Roles of the HEAT repeat proteins Utp10 and Utp20 in 40S ribosome maturation
Roles of the HEAT repeat proteins Utp10 and Utp20 in 40S ribosome maturation
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DOI：
10.1261/rna.609807
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发表时间：
2007-09-01
期刊：
影响因子：
4.5
通讯作者：
Tollervey, David
中科院分区：
文献类型：
--
作者：
Dez, Christophe;Dlakic, Mensur;Tollervey, David
在酿酒酵母中发现了一个含有核糖体合成因子的热重复序列家族。我们报告了其中两个因子Utp10和Utp20的详细特征，它们最初被确定为小亚单位过程组的组成部分。共沉淀分析证实Utp10和Utp20与U3 snoRNA和早期的前rRNA加工中间体有关。特别是与异常的加工中间体有很强的相关性，这可能有助于将这些RNA作为降解的目标。任何一种蛋白质的基因缺失都抑制了18S rRNA成熟过程中的前-rRNA加工步骤，但对前-rRNA的转录或25S或5.8S rRNA的合成几乎没有影响。多聚(A)聚合酶Trf5是TRAMP5复合体和外体辅助因子的一个组成部分，它的缺失导致了Utp10或Utp20缺失菌株中异常23S RNA的稳定。在Utp10的情况下，20S前rRNA合成也因这种监视活性的丧失而略有增加。
A family of HEAT-repeat containing ribosome synthesis factors was previously identified in Saccharomyces cerevisiae. We report the detailed characterization of two of these factors, Utp10 and Utp20, which were initially identified as components of the small subunit processome. Coprecipitation analyses confirmed the association of Utp10 and Utp20 with U3 snoRNA and the early pre-rRNA processing intermediates. Particularly strong association was seen with aberrant processing intermediates, which may help target these RNAs for degradation. Genetic depletion of either protein inhibited the early pre-rRNA processing steps in 18S rRNA maturation but had little effect on pre-rRNA transcription or synthesis of the 25S or 5.8S rRNAs. The absence of the poly( A) polymerase Trf5, a component of the TRAMP5 complex and exosome cofactor, led to stabilization of the aberrant 23S RNA in strains depleted of Utp10 or Utp20. In the case of Utp10, 20S pre-rRNA synthesis was also modestly increased by this loss of surveillance activity.