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:1976
卷号:73
期号:8
页码:2634-2638
DOI:10.1073/pnas.73.8.2634
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:Through the use of an assay that measures cellular capacity for specific enzyme synthesis, mRNA of alanine aminotransferase (EC 2.6.1.2 ; L-alanine:2-oxoglutarate aminotransferase) was found to be degraded with a half-life of 12-14 hr in cultured Reuber H-35 cells; mRNA of tyrosine aminotransferase (EC 2.6.1.5 ; L-tyrosine:2-oxoglutarate aminotransferase) has a half-life of 2 hr in the same cells. Rates of degradation of the mRNAs are the same whether new mRNA accumulation is blocked by removal of the steroid inducer or by inhibition of mRNA synthesis (actinomycin). Cycloheximide inhibits the normally rapid turnover of tyrosine aminotransferase mRNA, but agents such as puromycin and sodium fluoride, which disrupt polysome structure, do not alter the turnover rate of the tyrosine and alanine aminotransferase mRNAs. The tyrosine and alanine aminotransferase mRNAs appear to be translated at equivalent rates. The data suggest that the degradation rate of these two mRNAs is determined by the polynucleotide structure of the mRNA molecules at or near the site for ribosome binding and initiation.