Colman A, Morser J, Lane C, Besley J, Wylie C, Valle G
J Cell Biol. 1981 Dec;91(3 Pt 1):770-80. doi: 10.1083/jcb.91.3.770.
The effects of imbalanced subunit synthesis, temperature, colchicine, and cytochalasin on the secretion from Xenopus laevis oocytes of a variety of avian and mammalian proteins were investigated; these proteins were encoded by microinjected messenger RNA. Cytochalasin and colchicine together severely reduced secretion in a temperature-independent manner, the exact reduction varying among the different proteins. In contrast cytochalasin alone had no effect, whereas colchicine alone caused a smaller, temperature-dependent reduction. The synthesis and subcellular compartmentation of these proteins were unaffected by the drug treatments; however, the proteins did not accumulate in the drug-treated oocytes but were degraded. The rate of degradation of each protein was similar to its rate of exocytosis from untreated oocytes. A similar result was obtained without recourse to drugs by studying the fate of immunoglobulin light chains trapped in oocytes by a deficiency in heavy chain synthesis. These results are discussed in terms of the disruptive effects, as revealed by electron microscopy, of the drug treatments on the cytoskeleton of the oocyte.
研究了亚基合成失衡、温度、秋水仙碱和细胞松弛素对非洲爪蟾卵母细胞分泌多种鸟类和哺乳动物蛋白质的影响；这些蛋白质由显微注射的信使核糖核酸编码。细胞松弛素和秋水仙碱共同作用以不依赖温度的方式严重降低分泌，不同蛋白质的具体降低程度有所不同。相比之下，单独使用细胞松弛素没有效果，而单独使用秋水仙碱会导致较小的、依赖温度的降低。这些蛋白质的合成和亚细胞区室化不受药物处理的影响；然而，这些蛋白质在经药物处理的卵母细胞中并未积累而是被降解。每种蛋白质的降解速率与其从未经处理的卵母细胞中胞吐的速率相似。通过研究由于重链合成缺陷而被困在卵母细胞中的免疫球蛋白轻链的命运，在不使用药物的情况下也得到了类似的结果。根据电子显微镜揭示的药物处理对卵母细胞细胞骨架的破坏作用对这些结果进行了讨论。
