期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1977
卷号：74
期号：11
页码：4801-4805
DOI：10.1073/pnas.74.11.4801
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Poly(A)+ and poly(A)- mRNA from HeLa cells were separated and translated in heterologous messenger-dependent protein synthesizing systems. Two-dimensional electrophoretic analysis revealed three classes of polypeptides. At the level of detectability in the electropherograms, a small number (about 10) of proteins were detected only among the poly(A)- mRNA products, a larger number (about 40) were produced by both poly(A)- and poly(A)+ mRNA, and a large number of polypeptides were found exclusively in the poly(A)+ mRNA products. The major product of both poly(A)+ and poly(A)- mRNA was shown to be the {beta} form of actin. Previous cross hybridization measurements suggested little homology between poly(A)+ and poly(A)- mRNA populations. In view of the apparent identity of many poly(A)- products with those of poly(A)+, the homology between poly(A)+ and poly(A)- mRNA sequences was examined in greater detail. cDNA complementary to only the most abundant poly(A)+ message sequences was prepared. About 10% of this cDNA hybridized to abundant sequences in the poly(A)- fraction. This corresponded to only 2% of the total mass of poly(A)+ mRNA and accounted for the failure to detect cross hybridization in previous experiments. Thus, a small number of poly(A)+ sequences appear to be present in relatively high concentration in poly(A)- mRNA as evidenced by both the translation products and the cross hybridization results.
