Rapanotti M C, Pucci B, Amaldi F, Loreni F
Dipartimento di Biologia, Università di Roma, Tor Vergata, Italy.
Gene. 1995 Mar 10;154(2):199-203. doi: 10.1016/0378-1119(94)00873-q.
A cDNA clone was isolated from a Xenopus laevis embryo library and sequenced. Primer extension experiments indicated the full-length nature of the insert and the encoded product was identified on a two dimensional gel as ribosomal protein (r-protein) L22. The 510-bp L22 cDNA sequence presents short untranslated regions and a 5'-end polypyrimidine tract found in all other vertebrate r-protein mRNA (rp mRNA) so far analyzed. Both the nucleotide (nt) and the deduced amino acid (aa) sequences have been compared with the homologous sequences from other species. The L22 nt sequence is about 70% similar to the mammalian L27a rp mRNA and about 60% homologous to the Drosophila, Tetrahymena and yeast corresponding mRNAs. The 148-aa sequence presents a higher conservation, being 90% similar to the mammalian sequence and more than 70% to the other species. Expression analysis showed that, both during X. laevis embryogenesis and in X. laevis cultured cells during growth-rate changes, L22 synthesis is translationally regulated. Therefore X. laevis L22 mRNA is a new example of the correlation between the polypyrimidine terminal tract and the translational regulation observed in other rp mRNAs.
从非洲爪蟾胚胎文库中分离出一个cDNA克隆并进行测序。引物延伸实验表明插入片段的全长性质，编码产物在二维凝胶上被鉴定为核糖体蛋白（r蛋白）L22。510bp的L22 cDNA序列具有短的非翻译区和在迄今为止分析的所有其他脊椎动物r蛋白mRNA（rp mRNA）中发现的5'端多嘧啶序列。核苷酸（nt）序列和推导的氨基酸（aa）序列都已与其他物种的同源序列进行了比较。L22 nt序列与哺乳动物L27a rp mRNA约70%相似，与果蝇、四膜虫和酵母相应的mRNA约60%同源。148个氨基酸的序列具有更高的保守性，与哺乳动物序列90%相似，与其他物种超过70%相似。表达分析表明，在非洲爪蟾胚胎发育过程以及非洲爪蟾培养细胞生长速率变化期间，L22的合成受到翻译调控。因此，非洲爪蟾L22 mRNA是多嘧啶末端序列与在其他rp mRNA中观察到的翻译调控之间相关性的一个新例子。
