Colin A M, Hille M B
Dev Biol. 1986 May;115(1):184-92. doi: 10.1016/0012-1606(86)90239-3.
We have investigated whether the rate of protein synthesis in unfertilized and fertilization-activated sea urchin eggs is limited by the availability of mRNA by injecting eggs, zygotes, and ammonia-activated eggs with globin mRNA. Message-injected and buffer-injected cells were labeled with radioactive amino acids and the proteins separated on a polyacrylamide gel. The relative amounts of newly synthesized globin and endogenous proteins were obtained by scanning the gel fluorograph. Globin mRNA is translated poorly in Strongylocentrotus droebachiensis eggs and does not significantly increase or decrease endogenous protein synthesis. In zygotes and ammonia-activated eggs, however, globin mRNA is translated well and appears to compete with endogenous mRNAs for the limiting component of the translational machinery as it is released. Our results are consistent with the hypothesis that either ribosomes or recruitment factors are gradually activated after fertilization or ammonia treatment, that such components are the rate-limiting factor, and that they impart the typical sigmoidal increase in protein synthesis rate observed in fertilized eggs before the first cleavage.
我们通过向未受精及受精激活的海胆卵、受精卵以及氨激活的卵中注射珠蛋白mRNA，研究了未受精卵和受精激活的海胆卵中蛋白质合成速率是否受mRNA可用性的限制。注射了mRNA和注射了缓冲液的细胞用放射性氨基酸进行标记，蛋白质在聚丙烯酰胺凝胶上进行分离。通过扫描凝胶荧光图获得新合成的珠蛋白和内源性蛋白质的相对量。在强壮海胆的卵中，珠蛋白mRNA的翻译效率很低，并且不会显著增加或减少内源性蛋白质的合成。然而，在受精卵和氨激活的卵中，珠蛋白mRNA翻译良好，并且在其释放时似乎与内源性mRNA竞争翻译机制的限制成分。我们的结果与以下假设一致：核糖体或募集因子在受精或氨处理后逐渐被激活，这些成分是限速因子，并且它们导致在第一次卵裂前受精卵中观察到的典型的蛋白质合成速率呈S形增加。
