WHEAT EMBRYO RIBONUCLEATES .13. METHYL-SUBSTITUTED NUCLEOSIDE CONSTITUENTS AND 5'-TERMINAL DINUCLEOTIDE SEQUENCES IN BULK POLY(A)-RICH RNA FROM IMBIBING WHEAT EMBRYOS
WHEAT EMBRYO RIBONUCLEATES .13. METHYL-SUBSTITUTED NUCLEOSIDE CONSTITUENTS AND 5'-TERMINAL DINUCLEOTIDE SEQUENCES IN BULK POLY(A)-RICH RNA FROM IMBIBING WHEAT EMBRYOS
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DOI：
10.1139/o79-112
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发表时间：
1979-01-01
期刊：
影响因子：
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通讯作者：
LANE, BG
中科院分区：
文献类型：
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作者：
KENNEDY, TD;LANE, BG
N6 - 甲基腺苷此前未被检测为植物mRNA的一种成分，它存在于富含多聚（A）的RNA中，当小麦胚胎在含有[甲基 - 3H]甲硫氨酸的培养基中吸收水分时，这种RNA会被同位素标记。当富含多聚（A）的[甲基 - 3H]RNA样本中大部分由污染的rRNA带来的放射性被去除后，N6 - 甲基腺苷和7 - 甲基鸟苷帽可构成超过85%的放射性，其中N6 - 甲基腺苷占该放射性的75 - 80%，7 - 甲基鸟苷占20 - 25%。在来自吸水小麦胚胎的富含多聚（A）的RNA中，有3种主要的5′ - 末端二核苷酸序列（O型帽结构）：m7GpppA、m7GpppG和m7GpppC。5′ - 末端二核苷酸序列间放射性的比例分布随吸水小麦胚胎标记时间（30分钟和24小时）而变化，m7GpppA是标记最快的序列，m7GpppC是标记最慢的序列。来自吸水小麦胚胎的富含多聚（A）的mRNA，就其甲基取代核苷成分和5′ - 末端二核苷酸序列而言，与已研究的任何其他生物的相应RNA不同。吸水小麦胚胎富含多聚（A）的mRNA与其他生物之间这些差异和信号相似性的可能意义是讨论的主题。
N6-Methyladenosine, not previously detected as a component of plant mRNA, is present in the poly(A)-rich RNA which is isotopically labeled when wheat embryos imbibe water in a medium which contains [methyl-3H]methionine. N6-Methyladenosine and 7-methylguanosine caps can constitute more than 85% of the radioactivity when specimens of poly(A)-rich [methyl-3H]RNA are freed of most of the radioactivity contributed by contaminating rRNA, N6-methyladenosine accounting for 75-80% and 7-methylguanosine accounting for 20-25% of this radioactivity. There are 3 principal 5''-terminal dinucleotide sequences (type O cap structures) in the poly(A)-rich RNA from imbibing wheat embryos: m7GpppA, m7GpppG, and m7GpppC. The proportional distribution of radioactivity among the 5''-terminal dinucleotide sequences varies with the time of labeling of the imbibing wheat embryos (30 min and 24 h), m7GpppA being the most rapidly labeled sequence and m7GpppC being the most slowly labeled sequence. Poly(A)-rich mRNA from imbibing wheat embryos is distinct from the corresponding RNA from any other organism yet studied in terms of its component methyl-substituted nucleosides and 5''-terminal dinucleotide sequences. The possible significance of these differences and signal similarities between the poly(A)-rich mRNA of imbibing wheat embryos and other organisms, are subjects of discussion.