Thomas G, Thomas G, Luther H
Proc Natl Acad Sci U S A. 1981 Sep;78(9):5712-6. doi: 10.1073/pnas.78.9.5712.
The synthesis of cytoplasmic proteins from quiescent and serum-stimulated Swiss 3T3 cells was compared by two-dimensional polyacrylamide gel electrophoresis. Four new proteins of Mrs 26,000, 28,000, 45,000, and 47,000 designated N26, N28, N45, and N47, which were not detectable in quiescent cells, appeared 60 min after addition of serum. During the same period, the amount of [35S]methionine incorporated into 10 proteins present in quiescent cells, ranging in Mr from 23,000 to 98,000 and designated Q23-98, increased up to 6-fold, whereas the amount incorporated into three other proteins decreased by a factor of approximately 2. Of the new proteins, N26 was no longer detectable, and the amount of [35S]methionine incorporated into N47 was significantly reduced by 150 min. During this same time, a fifth new protein, N56, appeared, and there was a large increase in the amount of radioactivity incorporated into another protein, Q121. The increases in nine of the proteins were either strongly or completely inhibited by actinomycin D, arguing that the expression of these proteins was under transcriptional control. In contrast, the increases in seven other proteins were unaffected by actinomycin D, suggesting that their expression was under translational control. These proteins will serve as useful markers for determining how cells progress through early lag phase.
通过二维聚丙烯酰胺凝胶电泳比较了静止和血清刺激的瑞士3T3细胞中细胞质蛋白的合成情况。在静止细胞中无法检测到的四种新蛋白，分子量分别为26,000、28,000、45,000和47,000，分别命名为N26、N28、N45和N47，在添加血清后60分钟出现。在同一时期，掺入静止细胞中存在的10种蛋白（分子量范围为23,000至98,000，命名为Q23 - 98）中的[35S]甲硫氨酸量增加了6倍，而掺入其他三种蛋白中的量减少了约2倍。在新蛋白中，N26在150分钟后不再可检测到，并且掺入N47中的[35S]甲硫氨酸量显著减少。在同一时间，出现了第五种新蛋白N56，并且掺入另一种蛋白Q121中的放射性量大幅增加。九种蛋白的增加受到放线菌素D的强烈或完全抑制，这表明这些蛋白的表达受转录控制。相比之下，其他七种蛋白的增加不受放线菌素D的影响，表明它们的表达受翻译控制。这些蛋白将作为有用的标记物，用于确定细胞如何度过早期延迟期。
