DROSOPHILA RIBOSOMAL-PROTEIN S19 CDNA SEQUENCE
DROSOPHILA RIBOSOMAL-PROTEIN S19 CDNA SEQUENCE
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DOI：
10.1093/nar/21.16.3897
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发表时间：
1993-08-11
影响因子：
14.9
通讯作者：
CHIQUETEHRISMANN, R
中科院分区：
文献类型：
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作者：
BAUMGARTNER, S;MARTIN, D;CHIQUETEHRISMANN, R
真核生物核糖体是由82种不同的蛋白质和4种rRNA分子组成的复杂结构。核糖体蛋白的序列分析对于结构和功能研究以及理解核糖体的进化是必不可少的（1）。已经描述了几种来自果蝇的核糖体蛋白（2，3，4），其中一些显示出有趣的突变表型。例如，果蝇S6基因的突变导致造血器官的扩大和过度增殖（3，4），因此，S6可以被认为是一种肿瘤抑制基因。果蝇的许多微小（M）基因座被认为编码核糖体蛋白，并且这些基因座中的突变导致指示蛋白质合成减少或减慢的表型。这些包括幼虫发育时间延长，背甲蚀刻，tiin和短胸毛，生育力下降，细胞分裂速度降低和细胞体积小，导致体型缩小。与其他真核生物（例如酵母、青蛙、小鼠）不同，大多数果蝇核糖体蛋白基因是单拷贝基因（2）。我们从果蝇0-16 h胚胎poly A+ RNA构建的cDNA文库中分离到一个编码核糖体蛋白S19的cDNA克隆。该cDNA由22个核苷酸的5 '非编码序列、471个核苷酸的开放阅读框和23个核苷酸的3'非翻译区组成（数据未显示）。北方分析表明，果蝇S19 mRNA的大小约为700 bp，表明我们的cDNA不是全长cDNA。S19 mRNA在所有生命周期中都大量表达（数据未显示）。以S19 cDNA为探针对果蝇基因组DNA进行Southern印迹分析，显示单一条带，表明S19不是多基因家族的一部分（数据未显示）。对156个氨基酸的开放阅读框的分析显示，与人和大鼠S19核糖体蛋白具有65%的同一性或76%的相似性（如果允许保守改变）（5，6）（图1）。果蝇同源物含有羧基末端延伸，其比蛋白质的其他部分更加高度发散。果蝇S19蛋白与酵母（7）或构巢曲霉（8）S16蛋白有48%和45%的相同性，后者被证明是脊椎动物S19蛋白的真菌同源物。计算机进一步搜索与果蝇S19相似的蛋白质，从蛔虫（9）（52%同一性）中发现了一种假定的核糖体蛋白（ALEP-1），该蛋白似乎参与染色质减少过程。
The eukaryotic ribosome is a complex structure consisting of 82 different proteins and 4 rRNA molecules. Sequence analysis of ribosomal proteins is essential for structural and functional studies and for understanding the evolution of ribosomes (1). Several ribosomal proteins from Drosophila have been described (2, 3, 4), some of which show interesting mutant phenotypes. For example, mutations in the Drosophila S6 gene cause enlargement and overproliferation of the hematopoietic organs (3, 4), thus, S6 can be considered a tumor suppressor gene. Many Minute (M) loci of Drosophila are thought to code for ribosomal proteins and mutations in these loci result in phenotypes indicative of reduced or slowed protein synthesis. These include prolonged larval development, etched tergites, tiin and short thoracic bristles, reduced fertility, a reduced rate of cell division and small cell size leading to reduced body size. Unlike in other eukaryotes (eg yeast, frog, mouse) the majority ofDrosophila ribosomal protein genes are single copy genes (2). We haveisolated a cDNA clone which apparently encodes Drosophila ribosomal protein S19 from a cDNA library constructed using poly A+ RNA from 0-16 h embryos. This cDNA consists of 22 nucleotides of 5'non coding sequence, a 471 nucleotide open reading frame, and 23 nucleotides of the 3'untranslated region (data not shown). As demonstrated by Northern analysis, the Drosophila S19 mRNA is approximately 700 bp in size, indicating that our cDNA is not a full length cDNA. The S19 mRNA is expressed abundantly in all life cycles (data not shown). Southern blot analysis ofDrosophila genomic DNA using the S19 cDNA as a probe shows a single band indicating that S19 is not part of a multigene family (data not shown).Analysis of the open reading frame of 156 amino acids revealed a 65% identity or 76% similarity (ifconservative changes were allowed) to the human and rat S19 ribosomal proteins (5, 6)(Figure 1). The Drosophila homologue contains a carboxyterminus extension which appears more highly diverged than other parts of the protein. The Drosophila S19 protein is 48% and 45% identical to the yeast (7) or Aspergillus nidulans (8) S16 proteins, which were shown to be the fungal homologues of the vertebrate S19proteins. Furthercomputer searches for proteins similar to Drosophila S19 recovered a putative ribosomal protein (ALEP-1) from Ascaris lumbricoides (9)(52% identity) which appears to be involved in the process of chromatin diminution.