Ebp2p, yeast homologue of a human protein that interacts with Epstein-Barr virus Nuclear Antigen 1, is required for pre-rRNA processing and ribosomal subunit assembly
Ebp2p, yeast homologue of a human protein that interacts with Epstein-Barr virus Nuclear Antigen 1, is required for pre-rRNA processing and ribosomal subunit assembly
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DOI：
10.1046/j.1365-2443.2000.00346.x
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发表时间：
2000-07-01
期刊：
影响因子：
2.1
通讯作者：
Mizuta, K
中科院分区：
文献类型：
--
作者：
Tsujii, R;Miyoshi, K;Mizuta, K
背景资料：分泌途径的缺陷导致酿酒酵母中rRNA和核糖体蛋白基因的转录抑制，这表明核糖体合成和质膜合成的耦合。Rrs 1 p是一种必需的核蛋白，是分泌应答所必需的。结果：EBP 2，编码与EB病毒核抗原1相互作用的人蛋白的酵母同源物，在使用RRS 1作为诱饵的双杂交筛选中被克隆。rrs 1 -1突变，产生Rrs 1 p没有C-末端的一半，并导致分泌反应的缺陷，几乎取消了与Ebp 2 p的相互作用。Ebp 2 p是生长所必需的，并且主要定位于核仁中。Ebp 2 p缺失对核糖体生物合成的影响与Rrs 1 p缺失的影响非常相似;在Ebp 2 p缺失的细胞中，前rRNA加工的速率较慢，并且与野生型细胞相比，产生的25 S rRNA明显不成熟。多聚体模式表明Ebp 2 p缺失导致80 S单体和多聚体减少，40 S亚基积累，以及半聚体的出现。结论：Ebp 2 p是25 S rRNA和60 S亚基组装成熟所必需的。Ebp 2 p可能是Rrs 1 p执行信号调节核糖体生物合成的靶蛋白之一。
Background: A defect in the secretory pathway causes the transcriptional repression of both rRNA and ribosomal protein genes in Saccharomyces cerevisiae, suggesting a coupling of ribosome synthesis and plasma membrane synthesis. Rrs1p, an essential nuclear protein, is required for the secretory response.Results: EBP2, encoding the yeast homologue of a human protein that interacts with Epstein-Barr virus Nuclear Antigen 1, was cloned in a two-hybrid screen using RRS1 as a bait. The rrs1-1 mutation, which produces Rrs1p without the C-terminal half and causes a defect in the secretory response, almost abolished the interaction with Ebp2p. Ebp2p is essential for growth and is mainly localized in the nucleolus. The effects of Ebp2p depletion on ribosome biogenesis is quite similar to that of Rrs1p depletion; in the Ebp2p-depleted cells, the rate of pre-rRNA processing is slower, and significantly less mature 25S rRNA is produced compared to those in wild-type cells. The polysome pattern indicates that Ebp2p-depletion causes a decrease of 80S monosomes and polysomes, an accumulation of 40S subunits, and the appearance of half-mer polysomes.Conclusions: Ebp2p is required for the maturation of 25S rRNA and 60S subunit assembly. Ebp2p may be one of the target proteins of Rrs1p for executing the signal to regulate ribosome biogenesis.