Berchtold M W, Berger M C
Institut für Pharmakologie und Biochemie, Zürich, Switzerland.
Gene. 1991 Jun 30;102(2):283-8. doi: 10.1016/0378-1119(91)90091-o.
A cDNA from human brain poly(A)+RNA with significant similarity to the gene encoding yeast L17A large subunit ribosomal (r) protein (L17A) was isolated using the polymerase chain reaction. The deduced amino acid (aa) sequence of 140 aa (calculated pI of 10.79) exhibits a 78% similarity to that of the yeast L17A r protein (88% when conservative aa replacements are considered as well). This indicates that L17A is one of the best conserved r-proteins and therefore may play a critical role in ribosome function. In contrast to its eubacterial and chloroplast counterparts, human L17A contains an N-terminal extension of 19 aa which may be involved in nuclear targeting of the r-protein. Approximately five to seven genes in mammalian genomes give strong hybridization signals when probed with the human L17A homologue cDNA. Whereas the L17A homologue was found to be expressed at similar levels in several human tissues as a transcript of 600 nucleotides, a several-fold higher transcript level was detected in the rapidly growing neuroblastoma cell line, SK-N-BE.
利用聚合酶链反应从人脑多聚腺苷酸（poly(A)+）RNA中分离出一种与编码酵母L17A大亚基核糖体（r）蛋白（L17A）的基因具有显著相似性的互补DNA（cDNA）。推导的140个氨基酸（aa）序列（计算得到的等电点为10.79）与酵母L17A r蛋白的氨基酸序列具有78%的相似性（若考虑保守氨基酸替换，相似性为88%）。这表明L17A是保守性最强的r蛋白之一，因此可能在核糖体功能中起关键作用。与真细菌和叶绿体中的对应物不同，人L17A含有一个19个氨基酸的N端延伸，这可能与该r蛋白的核靶向有关。当用人类L17A同源物cDNA进行探针杂交时，哺乳动物基因组中大约有五到七个基因会产生强烈的杂交信号。虽然发现L17A同源物在几种人类组织中以600个核苷酸的转录本形式表达水平相似，但在快速生长的神经母细胞瘤细胞系SK-N-BE中检测到的转录本水平要高出几倍。
