Goldberg A L
Proc Natl Acad Sci U S A. 1971 Feb;68(2):362-6. doi: 10.1073/pnas.68.2.362.
The rate of degradation of cell proteins in Escherichia coli was studied under various conditions that affect levels of charged tRNA. Protein breakdown increased markedly when the synthesis of valyl-tRNA was prevented in strains containing temperature-sensitive valyl-tRNA synthetase or when the formation of N-formylmethionyl-tRNA was inhibited with trimethoprim. Conversely, protein breakdown decreased in a valine auxotroph-administered valine or an analog capable of attachment to the valyl-tRNA. It appears that changes in the levels of aminoacyl-tRNA regulate protein breakdown by mechanisms similar to those controlling the synthesis of ribosomal RNA. These experiments also demonstrate that protein synthesis is not essential for protein degradation and suggest that the inhibition of degradation in starving cells by chloramphenicol is a secondary effect of the accumulation of charged tRNA.
在影响带电tRNA水平的各种条件下，对大肠杆菌中细胞蛋白质的降解速率进行了研究。当含有温度敏感型缬氨酰-tRNA合成酶的菌株中缬氨酰-tRNA的合成被阻止时，或者当用甲氧苄啶抑制N-甲酰甲硫氨酰-tRNA的形成时，蛋白质分解显著增加。相反，在给予缬氨酸营养缺陷型缬氨酸或能够附着到缬氨酰-tRNA上的类似物时，蛋白质分解减少。似乎氨酰-tRNA水平的变化通过类似于控制核糖体RNA合成的机制来调节蛋白质分解。这些实验还表明蛋白质合成对于蛋白质降解不是必需的，并表明氯霉素对饥饿细胞中降解的抑制是带电tRNA积累的次要效应。
