SYNTHESIS OF LARGE RIBOSOMAL-RNAS BY RNA POLYMERASE-II IN MUTANTS OF SACCHAROMYCES-CEREVISIAE DEFECTIVE IN RNA POLYMERASE-I
SYNTHESIS OF LARGE RIBOSOMAL-RNAS BY RNA POLYMERASE-II IN MUTANTS OF SACCHAROMYCES-CEREVISIAE DEFECTIVE IN RNA POLYMERASE-I
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DOI：
10.1073/pnas.88.9.3962
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发表时间：
1991-05-01
影响因子：
11.1
通讯作者：
NOMURA, M
中科院分区：
文献类型：
--
作者：
NOGI, Y;YANO, R;NOMURA, M
将酿酒酵母的35S rRNA基因与GAL7启动子融合。 这种杂交基因，当存在于多拷贝质粒和半乳糖诱导，抑制生长缺陷的温度敏感的RNA聚合酶I（polI）突变体和突变体中的第二大亚基polI的基因被删除。 脉冲标记的RNA分析直接表明，rRNA合成在这个缺失突变体是从GAL7启动子。 这些实验表明，pol I的唯一基本功能是rRNA基因的转录，如果35S rRNA的合成是通过某些其他方法实现的，那么pol I对于rRNA和核糖体的合成或细胞生长不是绝对必需的，并且染色体rRNA基因的串联重复结构对于rRNA和核糖体的合成也不是绝对必需的。
The 35S rRNA gene of the yeast Saccharomyces cerevisiae was fused to the GAL7 promoter. This hybrid gene, when present on a multicopy plasmid and induced by galactose, suppressed the growth defects of a temperature-sensitive RNA polymerase I (pol I) mutant and those of a mutant in which the gene for the second largest subunit of pol I was deleted. Analysis of pulse-labeled RNA directly demonstrated that rRNA synthesis in this deletion mutant is from the GAL7 promoter. These experiments show that the sole essential function of pol I is the transcription of the rRNA genes, that pol I is not absolutely required for the synthesis of rRNA and ribosomes or cell growth if 35S rRNA synthesis is achieved by some other means, and that the tandemly repeated structure of the chromosomal rRNA genes is also not absolutely required for the synthesis of rRNA and ribosomes.