shift in mRNA distribution was species specific. Apparently, the content and metabolism of rp mRNA do not change significantly after growth stimulation. The rate of ribosomal protein synthesis appears to be controlled during the resting-growing transition by an alteration of the efficiency of translation of rp mRNA, possibly at the level of protein synthesis initiation.