Melero J A
J Cell Physiol. 1981 Oct;109(1):59-67. doi: 10.1002/jcp.1041090108.
The analysis of proteins synthesized by the temperature-sensitive cell line K12 at the restrictive temperature or after glucose starvation revealed that two main polypeptides were enhanced under both conditions. Besides having the same apparent molecular weights, these new proteins showed identical patterns of partial proteolysis products, irrespective of being isolated from cells incubated at the nonpermissive temperature or from glucose-starved cultures. These results identified the proteins overproduced by K12 cells at 39.5 degrees C as those described in order cell systems, called "glucose/glycosylation regulated proteins" (GR proteins). In addition, it is shown that K12 cells are defective in some step of the glycosylation pathway; this defect may be responsible for the overproduction of GR proteins in K12.
对温度敏感细胞系K12在限制温度下或葡萄糖饥饿后合成的蛋白质进行分析发现，在这两种条件下有两种主要的多肽表达增强。除了具有相同的表观分子量外，这些新蛋白质显示出相同的部分蛋白水解产物模式，无论它们是从在非允许温度下培养的细胞中分离出来，还是从葡萄糖饥饿培养物中分离出来。这些结果确定了K12细胞在39.5摄氏度时过量产生的蛋白质与有序细胞系统中描述的蛋白质相同，称为“葡萄糖/糖基化调节蛋白”（GR蛋白）。此外，研究表明K12细胞在糖基化途径的某些步骤存在缺陷；这种缺陷可能是K12中GR蛋白过量产生的原因。
