Polyadenylylated nuclear RNA contains branches

作者：John C. Wallace, Mary Edmonds · 发表于：Proceedings of the National Academy of Sciences · 年份：1983 · DOI：10.1073/pnas.80.4.950 · 被引用次数：120 · 研究领域：RNA Research and Splicing、RNA modifications and cancer、Circular RNAs in diseases

A highly charged component can be isolated from a total RNase T2 digest of nuclear polyadenylylated RNA from HeLa cells that is separable from caps by (dihydroxyboryl)aminoethyl-cellulose chromatography. Chemical and enzymatic analyses show that the component contains a 2'-5' phosphodiester bond that creates a branch at the 2'-hydroxyl group of one nucleotide already linked to an adjoining nucleotide through the usual 3'-5' phosphodiester bond. [Formula: see text] This structure was confirmed by analysis of a similar component isolated from nuclease P1 digests of the same nuclear polyadenylylated RNA. Branches occur in roughly 10% of nuclear polyadenylylated RNAs, including those >10S in size, but are absent from cytoplasmic polyadenylylated RNA. Possible implications for branches as intermediates in mRNA processing are discussed.