Ngo J L, Orlando R A, Ibsen K H
Arch Biochem Biophys. 1986 May 15;247(1):171-82. doi: 10.1016/0003-9861(86)90546-1.
Total protein content of P-815 mastocytoma cells decreases and then increases in response to initiation of a new growth cycle. As the level increases, the rate of synthesis declines. Both events occur prior to any decrease in the rate of cellular proliferation. These temporal relationships indicate that the rate of protein synthesis reflects the intracellular concentration of protein rather than the cellular growth rate, as has been hypothesized. Pyruvate kinase protein metabolism differs from that of total protein in three ways: (a) accumulation does not stop, (b) the rate of synthesis does not decrease, and (c) only the rate of pyruvate kinase degradation is altered by a factor present in conditioned media. These observations suggest that there are specific mechanisms regulating pyruvate kinase at a post-transcriptional level.
P-815肥大细胞瘤细胞的总蛋白含量在新生长周期开始时先下降然后上升。随着含量增加，合成速率下降。这两个事件都发生在细胞增殖速率出现任何下降之前。这些时间关系表明，正如所假设的那样，蛋白质合成速率反映的是细胞内蛋白质浓度而非细胞生长速率。丙酮酸激酶的蛋白质代谢在三个方面与总蛋白不同：（a）积累不会停止，（b）合成速率不会下降，（c）只有丙酮酸激酶的降解速率会受到条件培养基中一种因子的影响而改变。这些观察结果表明，在转录后水平存在调节丙酮酸激酶的特定机制。
