Saunders C A, Bostian K A, Halvorson H O
Nucleic Acids Res. 1980 Sep 11;8(17):3841-9. doi: 10.1093/nar/8.17.3841.
Thermal elution poly(U)-Sepharose chromatography was utilized to fractionate yeast mRNA based on poly(A) size. Analysis of the in vitro translation products of the fractionated RNAs in a wheat-embryo cell-free protein synthesis system shows a heterogeneous but equal distribution of these abundant translatable mRNAs in the different poly(A) size classes. By comparing the translational activity of inducible galactose-1-phosphate uridyl transferase mRNA, which can be monitored as a function of age, to contitutive mRNAs, we demonstrate that initially galactose-1-phosphate uridyl transferase mRNA has a uniformly large poly(A) tail which becomes heterogeneous and shorter with age in the cytoplasm. These observations are consistent with the previously observed cytoplasmic poly(A) catabolism in yeast and with cytoplasmic post-transcriptional modification of the poly(A) length of galactose-1-phosphate uridyl transferase mRNA.
采用热洗脱聚(U)-琼脂糖凝胶层析法,根据多聚腺苷酸(poly(A))的长度对酵母信使核糖核酸(mRNA)进行分级分离。在小麦胚无细胞蛋白质合成系统中,对分级分离后的RNA体外翻译产物进行分析,结果表明,这些丰富的可翻译mRNA在不同的poly(A)长度类别中分布不均一但数量相等。通过比较可随时间变化进行监测的诱导型1-磷酸半乳糖尿苷酰转移酶mRNA与组成型mRNA的翻译活性,我们证明,最初1-磷酸半乳糖尿苷酰转移酶mRNA具有均一的大poly(A)尾,随着时间推移,在细胞质中该尾变得不均一且变短。这些观察结果与之前在酵母中观察到的细胞质poly(A)分解代谢以及1-磷酸半乳糖尿苷酰转移酶mRNA的poly(A)长度的细胞质转录后修饰相一致。