Sinha K M, Gu J, Chen Y, Reddy R
Baylor College of Medicine, Department of Pharmacology, Houston, Texas 77030, USA.
J Biol Chem. 1998 Mar 20;273(12):6853-9. doi: 10.1074/jbc.273.12.6853.
The 3'-end sequences of several human small RNAs were determined, and the results show that a fraction of human cytoplasmic 7SL, ribosomal 5S, and nuclear U2, U6, and 7SK small RNAs contain a post-transcriptionally added adenylic acid residue on their 3'-ends. Incubation of HeLa cell extract in vitro in the presence of [alpha-32P]ATP resulted in labeling of several small RNAs including ribosomal 5S and cytoplasmic 7SL as well as U2 and U6 small nuclear RNAs. Analysis of 7SL RNA labeled in this in vitro adenylation system showed that a single adenylic acid residue is added to the 3'-end. These results show that the adenylation observed in the in vitro system reflects the post-transcriptional adenylation occurring in vivo.
测定了几种人类小RNA的3'端序列，结果表明，一部分人类细胞质7SL、核糖体5S以及细胞核U2、U6和7SK小RNA在其3'端含有转录后添加的腺苷酸残基。在[α-32P]ATP存在的情况下，对体外培养的HeLa细胞提取物进行孵育，导致包括核糖体5S、细胞质7SL以及U2和U6小核RNA在内的几种小RNA被标记。对在该体外腺苷酸化系统中标记的7SL RNA的分析表明，单个腺苷酸残基被添加到3'端。这些结果表明，在体外系统中观察到的腺苷酸化反映了体内发生的转录后腺苷酸化。
