REGULATION OF INTRACELLULAR PROTEIN-DEGRADATION IN IMR-90 HUMAN-DIPLOID FIBROBLASTS
REGULATION OF INTRACELLULAR PROTEIN-DEGRADATION IN IMR-90 HUMAN-DIPLOID FIBROBLASTS
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DOI：
10.1002/jcp.1041150210
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发表时间：
1983-01-01
影响因子：
5.6
通讯作者：
DICE, JF
中科院分区：
文献类型：
--
作者：
AUTERI, JS;OKADA, A;DICE, JF
人类二倍体成纤维细胞(IMR-90)根据培养介质的组成和环境温度调节其总的蛋白分解速率。反应的大小和方向，在某些情况下，取决于放射性标记的细胞蛋白质的半衰期和测量蛋白质降解的选择时间。胎牛血清、胰岛素、成纤维细胞生长因子、表皮生长因子和氨基酸选择性地调节长寿蛋白质的分解代谢，而不影响短寿蛋白质的降解。胎牛血清可降低长寿命蛋白质的降解率，在浓度为20%时效果最好，但对蛋白质降解的影响仅在24小时内明显。在有或无葡萄糖和氨基酸的情况下，胰岛素抑制长寿命蛋白质的降解，但只有在高浓度(10-5M)时才最有效。氨基酸缺乏会增加长寿命蛋白质在前6h的降解率，但在随后的20h会降低其分解代谢。温度降低是唯一显著改变短寿命蛋白质降解率的条件。尽管细胞孵化温度为27℃。与37度的细胞相比，C降低了短寿命和长寿命蛋白质的降解率。更低的温度在更大程度上减少了长寿蛋白质的分解代谢。
Human diploid fibroblasts (IMR-90) regulate their overall rates of proteolysis in response to the composition of the culture medium and the ambient temperature. The magnitude and, in some cases, the direction of the response depend on the half-lives of the cellular proteins that are radioactively labeled and the time chosen for measurements of protein degradation. Fetal calf serum, insulin, fibroblast growth factor, epidermal growth factor and amino acids selectively regulate catabolism of long-lived proteins without affecting degradation of short-lived proteins. Fetal calf serum reduces degradative rates of long-lived proteins and is maximally effective at a concentration of 20%, but the effect of serum on proteolysis is evident only for the first 24 h. Insulin inhibits degradation of long-lived proteins in the presence or absence of glucose and amino acids in the medium, but is maximally effective only at high concentrations (10-5 M). Amino acid deprivation increases degradative rates of long-lived proteins for the first 6 h, but then decreases their catabolism for the subsequent 20 h. Lowered temperature is the only condition tested that significantly alters degradative rates of short-lived proteins. Although cells incubated at 27.degree. C have reduced rates of degradation for both short-lived and long-lived proteins compared to cells at 37.degree. C, lowered temperature reduces catabolism of long-lived proteins to a greater extent.