Eukaryotic translation is important, complex and tightly regulated process. In eukaryotes, the place for transcription to take place is nucleus, and the place for translation to take place is cytoplasm. The eukaryotic transcription and eukaryotic translation are not synchronized, gene is first transcribed into mRNA in nucleus then mRNA translated into amino acid chains in cytoplasm. In the transcription process, RNA is transcribed from DNA template and maturated by addition of 5’cap and polyadenylation tailing at 3’ terminus. In the normal maturation step, canonical polyadenylate polymerase (PAP) generates polyA tail at 3’terminus of mRNA. Non canonical PAP can decorate mRNA tailing to increase the diversity. RNA tailing takes a lead in regulating translation process of mRNA and prolong...[ Read more ]

Eukaryotic translation is important, complex and tightly regulated process. In eukaryotes, the place for transcription to take place is nucleus, and the place for translation to take place is cytoplasm. The eukaryotic transcription and eukaryotic translation are not synchronized, gene is first transcribed into mRNA in nucleus then mRNA translated into amino acid chains in cytoplasm. In the transcription process, RNA is transcribed from DNA template and maturated by addition of 5’cap and polyadenylation tailing at 3’ terminus. In the normal maturation step, canonical polyadenylate polymerase (PAP) generates polyA tail at 3’terminus of mRNA. Non canonical PAP can decorate mRNA tailing to increase the diversity. RNA tailing takes a lead in regulating translation process of mRNA and prolonging mRNA half-life. Previous studies have been discovered that guanylation at mRNA tailling can shield mRNA from rapid decay. The reason why we start this project is to discover the mechanism of guanylation on mixed tail of mRNA. In this project, guanylation at mixed tailing decrease the translation efficiency and half-life of mRNA. Guanylation mechanism can be hijacked when virus infected. Therefore, we proposed that cellular self-defense might be the explanation. For the reason of protection, RNA protein kinase (PKR) is activated for apoptosis. Before the synthetic mRNAs enter cell to affect translation process, they are already discriminated by the cell.