Grummt I, Loening U, Slack J M
Eur J Biochem. 1975 Nov 1;59(1):313-8. doi: 10.1111/j.1432-1033.1975.tb02457.x.
Nucleoli isolated from rat liver were incubated for synthesis of RNA in vitro in the presence or absence of S-adenosyl [3H] methionine. The results obtained indicate that neither the rate of RNA synthesis not the processing of pre-ribosomal RNA was changed if methylation was allowed to take place. The methylation process acts on the RNA most recently synthesized, rather than on the bulk of the RNA already present in the nucleoli. The reaction seems to occur faithfully both quantitatively and qualitatively. It is calculated that 104 mol methyl groups were incorporated per mol of newly synthesized 45-S RNA. Methylation of the ribose rather than the bases predominated. The pattern of alkali-stable oligonucleotides of RNA methylated in vitro was analyzed and found to correspond closely to that of ribosomal RNA labelled in vivo.
从大鼠肝脏分离出的核仁在有或没有S-腺苷[3H]甲硫氨酸存在的情况下进行体外RNA合成孵育。所获得的结果表明，如果允许甲基化发生，RNA合成速率和前体核糖体RNA的加工过程均未改变。甲基化过程作用于最新合成的RNA，而不是核仁中已存在的大部分RNA。该反应在数量和质量上似乎都能如实地发生。据计算，每摩尔新合成的45-S RNA掺入了104摩尔甲基。核糖而非碱基的甲基化占主导。对体外甲基化的RNA的碱稳定寡核苷酸模式进行了分析，发现其与体内标记的核糖体RNA的模式密切对应。
