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：1975
卷号：72
期号：3
页码：1189-1193
DOI：10.1073/pnas.72.3.1189
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Methylated reovirus and vesicular stomatitis virus mRNAs, synthesized in vitro in the presence of S-adenosylmethionine by the virion-associated polymerases (RNA nucleotidyltransferases, EC 2.7.7.6 ), stimulate protein synthesis by wehat germ extracts to a greater extent than unmethylated mRNAs. Addition of S-adenosylmethionine to a cell-free extract programmed with unmethylated mRNA stimulates protein synthesis and results in methylation of the mRNA. An inhibitor of mRNA methylation. S-adenosylhomocysteine, blocks translation of unmethylated, but not of methylated, mRNAs. Aurintricarboxylic acid, which inhibits polypepetide chain initiation, also prevents mRNA methylation by wheat germ extracts. In contrast, sparsomycin, which inhibits polypeptide chain elongation, does not reduce mRNA methylation. The results indicate that methylation of viral mRNA is required for translation in vitro and suggest that mRNA methylation occurs at the initiation step of protein synthesis.
