YEAST RNA VIROLOGY

酵母RNA病毒学

• 批准号: 6289728
• 负责人: Reed B. WICKNER
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6289728
• 关键词: RNA virus; double stranded RNA; gene deletion mutation; gene mutation; genetic translation; messenger RNA; molecular cloning; nucleic acid sequence; virus RNA; virus genetics; virus protein; virus replication

We have described two dsRNA viruses (L-A and L-BC) and two ssRNA replicons (20S RNA and 23S RNA) in the yeast Saccharomyces cerevisiae. M dsRNA is a satellite of L-A encoding the killer toxin. We discovered 7 chromosomal genes, SKI1, 2, 3, 4, 6, 7, and 8, by their ability to prevent these replicons from causing pathogenicity to yeast cells. These four RNA replicons all make uncapped mRNAs and lack a 3 poly(A)structure. SKI1 is an exoribonuclease specific for uncapped mRNAs, while we showed that the SKI2, SKI3, SKI6, SKI7 and SKI8 gene products block the translation of non-poly(A) mRNAs. We showed that Ski2p is an RNA helicase, Ski6p has homology to a tRNA - processing RNAse, and Ski7p is similar to translation factor EF1alpha. We showed that mutations in 20 chromosomal genes resulting in loss of M dsRNA are deficient in 60S ribosomal subunits. These mutations are suppressed by ski mutations without restoration of the 60S subunit deficiency. We proposed that SKI2, SKI3 and SKI8 block translation of non-poly(A) mRNA by an effect on ribosome biogenesis affecting the interaction of 60S subunits with the 3 poly(A) structure of the mRNA.We find that a ski7 mutation increases both the initial rate and the duration of translation of electroporated non-polyA mRNAs, indicating effects of the gene on both translation and mRNA stability. The effect on mRNA stability may be secondary to the effect on translation. The ski7 deletion mutant is also hypersensitive to hygromycin, again suggesting an effect on translation. Overexpression of Ski7p lowers expression of non-polyA mRNAs and cures M dsRNA. We are now studying another yeast gene homologous to SKI2. We find that mutations of this gene also specifically derepress expression of non-polyA mRNAs. We are studying the mechanism of this effect and the interaction of this gene with SKI2. - double-stranded RNA, virus, replication, assembly, Saccharomyces cerevisiae, poly(A), translation, SKI6, SKI7, SKI2, SKI3, SKI8, FUN12

我们在酿酒酵母中描述了两个dsRNA病毒（L-A和L-BC）和两个ssRNA复制子（20S RNA和23S RNA）。M - dsRNA是L-A的卫星，编码杀伤毒素。我们发现了7个染色体基因，SKI1、2、3、4、6、7和8，它们能够阻止这些复制子对酵母细胞产生致病性。这四种RNA复制子都产生无帽mrna，并且缺乏3 poly(a)结构。SKI1是一种针对无帽mrna的外核糖核酸酶，而我们发现SKI2、SKI3、SKI6、SKI7和SKI8基因产物阻断了非聚(A) mrna的翻译。我们发现Ski2p是一种RNA解旋酶，Ski6p与tRNA加工RNAse具有同源性，Ski7p与翻译因子EF1alpha相似。我们发现，导致M dsRNA缺失的20个染色体基因突变是60S核糖体亚基缺陷。这些突变被ski突变所抑制，而60S亚基缺陷无法恢复。我们提出SKI2、SKI3和SKI8通过影响核糖体生物发生，影响60S亚基与mRNA 3 poly(A)结构的相互作用来阻断非poly(A) mRNA的翻译。我们发现ski7突变增加了电穿孔非多a mRNA翻译的初始速率和持续时间，表明该基因对翻译和mRNA稳定性的影响。对mRNA稳定性的影响可能次于对翻译的影响。ski7缺失突变体也对潮霉素过敏，再次表明对翻译有影响。过表达Ski7p可降低非多a mrna的表达并治愈M - dsRNA。我们现在正在研究另一个与SKI2同源的酵母基因。我们发现该基因的突变也特异性地抑制非多a mrna的表达。我们正在研究这种作用的机制以及该基因与SKI2的相互作用。-双链RNA，病毒，复制，组装，酿酒酵母，聚(A)，翻译，SKI6, SKI7, SKI2, SKI3, SKI8, FUN12