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Mechanisms and control of mRNA decapping in Saccharomyces cerevisiae
1Department of Molecular and Cellular Biology and Howard Hughes Medical Institute, University of Arizona, Tucson, Arizona 85721, USA.
Abstract:
The process of mRNA turnover is a critical component of the regulation of gene expression. In the past few years a discrete set of pathways for the degradation of polyadenylated mRNAs in eukaryotic cells have been described. A major pathway of mRNA degradation in yeast occurs by deadenylation of the mRNA, which leads to a decapping reaction, thereby exposing the mRNA to rapid 5' to 3' exonucleolytic degradation. A critical step in this pathway is decapping, since it effectively terminates the existence of the mRNA and is the site of numerous control inputs. In this review, we discuss the properties of the decapping enzyme and how its activity is regulated to give rise to differential mRNA turnover. A key point is that decapping appears to be controlled by access of the enzyme to the cap structure in a competition with the translation initiation complex. Strikingly, several proteins required for mRNA decapping show interactions with the translation machinery and suggest possible mechanisms for the triggering of mRNA decapping.
Insights
mRNA decapping regulates gene expression by controlling mRNA turnover. This process is tightly regulated, with decapping enzyme access competing with translation initiation complexes, linking mRNA decay to protein synthesis.
Area of Science:
- Molecular Biology
- Gene Expression Regulation
Background:
- mRNA turnover is crucial for controlling gene expression.
- Specific pathways for mRNA degradation in eukaryotes have been identified.
- In yeast, mRNA degradation often involves deadenylation, decapping, and subsequent 5' to 3' exonucleolytic degradation.
Purpose of the Study:
- To review the properties of the mRNA decapping enzyme.
- To discuss the regulatory mechanisms controlling decapping enzyme activity.
- To explore the link between decapping and differential mRNA turnover.
Main Methods:
- Review of existing literature on mRNA decapping and turnover.
- Analysis of the decapping enzyme's properties and regulation.
- Investigation of interactions between decapping factors and translation machinery.
Main Results:
- Decapping is a critical step in mRNA degradation, terminating mRNA existence.
- Decapping enzyme activity appears regulated by competition with translation initiation complexes for cap structure access.
- Proteins involved in mRNA decapping interact with the translation machinery.
Conclusions:
- mRNA decapping is a key regulatory point in gene expression.
- The regulation of decapping is influenced by the interplay with translation initiation.
- Interactions between decapping and translation factors suggest mechanisms for triggering mRNA decapping.