Wilcox C, Hu J S, Olson E N
Department of Biochemistry and Molecular Biology, University of Texas, M.D. Anderson Hospital and Tumor Institute at Houston 77030.
Science. 1987 Nov 27;238(4831):1275-8. doi: 10.1126/science.3685978.
Several proteins of viral and cellular origin are acylated with myristic acid early during their biogenesis. To investigate the possibility that myristylation occurred cotranslationally, the BC3H1 muscle cell line, which contains a broad array of myristylated proteins, was pulse-labeled with [3H]myristic acid. Nascent polypeptide chains covalently associated with transfer RNA were isolated subsequently by ion-exchange chromatography. [3H]Myristate was attached to nascent chains through an amide linkage and was identified by thin-layer chromatography after its release from nascent chains by acid methanolysis. Inhibition of cellular protein synthesis with puromycin resulted in cessation of [3H]myristate-labeling of nascent chains, in agreement with the dependence of this modification on protein synthesis in vivo. These data represent a direct demonstration that myristylation of proteins is a cotranslational modification.
几种病毒源和细胞源的蛋白质在其生物合成早期会被肉豆蔻酸酰化。为了研究肉豆蔻酰化是否在共翻译过程中发生，对含有多种肉豆蔻酰化蛋白质的BC3H1肌肉细胞系用[³H]肉豆蔻酸进行脉冲标记。随后通过离子交换色谱法分离与转运RNA共价结合的新生多肽链。[³H]肉豆蔻酸盐通过酰胺键连接到新生链上，并在通过酸性甲醇解从新生链释放后通过薄层色谱法进行鉴定。用嘌呤霉素抑制细胞蛋白质合成导致新生链的[³H]肉豆蔻酸盐标记停止，这与这种修饰在体内对蛋白质合成的依赖性一致。这些数据直接证明了蛋白质的肉豆蔻酰化是一种共翻译修饰。
