Rcl1p, the yeast protein similar to the RNA 3′-phosphate cyclase, associates with U3 snoRNP and is required for 18S rRNA biogenesis
Rcl1p, the yeast protein similar to the RNA 3′-phosphate cyclase, associates with U3 snoRNP and is required for 18S rRNA biogenesis
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DOI：
10.1093/emboj/19.9.2115
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发表时间：
2000-05-02
期刊：
影响因子：
11.4
通讯作者：
Filipowicz, W
中科院分区：
文献类型：
--
作者：
Billy, E;Wegierski, T;Filipowicz, W
RNA 3 ′-末端磷酸环化酶是一种进化上保守的酶，催化RNA 3 ′-末端磷酸转化为2 ′，3 ′-环磷酸二酯，其生物学作用尚不清楚。酵母酿酒酵母含有编码与来自人类和大肠杆菌的特征性环化酶具有强序列相似性的蛋白质的基因，该基因被命名为RCL 1（在bar下为（R），在bar下为NA末端磷酸（c），在bar下为环化酶（l），在bar下为ike），对于生长是必需的，并且其产物Rcl 1 p定位于核仁中。Rcl 1 p的缺失或失活损害了Ao、Al和Az位点的前rRNA加工，并导致18 S rRNA和40 S核糖体亚基水平的强烈下降。免疫沉淀表明Rcl 1 p与U3 snoRNP特异性相关，尽管基于梯度分析，它不是其结构组分。大多数Rcl 1 p沉积物与70- 80 S前核糖体颗粒和未知身份的10 S复合物相关联。在所有研究的真核生物基因组中均编码与Rcl 1 p相似的蛋白质，小鼠的直向同源物与缺失Rcl 1 p的酵母菌株互补。本文讨论了Rcl 1 p在pre-rRNA加工中的可能功能及其与RNA 3 ′-磷酸环化酶的关系。
RNA 3'-terminal phosphate cyclases are evolutionarily conserved enzymes catalysing conversion of the 3'-terminal phosphate in RNA to the 2',3'-cyclic phosphodiester, Their biological role remains unknown. The yeast Saccharomyces cerevisiae contains a gene encoding a protein with strong sequence similarity to the characterized cyclases from humans and Escherichia coli, The gene, named RCL1 (for (R) under bar NA terminal phosphate (c) under bar yclase (l) under bar ike), is essential for growth, and its product, Rcl1p, is localized in the nucleolus. Depletion or inactivation of Rcl1p impairs pre-rRNA processing at sites Ao, Al and Az, and leads to a strong decrease in 18S rRNA and 40S ribosomal subunit levels. Immunoprecipitations indicate that Rcl1p is specifically associated with the U3 snoRNP, although, based on gradient analyses, it is not its structural component. Most of Rcl1p sediments in association with the 70-80S pre-ribosomal particle and a 10S complex of unknown identity. Proteins similar to Rcl1p are encoded in genomes of all eukaryotes investigated and the mouse orthologue complements yeast strains depleted of Rcl1p, Possible functions of Rcl1p in pre-rRNA processing and its relationship to the RNA 3'-phosphate cyclase are discussed.