期刊
NUCLEIC ACIDS RESEARCH
卷 32, 期 12, 页码 3590-3600出版社
OXFORD UNIV PRESS
DOI: 10.1093/nar/gkh687
关键词
-
资金
- Wellcome Trust Funding Source: Medline
Dcs1, the m(7)GpppX pyrophosphatase of Saccharomyces cerevisiae, has been reported to 'scavenge' capped 51 end fragments generated by 3'-->5' mRNA degradation. We now show that the absence of Dcs1, and the closely related Dcs2 protein, compromises cellular responses to glucose-deprivation stress as well as to step changes in glucose availability. Dcs1 and Dcs2 form homo- and heterodimers, with the heterodimer appearing as cells enter diauxie. Despite the previously observed increase in abundance of the mRNA encoding the neutral trehalase (Nth1) in the stationary phase, the total enzyme activity of Nth1 decreases in this phase of growth. Changes in trehalase activity are significant because the non-reducing disaccharide trehalose is thought to stabilize cellular components under stress conditions. In the dcs1Delta and dcs1Deltadcs2Delta mutants, normal regulation of trehalase activity is lost. Nutrient stress induces DCS1 and DCS2 transcription via the cAMP-PKA signalling pathway. Dcs1 also becomes phosphorylated as the availability of glucose diminishes, and we test the role of this phosphorylation in the stress response. Further evidence indicates that Dcs1 plays a complementary role to the translation factor eIF4E in preventing capped 5' fragments of mRNA from interfering with translation initiation. We conclude that Dcs1 function influences cellular responses to changes in nutrient availability, while Dcs2 seems to act as a modulator of Dcs1 function.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据