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：1979
卷号：76
期号：8
页码：3809-3813
DOI：10.1073/pnas.76.8.3809
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：A 9S mRNA, purified from mouse thyrotropic pituitary tumors by sucrose density gradient centrifugation of poly(A)-enriched mRNA, directed the synthesis of only alpha and beta subunits of thyrotropin in the reticulocyte lysate translation system. Analysis of radioiodinated 9S mRNA, repurified by oligo(dT)-cellulose chromatography and sucrose gradient centrifugation, yielded two species of RNA on urea/polyacrylamide gel electrophoresis. The major RNA species contained 620 nucleotides, and the minor RNA species contained 560 nucleotides. Unlabeled 9S mRNA was further purified by urea/polyacrylamide gel electrophoresis; the mRNAs were separately eluted from slices of the gel containing material migrating with an apparent length of 620 and 560 nucleotides. Translation of these mRNAs in the reticulocyte lysate showed that the longer mRNA coded for the alpha subunit and the shorter mRNA coded for the beta subunit of mouse thyrotropin. Because more alpha than beta subunit of thyrotropin was consistently synthesized, unbalanced amounts of thyrotropin subunits appear to be synthesized by translation of unbalanced amounts of individual mRNAs. We have demonstrated that the synthesis of thyrotropin is directed by two separate mRNA molecules, each coding for a different subunit of the hormone.
