Regulation of protein synthesis in Dictyostelium discoideum: effects of starvation and anoxia on initiation.
Regulation of protein synthesis in Dictyostelium discoideum: effects of starvation and anoxia on initiation.
复制标题
盘基网柄菌蛋白质合成的调节：饥饿和缺氧对启动的影响。
DOI：
10.1021/bi00529a011
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发表时间：
1981
期刊：
影响因子：
2.9
通讯作者：
R. Dimond
中科院分区：
文献类型：
--
作者：
J. Cardelli;R. Dimond
James A. Cardelli* and Randall L. Dimond abstract: A rapid reduction in the size and amount of total polysomes is one of the earliest observed changes when the cellular slime mold Dictyostelium discoideum is starved for a nutrient source. The measured elongation rate of protein synthesis is similar in both starved and vegetative cells and measures approximately 100 and 120 amino acids per min, respectively. Therefore, the reduction in the size and amount of polysomes following starvation is the result of a rapid de-crease in the initiation rate of protein synthesis. Accompanying this reduction in the initiation rate is a decrease in the percentage of cellular messenger ribonucleic acid (mRNA) as-sociated with polysomes from 85-90% in fed cells to 65% in starved cells. When the elongation rate in starved cells is reduced by the addition of cycloheximide to cultures, poly-somes increase to vegetative levels in size and amount, dem-onstrating the lack of inactivation of either ribosomes or mRNA. Polysomes also rapidly increase in amount whenE^ ukaryotic cells regulate the rate of protein synthesis in response to a wide varietyof environmental conditions. As an example, polysomes disaggregate and the initiation rate of protein synthesis drops in manymammalian cells starved for amino acids or glucose (Christman, 1973; Hogan & Korner, 1968; Lee et al., 1971; Van Venrooij et al., 1972). This block in polypeptide chain initiation also leads to the accumulation in the cytoplasm of mRNA1 in the form of nonpolysomal
