Saccharomyces cerevisiae Ribosomal Protein L26 Is Not Essential for Ribosome Assembly and Function
Saccharomyces cerevisiae Ribosomal Protein L26 Is Not Essential for Ribosome Assembly and Function
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DOI：
10.1128/mcb.00539-12
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发表时间：
2012-08-01
影响因子：
5.3
通讯作者：
de la Cruz, Jesus
中科院分区：
文献类型：
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作者：
Babiano, Reyes;Gamalinda, Michael;de la Cruz, Jesus
核糖体蛋白在核糖体的生物发生和功能中起着重要的作用。在这里，我们研究了酿酒酵母中进化保守的L26，它在细胞核中组装成60年代前的核糖体颗粒。酵母L26是由两个功能基因编码的许多核糖体蛋白之一。我们已经扰乱了这两个基因；令人惊讶的是，由此产生的rpl26零突变株的生长显然与同基因野生型菌株的生长相同。L26的缺失对60S核糖体亚基的生物发生影响最小。多聚核糖体分析显示出现了Half-MERS。对Pre-rRNA处理的分析表明，L26主要是为了优化27S Pre-rRNA的成熟，否则会部分阻碍Pre-60S颗粒从核(Ol)的释放。缺乏L26的核糖体在25S/5.8S rRNAs的结构域I上对二甲基硫酸酯表现出不同的反应能力，但显然能够以野生型的准确性支持体内翻译。酵母L26、L24的细菌同源物是体内外50S核糖体亚基组装所需的主要rRNA结合蛋白。我们的结果强调了原核和真核核糖体组装之间的潜在差异。我们讨论了为什么酵母L26在细胞中扮演如此明显的非必要角色的原因。
Ribosomal proteins play important roles in ribosome biogenesis and function. Here, we study the evolutionarily conserved L26 in Saccharomyces cerevisiae, which assembles into pre-60S ribosomal particles in the nucle(ol)us. Yeast L26 is one of the many ribosomal proteins encoded by two functional genes. We have disrupted both genes; surprisingly, the growth of the resulting rpl26 null mutant is apparently identical to that of the isogenic wild-type strain. The absence of L26 minimally alters 60S ribosomal subunit biogenesis. Polysome analysis revealed the appearance of half-mers. Analysis of pre-rRNA processing indicated that L26 is mainly required to optimize 27S pre-rRNA maturation, without which the release of pre-60S particles from the nucle(ol)us is partially impaired. Ribosomes lacking L26 exhibit differential reactivity to dimethylsulfate in domain I of 25S/5.8S rRNAs but apparently are able to support translation in vivo with wild-type accuracy. The bacterial homologue of yeast L26, L24, is a primary rRNA binding protein required for 50S ribosomal subunit assembly in vitro and in vivo. Our results underscore potential differences between prokaryotic and eukaryotic ribosome assembly. We discuss the reasons why yeast L26 plays such an apparently nonessential role in the cell.