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：1974
卷号：71
期号：12
页码：5009-5013
DOI：10.1073/pnas.71.12.5009
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The kinetics of synthesis and turnover of animal cell nuclear precursor-mRNA fractions all of which, in the case of avian erythroblast RNA, are shown by specific complementary DNA hybridization to contain globin mRNA sequences, were analyzed by exponential polyacrylamide gel electrophoresis. Three metabolically distinct size-fractions were characterized: (1) nascent precursor-mRNA (apparent molecular weight 5 to 20 x 106, approximate half-life 30 min), (2) intermediate-size precursor-mRNA (molecular weight 1 to 5 x 106, approximate half-life 3 hr), (3) small precursor-mRNA (molecular weight 0.5 to 1.5 x 106, half-life more than 15 hr). Nascent precursor-mRNA behaves kinetically as a precursor to the smaller precursor-mRNAs that accumulate in the nucleus, as well as to cytoplasmic mRNA; however, no stringent proof can be given that the two smaller nuclear precursor-mRNA fractions are direct physical precursors of functional mRNA. In terms of total mass, more precursor-mRNA accumulates in the nucleus than there is translated mRNA in the cytoplasm. Globin mRNA of final size (9 S) does not accumulate in the nuclei of avian erythroblasts.
关键词：RNA turnover ; regulation ; complementary DNA ; hemoglobin
