Greenberg J R
Proc Natl Acad Sci U S A. 1981 May;78(5):2923-6. doi: 10.1073/pnas.78.5.2923.
The metabolism of mRNA--protein complexes present in polyribosomes of mouse L cells was investigated with the aid of ultraviolet light-induced crosslinking of proteins to RNA. It was shown that a set of at least seven proteins which are synthesized and become associated with mRNA under conditions permitting mRNA synthesis also are synthesized and become associated with mRNA when mRNA synthesis is inhibited with a high dose of actinomycin D. This set includes a protein of Mr 78,000 which can be crosslinked to poly(A). These findings imply that mRNA-associated proteins exchange in the cytoplasm with a pool of free proteins. Taken together with results from other laboratories, they suggest a role for mRNA-associated proteins in translation. The labeling kinetics of mRNA-associated proteins were also investigated and found to be consistent with cytoplasmic addition to mRNA and a half-life of more than 2 hr. Additional implications of these findings are discussed.
借助紫外线诱导蛋白质与RNA交联的方法，对小鼠L细胞多核糖体中存在的mRNA - 蛋白质复合物的代谢进行了研究。结果表明，在允许mRNA合成的条件下合成并与mRNA结合的一组至少七种蛋白质，当用高剂量放线菌素D抑制mRNA合成时也会合成并与mRNA结合。这一组包括一种分子量为78,000的蛋白质，它可以与多聚腺苷酸（poly(A)）交联。这些发现意味着与mRNA结合的蛋白质在细胞质中与游离蛋白质池进行交换。结合其他实验室的结果，它们提示了与mRNA结合的蛋白质在翻译中的作用。还研究了与mRNA结合的蛋白质的标记动力学，发现其与mRNA在细胞质中的添加情况以及半衰期超过2小时是一致的。讨论了这些发现的其他意义。
